Why minimse ventricular pacing
Ventricular pacing > 40% of the time in DDDR mode was associated with a 2.6-fold increased risk of heart failure hospitalization as compared with < 40% V-pacing. (MOST)
The risk of AF increased linearly with increasing cumulative percent V-pacing from 0% pacing up to 80-85% pacing in both DDDR and VVIR pacing modes.(MOST/SAVE-PACE)
Long-term DDDR pacing induces LA dilation, and a high proportion of RV pacing decreases LV function.(DANISH II)
MOST
Adverse effects of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunction (2003)
time to first heart failure hospitilisation (HFH) by cumulative VP % show an early, sustained and increasing incidence of HFH among DDDR patients with cumulative VP % >40% compared with <40% and among VVIR patients with cumulative VP % >80% compared with <80%
time to first episode of AF by cumulative VP % show an early, sustained and increasing incidence of AF among DDDR and VVIR patients with increasing cumulative VP %
SAVE-PACE
Minimising Ventricular pacing to reduce AF in SND (2007)
Support the use of AAI-DDD based modes in DDD over conventional DDD programming
Results
•AF lower in AAI-DDD group
(12.7% vs 7.9%)
DANPACE / DANISH
A randomized comparison of atrial and dual-chamber pacing in 177 consecutive patients with sick sinus syndrome: echocardiographic and clinical outcome (2003)
Compared AAI with DDD short AVs and DDD long Avs
High RV pacing results in decrease in LV function
DAVID
Dual Chamber and VVI Implantable Defibrillator Trial Investigators. Dual-chamber pacing or ventricular backup pacing in patients with an implantable defibrillator: the Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial.(2002)
In pts with intact AV conduction, RV pacing >40% leads to an increase in death and HFH
Conclusions from studies
Unnecessary/increased RV pacing can lead to
•Increased AF
•Decrease in LV function
•Increase in HFH
Increase in death