Hypertrophic cardiomyopathy is a genetic heart condition characterized by thickened heart muscle and potential outflow tract obstruction. It affects 0.2-0.5% of the population and is caused by mutations in genes encoding sarcomere proteins. Symptoms include chest pain, dizziness, and palpitations. Diagnosis is made via echocardiogram and genetic testing. Treatment focuses on symptom relief through medications or procedures to reduce outflow tract obstruction, as well as preventing sudden cardiac death through ICD implantation in high-risk patients.

1. Hypertrophic cardiomyopathy

2. Hypertrophic cardiomyopathy
 .2-.5% of
population affected
 Left ventricular
hypertrophy with
myocardial fiber
disarray
 Interstitial fibrosis
2

3. Hypertrophic cardiomyopathy
 Familial (autosomal dominant) or sporadic
(50%)
 Abnormalities in sarcomere proteins
 beta-myosin heavy chain (45%--chromosome
14) , cardiac myosin binding protein-C
 D/D genotype for ACE alters phenotype with
more hypertrophy
3

4. Hypertrophic cardiomyopathy
 Distribution of hypertrophy
 Asymmetric septal hypertrophy most common
(septal/posterior wall thickness > 1.5)
 Type 1: Hypertrophy anterior septum
 Type II : Hypertrophy of anterior and inferior
septum
 Type III: Extensive LVH with sparing of
posterior wall
 Type IV: Apical hypertrophy
4

5. Hypertrophic cardiomyopathy: May have resting
LVOT obstruction, latent obstruction or non-obstructive
 Normal systolic function but increased afterload if
LVOT obstruction
 Dynamic outflow tract obstruction created by
anterior motion of mitral leaflet during systole
obstructing the outflow tract
 Venturi forces b/o septal hypertrophy
 Anterior papillary muscle displacement and abnormally
long anterior mitral leaflet
 Gradient worse with decreased preload, increased
contractility
 Primarily diastolic dysfunction
 Decreased relaxation
 Increased stiffness
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6. Hypertrophic cardiomyopathy:
Symptoms
 May be asymptomatic
 Found on screening ECG, echocardiogram
 Dyspnea: High LV diastolic pressure because
of impaired LV relaxation and increased
stiffness. High afterload if LVOT obstruction
 Angina: Inadequate coronary arterial blood
supply for degree of hypertrophy and increased
demand
 Syncope: Arrhythmias or hypotension
secondary to LVOT obstruction
 Palpitations—AF is common
 Sudden cardiac death: Ventricular fibrillation6

7. Ischemia in HCM
 Myocardial bridging
 Impaired vasodilator reserve
 Decreased capillary density and increased
capillary separation
 Myocardial fibrosis
 Small vessel disease/microvascular
dysfunction
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8. Apical hypertrophic cardiomyopathy
 Apical segment >/=15 mm
 Good prognosis (95% survival at 15
years)
 Often need contrast echo or cardiac MR to
make diagnosis

9. Apical hypertrophic cardiomyopathy
 1/3 of patients had complications—atrial
fibrillation, myocardial infarction, HF,
TIA/stroke, VT/VF
 May have mid cavitary obstruction and
apical aneurysm

10. Hypertrophic cardiomyopathy: Signs
 Spike and dome carotid pulse
 Triple ripple apical impulse
 Fourth heart sound (increased filling with
atrial contraction because of decreased LV
relaxation)
 Systolic ejection murmur of LV outflow
tract obstruction
 Increases if decreased preload ie increases
with standing from squat
 Murmur of mitral regurgitation
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11. Hypertrophic cardiomyopathy:
Diagnosis
 Echocardiogram shows left ventricular
hypertrophy in the absence of
hypertension or aortic stenosis
 LVOT obstruction caused by mitral leaflet SAM
 Eccentric lateral jet of MR
 ECG: Usually abnormal
 Left ventricular hypertrophy
 Abnormal Q waves
 Family history/genetic testing
 Cardiac MR: LV/RV thickness, late
gadolinium enhancement
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12. Increased wall thickness
 LVH for other reasons: hypertension,
aortic stenosis, athlete’s heart (< 14 mm)
 Sigmoid septum of the elderly
 Infiltrative : amyloidosis, hypereosinophilic
syndrome
 Children with HCM
 Idiopathic (75%)
 Inborn errors of metabolism (Fabry, Danon disease)
 Malformation syndromes (Noonan’s)
 Neuromuscular disorders (Friedrich’s ataxia)
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13. Brockenbrough-Braunwald-Morrow sign
After a PVC, there is a decrease in carotid pulse pressure
in patients with HOCM. Increased contractility results in
increased LVOT obstruction.
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14. Hypertrophic Cardiomyopathy:
Management
 Medical therapy for symptomatic
dynamic LVOT obstruction:
 Beta-blockers, verapamil, disopyramide
 Interventions for symptomatic LVOT
obstruction: septal myomectomy or septal
alcohol ablation
 Prevent death from ventricular
arrhythmias:
 Assess all patients with HCM for SCD risk factors
 Syncope, non-sustained VT, family history SCD, exercise induced
hypotension, septum > 30mm (class IIA for ICD), gradient > 30
mm Hg, high risk mutations 14
 Defibrillator if VF or sustained VT (class 1)

15. Septal myectomy
 3-15 gm of septal muscle removed
 Indicated in severely symptomatic
patients with resting LVOT obstruction
despite medical therapy
 Dramatic improvement of symptoms
 Probable decrease in SCD rates
 Complications
 VSD
 LBBB/CHB (5-10%)
 Aortic regurgitation
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16. Ethanol ablation: Complications
 CHB 10-25%
 RBBB
 Ventricular
arrhythmias
 Coronary dissection
 Pericardial effusion
 Large MI
Best suited for older patients with
comorbidities

17. Management of asymptomatic
patient with HCM
 Screen first degree relatives with echo
 Assess for SCD risk with Holter and stress
test
 Avoid competitive sports. Avoid extreme
exertion and dehydration
 Annual F/U
 No endocarditis prophylaxis
 No beta-blocker if no symptoms
 Pregnancy well tolerated—50% chance of
affected child 17

18. Patient with HCM and PAF
 Beta-blocker
 Disopyramide if LVOT obstruction
 Otherwise amiodarone or sotalol
 Anticoagulation
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19. Patient with HCM, NYHA class III,
severe LVOT obstruction
 Beta-blocker
 Disopyramide 100 mg QID or 200 mg TID
 Surgical myectomy (preferred in younger
patients—90% long term symptom
improvement)
 Septal alcohol ablation—localized septal
infarct
 DDD pacing—no long term benefits
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20. Post-operative severe LVOT
obstruction
 Volume expansion
 Avoid beta-agonists
 Phenyephrine
 iv metoprolol/esmolol
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