Fig. 1

Adenosine test in intermittent AV-block. Individual changes of heart rate in patients with intermittent AV-block and currently preserved AV-conduction under a 3 min infusion of adenosine at 140μg/kg body weight/min. PQ-interval and Wenckebach point was assessed before the test and is indicated by different lines. Progression to AV-block II/III was only observed in patients with both prolonged PQ-interval (AV-block I°) and pathologic Wenckebach point (< 120 bpm). AV, atrioventricular; WP, Wenckebach point; bpm, beats per minute