The Cardiac Apex Impulse

The bedside features of the cardiac apex impulse were studied in 50 patients and correlated with impulse recordings and angiographic determinations of left ventricular volume and mass. Left ventricular hypertrophy was assessed most accurately by the duration of the outward deflection of the impulse. Eighty-eight percent of the patients with a holosystolic impulse had an increased left ventricular mass, whereas 78% of the patients with an early systolic impulse had normal left ventricular mass. An impulse occupying two or more rib interspaces also was associated with increased left ventricular mass. A normal chamber volume could be predicted if the impulse was palpated in only one rib interspace. Displacement to the left was less useful in predicting increases in left ventricular mass. In this study the bedside characteristics of the apex impulse more accurately predicted left ventricular hypertrophy than did the electrocardiogram or the chest roentgenogram.