Craig McPherson

The stunned atrial lead: Transient malfunction of a permanent atrial pacer lead following acute myocardial infarction

Proximal right coronary artery occlusion caused transient loss of sensing and capture of the atrial lead of a permanent dual-chamber pacemaker. Forty-five days after percutaneous revascularization, the atrial lead was discovered to be functioning normally. We hypothesize that ischemia of the right atrium caused stunning of the atrial myocardium at the pacer–lead interface, which gradually improved following percutaneous coronary intervention (PCI), leading to return of lead function over time. So far only one similar case has been described in the literature.

Epinephrine use results in ‘stress’ cardiomyopathy

Epinephrine is a frequently used catecholamine, particularly in emergencies and during resuscitation attempts. It is not without side effects. We report a rare case of epinephrine-induced cardiomyopathy. Epinephrine was administered for bradycardia in our patient. He was treated conservatively and responded well to the treatment. Through our work we wish to highlight this adverse cardiac effect of epinephrine. We hope to increase awareness among residents and practicing physicians while using epinephrine. <Learning objective: Epinephrine, although a lifesaving drug, has adverse side effects. Dosages and routes of administration determine its toxicity. Exogenous catecholamines can cause presentations similar to takotsubo cardiomyopathy. Management is supportive and the outcomes are good.>.

RECOGNIZING MYOCARDIAL INFARCTION IN BI-VENTRICULAR PACING

The ECG recognition of coronary ischemia in the presence of biventricular pacing (BiV-P) has been little studied. We present a patient with chest pain in whom ECG changes seen during BiV-P raised suspicion of MI, which was more obviously unveiled by transient inhibition of pacing. A 54 year-old-man