Hypertrophic Cardiomyopathy: Hypertrophic Cardiomyopathy - Dr. Mohammed Sadiq Azam M.D. (Int Med) DNB Cardiology Resident KIMS Hypertrophic Cardiomyopathy: Hypertrophic Cardiomyopathy Definition: : Definition: WHO: left and/or right ventricular hypertrophy, usually asymmetric and involves the interventricular septum. Differential Diagnosis: : Differential Diagnosis: HCM Can be asymmetric Wall thickness: > 15 mm LA: > 40 mm LVEDD : < 45 mm Diastolic function: always abnormal Athletic heart Concentric & regresses < 15 mm < 40 mm > 45 mm Normal Stimulus: : Stimulus: Unknown Disorder of intracellular calcium metabolism Neural crest disorder Papillary muscle malpositioned and misoriented Genetic abnormality:: Genetic abnormality: Autosomal dominant. Mutations in genes for cardiac sarcomeric proteins. Polymorphism of ACE gene. ß -myosin heavy chain gene on chromosome 14. Variants of HCM:: Variants of HCM: Most common location: subaortic , septal, and ant. wall. Asymmetric hypertrophy (septum and ant. wall): 70 %. Basal septal hypertrophy: 15- 20 %. Concentric LVH: 8-10 %. Apical or lateral wall: < 2 % (25 % in Japan/Asia): characteristic giant T-wave inversion laterally & spade-like left ventricular cavity: more benign. Hypertensive hypertrophic Cardiomyopathy: Hypertensive hypertrophic Cardiomyopathy Elderly women Simulates HCM Prognosis better than non-hypertensive HCM Pathophysiology of HCM: Pathophysiology of HCM Dynamic LV outflow tract obstruction Diastolic dysfunction Myocardial ischemia Mitral regurgitation Arrhythmias Slide11: Left ventricular outflow tract gradient ↑ with decreased preload, decreased afterload, or increased contractility. Venturi effect: anterior mitral valve leaflets & chordae sucked into outflow tract → ↑ obstruction, eccentric jet of MR in mid-late systole. Slide13: Maneuvers that ↓ end-diastolic volume (↓ venous return & afterload, ↑ contractility) Vasodilators Inotropes Dehydration Valsalva Amyl nitrite Exercise → ↑ HCM murmur Slide15: Arrhythmias: Sustained V-Tach and V-Fib: most likely mechanism of syncope/ sudden death. Dependant on atrial kick: CO ↓ by 40 % if A. Fib present. Histology:: Histology: Myocardial fiber disarray, endocardial plaques. Abnormal relaxation and diversely oriented myocardial fibers. Intimal hyperplasia of intramural coronary arteries, endothelial dysfunction, myocardial perfusion defects. Clinical presentation:: Clinical presentation: Any age Leading cause of sudden death in competitive athletes Triad: DOE, angina, presyncope/syncope. Physical exam:: Physical exam: Apex localized, sustained Palpable S4 Tripple ripple Prominent “a” wave Rapid upstroke carotid pulse, “jerky” bifid ( spike-and-dome pulse) Harsh systolic ejection murmur across entire precordium → apex & heart base MR: separate murmur: severity of MR related to degree of outflow obstruction Physical Exam: Physical Exam HOCM vs. Valvular AS Intensity of murmur HOCM AS Valsalva ( preload, afterload) Squatting ( preload, afterload) Standing ( preload, afterload) EKG:: EKG: Echocardiography: : Echocardiography: 2D-echo: Asymmetric septal hypertrophy: septum >1.4x free wall Diffuse concentric or localized to apex/anterior wall Systolic anterior motion of MV (SAM) Slide24: Doppler Echocardiography : Typical appearance: late-peaking signal “dagger-shaped” Bernoulli for peak systolic gradient (+ maneuvers) Obstructive or non-obstructive Distinguish MR and intra- cavitary obstruction (looking for the aortic closure signal) Brockenbrough response: Brockenbrough response ↑ LV systolic pressure ↓ Ao systolic pressure ↑ gradient between LV & Ao Post PVC Brockenbrough response: Brockenbrough response Imitator of HCM: Imitator of HCM Amyloidosis: Thickened walls & low voltage on ECG . Natural history of HCM: Natural history of HCM Mortality: 3 %/year (6-8 % with NSVTach) Poor prognosis: - Younger age - Male sex - + family hx. of sudden death - Hx. of syncope - Genetic markers (mutations of arginine gene) - Exercise-induced hypotension (worst) Genetic defect and prognosis: Genetic defect and prognosis Management: Management All first degree relatives: screening… echocardiography/genetic counseling Avoid competitive athletics Prophylactic antibiotics before medical & dental procedures Holter x 48 hours Slide35: β - Blockers: Propranolol 200-400 mg/d (large doses)/ Selective β - B lose selectivity at high doses: Slow HR → longer diastolic filling time → ↓ myocardial O2 consumption → ↓ myocardial ischemia & LVOT obstruction CaCh- Blockers: Verapamil 240-320 mg/d (with caution for hemodynamic deterioration) Combination of both Slide36: Disopyramide: class I antiarrhythmic + strong –ive inotropic effect Non-responders to Medical therapy ??? : Non-responders to Medical therapy ??? 1- Surgery (Myotomy/Myectomy) +/- MVR 2- ICD 3- DDD pacemaker 4- NSRT (alcohol septal ablation) 1- Surgery:: 1- Surgery: Septal myotomy/myectomy: Patients < 40 years: mortality < 1 % Patients > 65 years: mortality 10-15 % Survival better than medically treated patients Should be considered in: resting gradient > 50 mmHg, or refractory to medical Rx. Young patients, particularly those with severe disease Additional structural abnormalities affecting the mitral valve or coronary arteries. Complication (rare): Aortic incompetence Myotomy/Myectomy: Myotomy/Myectomy 2- ICD:: 2- ICD: Previous sudden death High risk of sudden death EPS use ? 3- DDD pacemaker: 3- DDD pacemaker Substantial ↓ gradient(~ 50 %) Effect of DDD pacemaker in HCM: Effect of DDD pacemaker in HCM Potential Mechanisms of benefit of Pacing in HCM: : Potential Mechanisms of benefit of Pacing in HCM: RV apical pacing & maintenance of AV synchrony → abnormal pattern of septal contraction → ↓ early systolic bulging of hypertrophic subaortic septum in LVOT & ↓ Venturi forces that produce SAM. ↑ LVOT width during systole ↓ systolic hypercontractility: ↑ end-systolic volume → ↓ intraventricular pressure gradients & myocardial work Slide45: ↓ MR May favorably alter diastolic function LVH regression 4- Alcohol septal ablation (NSRT): 4- Alcohol septal ablation ( NSRT) Controlled myocardial infarction of the basal ventricular septum to ↓ gradient. First septal artery occluded with a balloon catheter and ETOH injected distally NSRT (Non Surgical Septal Reduction Therapy): NSRT (Non Surgical Septal Reduction Therapy) The most appropriate candidates for NSRT should meet all of the following criteria : - HCM with severe symptoms of heart failure (NYHA class III to IV) despite adequate tolerated drug therapy - An LVOT gradient 50 mmHg at rest or after exercise or >30 mmHg at rest or 60 mmHg under stress - Basal septal thickness 18 mm - NYHA class II heart failure with a resting LVOTgradient >50 mmHg or >30 mmHg at rest and 100 mmHg with stress . - Elderly or comorbidities that may increase the risk of surgical correction. Thank You: Thank You Any QUESTIONS???