Electrical Alternans Clinical Presentation

Updated: Sep 12, 2019
  • Author: Bharat K Kantharia, MD, FRCP, FAHA, FACC, FESC, FHRS; Chief Editor: Mikhael F El-Chami, MD  more...
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History and physical examinations findings often provide a clue regarding the underlying cardiac pathology leading to electrical alternans. For example, electrical alternans in the setting of hypotension or worsening dyspnea in patients with pericarditis would indicate the development of cardiac tamponade. Similarly, ST-T alternans in the setting of chest pain, diaphoresis, and dyspnea would indicate severe myocardial ischemia. T-wave alternans observed in the setting of palpitations and syncope would point toward an underlying ventricular arrhythmia.


Physical Examination

Physical examination should be directed toward diagnosis of the underlying cardiac etiology for electrical alternans. The classical Beck triad of jugular venous distention, hypotension, and muffled heart sounds, or any of its individual features could arise from cardiac tamponade. Additional pulsus paradoxus may be noted. The presence of added heart sounds and signs of fluid overload suggest an underlying cardiomyopathy or heart failure.