Ventricular pacing leads dislodged

Dual chamber pacemakers are more expensive and are also associated with an almost two fold risk of implant-related complications compared to ventricular pacing (2,15). Most of these additional complications are related to the atrial lead (e.g. dislodgement, perforation). Ventricular pacing is more likely to cause pacemaker syndrome particularly in patients with sinus node dysfunction (1,16). For patients with sinus node disease, atrial pacing should be considered for those with intact AV conduction and dual chamber pacemakers should be considered for those with associated AV node conduction abnormalities (17). The dual chamber pacanakers should be programmed to minimize the amount of ventricular pacing. 

Lead dislodgment occurs in approximately 2% of cases despite the use of active fixation leads, and myocardial penetration or perforation occurs in approximately 1% of cases (58). Movement of the lead tip is detected by changes in lead performance and by changes in the paced QRS complex morphology on the surface ECG. The typical paced QRS complex has a left BBB-hke pattern with either a superior (with a right ventricular apex position) (Fig. 16.5) or an inferior (with a right ventricular outflow tract position) (Fig. 16.6) mean frontal plane axis. A right BBB-like pattern may indicate perforation of the lead into the left... 

Fig. 18.16 Posteroanterior (A) and lateral (B) chest radiographs of a dual-chamber pacing system. Both the atrial and the ventricular leads have inadequate redundancy, which may result in poor pacing thresholds or lead dislodgment.

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