Phonocardiogram of the ball-and-cage aortic valve prosthesis.

Abstract

The sounds and murmurs produced by the ball-and-cage aortic valve prosthesis were studied and described. A number of opening sounds may occur, and observations on their mechanism of production were made. Systolic murmurs were common, but diastolic murmurs were very difficult to hear or record, even when incompetence was severe. The phonocardiogram did not safely allow distinction between incompetence around the artificial valve ring and incompetence around the artificial valve ring and incompetence around the ball. The phases of the cardiac cycle were accurately measured, and isometric contraction was found to be prolonged while the ejection time was shortened. The RQS to 2nd heart sound was within the normal range, and it was suggested that this interval is not a good indicator of myocardial function in patients after cardiac surgery. It was also suggested that a slow heart rate is important for survival in the immediate post-operative period.