RT Journal A1 THAYER W T1 FUrther observations on the third heart sound JF Archives of Internal Medicine JO Archives of Internal Medicine YR 1909 FD October 1 VO IV IS 4 SP 297 OP 305 DO 10.1001/archinte.1909.00050200003001 UL http://dx.doi.org/10.1001/archinte.1909.00050200003001 AB At the last meeting of the Association of American Physicians1 I made a few remarks concerning the frequency, especially in young people, of a third heart sound heard in early diastole somewhere between one-tenth and two and one-tenth of a second after the second sound of the heart, causing a characteristic protodiastolic gallop. This sound is especially common in the recumbent and left lateral postures and is more frequent in young individuals. It was pointed out that it was often associated with a palpable and sometimes even with a visible impulse, and this impulse was shown to be identical with the normal early diastolic elevation of the apex cardiogram. Further analogies were pointed out between this sound and that which characterizes the early diastolic gallop rhythm heard under various pathological conditions, especially in aortic insufficiency, in mitral stenosis and in adherent pericardium. Cardiograms and jugular tracings