anne-marie anagnostopoulos, md non-invasive conference december 9, 2009
TRANSCRIPT
TETRALOGY OF FALLOT FOR THE ADULT CARDIOLOGIST
Anne-Marie Anagnostopoulos, MDNon-Invasive ConferenceDecember 9, 2009
Outline
History and Epidemiology Anatomy and Embryology Spectrum of TOF Surgical Repair Imaging The Adult with Repaired TOF Summary
Special Thanks
Special thanks to Dr. Anne Marie Valente who helped me enormously
History of Tetralogy of Fallot 1671: Stenson first describes pathology of
what would later be confirmed as TOF 1888: Etienne-Louis Fallot first recognizes a
group of complex cardiac malformations that leads to cyanosis and identifies 4 abnormalities: pulmonary stenosis, VSD, dextroposition of the aorta, and RVH Fallot postulated that these abnormalities
resulted from abnormal development of the subpulmonary infundibulum and pulmonary valve.
1924: Abbott and Dawson name the malformation “Tetralogy of Fallot”
History
From Wikipedia: E. L. A. Fallot.
Contribution à l’anatomie pathologique de la maladie bleue (cyanose cardiaque). Marseille médical, 1888, 25: 77-93, 138-158, 207-223, 341-354, 370-386, 403-420.
Epidemiology
Overall, congenital heart disease is rare
However, of the cyanotic congenital heart abnormalities, TOF is the most common
TOF has an incidence of approximately 32.6 per 100,000 live births
The success of early surgical repair has led to a large population of adults with repaired TOF
Anatomy and Embryology
The fundamental embryologic malformation in TOF is abnormal development of the cono- truncus (also known as: conal septum, subpulmonary infundibulum)
There is hypoplasia of the conotruncus and anterior/superior displacement of the infundibular septum
This results in failure of ventricular septation, subpulmonary and/or pulmonary valve stenosis and overriding aorta
The Worlds Best Anatomical Charts. Anatomical Chart Company Skokie, IL. ISBN 0-9603730-5-5.
Anatomy and Embryology in Tetralogy of Fallot
Figures Emily Flynn, Echocardiography in Pediatric and Congenital Heart Disease Editors Lai, Mertens, Cohen, Geva 2009
Anatomy and Embryology – Simplified Diagram
2D Echo TOF
Source: Feigenbaum’s 6th Ed.
Spectrum of Tetralogy
There is a spectrum of anatomy in TOF with an associated variation in clinical presentation
Children with minimal pulmonary stenosis are at one end and can be “pink”
At the other extreme is a form of TOF with pulmonary valve atresia and VSD (severely blue)
In the latter case, life is sustained by PDA or aorto-pulmonary collateral vessels
TOF:Pulmonary Atresia and VSD
• Obliterated subpulmonary infundibulum• Marked anterior/left shift of conal septum
•Figure Emily Flynn, Echocardiography in Pediatric and Congenital Heart Disease Editors Lai, Mertens, Cohen, Geva 2009
Anatomy and Embryology: Coronary Anomalies
Because the aortic root is rotated in TOF, coronary artery anomalies can occur
Most common (3%) is origin of LAD from RCA
Double LAD occurs 1.8% of time Least common anomalies are single
RCA or LCA (0.3% and 0.2% respectively)
Surgical Repair
Symptomatic infants are repaired early – can be palliated with a variety of shunts
Asymptomatic children are usually electively repaired early as well
Surgery involves repair of the VSD and enlargement of the RVOT with infundibular septum resection +/- use of a transannular patch
This can usually be performed in one step as long as pulmonary artery and its main branches are of adequate size
The surgery uniformally results in pulmonic regurgitation
Palliative Shunts
Glenn Shunt
2D Echo Glenn Shunt: SVC->PA
Source: Feigenbaum’s 6th Ed.
Surgical Repair – Transannular Patch
Patients post-repair do well up to ~25 yrs post-operatively
Modes of death:Sudden cardiac deathArrhythmiasCongestive heart
failure
Natural History
Nollert G. JACC 1997; 30:1374
The Adult with Repaired TOF Patients often remain asymptomatic Although decreased exercise
capacity can often be elicited with objective testing
Clinical Presentation: heart failure, dyspnea on exertion, atrial and ventricular arrhythmias, syncope, sudden death
ECG findings include RAD, RVH/RAA and RBBB; QRS duration can be prolonged (>180ms is important to note)
Sequelae of TOF Repair
Residual lesions: Ventricular septal defect Branch pulmonary artery stenosis
Tricuspid regurgitation Pulmonary regurgitation Progressive RV dilation and dysfunction Progressive LV dysfunction Aortic root dilation Exercise intolerance, heart failure, arrhythmias and
sudden cardiac death
Courtesy A. Valente MD
Imaging in Repaired TOF
Non-invasive imaging is the mainstay of longitudinal follow-up in previously repaired TOF
Echocardiography is used to evaluate: residual VSD/PS, Ao Root size and associated AR, PR, and RV/LV function
CMR is used to determine RV volumes and severity of PR
Often these modalities are used in a complementary fashion
Pulmonary Regurgitation
Nearly universal Severity is dictated by:
compliance of the RV capacitance of the pulmonary
arteries
Early: presence of RVH (↓ RV compliance) and small PAs (↓ capacitance) →↓ PR
Late: dilation and thinning of the RV ( ↑ compliance) and dilation of the PAs (↑ capacitance) →↑ PR
Courtesy A. Valente MD
Pulmonary Regurgitation
Courtesy A. Valente
Effects of Chronic PR
Adaptive mechanisms in chronic PR increased RV end-diastolic volume increased RV stroke volume
These mechanisms compensate for the hemodynamic burden placed on the RV for many years
Studies in the 1970’s – 1980’s on survivors of TOF repair were largely asymptomatic (based on self-reporting)
Geva T. STCVS 2006; 9:11.
Effects of Chronic PR
Compensatory mechanisms exist up to a certain point, but ultimately these mechanisms fail
Courtesy A. Valente MD
Effects of Chronic PR
Good RV Function Poor RV Function
Courtesy A. Valente
Severity of Pulmonary Regurgitation
• Prospective study of 34 adults with repaired TOF• Echocardiogram & cardiac MRI within 3 months• Median age 33 yrs (12 yrs)• Mean time since initial surgical repair 25 8 yrs• 13 subjects had undergone transannular patch• 6 subjects had undergone bioprosthetic PVR
Silversides C. JASE 2003; 16: 1057
Pulmonary Regurgitation
% PR and volume are inversely related to the pressure half-time: r = -0.6, p <0.001
Mild PR Severe PR
Silversides C. JASE 2003; 16: 1057
Pulmonary Regurgitation
Silversides C. JASE 2003; 16: 1057
• In addition, PHT <100ms had highest sensitivity and specificity for detecting significant PR (RF >20%)
Geva T. JACC 2004; 43(6): 1068
Biventricular Interaction
Median age from repair 21 years
Unfavorable ventricular-ventricular interaction
Confirmatory data that RV mechanics are only part of the problem
Patients repaired at older age, more likely to have poor clinical status later
RV Function by Echocardiography Often adults with repaired TOF
cannot undergo CMR due to devices Myocardial Performance Index (MPI)
has been shown to correlate with MRI RVEF
Retrospective study of 57 adults (repaired TOF) with a CMR and Echo within 6 months of each other
RV MPI = (Doppler duration of TR-RV ejection time)/RV ejection timeSchwerzmann, M. AJC
2007;99:1593
RV MPI Correlation With CMR RVEF
Schwerzmann, M. AJC 2007;99:1593MPI = (a-b)/b
RV MPI Correlation With CMR RVEF
Schwerzmann, M. AJC 2007;99:1593
Regional Wall Motion Abnormality
Davlouros et al. JACC 2002; 40:2044
• 85 subjects repaired TOF underwent MRI
RVOT outflow aneurysm/akinesia present in 57%
No significant difference in the type of repair
Aneurysm/akinesia negative effect on RVEF
Pulmonary Valve Replacement
Operative risk is small: mortality < 2%
What criteria should we use in patient selection?
Traditional indication: patient symptoms Is there a risk to waiting until patients
develop symptoms?
*Oosterhof T. Heart 2007; 93: 506
Patients may not detect subtle changes in exercise capacity
By the time patients notice symptoms, problems may be severe and irreversible
Predictors of Adverse Outcome
88 subjects with repaired TOF Surgical repair between 1966-1987 CMR between 1997-2001
Median follow-up from MRI 4.2 yrs 22 subjects had a major clinical event
4 deaths 8 sustained VT 10 change in NYHA class from good to
poor Larger RVEDV, LVEF<50%, RVEF<45% by
CMR predicted adverse eventsKnauth A. Heart 2008; 94: 211-16.
Proposed Criteria for PVR
Balance between patient’s clinical status (exercise capacity, heart failure symptoms, arrhythmia) and quantitative information
Decision to do PVR is quite variable center to center
Repaired TOF with moderate or severe PR (PR RF >25% by CMR) and > 2 criteria RVEDVi > 160 cc/m2 ( z > 5) RVESVi > 70 cc/m2
LVEDVi < 65cc/m2
RVEF < 45% RVOT aneurysm LVEF < 50%
Geva T. STCVS 2006; 9:11.
Aortic Root Dilation
Aortic root dilation occurs in a subset of repaired TOF adults and can lead to significant AR
May be a result of R L shunt prior to repair though not fully understood why it progresses after
A small retrospective study identified risk factors for Ao root dilation (defined as Ao root size observed:expected >1.5)
Therefore it is important to closely follow Ao root size with imaging longterm
Aortic Root Dilation
Niwa, K. Circulation 2002;106:1374
Predictors of Arrhythmia and SCD A study in England
evaluated data from 793 repaired TOF patients
QRS duration >180ms was found to be predictive of SCD and ventricular arrhythmias
Older age at repair was associated with Afib/AFlutter and SCD
QRS duration rate of change may also be significant predictor of SCD
Gatzoulis, M. Lancet 2002; 356:95
Recommendations
ECG (QRS duration): every 12 months
Exercise Testing: every 24-36 months Echo: every 24 months CMR (RVEDVi, RV/LV EF): every 24
months EP testing: when clinically indicated Echo and CMR are used together
Authors from CHBGeva T. STCVS 2006; 9:11.
Summary
Because of successful childhood repair, larger population of adults with repaired TOF exists and can present to adult cardiologists
Pulmonary Regurgitation is predominant hemodynamic abnormality leading to RV dilation and dysfunction
Timing of surgery for PR is an area of great interest as clinical symptoms do not always correlate with severity of PR and RV dysfunction.
Echo and CMR are used together to follow repaired patients long term
Aortic root dilation occurs in a subset of patients and must also be followed closely
QRS duration >180 ms is an important predictor of ventricular arrhythmias and SCD
References
Feingenbaum’s Echo Textbook, 6th Ed.
Echocardiography in Pediatric and Congenital Heart Disease Editors Lai, Mertens, Cohen, Geva 2009
Yale Congenital Heart Disease website: www.med.yale.edu/intmed/cardio/chd/
Braunwald’s Textbook Heart Disease