Disappearance of Electrical Alternans Following Pericardiocentesis

Electrical alternans is a regularly occurring variation in amplitude configuration, or direction of one or more of the components of the electrocardiogram. Those components which represent ventricular activity are most frequently involved, while P-wave alternation is unusual.1,7,11,12,17Alternation of the QRS and T complexes may occur alone or in combination with each other. This electrocardiographic abnormality is apparently rare. Hamburger, Katz, and Saphir7saw only one example of it in 10,000 electrocardiograms; Feldman5observed one instance in over 6000 electrocardiograms. The following is a report of electrical alternans occurring in association with cardiac tamponade secondary to malignant involvement of the pericardium. Report of a Case A 34-year-old railroad worker was admitted to the Grace-New Haven Community Hospital on Jan. 22, 1957, because of an episode of syncope. He was apparently well until three months prior to admission, when he consulted his physician because of a dull boring