The Effect of Cycle Length on the Time of Occurrence of the First Heart Sound and the Opening Snap in Mitral Stenosis

Abstract

Phonocardiography is-often more valuable than electrocardiography in timing mechanical events in the cardiac cycle. This study shows that the opening and closing of the mitral valve are related to the length of the previous heart cycle as demonstrated by the variations occuring in aluricular fibrillation. These variations in valve action are controlled by the pressure gradient between left auricle and ventricle.

The Apex Cardiogram in the Study of the 2 Os Interval

“…The 2-OS interval representing the period of isometric relaxation has been studied by various authors in patients with mitral valvular disease and its usefulness has been repeatedly emphasized (Margolies and Wolferth, 1932;Messer et al, 1951;Julian and Davies, 1957;Mounsey, 1953;Wells, 1954;Kelly, 1955;Bayer et al, 1956;Steinzeig et al, 1957;Wells, 1957;Di Perri and Fabrizi, 1958;Proctor et al, 1958;Donnelly et al, 1959;Rich, 1959;Muiesan et al, 1960). However, this measurement can only be obtained in patients in whom an opening snap is present.…”

“…Since the report in 1932 by Margolies and Wolferth on the opening snap in mitral stenosis, attempts have been made to evaluate this lesion by phonocardiography (Messer et al, 1951;Mounsey, 1953;Wells, 1954;Kelly, 1955;Bayer, Loogen, and Wolter, 1956;Craige, 1957;Julian and Davies, 1957;Steinzeig, et al, 1957;Wells, 1957;Di Perri and Fabrizi, 1958;Proctor et al, 1958;Donnelly, Maha, and Orgain, 1959;Leo and Hultgren, 1959;Rich, 1959;Dack et al, 1960;Muiesan et al, 1960;Nixon, Wooler, and Radigan, 1960;Di Bartolo, Nuniez-Dey, and Bendezu'-Prieto, 1962). The 2-OS interval measured from the aortic component of the second heart sound to the opening snap has been used for evaluation of the degree of severity of the stenotic lesion.…”

Intracardiac Phonocardiography and Hemodynamics in Pure Mitral Insufficiency

“…Since our patients are classified by selective dye dilution tech niques and angiocardiography we have been interested to see whether there is a correlation between the hemodynamic results obtained in this way and the time intervals of the heart sounds in pure MI. Several groups have been reported about the significance of the time interval IIA-MOS in mitral stenosis since M e sse r et al, in 1951, have investigated the dépendance of this interval and the interval Q-Ia upon the frequency and hemodynamics [15]. Now it is quite clear that in MS these time intervals are more closely re lated with the atrial pressure (V wave) than with the actual size of the diastolic mitral opening area.…”

Observations on the Delayed First Heart Sound in Mitral Stenosis and Hypertension

“…9 The delayed appearance of the major vibrations of the first sound results in further separation of the 2 …”

“…With the advent of valvular surgery and the consequent need for more accurate assessment of mitral stenosis, interest in this observation has been renewed. [2][3][4][5][6][7][8] The measurement of the Q-1 interval, that is the interval between the onset of ventricular depolarization and the first heart sound has been accordingly evaluated as an index of the severity of stenosis. Recent observations in this laboratory have suggested that, in addition, the timing of the first heart sound may be altered in patients with hypertensive vascular disease."…”