Supraventricular Tachycardia with Irregular Ventricular-Atrial Intervals and Ventriculo-Atrial Block.

The patient was a 68-year-old female with recurrent paroxysmal, regular narrow QRS complex tachycardia. We observed complete VA conduction block, during tachycardia in our patient. A characteristic feature of our patient is the noticeable irregular atrial and ventricular rates. We considered that possible mechanism of this tachycardia was atrioventricular nodal reentrant tachycardia (AVNRT) with retrograde complete type block in the upper common pathway.