Electrical and mechanical alternans during percutaneous transluminal coronary angioplasty in a patient with acute myocardial infarction--a case report.

The authors report a rare type of cardiac alternans during percutaneous transluminal coronary angioplasty (PTCA) in a patient with acute myocardial infarction. Not only ST segment but also QRS alternans were observed on electrocardiogram and were accompanied by mechanical alternans. The mechanism of these unusual findings is briefly discussed.