Abstract
Isolated sinus node dysfunction with its pursuant long-term risk for atrioventricular (AV) conduction disease poses a unique dilemma for proponents of CSP due to paucity of imprimatur guidelines. In such scenarios, the risk and prognosis of iatrogenic AV block is not well elucidated but is a valid concern. We report a case where CSP was complicated by iatrogenic AV block and peculiarly the rare phenomenon of intra-Hisian Wenckebach.