A 29-year-old male athlete suddenly collapsed and died during a football game. At autopsy the following finding was seen on gross examination. He had a history of two similar deaths in the family previously. What is the most likely cause of death?
Ans. a. Hypertrophic cardiomyopathy (Ref Harrison l9/e p1568. l8/e p1967; Robbins 9/e p, 8/e p576)vHistory of sudden death during exertion and on autopsy hypertrophy of ventricular wall is highly suggestive of Hypertrophic cardiomyopathy."Hypertrophic cardiomyopathy: Macroscopically, hypertrophy is typically manifest as nonuniform ventricular thickening. The interventricular septum is the typical location of maximal hypertrophy although other patterns of hypertrophic remodeling include concentric and midventricular. "-- Harrison 19/e p1568Hypertrophic Obstructive Cardiomyopathy (HOCM)HOCM is defined as left ventricular hypertrophy that develops in the absence of causative hemodynamic factors, such as hypertension, aortic valve disease, or systemic infiltrative or storage diseases.Pathophysiology:Macroscopically, hypertrophy is typically manifest as nonuniform ventricular thickening. The interventricular septum is the typical location of maximal hypertrophyQ.Septal hypertrophy: Asymmetrical septal hypertrophy is characteristicQ, thickness of ventricular septum is disproportionately increased when compared with the free wallQLeft ventricular outflow tract obstruction represents MC focus of diagnosis & interventionQ.Clinical Features:Many patients are asymptomaticQSudden deathQ may be first clinical manifestation of disease (commonly seen in young adults after competitive sports).Clinical Features of HOCMSymptomsSigns* MC symptom: DyspneaQ* Angina pectoris/chest painQ* FatigueQ* SyncopeQ* Double or triple precordial impulse* Brisk carotid upstrokeQ (Rapidly rising carotid pulse)* Fourth heart soundQ* Systolic murmur (Hallmark of disease): HarshQ, diamond shaped (crescendo decrescendo), best heard at lower left sternal border as well as at apexQ Condition increasing obstruction & intensity of murmurConditions decreasing obstruction & intensity of murmur* Factors that increase myocardial contractility:* Sympathomimetic aminesQ, Digitalis glycosidesQ* Factors which decrease Ventricular volume: Valsalva maneuverQ, sudden standingQ, nitroglycerineQ, amyl nitriteQ tachycardiaQ* Decreased aortic impedance & afterloadQ* Factors that decrease myocardial contractility:* Beta blockers, Calcium channel blockersQ* Factors which increase Ventricular volume: Augmentation of venous return by passive leg raisingQ, expansion of blood volumeQ, supine position* increased aortic impedance & afterload: Elevation of arterial pressure by phenylephrine, sustained hand gripQ, squattingDiagnosis:Cardiac imaging is central to diagnosis due to the insensitivity of examination and ECG & need to exclude other causes for hypertrophyQManagement of HOCM:Avoidance of strenuous physical activityQBeta-bloekers should be the initial drug in symptomatic individualsQ. They reduce heart rate, BP. stiffness of left ventricle, fatal arrhythmiasQCalcium channel blockersQ (verapamil & diltiazem) are alternative drugs. They reduce-stiffness of ventricle & elevated diastolic pressuresQ.Amiodarone may be used to reduce arrhythmiasQ.Surgical myomectomyQFeaturesDilatedRestrictiveHypertrophicEjection fraction (Normal 55%)<30%Q> 30-50%Q>60QLeft ventricular diastolic dimension (Normal <55 mm)>60 mmQ<60 mmQOther decreasedQLeft ventricular wall thicknessDecreasedQNormal or increasedQMarkedly increasedQAtrial sizeIncreasedQIncreasedQIncreasedQValvular regurgitationRelated to annular dilation; Mitral appears earlier, during decompensating; Tricuspid regurgitation in late stagesRelated to endocardial involvement;Frequent mitral and tricuspid regurgitation, rarely severeRelated to valve-septum interaction; Mitral regurgitationCommon first symptomsExertional intoleranceQExertional intolerance, Early fluid retentionQExertional intolerance; May have chest painQCongestive symptomsLeft before right, except right prominent in young adultsRight often dominatesLeft-sided congestion may develop lateArrhythmiaVentricular tachyarrhythmia; Conduction blocks in Chagas' disease, atrial fibrillation.Ventricular tachyarrhythmia uncommon except in sarcoidosis Conduction block in sarcoidosis & atrial fibrillation.Ventricular tachy a rrhythmia's; Atrial fibrillation
Hypertrophic cardiomyopathy
RHD
Coronary heart disease
Dilated cardiomyopathy
C.V.S.