Hocm
-
Upload
mohammed-alsheikh -
Category
Documents
-
view
2.261 -
download
3
Transcript of Hocm
Hypertrophic cardiomyopathy
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
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
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
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 fibrillation
Ischemia in HCM Myocardial bridging Impaired vasodilator reserve Decreased capillary density and increased
capillary separation Myocardial fibrosis Small vessel disease/microvascular
dysfunction
7
Apical hypertrophic cardiomyopathy Apical segment >/=15 mm Good prognosis (95% survival at 15 years) Often need contrast echo or cardiac MR to
make diagnosis
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
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
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
Brockenbrough-Braunwald-Morrow signAfter 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
Defibrillator if VF or sustained VT (class 1)
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
Ethanol ablation: Complications CHB 10-25% RBBB Ventricular
arrhythmias Coronary
dissection Pericardial effusion Large MI
Best suited for older patients with comorbidities
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 child17
Patient with HCM and PAF Beta-blocker Disopyramide if LVOT obstruction Otherwise amiodarone or sotalol Anticoagulation
18
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
Post-operative severe LVOT obstruction Volume expansion Avoid beta-agonists Phenyephrine iv metoprolol/esmolol
20