Alternation of the form of the electrocardiographic complexes in the presence of a regular rhythm is a rare phenomenon. Sometimes it is associated with pericardial tamponade 1-9 and may be an important clue when the diagnosis is not clear from wellknown signs such as elevated venous pressure, pulsus paradoxus, and faint heart sounds.
Report of a Case
A 42-year-old man was hospitalized on Nov 20, 1961, after several weeks of an undiagnosed illness which included fever, muscle aching, low back pain, and thrombophlebitis of the lower extremities. While in another hospital he had been given anticoagulants but nevertheless developed signs of pulmonary embolism. Chest x-rays showed progressive cardiomegaly. There was a history of chronic cigarette smoking.On examination the patient appeared emaciated. The venous pressure was elevated. There was dullness at the lung bases, and the heart seemed enlarged on percussion. There was no precordial impulse. The heart sounds were
LAWRENCE LT, CRONIN JF. Electrical Alternans and Pericardial Tamponade. Arch Intern Med. 1963;112(3):415-418. doi:10.1001/archinte.1963.03860030169020