echocardiographic spectrum of hypertrophic cardiomyopathy' · british heartjournal, 1975, 37,...

British Heart Journal, 1975, 37, 1286-1302.

Echocardiographic spectrum of hypertrophiccardiomyopathy'

Ozgen Feizi2 and Richard EmanuelFrom the Department of Cardiology, The Middlesex Hospital, London

Echocardiographic patterns in 15 patients with hypertrophic cardiomyopathy were compared with thosein 30 healthy persons. Correlations with angiocardiographic data indicated that most of the anatomicalabnormalities in hypertrophic cardiomyopathy can be assessed reliably by echocardiography. These includeabnormal mitral valve motion, a reduction of the anteroposterior dimension of the left ventricular outflowtract and of the left and right ventricular cavities, increased thickness of the interventricular septum andthe posterior left ventricular wall. Comparison of the haemodynamic and echocardiographic data showed thatsome degree of abnormal mitral valve motion during systole may occur in the absence of left ventricularoutflow tract obstruction. On the other hand, it need not always be present with left ventricular outflowtract obstruction.

Other, hitherto unrecognized, abnormalities in hypertrophic cardiomyopathy detected by this techniquewere: (1) Aortic valve regurgitation in three out of nine patients with evidence of left ventricular cutflowtract obstruction at cardiac catheterization. (2) Left ventricular inflow tract obstruction at the mitral valvelevel associated with gross septal hypertrophy (five cases). (3) Abnormalforward displacement of the posteriormitral valve leaflet and of the chordae tendineae during systole in 10 patients, in seven of whom there was

confirmatory angiocardiographic evidence.Seven patients with miscellaneous cardiac disorders are described in whom asymmetric septal hypertrophy

was revealed by echocardiography. In one of these patients coexisting hypertrophic cardiomyopathy was

excluded histologically; thus asymmetrical septal hypertrophy is not confined to patients with hypertrophiccardiomyopathy.

During the past four years echocardiography hasproved of diagnostic value in hypertrophic cardio-myopathy with or without obstruction. Moreyraet al. (1969) were the first to study patients withhypertrophic cardiomyopathy and described acluster of echoes of varying thickness impinging onthe anterior mitral leaflet echoes during diastole.They suggested that the thickened interventricularseptum was responsible for this appearance. Some-times they observed a reduction of the slope of theanterior mitral leaflet echoes, and they attributed thisto decreased left ventricular filling as a result of re-duced left ventricular compliance. However, theseearly recordings were lacking in definition and didReceived 18 March 1975.'Presented in part at the Nineteenth American Institute of

Ultrasound in Melicine Conference, October 1974, Seattle,U.S.A.

2Charles Wolfson Fellow in Clinical Cardiology.

not permit accurate evaluation of all the featuresdescribed.The occurrence of an abnormal forward move-

ment of the anterior mitral leaflet during systolein hypertrophic obstructive cardiomyopathy wasfirst suspected by Bjork (1964) and was angio-graphically documented by Dinsmore, Sanders, andHarthorne (1966). This abnormalitywas confirmedby Simon, Ross, and Gault (1967), who also ob-served a similar abnormality involving the posteriormitral valve leaflet. They postulated that theabnormal systolic motion of the mitral valveleaflets resulted from abnormal traction on thechordae tendineae, secondary to maldirection of thehypertrophied papillary muscles. They also sug-gested that the abnormal systolic position of themitral valve leaflets together with asymmetricalseptal hypertrophy played an important part in theproduction of intraventricular pressure gradients.

on May 13, 2021 by guest. P

rotected by copyright.http://heart.bm

j.com/

Br H

eart J: first published as 10.1136/hrt.37.12.1286 on 1 Decem

ber 1975. Dow

nloaded from

http://heart.bmj.com/

Echocardiographic spectrum of hypertrophic cardiomyopathy 1287

Soon afterwards Shah, Gramiak, and Kramer(1969) reported that the abnormal forward displace-ment of the anterior mitral leaflet in hypertrophicobstructive cardiomyopathy could be visualizedechocardiographically. Furthermore, they suggestedthat the forward displacement of this leaflet towardsthe interventricular septum during systole was re-sponsible for the left ventricular outflow tractobstruction and for the mitral valve regurgitation,which are commonly seen in this disease. Theseobservations and interpretations have been sup-ported by Popp and Harrison (1969) and Pridie andOakley (1970).

Echocardiographic evidence of extreme narrow-

ing of the left ventricular outflow tract in hyper-trophic cardiomyopathy was presented by Gramiak,Shah, and Kramer (1969). This was in contrast tothe wide left ventricular outflow tract observed inpatients with aortic valve disease. However, no

details of their measurements were given. Gramiaket al. (1969) also noted an abnormal aortic valve echopattern in this disease. The aortic cusp echoes were

seen to move centrally towards a position of closureduring mid-systole and then back towards theoriginal systolic position. They suggested that thispattern was secondary to obstruction in the leftventricular outflow tract produced by the abnormalmovement of the anterior mitral leaflet duringsystole.More recently Abbasi et al. (1972) and Henry,

Clark, and Epstein (1973) have measured the thick-ness of the interventricular septum and of the post-erior left ventricular wall by echocardiography. Theyhave suggested that a significant increase in the ratioof septal to posterior freewall thickness is a specificfinding in hypertrophic cardiomyopathy and is use-

ful in detecting the non-obstructive cases in whomthe abnormal anterior displacement of the anteriormitral echoes does not occur.

In the present report the echocardiographicpatterns in documented cases of hypertrophiccardiomyopathy are described in detail and com-

pared with the patterns found in patients withasymmetrical septal hypertrophy from other causes.

A spectrum of abnormalities of the aortic valveechoes and some new observations on the anteriorand the posterior mitral valve leaflet echoes in assoc-

iation with hypertrophic cardiomyopathy are des-cribed.

Subjects and methods

Echocardiographic studies of the mitral and aorticvalves, the left and right ventricular cavities, the inter-ventricular septum, and the posterior left ventricularwall were performed in 30 healthy persons (aged 15 to

55 years) with no symptoms or signs referable to thecardiovascular system, in 15 patients with hypertrophiccardiomyopathy, and in seven patients with asymmetricventricular septal hypertrophy from miscellaneouscauses.The echocardiograms were recorded with an Ekoline

20 ultrasonoscope and a focused 0-75-in (19.1 mm)diameter 2-25 MHz transducer with a repetition rate of1000 impulses/s. The patients were examined in theleft lateral position with the transducer applied over theleft third or fourth intercostal space near the left sternaledge. As an initial point of reference the echoes fromboth mitral leaflets were identified together with thosefrom the ventricular septum and posterior free wall of theleft ventricle. Tilting the transducer slightly inferiorlyuntil the mitral echoes were just lost permitted examina-tion of the left ventricular cavity in the submitral valvereg.on. From this position the transducer was graduallydirected superiorly so that the ultrasound was beamed inan arc towards the aortic root, according to the methodof Feigenbaum (1972). The ultrasound patterns wereviewed on an oscilloscope using M mode of display.Permanent recordings were made with a polaroid camerain 16 of the 52 cases studied, and in the remaining 36 theinformation from the Ekoline was displayed on a Cam-bridge recorder 03cilloscope, and strip chart recordingswere made together with simultaneous electrocardiogramand phonocardiogram. The recordings in these in-stances were made on photographic paper.

Fig. 1 illustrates the levels at which the various echo-cardiographic measurements were made. The tube-likeleft ventricular outflow tract is bounded anteriorly by theinterventricular septum and posteriorly by the anteriormitral leaflet. The echocardiographic assessment of thehigh and the low anteroposterior dimensions of the leftventricular outflow tract were made by measuring thedistances between the endocardial echoes from theinterventricular septum (on the left side) and the nearestanterior mitral leaflet echoes during mid-systole inpositions 3 and 2, respectively (as defined in Fig. 1).With the mitral valve leaflets open during diastole theanteroposterior dimension of the left ventricular inflowtract extends from the interventricular septum to theposterior left ventricular wall and corresponds again toposition 2. The submitral valve region corresponds tothe left ventricular cavity at the level between the tipsof the mitral valve leaflets and the posterior papillarymuscle and corresponds to position 1. The left ventri-cular inflow tract and the left ventricular submitral valvedimensions were measured as the distance between theechoes of the endocardial surfaces of the interventricularseptum and posterior left ventricular wall at positions2 and 1 respectively. The right ventricular dimensionswere measured by the distance between the echoes fromthe anterior right ventricular wall endocardial surfaceand the endocardial surface of the right side of the inter-ventricular wall at position 2. All the end-diastolicdimensions were measured at the time of the R waveof the simultaneously recorded electrocardiogram. Theend-systolic dimensions of the ventricular cavities weretaken at the point when the endocardial echoes of theposterior left ventricular wall and anterior right ventri-



j.com/

Br H


ber 1975. Dow

nloaded from


1288 Feizi and Emanuel

ANTER I OR

4

POSTER I ORFIG. 1 Diagrammatic cross-section of the heart.Arrows indicate presumed path taken by the ultra-sonic beam in the M-mode scan positions 1 to 4.Position 1 = Submitral valve level. Position 2 = Leftventricular inflow tract (LVIT) and lower left ventri-cular outflow tract (LVOT) level. Position 3 = UpperLVOT level (position at which the PM echoes are

just lost). Position 4 = Aortic root (AO) level. T =transducer; CW= chest wall; ARV= anterior rightventricular wall; RV= right ventricular cavity;IVS= interventricular septum; Aa andAp = anteriorand posterior aortic root walls; LV = left ventricularcavity; LA = left atrium; AM and PM = anteriorand posterior mitral valve leaflets; PLV= posteriorleft ventricular wall; PPM= posterior papillarymuscle; PLA = posterior left atrial wall.

cular wall were nearest the ventricular septal echoes.The aortic valve was assessed as described by Feizi,Symons, and Yacoub (1974). The left atrial dimensionwas measured at end-systole by the distance between theechoes from the posterior aortic root wall and theposterior left atrial wall. The amplitude of the excursionof the anterior mitral leaflet echoes was measured as thevertical distance between point C and E of the mitralvalve echogram (Fig. 2A). The E-F slope of the mitralvalve was estimated as described by Edler (1966).

Results

Echocardiographic studies of 30 healthypersons

The echocardiographic patterns of the mitral and theaortic valves of one of the healthy controls are shown

in Fig. 2A and 2B for comparison with patterns seenin patients with hypertrophic cardiomyopathy.Fig. 2A shows the mitral valve echocardiogram;both the anterior and posterior leaflet echoes aredemonstrated. These echoes come together at theonset of ventricular systole (C) and stay togetheruntil the onset of ventricular diastole (D). Fig. 2Bshows the aortic valve echocardiogram. Theanteriorly and posteriorly visualized slender cuspechoes (Ca and Cp respectively) are seen within theaortic root area (Aa and Ap). At the onset of ven-tricular systole echoes (C), which represent cuspechoes in the closed position, are rapidly replacedby two parallel lines Ca and Cp which represent thevalve cusps in the fully open position. Ca and Cp liein close proximity to the Aa and Ap echoes. Fig. 3shows the M-mode scan of the left ventricularcavity.The measurements of the various echocardio-

graphic parameters in the 30 healthy controls areshown in Table 3.

Studies on 15 patients with hypertrophiccardiomyopathyThe clinical, catheter-angiographic, and some of theechocardiographic data are shown in Tables 1, 2,and 3.

Additional echocardiographic data on individualpatients. Case 1. The mitral valve echogram (Fig. 4A)showed pronounced forward displacement of the anteriorleaflet echoes during systole, with apparent completeobliteration of the lower left ventricular outflow tractduring mid-systole. The posterior leaflet and theposterior chordal echoes also showed forward displace-ment. In diastole the anterior leaflet echoes were again incontact with the wide interventricular septal echoes. Theexcursion of the anterior leaflet echoes was reduced.These suggested that there was incomplete opening ofthe anterior leaflet resulting in left ventricular inflowobstruction. Fig. 4B is a diagram of the cross-sectionof a heart with septal hypertrophy to illustrate how grossinterventricular septal hypertrophy may mechanicallyinterfere with full opening of the anterior leaflet andresult in left ventricular inflow obstruction. The inter-ventricular septal echoes showed reduced amplitude ofmotion, suggesting impaired contractility. The posteriorleft ventricular wall echoes were slightly widened and theamplitude of motion suggested good contractility. Theaortic valve echogram (Fig. 4C) was abnormal. The Caechoes showed a succession of chaotic posterior andanterior movements throughout systole. The posteriormotion invariably coincided with increased intensity ofthe murmur recorded by phonocardiogram. The Cpechoes, though visualized, were not clearly defined.

Case 2. The mitral valve echogram showed variableforward displacement of the anterior leaflet. Theposterior leaflet echoes, on the other hand, showedregular, pronounced forward displacement during



j.com/

Br H


ber 1975. Dow

nloaded from



A PHONO B

1111_

ECG I v

P

~ ~ ~ ~ L

lcm--0-5sec_

_ P

FIG. 2 Normal echocardiogram. A) Mitral valve area corresponding to position 2 in Fig. 1.AM= anterior mitral valve leaflet echoes, of which C denotes leaflet echoes at onset of ventricularsystole. D =leaflet echoes at onset of ventricular diastole. E=most anterior point of the anteriorleaflet (AM) echoes during diastole. F=echoes representing partial closure of the mitral valveduring diastole. PHONO=phonocardiogram. ECG=electrocardiogram. B) Aortic valve area.

Ca and Cp= echoes from the anteriorly and posteriorly positioned aortic valve cusps. C'= cuspechoes during diastole. Other abbreviations as in Fig. 1.

systole. During diastole the anterior leaflet echoes were

in contact with the interventricular septal echoes.The septal echoes suggested gross hypertrophy andreduced contractility while the posterior left ven-tricular wall echoes suggested mild hypertrophy andgood contractility. The aortic valve echogram was com-patible with incomplete closure during mid-systole andthen reopening of the valve. Both Ca and Cp echoes wererecorded.

Case 3. The mitral valve echogram did not showabnormal forward displacement of the anterior orposterior leaflet echoes during systole (Fig. 5) even afteramyl nitrite inhalation. The interventricular septalechoes suggested gross hypertrophy and reduced con-tractility, while the posterior ventricular wall echoessuggested normal thickness and contractility. Theaortic valve echogram was compatible with incompleteclosure of the valve during mid-systole. Both Ca and Cpechoes were recorded.

Case 4. The mitral valve echogram (Fig. 6A)showed pronounced forward displacement of theanterior leaflet echoes similar to that seen in Case 1.However, the posterior leaflet echoes showed a minordegree of displacement during systole. The septal

echoes and the posterior wall echoes suggested poorcontractility. The aortic valve echogram was recordedwith difficulty (Fig. 6B), presumably because of a

bulging septum. Only the Ca echoes were clearly re-corded and these moved normally anteriorly to the fullyopen position at the onset of ventricular systole; theythen immediately moved posteriorly towards a positionof almost complete closure instead of remaining in theopen position until the onset of ventricular diastole.

Case 5. The mitral valve echogram (Fig. 7A)showed pronounced forward displacement ofthe anteriorleaflet echoes during systole. The posterior leaflet echoesalso showed forward displacement. The appearance ofthe anterior and posterior leaflet echoes suggested thick-ening of these leaflets. The septal echoes were wide andshowed reduced amplitude of motion, the posterior wallechoes were slightly widened and showed normalamplitude of motion. The aortic valve echogram wasabnormal (Fig. 7B). The Ca echoes showed a successionof chaotic posterior and anterior movements throughoutsystole. The Cp echoes also showed chaotic motionduring systole. In addition the Ca and the Cp echoesshowed increased intensity and abnormal separationduring diastole, suggesting thickened cusps and aorticregurgitation. The M-mode scan (Fig. 8) showed

PHONO

CG 0

r--N iV,-



j.com/

Br H


ber 1975. Dow

nloaded from



Position 1 _ 2 3 u 4

No I I .1 '1 1 I 11 -A I 1 1 1II, I_ I I 1'-I I i 1 11 fi-

I~~~ L _A-1Iv 1, " __ I IV I

s.-,,--, , r. 7 - .f. ,. -7,,.;, , F i,WE, ,* Z. !^ . . . .<

RV '0 5sec , . ..-,.,t. ." ' . .

|X^-*̂'.''. ^ ':t. '* S . , 0. * ^_ , 4 , . . . . . . . . . .,.. ! '

FIG. 3 M-mode scan of normal left ventricle. Echocardiographic patterns corresponding topositions 1 to 4 are shown. Abbreviations as in Fig. I and 2.

TABLE I Clinical data on 15 patients with hypertrophic cardiomyopathyMurmurs

Case Age and Presenting features RhythmNo. sex Systolic

Grade timing Location Grade

1 25 M Dyspnoea and palpitation junctional 3/4 Late LSE andanex

2 50 F Dyspnoea (previous hemiparesis) AF 2/4 Late LSE 1/43 72 F Dyspnoea AF* 1/4 Late LSE4 47 M Hemiparesis, palpitation, and dyspnoea AF 4/4 Pan Generalized 1/45 58 M pectoris and palpitation AF 3/4 Late LSE 2/46 65 M Syncope and palpitation AF* 3/4 Late LSE 1/47 25 M Murinur SR 3/4 Late LSE 1/48 10 m Murmur and chest pain SR 3/4 Late LSE

9 38 F Murmur and dyspnoea SR 2/4 Mid LSE 1/410 27 M Abnormal electrocardiograph and atypical chest pain SR 1/4 Mid Apex11 41 M Murmur and abnormal electrocardiograph SR 2/4 Mid LSE12 51 M Epigastric pain SR 2/4 Late LSE13 17 M Dyspnoea and angina pectoris SR 3/4 Mid LSE14 43 M Palpitation SR 2/4 Mid LSE15 39 M Dyspnoea and syncope AF* 1/4 Mid LSE

*Recent onset.tCHnical diagnosis before echocardiography and cardiac catheterization.LSE=Left stemal edge. AF=Atrial fibriHation. SR=Sinus rhythm. AR=Aortic regurgitation.



j.com/

Br H


ber 1975. Dow

nloaded from



complete obliteration of the left ventricular cavity area atthe submitral valve level.

Case 6. The mitral valve echogram resembled thatof Case 1. However, the forward displacement of theanterior leaflet echoes was less pronounced for theyfell just short of those from the ventricular septum. Indiastole the anterior leaflet made variable contact withthe septal echoes. The septal echoes were compatiblewith septal hypertrophy and impaired contractility.The posterior wall echoes were slightly widened and theamplitude of motion suggested good contractility. Theaortic valve echogram was abnormal (Fig. 9). It showeda pattern compatible with normal opening at the onset ofventricular systole. This was followed by partial closureduring mid-systole. The abnormality was more pro-nounced after extrasystolic beats, when a pattern wasrecorded compatible with normal opening of the valvefollowed by closure and then reopening. As in Case 5,the Ca and Cp echoes showed increased intensity andabnormal separation during diastole.

Case 7. The mitral valve echogram showed amoderate degree of forward displacement of the anteriorand posterior leaflet echoes during systole. The septalechoes were compatible with gross thickening and poorcontractility while those from the posterior wall suggestednormal thickness and good contractility. The aorticvalve echogram was compatible with partial closure ofthe valve during mid-systole, as in Cases 2 and 3.

Case 8. The mitral valve echogram showed pro-nounced forward displacement of the anterior andposterior leaflet echoes during systole. The septal echoessuggested septal hypertrophy with good contractility.The posterior wall echoes were slightly widened and theamplitude of motion suggested good contractility. Theaortic valve echogram was similar to that in Cases 2, 3,and 7.

Initial clinicaliastolic diagnosistning Location

ot heard Hypertrophic cardiomyopathy

id Apex Mitral stenosis and regurgitationot heard Aortic stenosisid Apex Hypertrophic cardiomyopathyunediate LSE Hypertrophic cardiomyopathyid Apex Hypertrophic cardiomyopathyid Apex Mitral stenosisot heard Noonan's syndrome and pulmonary

stenosisamediate LSE Aortic stenosis +ARDt heard Coronary artery diseaseot heard Coronary artery diseaseot heard Peptic ulcer or coronary artery diseaseot heard No diagnosisot heard No diagnosisot heard Hypertrophic cardiomyopathy

Case 9. The mitral valve echogram showed no for-ward displacement of either anterior or posterior leafletechoes during systole. The anterior leaflet echoes showedfine fluttering during diastole suggestive of aortic re-gurgitation. The septal echoes suggested hypertrophyand poor contractility while the posterior wall echoeswere compatible with normal thickness and reducedcontractility. The aortic valve echogram could not berecorded, presumably because of a bulging septum.

Case 10. The mitral valve echogram showed pro-nounced forward displacement of the anterior leafletechoes during systole (Fig. 10). The posterior leafletechoes showed mild displacement. The septal echoeswere compatible with hypertrophy and poor contractility.The posterior wall echoes were unremarkable.

Case 11. The mitral valve echogram showed for-ward displacement of the anterior and posterior leafletechoes during systole. Furthermore, the anterior chordaetendineae (AC) echoes were prominent and also showedforward displacement. The septal echoes suggestedhypertrophy and very good contractility. The posteriorwall echo pattern also suggested good contractility(Fig. llA).

Case 12. The mitral valve echogram was similar inmost respects to that ofCase 11, but the forward displace-ment of the anterior and posterior leaflet echoes duringsystole was less pronounced. The septal echoes were wideand suggested good contractility. The posterior wallechoes were unremarkable.

Case 13. The mitral valve echogram was normal(Fig. 11B) even after amyl nitrite inhalation. Theseptal and posterior wall echoes suggested hypertrophyand good contractility.

Case 14. The mitral and aortic valve echogramswere normal, as in Case 13. The septal pattern sug-gested hypertrophy and good contractility.

Case 15. The mitral and aortic valve echogramswere normal, as in Cases 13 and 14. The septal echoessuggested hypertrophy and poor contractility while theposterior wall echoes were unremarkable.

Echocardiographic studies of seven patientswith asymmetrical septal hypertrophy due tomiscellaneous causesA 15-year-old boy with aortic stenosis clused by acongenital bicuspid aortic valve was studied byechocardiography four weeks after valvotomy. Ex-ploration at operation had shown an abnormalanterolateral papillary muscle and a muscular bandextending from its apex to the anterior leaflet of themitral valve. At the end of the operation a with-drawal pressure trace from the left ventricle to theaorta showed the following peak systolic pressures:at mid-left ventricular cavity 230mm Hg (30*6 kPa);outflow tract 120 mm Hg (16-0 kPa); aorta 80 mmHg (10-6 kPa). The echocardiogram (Fig. 12A)showed wide interventricular septal echoes (2 0 cm),slightly widened posterior left ventricular wallechoes (1I 2 cm), and the ratio of septal to posterior



j.com/

Br H


ber 1975. Dow

nloaded from



TABLE 2 Catheter-angiographic data on 15 patients with hypertrophic cardiomyopathy

CaseNo. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Peak systolic LVOT pressure fResting 40 20-75 20 192 60 10 30 40 40 0 0 0 0 0 0gradient (mmHg) iPostectopic 60 75 NE 200 NE 85 60 80 NE 0 0 0 0 0 0

Indirect MV diastolic gradient 7 0 0 7 0 6 NT 0 0 0 NT NT NT NT 0(mmHg) (early)

Grade of mitral regurgitation 2/4 0 0 2/4 NC 0 0 1/4 0 0 0 0 0 0 0Grade of aortic regurgitation NC NC NC NC NC 1/4 NC NC 1/4 NC NC NC NC NC NCAbnormal V-shaped MV + + 0 + NC + + NV 0 + + NV 0 0 0

configuration by angiographyCoronary arteriography NC NC NC NC NC NC NC NC NC N N N NC N NC

LVOT=Left ventricular outflow tract. MV=Mitral valve. NT=Simultaneous left ventricular and pulmonary wedgepressure not taken. NE=Not examined. + =Present. NC=Investigation not carried out. NV=Mitral valve not visualized.N=Normal.Conversion factors from Traditional units to Sl units: 1 mmHg r 0-133 kPa.

TABLE 3 Echocardiographic data on 30 healthy controls and 15 patients with hypertrophic cardiomyopathy

Healthy controlsEchocardiographic data range mean

Upper LVOT dimension (cm) 1-8-3-0 2-0Lower LVOT dimension (cm) 2-2-3-0 2-4End-diastolic LV dimension (cm)LVIT level 4-0-5-0 4-5Sub-MV level 4-0-5-2 4-6

End-systolic LV dimension (cm)LVIT level 130-3 8 3-1Sub-MV level 2 9-3 6 3-3

RV dimension (cm)diastolic f 1-5-3-0 1-8systolic 1-3-3-0 1-4

LA dimension (cm)systolic 2-0-4-0 3-2

IVS thickness (cm)upper LVOT level r0 8-1 1 0-9lower LVOT level 0-7-1-2 1-0sub-MV level L0-8-1-3 1 1

PLV thickness (cm)lower LVOT level f0 7-1 1 1-0sub-MV level ) 07-1 1 1-0

IVS to PLV thickness ratio (diastolic)lower LVOT level f0.8 1-0sub-MV level \1.1 1.0

Amplitude ofAM echoes at diastole (cm) 1-8-3-0 2-0E-F slope mm/sec(mean of 6 beats) 60-170 130

Duration ofAM to IVS apposition(% of diastolic period) 0-5 3

Duration ofAM to IVS apposition(% of systolic period) 0 0

Aortic valve echocardiogram

1 2 3*

2-0 1-8 1.50-0 0-0-6 1-0

5.0 3-8 3-25.5 3-2 3 0

2-6 2-8 3-34-0 1-8 1-5

2-0 2-6 2-31-8 1-7 1-3

3-8 6-5 5-6

2-0 2-0 2-02-1 2-7 2-52-3 30 30

1-2 1-2 1 11-2 1-4 1.1

1-7 2-2 2-519 2-1 301-5 1-6 1-8

NM NM 60

45 35 < 5

40 0-50 0Abn Abn Abn

*Echocardiography carried out simultaneously with cardiac pressure traces.**Aortic valve examined after amyl nitrite inhalation.LV=Left ventricular. RV=Right ventricular. LVOT=Left ventricular outflow tract. MV=Mitral valve.LVIT=Left ventricular inflow tract. LA=Left atrial. IVS=Interventricular septum. PLV=Posterior left ventricular wall.AM=Anterior mitral valve leaflet. E-F slope= Slope of mitral valve echoes during diastole (see text). NM=Not measurable.Abn=Abnormal. NR=Not recorded. Other abbreviations as in Table 2.

4 5

1-0 1.10.0 0.0

4-5 4-3NE 1-7

40 2-3NE 0.0

NE 2-0NE 1-5

6-0 4-0

1-7 1-62-0 2-0NM 2-5

NM 1.1NM 1-4

NM 1-8NM 1-81-4 1.9

NM 110

60 <5

80 65Abn Abn

6* 7

1-6 1-80-7 0.9

5*0 3-440 3-5

3-8 2-52-5 30

3-0 1-32-0 1-3

4-4 30

2-0 1-52-2 2-62-6 2-6

1-1 1.11*3 1-2

2-0 2-32-0 2-21-7 1-5

NM NM

5-10 45

0 0Abn Abn

8

2-00'0

2-42-4

1-30.0

1-3 (approz1-3 (appro3

3-2

1-82-32-3

0*81-2 (appro,

2-81-91-5

45

<5

30Abn



j.com/

Br H


ber 1975. Dow

nloaded from



wall thickness was increased (1-7). The anteriormitral leaflet echoes recorded showed forward dis-placement during systole which became moreprominent after amyl nitrite inhalation (Fig. 12B).The posterior leaflet echoes also showed forwarddisplacement during systole.

Four other patients (aged 14, 16, 18, and 23)with aortic stenosis due to bicuspid valve have beenstudied by echocardiography. In three the studywas carried out after valvotomy and in one pre-operatively. All four showed echocardiographicfeatures compatible with severe asymmetric septalhypertrophy and two showed abnormal forwarddisplacement of the anterior mitral leaflet echoesduring systole. One of the patients who did not showthe abnormal mitral valve pattern at rest or afteramyl nitrite inhalation had a myotomy. All fourpatients, like the patient described above, had valvarand subvalvar gradients. These cases will be de-scribed in detail elsewhere.

10* 11* 12* 13 14* 15

1.0 2-1 2-0 2*8 2-0 1-61.0 1.0 1-5 3 0 1-8 1-7

5 0 4-0 4-8 4-8 4-8 4 03*8 40 (approx) NE 4'9 NE 4-0

2-8 2-0 3*3 3-5 3*5 3 01-3 1-7 (approx) NE 30 NE 30

1.5 NE 19 1-3 (approx) 2-0 2-01-5 NE 1-2 1-3 (approx) 1-5 1-5

4 0 3-8 3-5 3-3 3-0 4-3

2-0 1-3 1 5 1-3 1-3 2*82-3 1-6 2-5 1-6 1-8 2-02-3 1-6 NE 1-6 NE 2-0

0-8 1.1 1.1 1-0 0-8 1.01-5 1.1 NE 1.0 NE 1-0

2-8 1-5, 2-3 1-6 2-3 2-01-5 1-5 NE 1-6 NE 2-02-4 1-5 2-0 2-4 2-4 1-3

120 50 106 130 120 110

<5 0 0 0 0 0

o o 0 0 0 0N** N** N** N** N** N**

A 28-year-old man with pulmonary valve atresiaand a small ventricular septal defect, and whohad Blalock's operation at the age of 23 years, wasalso studied (Fig. 13A). The echocardiogramshowed wide interventricular septal echoes (1'7 cm)and a normal posterior left ventricular wall pattern(1-0 cm), thus the ratio of the septal to posteriorwall thickness was increased (1.7). This patientsubsequently died. At necropsy the measurement ofthe septal and posterior wall thickness correlatedwell with those measured by echocardiography. Thehistological appearance of both the septum and ofthe posterior wall was that of secondary hyper-trophy.A 16-year-old girl with Eisenmenger's syndrome

associated with a persistent ductus arteriosus wasstudied by echocardiography (Fig. 13B). Thisshowed wide interventricular septal echoes (1 8 cm)and normal posterior wall echoes which measured1 0 cm. Thus the ratio of the septal to posterior wallthickness was increased (1 8).

DiscussionThe abnormal forward displacement of the anteriormitral valve leaflet echoes during systole is generallyaccepted to be pathognomonic of hypertrophicobstructive cardiomyopathy. Our experience thusfar has shown this abnormal mitral valve pattern tobe specific for hypertrophic cardiomyopathy but notnecessarily with obstruction, since three patients(Cases 10, 11, and 12) showed some degree ofabnormal systolic displacement of the anteriormitral valve leaflet echoes and yet no pressuregradients were recorded at cardiac catheterization,even after provocation with isoprenaline. Thissuggests that echocardiography can detect abnormalmitral valve leaflet motion when there is no de-tectable haemodynamic effect.

Contrary to previous reports (Shah et al., 1969)we have not found it possible to predict the severityof the left ventricular outflow tract obstruction byassessing echocardiographically the degree of theabnormal systolic displacement of the anterior mitralvalve leaflet echoes. For example, in Cases 6 and 10pronounced systolic forward displacement of theanterior leaflet echoes was observed with apparentnarrowing of the left ventricular outflow tract yetthe resting outflow tract gradient was zero in Case10 and only 10mm Hg (1'3 kPa) in Case 6. InCase3there was no abnormal forward displacement of themitral valve leaflets, yet an outflow tract gradient of20mm Hg (2 6 kPa) was present. (The echocardio-grams were carried out simultaneously with the car-diac catheterization studies.) It is of interest that theangiocardiograms also suggested a narrowed outflow



j.com/

Br H


ber 1975. Dow

nloaded from


A ANTERIOR B

'H1 N1d*-' l

yEiA Mi

RV - -

POSTER OR

p P P PPP C. D~

A-----------==~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~---------

;~~~~~1tiszvw- i *........,...6W.

FIG. 4 Echocardiogram of Case 1 with hypertrophic cardiomyopathy. A) Mitral valve area.

Arrows indicate pronounced abnormal forward displacement of the anterior mitral leaflet(AM), posterior mitral leaflet (PM), and posterior chordal (PC) echoes during systole. Excur-sion ofAM echoes in diastole is reduced; these echoes make contact with the interventricular sep-tum (IVS) during 40% of systole and 45% of diastole. IVS echoes are wide and show reducedamplitude of motion while those ftom the posterior left ventricular wall (PLV) are slightlywidened andshow good amplitude of motion. B) Diagram of cross-section of a heart showing gross

septal hypertrophy to illustrate how IVS hypertrophy may interfere with fullAM leaflet openingand cause left ventricular inflow tract obstruction. Abbreviations as in Fig. 1. C) Aorticroot area. Arrows indicate pronounced posterior displacement of anteriorly visualized cuspechoes (Ca) during systole, coinciding to peaks (P) in accompanying phonocardiogram. D) Leftventriculogram in right anterior oblique position during systole. Arrow indicates V-shapedconfiguration produced during systole by the anterior and posterior mitral leaflets. Left atrial(LA) opacification is also demonstrated. Abbreviations as in Fig. 1.

tract. This is presumably because of the limitationof one-dimensional visualization of the outflowtract by these techniques. Furthermore, Cases 1, 4,5, and 8 showed apparent complete obliteration ofthe lower outflow tract during mid-systole, yet

there was a wide range of gradients (40 to 192 mmHg (5 3 to 25-5 kPa).We have confirmed that distinct narrowing of the

anteroposterior dimensions of the outflow tract mayoccur in hypertrophic cardiomyopathy. However,


PHONO P



j.com/

Br H


ber 1975. Dow

nloaded from



FIG. 5 Echocardiogram of Case 3 with hyper-trophic cardiomyopathy showing mitral valve area.

No abnormalforward displacement of the AM or thePM echoes. IVS echoes are very wide and show re-

duced amplitude of motion; thosefrom the PLVshownormal motion.. Other abbreviations as in Fig. 2A.

recent studies (0. Feizi, unpublished observations)have shown similar degrees of narrowing in severalpatients with fixed outflow tract obstruction. Inhypertrophic cardiomyopathy the narrowed out-flow tract appears to be the result of hypertrophyof the interventricular septum with or without theabnormal forward displacement of the anteriormitral valve leaflet towards the interventricularseptum during systole.This study has shown that in hypertrophic cardio-

myopathy forward displacement of the echoes fromthe posterior mitral valve leaflet and from thechordae tendineae often occurs in addition to theforward displacement of the anterior leaflet echoesduring systole. In seven of the 10 patients whoshowed abnormal displacement of the mitral valveleaflet echoes there was confirmatory angiocardio-graphic evidence. Our experience has also shownthat the presence of the abnormal systolic forwarddisplacement of the mitral valve leaflet echoes is notinvariably associated with mitral regurgitation. Thepresence of haemodynamically significant mitralregurgitation was usually reflected on the echo-cardiogram by an increase in size of the leftatrium and a relatively large left ventricular di-mension. The aneurysmal left atrium in the patient

(Case 2) who did not have mitral regurgitation waspresumably secondary to the left ventricular inflow-tract obstruction at the mitral valve level.

Table 3 shows that the finding of a reduced upperleft ventricular outflow tract dimension and aprolonged period of apposition of the anteriormitral leaflet to the septum during systole is helpfulin detecting the patients with moderate to severeoutflow tract gradient, presumably because it re-flects the extent of the outflow tract narrowing.However, a better prediction of the presence of out-flow tract obstruction and its haemodynamicsignificance can be made by inspecting the aorticvalve echogram. Case 4, in which there was severeleft ventricular outflow obstruction, showed apattem compatible with almost complete closure ofthe aortic cusp during systole, while patients withrelatively smaller gradients showed pattems sug-gesting variable degree of incomplete closure of thecusp during systole. Patients with no detectableoutflow tract gradient showed a normal pattem ofaortic cusp movement.

Left ventricular outflow-tract obstruction inhypertrophic cardiomyopathy has received muchattention but less mention has been made of leftventricular inflow-tract obstruction. The latter hasbeen attributed to impaired left ventricular fillingsecondary to reduced cavity size and to loss ofventricular wall compliance associated with extremehypertrophy (Hansen, Davidsen, and Fabricius,1962; Goodwin, 1964; Wigle, 1964). In this study,in order to evaluate further the cause of the leftventricular inflow-tract obstruction, the E-F slopeof the mitral valve leaflet was examined, since this isknown to be affected by the rate of blood flowacross the mitral valve (Shah et al., 1968; Moreyraet al., 1969). A reduced E-F slope (in the absence ofmitral valve stenosis (Duchak, Chang, and Feigen-baum, 1972) would be expected when there is de-creased compliance. We found that prolongedcontact of the anterior leaflet with the septal echoesprecluded the measurement of the E-F slope in fivepatients with hypertrophic cardiomyopathy (Cases1, 2, 4, 6, and 7) (Figs. 4A and 6A). In addition,these patients had a reduced amplitude of anteriorleaflet echo excursion during diastole. Cardiaccatheterization in three of these five patients showeda mitral diastolic gradient (Tables 2 and 3).These observations suggest that in hypertrophic

cardiomyopathy there can be mechanical left ventri-cular inflow-tract obstruction at the mitral valvelevel, due presumably to incomplete valve opening,secondary to gross septal hypertrophy of the typedescribed in a single case by Teare (1958). It is ofinterest that two or the five patients who had leftventricular inflow-tract obstruction suffered acute



j.com/

Br H


ber 1975. Dow

nloaded from



FIG. 6 Echocardiogram of Case 4 with hypertrophic cardiomyopathy. A) Mitral valve area.Arrow indicates pronouncedforward displacement ofAM echoes during systole. Excursion ofAMechoes in diastole is reduced. These echoes made contact with IVS echoes during 80% of systoleand 60% of diastole. IVS pattern is compatible with gross hypertrophy andpoor contractility(c.f. Fig. 2A). B) Aortic root area. Anteriorly visualized echoes (Ca) show pattern compatiblewith premature closure (arrowed) during systole. LA dimension is compatible with aneurysmaldilatation (c.f. Fig. 2B). Other abbreviations as in Fig. 2.

hemiparesis thought to have been embolic in origin.By demonstrating inflow tract obstruction, echo-cardiography may thus predict the risk of embolismin hypertrophic cardiomyopathy and also assist theselection of patients suitable for septal myotomy andmyectomy. It may be this category of patients inwhom mitral valve replacement has been foundeffective (Cooley et al., 1971). However, septalmyectomy (Bentall et al., 1965) may be more logical,since septal hypertrophy appears to be the maincontributing factor to the development of both in-flow and outflow tract obstruction to the leftventricle. The majority of the patients with hyper-trophic cardiomyopathy were found to have anormal mitral valve mechanism (Wigle et al., 1969).Shabetal and Davidson (1972) reported three casesof asymmetrical hypertrophic cardiomyopathy inwhom left ventricular inflow-tract obstruction at themitral valve level was suspected clinically. Only oneof their patients was shown to have a mitral diastolicgradient. Though echocardiography was carried outto exclude mitral stenosis this might have beenoverlooked, since the posterior mitral valve leaflet

echoes were not recorded (Duchak et al., 1972).Furthermore, they did not observe any echocardio-graphic pattern diagnostic of left ventricular inflow-tract obstruction. In the remaining 10 patients inthe present series with hypertrophic cardiomyopathytwo had a reduced E-F slope, suggesting underlyingnon-compliant left ventricle, and eight had valueswithin the normal range, thus showing that anormal E-F slope does not exclude the diagnosisof hypertrophic cardiomyopathy.Though there are a few reports of the occurrence

of both early and mid-diastolic murmurs in hyper-trophic cardiomyopathy (Brachfeld and Gorlin,1961; Hansen et al., 1962; Braunwald et al., 1964)there has been no satisfactory explanation of theirmechanism. Some authors, however, do not regardearly diastolic murmurs to be an integral feature ofthis disease and would consider that its presencemakes the diagnosis of hypertrophic cardiomyo-pathy unlikely (Menges, Brandenburg, and Brown,1961; Wigle, 1964). We propose that an earlydiastolic murmur present in hypertrophic cardio-myopathy is likely to be secondary to aortic valve

.. II -. ..-



j.com/

Br H


ber 1975. Dow

nloaded from



A_,A* A -.Ah-1 1

FIG. 7 Echocardiogram of Case 5 with hypertrophic cardiomyopathy. A) Mitral valve areashowing pronouncedforward displacement ofAM (white arrow) and PM (black arrow) leafletsduring systole. Echoes from leaflets are dense. LSE= left sternal edge. B) Aortic root area.Arrows indicate pronounced posterior displacement of Ca echoes during systole coinciding withpeaks (P) in accompanying phonocardiogram. Cp echoes also showing abnormal motion. Ca andCp echoes are dense and abnormal diastolic separation is demonstrated (c.f. Fig. 2B). Otherabbreviations as in Fig. 2.

Position 2 34 4ItsT~~~mH,rrrrrrrrrrrrrrrrr

FIG. 8 M-mode scan of left ventricle of Case 5. Arrows show fusion of IVS andPPM echoescompatible with complete left ventricular cavity obliteration at submitral valve level, position 1(c.f. Fig. 3). Other abbreviations as in Fig. 2.



j.com/

Br H


ber 1975. Dow

nloaded from



PA

ECG

_. ._.

LA

FIG. 9 Echocardiogram of Case 6 with hypertrophic cardiomyopathy showing aortic valvearea. Aortic valve echogram shows posterior displacement of the Ca echoes during systole coin-ciding with peaks in the murmur on accompanying phonocardiogram. The arrow shows failure ofvalve opening after ventricular ectopic beat. Increased intensity of murmur and pronouncedabnormality of aortic valve pattern are shown after ventricular ectopic beat. As in Fig. 7B, theCa and Cp echoes are dense and abnormal separation is demonstrated during diastole. Otherabbreviations as in Fig. 2.

AAid LIHO N ' ! 11!!!Ll!.l l 1! 1_14 11 i MO

B

....'j ..

:....::tI

1lllj1--1w-r1--z1nl--n-- 1l S . - . l . |-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-----------

%00~~ ~ ~ ~ ~ ~ 0

.....x

hc.n _iKet.tjl

.......----...-----..~~---~-~ . .. .

: . . .

FIG. 10 Case 10 with hypertrophic cardiomyopathy. A) Echocardiogram showing mitral valvearea. Arrow shows pronounced forward displacement of AM echoes during systole. PA=pulmonary area. APEX= apical area. B) Left ventricular angiogram in right oblique positionduring systole. Arrow indicates V-shaped configuration produced during systole by the AM andPM leaflets. No LA opacification demonstrated (c.f. Fig. 4). Other abbreviations as in Fig. 4.



j.com/

Br H


ber 1975. Dow

nloaded from



FIG. 11 Mitral valve echograms of Cases 11 and 12 with hypertrophic cardiomyopathy.A) Echogram of Case 11 showing wide IVS echoes with good amplitude of motion. AM, PM,and anterior chordae (AC) echoes show forward displacement (arrowed) during systole.B) Echogram of Case 13 showing patterns of IVS and PLV echoes compatible with musclehypertrophy andgood contractility. E-F slope is fast. No abnormal systolic forward displacementof the AM echoes.

FIG. 12 Mitral valve echogram of patient with bicuspid aortic valve. A) Wide IVS echoeswith good amplitude of motion. Slight forward displacement of AM echoes during systole.B) Increased forward displacement of AM echoes after amyl nitrite inhalation. PM echoesshow forward displacement (arrowed) during systole.

regurgitation, since there was evidence of this inthree patients in this small series of haemodynami-cally documented hypertrophic cardiomyopathy.The regurgitation in one patient was clinically silentbut was confirmed by angiography. The regurgita-tion could conceivably be caused by distortion of theaortic valve ring by the grossly hypertrophiedseptum, resulting in impaired aortic valve approxi-

mation during diastole. On the other hand, it couldhave been secondary to valve damage associatedwith infective endocarditis of the type described byBoiteau and Allenstein (1961), Nagle (1967), Frankand Braunwald (1968), and Cardelia et al. (1971).In our cases subclinical infective endocarditis couldhave caused the aortic dysfunction. The incidenceof aortic regurgitation in hypertrophic cardiomyo-

I



j.com/

Br H


ber 1975. Dow

nloaded from



pathy is unknown, as routine aortography is rarelyundertaken in this condition. In some patients thislesion can be detected by echocardiography (Feiziet al., 1974), as was shown in three cases reportedhere. In only two of these was the reflux shownangiocardiographically. In the third case aorto-graphy had to be abandoned because of technicalproblems. However, this patient had the classic

A

EA~RV-miii~~~A

pathy was clinically excluded in all and at necropsyin one case. In the latter case cardiac muscle histo-logy was compatible with secondary hypertrophy.The four patients with bicuspid aortic valve andasymmetrical septal hypertrophy are an interestinggroup, since in three there was also echocardio-graphic evidence of abnormal forward displacementof the anterior mitral valve leaflet echoes during

FIG. 13 Mitral valve echocardiogram of cases with pulmonary atresia and Eisenmenger'ssyndrome. Both show patterns compatible with asymmetric septal hypertrophy. B) Echoesfrom anterior right ventricular wall (ARV) thickened and suggest hypertrophy of thisstructure also.

early diastolic murmur of aortic regurgitation. Themid-diastolic murmur, on the other hand, may besecondary to mechanical left ventricular inflow-tractobstruction associated with incomplete mitral valveopening secondary to gross septal hypertrophy, andthis could simulate mitral stenosis. The mid-diastolic murmur could also be caused by under-lying regurgitation when this is severe.

It has been suggested that an interventricularseptal to posterior left ventricular walJ thickness ratiogreater than 1V3 is a specific finding in hypertrophiccardiomyopathy. Our findings confirm that a distinctincrease of this ratio occurs in this disease, since allthe patients in our series had values ranging from1-5 to 3 0 (normal 0-8 to 1 1). However, this does notappear to be specific for hypertrophic cardiomyo-pathy, since in the miscellaneous group of patientsin whom asymmetrical septal hypertrophy wasshown the diagnosis of hypertrophic cardiomyo-

systole indistinguishable from the pattern of hyper-trophic cardiomyopathy. Thus the possibility wasraised of coexisting cardiomyopathy. During thepreparation of this paper the possibility of hyper-trophic cardiomyopathy coexisting with fixed leftventricular outflow obstruction has been reported infour children (Chung, Manning, and Gramiak,1974). One had valvar aortic stenosis, two haddiscrete subaortic stenosis, and one had coarctationof the aorta. However, myocardial histological con-firmation is lacking in their study and also in ourown. Since reports from many centres have shownthe abnormal displacement of the mitral valveduring systole to be specific for hypertrophic cardio-myopathy, probably these patients do indeed havethis condition, or that they develop secondary myo-cardial changes which can produce echocardio-graphic pattern and haemodynamic abnormalitiesof the types seen in hypertrophic cardiomyopathy.

illuflillIff iffu



j.com/

Br H


ber 1975. Dow

nloaded from



In conclusion, the diagnosis of hypertrophiccardiomyopathy can be made by echocardiographyalone. It is possible to assess the extent of theanatomical abnormalities by this technique withoutresort to angiocardiography. Aortic valve echo-cardiography has proved to be of undoubted valuenot only in detecting some cases of aortic regurgita-tion but also in assessing and quantifying leftventricular outflow-tract obstruction. Mitral valveechocardiography has been shown to be of value inestablishing the diagnosis of hypertrophic cardio-myopathy and in detecting mechanical left ventri-cular inflow-tract obstruction.This study casts doubt on the need for routine

cardiac catheterization and angiography in investigat-ing suspected hypertrophic cardiomyopathy. Whenthese results have been confirmed in a larger numberof patients we believe that cardiac catheterizationshould be reserved for the following situations: (1)when surgery is indicated because of persistent symp-toms despite medical treatment or in situations whenthe drugs are not tolerated in symptomatic patients;(2) to confirm or to exclude aortic valve disease;(3) when it is necessary to confirm the presence ofmitral regurgitation and to assess its severity; and(4) when the echocardiographic findings aretechnically unsuitable to make a definitive diagnosis.

It is true that echocardiography in hypertrophiccardiomyopathy does not give precise pressuregradients, but this is of doubtful importance in adisease that is known to have a labile left ventriculartract obstruction which can alter from beat to beat.

We thank Dr. Walter Somerville and Dr. KeithJefferson for reviewing the haemodynamic and the angio-cardiographic data, respectively. We are grateful to Drs.Roderick Brown, Graham Hayward, Lawson McDonald,Walter Somerville, and Cecil Symons for the opportunityto study their patients. This work was undertaken whileO.F. was in receipt of the Charles Wolfson Fellowship inClinical Cardiology at the Middlesex Hospital.

References

Abbasi, A. S., MacAlpin, R. N., Eber, L. M., and Pearce,M. L. (1972). Echocardiographic diagnosis of idiopathichypertrophic cardiomyopathy without outflow obstruction.Circulation, 46, 897.

Bentall, H. H., Cleland, W. P., Oakley, C. M., Shah, P. M.,Steiner, R. E., and Goodwin, J. F. (1965). Surgical treat-ment and post-operative hemodynamic studies in hyper-trophic obstructive cardiomyopathy. British Heart Journal,27, 585.

Bjork, V. 0. (1964). Discussion on R. J. Linden's Relatedphysiology of cardiac contraction. In Ciba FoundationSymposium on Cardiomyopathies, p. 127. Ed. by G. E. W.Wolstenholme and M. O'Connor. Churchill, London.

Boiteau, G. M., and Allenstein, B. J. (1961). Hypertrophicsubaortic stenosis. American Jrournal of Cardiology, 8, 614.

Brachfeld, N., and Gorlin, R. (1961). Functional subaorticstenosis. Annals of Internal Medicine, 54, 1.

Braunwald, E., Lambrew, C. T., Rockoff, S. D., Ross, J., andMorrow, A. G. (1964). Idiopathic hypertrophic subaorticstenosis: 1, a description of the disease based upon ananalysis of 64 patients. Circulation, 30, Suppl. IV.

Cardelia, J. U., Befeler, B., Hildner, F. J., and Samet, P.(1971). Hypertrophic subaortic stenosis complicated byaortic insufficiency and subacute bacterial endocarditis.American Heart Journal, 81, 543.

Chung, K. J., Manning, J. A., and Gramiak, R. (1974).Echocardiography in coexisting hypertrophic subaorticstenosis and fixed left ventricular outflow obstruction.Circulation, 49, 673.

Cooley, D. A., Leachman, R. D., Hallman, G. L., Gerami, S.,and Hall, R. J. (1971). Idiopathic hypertrophic subaorticstenosis: surgical treatment induding mitral valve re-placement. Archives of Surgery, 103, 606.

Dinsmore, R. E., Sanders, C. A., and Harthorne, J. W. (1966).Mitral regurgitation in idopathic hypertrophic subaorticstenosis. New England Journal of Medicine, 275, 1225.

Duchak, J. M., Chang, S., and Feigenbaum, H. (1972). Theposterior mitral valve echo and the echocardiographicdiagnosis of mitral stenosis. American Journal of Cardio-logy, 29, 628.

Edler, I. (1966). Mitral valve function studied by the ultra-sound echo method. In Diagnostic Ultrasound: Proceedingsof the First International Conference, University of Pitts-burg, 1965, p. 198. Ed. by C. C. Grossman, J. H. Holmes,C. Joyner, and E. W. Purnell. Plenum Press, New York.

Feigenbaum, H. (1972). Clinical applications of echocardio-graphy. Progress in Cardiovascular Diseases, 14, 531.

Feizi, O., Symons, C., and Yacoub, M. (1974). Echocardio-graphy of the aortic valve. 1: Studies of the normalaortic valve, aortic stenosis, aortic regurgitation, andmixed aortic valve disease. British Heart Journal, 36, 341.

Frank, S., and Braunwald, E. (1968). Idiopathic hypertrophicsubaortic stenosis: clinical analysis of 126 patients withemphasis on the natural history. Circulation, 37, 759.

Goodwin, J. F. (1964). Cardiacfunction in primarymyocardialdisorders. British Medical Journal, 1, 1527.

Gramiak, R., Shah, P. M., and Kramer, D. H. (1969). Ultra-sound cardiography: contrast studies in anatomy andfunction. Radiology, 92, 939.

Hansen, P. F., Davidsen, H. G., and Fabricius, J. (1962).Subvalvar aortic stenosis of muscular type. Acta MedicaScandinavica, 171, 743.

Henry, W. L., Clark, C. E., and Epstein, S. E. (1973).Asymmetric septal hypertrophy: echocardiographic identi-fication of the pathognomonic anatomic abnormality ofIHSS. Circulation, 47, 225.

Menges, H., Brandenburg, R. O., and Brown, A. L. (1961).The clinical, hemodynamic and pathologic diagnosis ofmuscular subvalvular aortic stenosis. Circulation, 24, 1126.

Moreyra, E., Klein, J. J., Shimada, H., and Segal, B. L. (1969).Idiophathic hypertrophic subaortic stenosis diagnosed byreflected ultrasound. American Journal of Cardiology,23, 32.

Nagle, J. P. (1967). Idiopathic hypertrophic subaortic stenosisand bacterial endocarditis. Journal of the American MedicalAssociation, 200, 643.

Popp, R. L., and Harrison, D. C. (1969). Ultrasound in thediagnosis and evaluation of therapy of idiopathic hyper-trophic subaortic stenosis. Circulation, 40, 905.

Pridie, R. B., and Oakley, C. M. (1970). Mechanism of mitralregurgitation in hypertrophic obstructive cardiomyopathy.British Heart Journal, 32, 203.

Shabetal, R., and Davidson, S. (1972). Asymmetrical hyper-trophic cardiomyopathy simulating mitral stenosis.Circulation, 45, 37.



j.com/

Br H


ber 1975. Dow

nloaded from



Shah, P. M., Gramiak, R., and Kramer, D. H. (1969).Ultrasound localization of left ventricular outflow obstruc-tion in hypertrophic obstructive cardiomyopathy. Circula-tion, 40, 3.

Shah, P. M., Gramiak, R., Kramer, D. H., and Yu, P. N.(1968). Determinants of atrial (S,) and ventricular (S4)gallop sounds in primary myocardial disease. New EnglandJournal of Medicine, 278, 753.

Simon, A. L., Ross, J., and Gault, J. H. (1967). Angiographicanatomy of the left ventride and mitral valve in idiopathicsubaortic stenosis. Circulation, 36, 852.

Teare, R. D. (1958). Asymmetrical hypertrophy of the heartin young adults. British Heart Journal, 20, 1.

Wigle, E. D. (1964). Muscular subaortic stenosis: the clinical

syndrome, with additional evidence of ventricular septalhypertrophy. In Cardiomyopathies: Ciba Symposium, p.49. Ed. by G. E. W. Wolstenholme and M. O'Connor.Churchill, London.

Wigle, E. D., Adelman, A. G., Auger, P., and Marquis, Y.(1969). Mitral regurgitation in muscular subaortic stenosis.American Journal of Cardiology, 24, 698.

-0*

Requests for reprints to Dr. 0. Feizi, Department ofCardiology, The Middlesex Ho3pital, London WlN8AA.



j.com/

Br H


ber 1975. Dow

nloaded from


echocardiographic spectrum of hypertrophic cardiomyopathy' · british heartjournal, 1975, 37,...

Documents