Paired narrow QRS complexes, each preceded by a P wave, certainly raise the possibility of atrial bigeminy. But there are other causes of paired QRS complexes during sinus rhythm. One should look ...

The diagnosis is normal sinus rhythm, second-degree atrioventricular (AV) block-Mobitz type I or Wenckebach, and sinus node exit block (Figure 2). The rhythm is regular except for two long RR ...

Classic changes of ischemia may be described or explained as follows: 1. ST-segment elevations or depressions that are usually localized (but may be diffuse) and may be associated with such T-wave ...