A unitary concept of cardiac vibrations

The authors discuss the mechanism of the two main heart sounds and advance a unitary concept of cardiac vibration

Peculiarities of the first heart sound in bundle branch blocks. A new interpretation based on graphic analysis

A phonocardiographic study in a medium frequency range was made over various areas of the precordium in 27 cases of right bundle branch block (RBBB), 28 cases of left bundle branch block (LBBB), and 30 normal subjects of the same age. The various components of the first heart sound plus the pulses at the suprasternal notch and the right carotid artery were studied in regard to timing, relationship with the ECG and the arterial pulses, intervals between components, and amplitude. The timing and intervals of the three components of the first sound were found normal in RBBB and so were the arterial pulses; apparent wide splitting was occasionally noted, due to recording of the first (a) and third (c) components, the latter being larger, as frequently observed in old age. All three components of the first sound were found small and delayed in LBBB; a delay of the arterial pulses was also noted. No additional component that might be attributed to the right heart preceded the delayed first sound. This study confirms that the first heart sound recorded on the chest wall originates only in the left heart and aorta

The Heart Sounds. New Facts and Their Clinical Implications

A textbook of auscultation of the heart and heart sounds physiolog

Considerations on the mechanism of the systolic click of mitral valve prolapse

The Authors briefly discuss the mechanism of production of the systolic click of mitral valve prolapse. A "valvular" mechanism seems inadequate to explain the genesis of vibrations that can be recorded, not only in the external phonocardiogram, but also in the intraventricular pressure tracing, in the apex cardiogram, and even in the left atrial pulse (esophagus). It seems more logical to postulate that the force of deceleration created by the sudden eversion of a mitral leaflet set the whole cardiohemic system (blood, myocardial walls, and the mitral apparatus) into vibration, thus producing the click. In mitral valve prolapse, the contribution to sound production of mitral leaflets and chordae is likely to be minor, as it had been demonstrated for the first heart sound

The main heart sounds as vibrations of the cardiohemic system: old controversy and new facts

An editorial on the old controversy and new facts about the main heart sounds, deriving from vibrations of the cardiohemic system, not from vibrations of the moving valve leaflets

Assessment of left ventricular function by noninvasive methods

A review of the noninvasive methods to assess left ventricular functio

Transmission delays of different portions of the arterial pulse. A comparison between the indirect aortic and carotid pulse tracings

The transmission delays of the upstroke and incisura of the arterial pulse were measured in 128 normal subjects, divided in three groups of increasing age, by comparing the timing of the indirect aortic arch pulse (recorded at the suprasternal notch) (SSN) and the indirect, right carotid tracing (CAR). In the total group, the mean delay of the upstroke was 24.4 msec while the mean delay of the incisura was 19 msec (P less than 0.005). This difference was maximal in the oldest age group and became non significant in the group of children under 12. At slow heart rate, this difference was greater than at a more rapid heart rate. The left ventricular ejection times (LVET), measured on the two pulses, showed a very close correlation (r = 0.96) but the LVET was significantly longer in the SSN tracing, especially in the older subjects. These data reveal that the incisura of the arterial pulse travels more rapidly than the upstroke, especially in older patients and at lower heart rates. The most likely explanation of this fact resides in the frequency-dependent influence of vascular reflections, which is more important with increasing age and slower heart rate. Thus, the transmission velocity along the arterial wall is higher for the higher harmonics of the pulse wave (incisura) than for the lower harmonics (upstroke)