Left Ventricular Outflow Tract-Aorta Pressure Gradient
Incidence: pressure gradient between the left ventricular outflow tract and the aorta is present in 75% of hypertrophic cardiomyopathy cases (either at rest or with provocation)
Dynamic Nature of Outflow Tract Gradients: gradients fluctuate from day to day (based on factors which alter myocardial contractility and loading (such as dehydration, ethanol ingestion, or large meals)
Severe Concentric Left Ventricular Hypertrophy with Cavity Obliteration
Sigmoid Septum: more common in older adults
Exercise Stress Echocardiogram
Preferred Method to Determine if Outflow Tract Gradient is Present: mimics the conditions under which gradient might occur during normal daily activities
Dobutamine Stress Echocardiogram
Alternative to Exercise Stress Echocardiogram: although is less reliable than exercise stress echocardiogram
Valsalva Manuever with Echocardiogram
May Induce Gradient: although is less reliable than exercise stress echocardiogram
Clinical Manifestations
Cardiovascular Manifestations
Angina/Chest Pain (see Chest Pain, [[Chest Pain]])
Mechanism: due to systolic anterior motion (SAM) of the mitral valve or papillary muscle/chordae tendineae abnormalities -> abnormal mitral valve leaflet coaptation (usually with a posteriorly-directed jet)
Characteristics of Murmur: mid-late systolic murmur
In contrast, primary mitral valve disease usually presents with a central-directed jet with holosystolic murmur, loudest at the apex and radiating to the axilla
Radiation: may radiate toward the base of the heart (due to the eccentric jet)
Other Findings Related to Hypertrophic Cardiomyopathy Itself
