Hypertrophic Cardiomyopathy General Also called Hypertrophic Obstructive Cardiomyopathy (HOCM) HCM is preferred as some patients with HCM have no obstruction Asymmetric hypertrophy of the left ventricle as compared to the rest of the heart and includes notable thickening of the Interventricular septum Disordered myocytes, small vessel disease, replacement scarring, interstitial fibrosis Definition: LV wall thickness ≥15mm at any location in the absence of other potential causes (HTN/VHD) 100% genetic Causes (Autosomal Dominant) Variable expressivity/penetrance Sarcomere Protein Gene Mutation (MC) Defect in energy transfer from mitochondria to sarcomere and or direct dysfunction Reduced SV due to impaired diastolic filling B-myosin heavy chain MC > myosin binding protein C Hypercontraction heart Massive Myocardial hypertrophy w/o dilatation Disproportionate thickening of the ventricular septum > left ventricular free wall Most prominent subaortic region Abnormality: Systolic anterior motion of mitral valve, moves toward IV septum Symptoms May be asymptomatic or patient may have family with heart attack Young athlete with a murmur, signs or symptoms or heart disease MCC of SCD <35 (36%) HF, fatigue, chest pain, palpitations, syncope, asymptomatic Occasional lightheadedness and vague chest discomfort when playing sports or with strenuous activity (Systolic Ejection murmur exacerbated by dehydration/impaired LV filling) Murmur Mitral Regurgitation LVOT Obstruction Left sternal border without carotid radiation Harsh systolic Crescendo/decrescendo ejection murmur Worse with dehydration/impaired LV filling Hypertrophy causes a 4th heart sound Progression to HF causes a 3rd heart sound Louder with Valsalva (decreased preload), Softer with squatting/hand grip (increased preload) Carotid pulse with brisk upstroke (bifid in ⅔) Diagnosis Confirmation: Transthoracic Echocardiography ECG: LVH + depolarization/repolarization abnormalities Abnormal in >90% Prominent Q waves Inferior and lateral indicating septal depolarization T-wave inversions TTE: LVH, increased LVOT gradient, SAM of mitral valve Focal septal hypertrophy present LV diastolic function impaired LV cavity size decreased Enlarged LA Exercise testing and family screening Complications Afib 20-25% develop afib Increased stroke risk Need to be treated with warfarin (CHADSVASC is not useful here) SCD 1% per year RF for SCD: FH of SCD in 1st degree relative History of Cardiac Arrest (or sustained spontaneous VT) Personal history of syncope suspected to be arrhythmic in nature Non-sustained VT on Holter Failure to augment SBP on ETT (<10 increase at peak exercise) Septal thickness ≥30mm in any segment EF <50% Risk stratification Heart Failure Prognosis Most have normal life expectancy, no symptoms Should not participate in high-intensity competitive sports regardless of symptoms, LVOT, or prior treatment Symptomatic 1) Non-vasodilating Beta-Blockers, ensure adequate hydration if symptomatic Not Carvedilol, Labetalol Metoprolol should be ok BBs only in patients with symptoms Prolong diastole and decrease contractility, decreasing LVOT Can be used in obstructive and non-obstructive IV phenylephrine if acute hypotension and no fluid response 2) CCBs additionally in pts with persistent symptoms Verapamil, Obstructive only Avoid Amlodipine/ACEI, Diuretics 3) Add Disopyramide ICD placement Wall thickness >30mm HCM + Arrest or sustained VT (Class I recommendation) Syncope Blunted BP or hypotension during exercise RF above you can offer (Class IIa recommendation) Indicated for primary and secondary prevention of SCD in patients with ≥1 major high-risk features Septal reduction therapy (SRT) Septal myectomy or Alcohol septal ablation Peak LV outflow (resting or Valsalva gradient) of ≥50 mmHg and drug refractory HF/Symptoms Surgery if persistent/ascending aorta (septal myectomy if HF III/IV, transcatheter ethanol injection to reduce LVOT symptoms)