A 15-year-old student presents to your office on the advice of his football coach. The patient started playing football this year and suffered a syncopal episode at practice yesterday. He reports that he was sprinting with the rest of the team and became light-headed. He lost consciousness and fell to the ground, regaining consciousness within 1 or 2 minutes. He has had no prior episodes of syncope. The patient is adopted and family history unavailable. Physical examination reveals a systolic murmur heard at the left lower sternal border and apex. ECG reveals sinus rhythm with evidence of left ventricular hypertrophy (LVH). What physical examination findings would likely be present?
A. A systolic ejection murmur heard best at the apex that diminishes with squatting and handgrip, and increases with Valsalva maneuver and standingThe patient has hypertrophic cardiomyopathy, which is one of the causes of exertional syncope in young persons and is associated with left ventricular hypertrophy on EKG. The typical murmur of hypertrophic cardiomyopathy is a harsh systolic diamond-shaped murmur heard best at the lower sternal border and apex. Factors that increase myocardial contractility (eg, exercise, sympathomimetics, or aminophylline) and decrease preload (eg, Valsalva maneuver, standing or nitroglycerin) reduce left ventricular end-diastolic volume, increase the turbulence of blood flow exiting the ventricle during systole, and hence accentuates the murmur. On the other hand, elevation of arterial pressure (squatting and hand grip), increase in venous return or preload (leg raising), and expansion of blood volume (pregnancy) all increase left ventricular volume and decrease intensity of the murmur. Choice b is a typical murmur of mitral valve prolapse (MVP) which is characterized by a mid- or late- (nonejection) systolic click. The click may be followed by a highpitched, late-systolic crescendo-decrescendo murmur heard best at the apex. The click and murmur occur earlier with maneuvers that decrease left ventricular volume which exaggerates the propensity of mitral leaflet prolapse. These maneuvers include standing, and the Valsalva maneuver. Maneuvers that increase left ventricular volume, such as squatting and isometric exercise diminish the degree of prolapse, and the click-murmur is delayed and decreases in intensity. Choice c is a murmur of mitral regurgitation (MR). It is usually holosystolic, best heard at the apex, and radiates to the axilla. The systolic murmur of chronic MR not due to MVP is intensified by isometric exercise (handgrip) but is reduced with the Valsalva maneuver. Choice d is a murmur of tricuspid regurgitation. It is usually a blowing holosystolic murmur along the lower left sternal margin, which may be intensified during inspiration and reduced during expiration or with the Valsalva maneuver (Carvallo’s sign). This murmur is sometimes associated with a prominent right ventricular pulsation along the left parasternal region or regurgitant waves seen in the neck veins. Choice e is a murmur of aortic stenosis (AS). The murmur of AS is characteristically an ejection (mid) systolic murmur, low-pitched, rough and rasping in character, and loudest at the base of the heart, most commonly in the second right intercostal space and usually radiates upward along the carotid arteries.