cardiomyopathy my lecture

CARDIOMYOPATHY

Abraha Hailu, MD

Etiology and classification

• Cardiomyopathies: Are group of diseases that primarily affect the heart muscle and are

not the result of congenital, acquired valvular, hypertensive, coronary arterial, or pericardial abnormalities

• Two fundamental forms: primary type: disease predominantly involving the myocardium

and/or of unknown cause secondary type: myocardial disease of known cause or associated

with a systemic disease such as amyloidosis or chronic alcohol use In many cases it is not possible to arrive at a specific etiologic diagnosis,

and thus it is often more desirable to classify the cardiomyopathies into one of three morphologic types (dilated, restrictive, and hypertrophic) on the basis of differences in their pathophysiology and clinical presentation

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Classification of Cardiomyopathies

• Primary Myocardial Involvement: Idiopathic (D,R,H) Familial (D,R,H) Eosinophilic endomyocardial disease (R) Endomyocardial fibrosis (R)

• Secondary Myocardial Involvement: Infective (D):

Viral myocarditis Bacterial myocarditis Fungal myocarditis Protozoal myocarditis Spirochetal , Rickettsial



Familial storage disease (D,R) Glycogen storage disease Mucopolysaccharidoses Hemochromatosis

Connective tissue disorders (D):Systemic lupus erythematosus Polyarteritis nodosa Rheumatoid arthritis Progressive systemic sclerosis Dermatomyositis

Infiltrations and granulomas (R,D): Amyloidosis Sarcoidosis Malignancy



Neuromuscular (D) Muscular dystrophy Myotonic dystrophy

Friedreich's ataxia (H,D) Sensitivity and toxic reactions (D)

Alcohol Radiation Drugs

Peripartum heart disease (D)



• Dilated CMP: Left and/or right ventricular enlargement, impaired systolic function, congestive heart failure, arrhythmias, Emboli

• Restrictive CMP: Endomyocardial fibrosis/scarring or myocardial infiltration resulting in

restriction to left and/or right ventricular filling

• Hypertrophic CMP: Disproportionate left ventricular hypertrophy, typically involving septum

more than free wall, with or without an intraventricular systolic pressure gradient; usually of a nondilated left ventricular cavity

Clinical Classification of Cardiomyopathies


Clinical Classification of Cardiomyopathies


Dilated Cardiomyopathy

• LV and/or RV systolic pump function is impaired, leading to progressive cardiac dilatation Symptoms of heart failure typically appear only after

remodeling has been ongoing for some time (months/yrs)• is either familial or the end result of myocardial damage

produced by a variety of known or unknown infectious, metabolic, or toxic agents

• may occur at any age, but most commonly becomes apparent clinically in the third or fourth decades

• reversible form of DCM may be found with alcohol abuse, pregnancy, thyroid disease, cocaine use, and chronic uncontrolled tachycardia


Clinical Features

• Symptoms of left- and right-sided CHF usually develop gradually

• vague chest pain may be present, typical angina pectoris is unusual and suggests the presence of IHD

• Syncope due to arrhythmias and systemic embolism may occur

• Physical Examination: Variable degrees of cardiac enlargement In patients with advanced disease, the pulse pressure is narrow and

the jugular venous pressure is elevated Third and fourth heart sounds are common, and mitral or tricuspid

regurgitation may occur


Laboratory Examinations

• CXR: enlargement of the cardiac silhouette due to LV dilatation or

generalized cardiomegaly The lung fields may demonstrate pulmonary vascular redistribution

and interstitial or, in advanced cases, alveolar edema

• ECG: shows sinus tachycardia or atrial fibrillation, ventricular arrhythmias,

left atrial abnormality, low voltage, diffuse nonspecific ST-T-wave abnormalities, and sometimes intraventricular and/or AV conduction defects

• Echocardiography, Cardiac MRI, CT show LV dilatation, with normal, minimally thickened, or thinned walls, and systolic dysfunction

• Circulating levels of BNP are usually elevated04/07/23 10ABRAHA HAILU

Prognosis and treatment

• Patients of African ancestry are more likely to suffer rapidly progressive CHF and death than Caucasians

• Death is due to either progressive HF or ventricular tachy- or bradyarrhythmia

• Systemic embolization is a concern, and patients should be considered for chronic anticoagulation

• Standard therapy of HF

• Cardiac resynchronization therapy and insertion of an implantable cardioverter defibrillator (ICD)…if indicated


Alcoholic Cardiomyopathy

• Individuals who consume large quantities (>90 g/d) of alcohol over many years may develop a clinical picture resembling idiopathic or familial DCM

• The risk of developing cardiomyopathy is partially determined genetically A polymorphism of the gene encoding the alcohol metabolizing

enzyme, alcohol dehydrogenase (ALDH2*2), as well as the DD form of the angiotensin-converting enzyme (ACE) gene increase the predilection for the development of alcoholic cardiomyopathy

• Patients with advanced alcoholic cardiomyopathy and severe CHF have a poor prognosis

• Management consists of abstention, which may halt the progression or even reverse the course of this disease


• holiday heart syndrome: typically appears after a drinking bingemay be found in individuals without overt HF and consists

of recurrent supraventricular or ventricular tachyarrhythmias

atrial fibrillation is seen most frequently, followed by atrial flutter and frequent PVCs


Alcoholic Cardiomyopathy

Peripartum Cardiomyopathy

• cause is unknown, although inflammatory myocarditis, immune activation, and gestational hypertension have all been incriminated

• The patient who develops peripartum cardiomyopathy typically is multiparous, of African ancestry, and >30 years, although the disease may be found in a wide spectrum of patients

• The mortality rate of this disorder is around 10%


• The prognosis is related to whether the heart size returns to normal after the first episode of CHF– If it does, subsequent pregnancies may sometimes be tolerated, albeit

with an increased risk of recurrent CHF– if the heart remains enlarged, and/or the LV ejection fraction (EF)

remains depressed after 6 months, the prognosis is poor, and further pregnancies frequently produce additional myocardial damage, ultimately leading to refractory CHF

• Patients who recover from peripartum cardiomyopathy should be encouraged to avoid further pregnancies, particularly if LV dysfunction persists


Peripartum Cardiomyopathy

Anthracycline CMP

• anthracycline derivatives (EX- doxorubicin)… usual culprits• Systolic dysfunction and ventricular arrhythmias occur in a

dose-dependent manner with a dose >450 mg/m2 and are frequent with doses >550 mg/m2

The development of these complications appears to be related to damage to the inner mitochondrial membrane and interference with the synthesis of ATP

• is related not only to the dose of the drug but also to the presence or absence of several risk factors, which include cardiac irradiation, underlying heart disease, hypertension, and concurrent treatment with cyclophosphamide


Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia


•familial cardiomyopathy characterized by progressive fibrofatty replacement of predominantly the RV myocardium

On clinical examination, patients may manifest RV failureThe ECG typically shows QRS prolongation localized to the right precordial leads

CTI and CMRI typically show RV dilatation, RV aneurysm, and fatty replacement

Tako-Tsubo Cardiomyopathy

• Also known as apical ballooning syndrome• characterized by the abrupt onset of severe chest discomfort

preceded by a very stressful emotional or physical event• most common in women >50 years and is accompanied by ST-

segment elevations and/or deep T-wave inversions in the precordial leads – No obstruction in the epicardial coronary arteries is noted on

angiography– There is severe akinesia of the distal portion of the left ventricle with

reduction of the EF

• Troponins are usually mildly elevated


• Cardiac imaging typically shows "ballooning" of the left ventriclar apex in end-systole– these changes, are reversible within 3–7 days and do not cause long-

term cardiac dysfunction or disability

• mechanism responsible is not clear, although it is likely that an adrenergic surge that includes circulating catecholamines, acting on the epicardial coronary vessels and/or coronary microcirculation, is involved

• Rx: BB?


Tako-Tsubo Cardiomyopathy

Hypertrophic Cardiomyopathy

• characterized by LV hypertrophy, typically of a nondilated chamber, without obvious cause, such as hypertension or aortic stenosis

• Two features of HCM: asymmetric LV hypertrophy, often with preferential hypertrophy of

the interventricular septum; and a dynamic LV outflow tract pressure gradient, related to narrowing of

the subaortic area

• diastolic dysfunction results in elevated LV end-diastolic pressures


• patterns of hypertrophy:Majority ventricular septum symmetric hypertrophy, mid-ventricular cavity apex or LV free wall

About half of all patients with HCM have a positive family history

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Hypertrophic Cardiomyopathy

Clinical Features

• Many patients are asymptomatic or mildly symptomatic• Unfortunately, the first clinical manifestation may be SCD• the most common complaint is dyspnea• Other symptoms include presyncope/syncope, angina pectoris, and

fatigue

Physical Examination• a double or triple apical precordial impulse and a fourth heart sound• a systolic murmur, which is typically harsh, diamond-shaped, and usually

begins well after the first heart sound• The murmur is best heard at the lower left sternal border as well as at the

apex


Hemodynamics

• Obstruction appears to result from narrowing of the LV outflow tract by systolic anterior movement (SAM) of the mitral valve against the hypertrophied septum

• Three basic mechanisms are involved in the production and intensification of the dynamic intraventricular obstruction:– increased LV contractility,– decreased ventricular preload, and– decreased aortic impedance and pressure (afterload)


Laboratory Evaluation

• ECG commonly shows LV hypertrophy and widespread deep, broad Q waves or arrhythmias

• Echocardiogram: septum 1.3 times the thickness of the posterior LV free wall SAM of the mitral valve + MR is found in patients with pressure

gradients

• CMRI


• Patients at increased risk of SCD include those with:a history of resuscitation, recurrent syncope, ventricular

tachycardia on ambulatory monitoring or at electrophysiologic testing,

marked ventricular hypertrophy (ventricular septal thickness >30 mm),

failure of blood pressure to rise during exercise, a family history of SCD, and certain genetic mutations


Treatment

• competitive sports and very strenuous activities should be avoided

• Dehydration should be avoided, and diuretics used with caution

• B-Adrenergic blockers ameliorate angina pectoris and syncope in 30-50% of patients these drugs may limit the increase in the gradient that occurs during

exercise

• Amiodarone appears to be effective in reducing the frequency of supraventricular as well as of life-threatening ventricular arrhythmias, and anecdotal data suggest that it may reduce the risk of SCD


• diuretics, nitrates, dihydropyridine calcium blockers, vasodilators, and B-adrenergic agonists are best avoided

• Atrial fibrillation is poorly tolerated, and a strong effort should be made to restore and then maintain sinus rhythm

• Surgical myotomy/myectomy of the hypertrophied septum usually abolishes intraventricular obstruction and provides lasting

symptomatic improvement in about three-quarters of severely symptomatic patients with large pressure gradients who are unresponsive to medical management

• alcohol septal ablation can also reduce obstruction and improve symptoms


Treatment

Restrictive Cardiomyopathy

• The hallmark is abnormal diastolic function – the ventricular walls are excessively rigid and impede ventricular filling

In late stages systolic function is also impaired

• Etiology: Myocardial infiltration, hypertrophy, or endomyocardial fibrosis due to:– Amyloidosis, sarcoidosis, hemochromatosis, glycogen

deposition, endomyocardial fibrosis, sarcoidosis, hypereosinophilic syndrome, and scleroderma; following mediastinal irradiation; and in neoplastic infiltration…..


• In many of these conditions, particularly those with substantial concomitant endocardial involvement, partial obliteration of the ventricular cavity by fibrous tissue and thrombus contributes to the abnormally increased resistance to ventricular filling

Thromboembolic complications are frequent in such patients


Left: Gross specimen, demonstrating prominent biatrial enlargement, with normal-sized ventricles

Right: Light microscopy showing marked interstitial fibrosis


Clinical Features

• The inability of the ventricles to fill limits cardiac output and raises filling pressures; thus, exercise intolerance and dyspnea are usually prominent these patients commonly have dependent edema, ascites, and an

enlarged, tender, and often pulsatile liver

• The jugular venous pressure is elevated and does not fall normally with inspiration (Kussmaul's sign)

• third and fourth heart sounds are common In contrast to constrictive pericarditis, the apical impulse is usually

easily palpable, and mitral regurgitation is more common Differentiation of RCM from constrictive pericarditis is of importance

b/c the latter is often curable by surgery


Features that help to distinguish RCMP from constrictive pericarditis

RCMP• Hx of systemic diseases that

involve the myocardium: amyloidosis, sarcoidosis….

• CXR: no pericardial calcification• ECG: BBB, AV Blocks• CT/MRI: Normal pericardium• Echo: myocardial thickening,

markedly enlarged atria• Biopsy: Fibrosis, hypertrophy,

infiltration

Constrictive pericarditis• Hx of acute pericarditis, cardiac

surgery, radiation Rx,….

• CXR: pericardial calcification present• ECG: abnormal repolarization• CT/MRI: thick pericardium (>4mm)• Echo: normal myocardial thickness

and atrial sizes• Biopsy: Normal


cardiomyopathy my lecture

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fourth heart

jugular venous

constrictive

peripartum

endomyocardial

clinical classification

increased

hypertrophied