TITLE PAGETitle: Interesting changeover from short VA to long VA tachycardia with single atrial premature depolarisation: What is the mechanism?Short title: Concomitant AVNRT and atrial tachycardia: Killing two birds with one stone.

Title pageTitle : Long VA tachycardia after slow pathway modification for slow-fast atrioventricular nodal reentrant tachycardia : Insights about the mechanism from intriguing electrogram and polarity reversal.Short Title: Mechanism of long VA tachycardia after slow pathway modification.