Hemodynamic parameters during supine leg exercise-induced myocardial ischemia were investigated in ten patients without left ventricular hypertrophy (group I), and in ten patients with left ventricular hypertrophy (group II) . Both groups of patients had previously been diagnosed as having totally asymptomatic silent myocardial ischemia. Both groups were comparable in age, sex, left ventricular ejection fraction at rest, and extent of coronary artery disease. All of the patients exercised to the same extent without angina or its usual equivalent. Left ventricular filling pressure increased from 4±2 mmHg at rest to 11±3 mmHg at peak exercise in group I, and from 7±4 mmHg at rest to 19±7 mmHg at peak exercise in group II. Left ventricular filling pressure at peak exercise was significantly greater in group II than in group I (p<0.01). Totally asymptomatic silent myocardial ischemia can be seen with either normal or mildly abnormal left ventricular filling dynamics during exercise. In addition, patients with coexistent left ventricular hypertrophy can have severely abnormal left ventricular filling dynamics during exercise without ischemic cardiac pains. Therefore, severe ischemia and/or stretching of the ventricular wall may be necessary, but not sufficient, for the occurrence of chest pain.