The ECG shows normal sinus rhythm with a first-degree atrioventricular block with frequent premature ventricular complexes. There is no evidence of ongoing ischemia or recent myocardial injury or infarction.
First-degree atrioventricular block occurs when atrial activation and conduction are always transmitted to the ventricles, albeit with an unusual delay at or below the atrioventricular node. It is characterized by a PR interval greater than 200 ms.
Three premature ventricular complexes are also seen (see beats 3, 9, and 12). These are characterized by wide complexes originating in the ventricle, which do not occur within the conduction atrioventricular node or the His–Purkinje system. Premature ventricular complexes are not preceded by a P wave, and the QRS complex is wider than 100 ms. They do not affect atrial conduction unless they are conducted retrograde up the atrioventricular node or an accessory pathway into the right atrium.