411. What is the first sign of battery voltage depletion? / Most common cause of failure to capture / Where do leads commonly displace? / Where do lead fractures occur? July 11th, 2008 by reuben in pacemaker Back Top Tags: card 410. Management of ?pacemaker syndrome / 4 types of pacemaker malfunction and their causes 412. What is exit block and what are its causes? / Most common cause of undersensing / What does undersensing look like on ECG? Leave a Reply Cancel reply Please post any discussion to the emupdates Reddit page.