Pre-excitation as a cause of appearance and increased intensity of systolic murmurs.

ASSOCIATION of cardiac murmurs with the Wolff-Parkinson-White (WPW) syndrome has been reported by several investigators .1 In the reported cases, however, the murmurs were not directly attributed to hemodynamic alterations produced by pre-excitation. This communication describes three patients with systolic murmurs related to pre-excitation. In one patient the murmur was heard only when the electrocardiographic WPW pattern was present, whereas in the other two the intensity of the murmur was significantly increased when the WPW pattern was present. Figure 1 Case 1. A. Electrocardiogram with WPW pattern. B. Lead I and two simultaneous phonocardio-grams, the upper with a nominal frequency of 50 c/s and the lower 300 c/s, recorded in the fourth intercostal space at the left sternal border. Note the fourth heart sound and the de