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.1,7,11,12,17 Alternation of the QRS and T complexes may occur alone or in combination with each other. This electrocardiographic abnormality is apparently rare. Hamburger, Katz, and Saphir7 saw only one example of it in 10,000 electrocardiograms; Feldman5 observed 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