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Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy

1. Definition

A. Unknown etiology
B. Genetically determined
C. Primary cardiac muscle hypertrophy
D. Dynamic LVOT obstruction
E. Myocardial fiber disarray

2. Morphology

A. Asymmetric septal hypertrophy
B. Systolic anterior motion (SAM) mitral valve
C. Small LV cavity
D. Myocardial fiber disarray
E. Left atrial enlargement
F. Distortion right ventricle
G. Large diameter coronary arteries
H. Impaired coronary perfusion

3. Clinical features

A. Symptoms
B. Dyspnea Diastolic dysfunction
C. Syncope <===== Arrhythmias
D. Angina Myocardial ischemia
E. Outflow obstruction
F. Signs
G. Rapid pulse upstroke
H. Jugular a-wave
I. Double LV impulse (S4)
J. S3 at apex
K. Mid-systolic precordial murmur

4. Diagnostic Criteria

A. Electrocardiography
B. LV strain
C. RBBB, LBBB, left anterior hemiblock
D. Chest radiography
E. Cardiomegaly
F. Increased pulmonary vascular markings
G. Echocardiography
H. LVOT obstruction
I. Early aortic valve closure
J. Small LV cavity
K. SAM

5. Cardiac catheterization

A. Right sided pressures - normal or increased
B. LVOT obstruction
C. Increased LVEDP
D. Post-PVC gradient potentiation (Brockenbrough)
E. Dynamic gradient (provocative)
F. Mitral regurgitation
G. Coronary arteriography

6. Natural History

A. Asymptomatic ASH ===?===> clinical HOCM
B. Ages 20-30 most common
C. Obstruction in only 20%
D. Progressive symptomatic course
E. Mortality without operation
F. 15% at 5 years
G. 25% at 10 years

7. Operative Treatment

A. Indications for Operation
B. NYHA class III or IV
C. Symptoms not relieved by medical treatment
D. Gradient (rest or provocative) > 50 mmHg
E. Goals of Operation
F. Relieve gradient
G. Abolish SAM
H. Enlarge LVOT
I. Abolish MR

8. Technique

A. Myotomy - Myectomy
B. Aortic root
C. Aortic root and LV
D. Modified Konno
E. LV-Ao conduit
F. MVR
G. Myectomy and MVR
H. DDD pacemaker

9. Complications

A. Complete heart block (3-5%)
B. Myocardial infarction (3-4%)
C. Embolism
D. Iatrogenic
E. VSD (3%)
F. Aortic valve injury
G. Mitral valve injury
H. LV pseudoaneurysm
I. Results
J. Early death (5-8%)
K. Late death - CHF, arrhythmias, stroke