Antiarrhythmic Therapy Pathophysiologic AV node reentrant tachycardia Arrhythmia Diagnosis Known or suspected AV node reentry mechanisms Anatomical fast/slow Critical components pathway Vulnerable parameters Targeted subcellular units L-type Ca** channel Interventions Cat+ channel blocker B-blocker L→ Clinica| Outcomes Sinus rhythmAntiarrhythmic Therapy Pathophysiologic Arrhythmia Diagnosis Interventions Clinical Outcomes Known or suspected mechanisms Critical components Vulnerable parameters Targeted subcellular units AV node reentrant tachycardia AV node reentry Anatomical fast/slow pathway AV node (slow conduction) AV nodal action potential L-type Ca++ channel Ca++ channel blocker -blocker Sinus rhythm