Nitrate tolerance as a possible cause of multidrug-resistant coronary artery spasm.

Coronary spasm can usually be controlled by administration of Ca antagonists. However, there are some cases of coronary spasm whose attacks cannot be controlled even with large doses of Ca antagonist and/or its combination with nitrates. Here we describe the case of a 41-year-old man whose attacks of coronary spasm were resistant to the combined administration of nitrates, Ca antagonists, and a statin.

Electrical connections between pulmonary veins: implication for ostial ablation of pulmonary veins in patients with paroxysmal atrial fibrillation.

Background: Electrical disconnection of the myocardial extensions into arrhythmogenic pulmonary veins (PVs) is recognized as a curative technique for paroxysmal atrial fibrillation (AF). However, the presence of electrical connections between the PVs, which may make achievement of PV disconnection difficult, has not been systematically evaluated.

Methods And Results: Forty-nine consecutive patients with drug-resistant AF underwent ostial radiofrequency (RF) catheter ablation of arrhythmogenic PVs with foci triggering AF.