title: "Sensing alternans" in a patient with a newly implanted pacemaker.
abstract: This report describes the case of an 80-year-old man with a history of coronary artery disease who presented with acute pericarditis secondary to pacemaker lead perforation of the ventricular wall 2 days after undergoing dual lead pacemaker implantation. The electrocardiogram revealed sinus rhythm with an intra-atrial conduction delay and intermittent failure of atrial sensing as evidenced by alternating atrial spikes in every other P wave. The noted pericardial effusion and the likely shifting of the atrial lead with each alternate beat caused the "sensing alternans" that was seen on the admission electrocardiogram.
authors.affiliation: Division of Cardiology, Section of Electrophysiology, North Shore University Hospital, Manhasset, New York 11030, USA.
authors.forename: Amgad N
authors.initials: AN
authors.lastname: Makaryus
authors.forename: Bernard
authors.initials: B
authors.lastname: Boal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D010490:Pericardial Effusion / Q000175:diagnosis / Q000209:etiology*; D010493:Pericarditis / Q000175:diagnosis / Q000209:etiology*; D018570:Risk Assessment; D012804:Sick Sinus Syndrome / Q000175:diagnosis / Q000628:therapy*