[Adams-Stokes syndrome in a case of Mobitz type II AV-block triggered by premature atrial contractions].

The case of a patient with Mobitz type II AV-block is presented who suffered from recurrent dizzy spells and syncopal attacks. These episodes were due to intermittent asystoles lasting for 3-17 seconds, and it could be shown that they were triggered by two or more successive premature atrial contractions. The observation that there were no subsidiary escape beats or rhythms during the asystolic intervals and the ECG pattern for the conducted beats (RBBB and LAH) suggest an intraventricular (trifascicular) level of AV-block. The exact analysis of the asystolic pauses makes it likely that these were initiated by the penetration of the premature atrial impulses into the left posterior subdivision of the left bundle (concealed conduction). The present case demonstrates the fact that premature atrial contractions may produce prolonged asystolic attacks in patients with advanced intraventricular conduction disturbances.