17 research outputs found
Ventricular tachycardia : Challenges in the era of the implantable cardioverter difibrillator
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Electrocardiographic predictors of successful resynchronization of left bundle branch block by His bundle pacing
Background
His bundle pacing (HBP) is an alternative to biventricular pacing (BVP) for delivering cardiac resynchronization therapy (CRT) in patients with heart failure and left bundle branch block (LBBB). It is not known whether ventricular activation times and patterns achieved by HBP are equivalent to intact conduction systems and not all patients with LBBB are resynchronized by HBP.
Objective
To compare activation times and patterns of HisâCRT with BVPâCRT, LBBB and intact conduction systems.
Methods
In patients with LBBB, noninvasive epicardial mapping (ECG imaging) was performed during BVP and temporary HBP. Intrinsic activation was mapped in all subjects. Left ventricular activation times (LVAT) were measured and epicardial propagation mapping (EPM) was performed, to visualize epicardial wavefronts. Normal activation pattern and a normal LVAT range were determined from normal subjects.
Results
Fortyâfive patients were included, 24 with LBBB and LV impairment, and 21 with normal 12âlead ECG and LV function. In 87.5% of patients with LBBB, HisâCRT successfully shortened LVAT by â„10âms. In 33.3%, HisâCRT resulted in complete ventricular resynchronization, with activation times and patterns indistinguishable from normal subjects. EPM identified propagation discontinuity artifacts in 83% of patients with LBBB. This was the best predictor of whether successful resynchronization was achieved by HBP (logarithmic odds ratio, 2.19; 95% confidence interval, 0.07â4.31; pâ=â.04).
Conclusion
Noninvasive electrocardiographic mapping appears to identify patients whose LBBB can be resynchronized by HBP. In contrast to BVP, HisâCRT may deliver the maximum potential ventricular resynchronization, returning activation times, and patterns to those seen in normal hearts