The effect of posture on added heart sounds.

The value of change of posture in discriminating between the various added heart sounds has not been generally recognized. Moreover, apart from Evans' study in 1943, the influence of heart failure on the results has received little attention. Thayer (1909) stated that the physiological third heart sound was rarely heard in the erect posture, and Boyer, Eckstein, and Wiggers (1940) could record the sound more commonly in recumbent than in sitting subjects. Evans (1943) also found that the physiological third sound usually disappeared when the upright posture was adopted whereas the third sound associated with heart failure usually remained audible. The atrial sound disappeared in 31 of 33 patients, mostly with coronary arterial disease or hypertension, when the erect posture was assumed (Engelbertz, 1953), and in 9 of 18 patients when sitting upright with the feet down (Parry and Mounsey, 1961). Mitral opening snaps persisted in the erect posture but the interval between the second sound and the snap was usually increased (Sch6lmerich and Gehl, 1951; and Surawicz, 1957). In the present study we have investigated the effect of posture on the atrial sound, physiological and pathological third heart sounds, quadruple rhythm, pulmonary and aortic early systolic ejection sounds, and mitral opening snaps. In addition, some observations on the effect ofchange of posture on the widely-split second sound are reported in order to help assess the value of the manoeuvre in differentiating this splitting from the mitral opening snap.