CSP involves implanting pacing lead targeting at various levels in the conduction system that includes His bundle and left bundle branch area. Of late conduction system pacing (CSP) has come up as a promising pacing strategy gaining acceptance worldwide. These considerations have led to the recommendation of cardiac resynchronization therapy (CRT) in patients needing pacemaker if there is left ventricular (LV) dysfunction.6 But the patients with normal LV function and indication for pacing are predominantly offered conventional pacing strategy with RVP.

Even programming a long fixed AV delay above baseline PR interval though promotes intrinsic AV conduction to occur, but still results in % VP > 50% to occur in 88% of patients due to PR prolongation on exercise.

But it may not be effective in reducing %VP in patients for whom VP is inevitable (e.g.complete heart block, AF with bradycardia). Strategies to reduce the percentage of RV pacing include algorithms that promote AAI(R) mode permitting first degree or Mobitz Type 1 heart block to occur. In the sub-study from the MOST trial, it was evident that % VP >40% was associated with a 2.6-fold increased risk of HFH compared with pacing Īlternate RV sites, like mid septal or right ventricular outflow tract (RVOT) septal pacing have so far shown conflicting data in terms of QRSd narrowing as well as hemodynamic and clinical outcomes. The ventricular desynchronization as a result of RVP leads to an increased risk of heart failure hospitalization (HFH) and AF, and this effect is dependent on cumulative percent ventricular paced ( % VP). RVP often results in prolonged QRS duration(QRSd) and ventricular desynchronization. Long-term right ventricular pacing (RVP) is associated with more cardiovascular death, atrial fibrillation (AF), thromboembolic complications and heart failure(HF).

Percent of ivcd vs rbbb crt