THE LEFT VENTRICULAR IMPULSE IN HYPERTENSIVE HEART DISEASE

Abstract

The apical impulse in patients with hypertension has been studied using a new instrument for recording the impulse, which measures total displacement at the chest wall by means of a photoelectric cell. The apical impulse record was examined in 18 healthy subjects and it was noted that the outward impulse was composed of two main beats. The outward impulse was never prolonged beyond the first two-thirds of systole. The 25 hypertensive patients studied were divided into 3 groups, those with left ventricular hypertrophy in the electrocardiogram and chest X-ray, those with borderline hypertrophy, and those without hypertrophy. Abnormal prolongation of the apical impulse up to, or beyond, the second heart sound was related to the presence of left ventricular hypertrophy. Patients with borderline hypertrophy showed inconstant changes in the apical impulse, while those without hypertrophy had an entirely normal impulse. It was, therefore, possible to predict with considerable accuracy the changes in the electrocardiogram and X-ray from palpation of the impulse. Displacement of the apex beat and increased amplitude of pulsation were found in less than half the patients with left ventricular hypertrophy and should not, therefore, be regarded as essential components of the left ventricular type of impulse, apical displacement being usually met only in the largest hearts. A palpable praecordial impulse accompanying atrial contraction, an "atrial beat", was recorded in the majority of patients with left ventricular hypertrophy, of which, together with the atrial sound, it forms a useful confirmatory sign. Reduction of blood pressure in the acute observation with intravenous pentolinium did not alter the length of the apical impulse, although variations in its amplitude were seen in association with an increased pulse pressure under conditions of stress.