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)
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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)
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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)
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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%
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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)
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Support the use of AAI-DDD based modes in DDD over conventional DDD programming
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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)
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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)
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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