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
5
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
7
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
10
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
11
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)
12
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.
13
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
15
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
18
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
19
