Our increased knowledge of phonocardiography and of hemodynamics have now provided a firm basis for a revision of our knowledge of the ancient art of auscultation and have greatly increased its value. It is no longer necessary or advisable to make an auscultatory diagnosis by memorizing the "bark" of a murmur. The diagnosis can be achieved more accurately by careful analysis of the sounds and murmurs and relating them to the events of the cardiac cycle.
Modern auscultation is a complicated affair. The first heart sound is split into mitral and tricuspid components; the second, into aortic and pulmonary, and the normal slight asynchrony between the two ventricles—producing physiological splitting of sounds—is exaggerated by unilateral delay in conduction or by unilateral changes in the hemodynamics. The onset of ejection in early systole may be audible as a sound; and so may rapid distention of the ventricles in diastole as a