Mechanically Induced Cardiac Arrhythmia following Open Heart Surgery

¹ Department of Medicine
² Senior Associate Physician and Director, Cardiology-Physiology Laboratory
³ Associate Physician and Associate, Cardiology-Physiology Laboratory

Since the advent of cellular electrophysiology, a mechanical etiology for cardiac arrhythmias is rarely proposed. We observed a 23-year-old man, three months following mitral valve replacement surgery, who complained of palpitations that occurred only on deep inspiration in recumbency. Following physiologic and pharmacologic evaluation, we concluded that the mechanism for the arrhythmia causing the palpitations (junctional or ventricular tachycardia) is most likely direct stimulation of the irritable focus by the prosthetic valve struts. The mechanical etiology for the arrhythmia in this case suggests that patients with arrhythmias occurring under unusual circumstances should be pharmacologically and physiologically evaluated to determine the mechanism of their arrhythmias. A more accurate prognostic evaluation and therapeutic regimen would then result.