Chapter 4

Keeping up the CRT

Why BiV pacing is lost and how to get it back: AF, PVCs, PACs, sinus rates above the MTR (and the risk of a too high MTR), PMT termination, AV delay and atrial undersensing.

The cases

1CRT-P in AF: two different pacing percentages 2CRT-D in sinus rhythm, BiV pacing 89%3CRT pacing alert at 57%, and 2 years later 4RV paced 100%, LV only 86%5CRT drop in a patient with atrial ectopy 6A stored PMT episode at 130 min-1 7Exercise: sinus tachycardia in the VT-1 zone 8Exercise, anti-PMT algorithm and long PR 9Exercise, anti-PMT algorithm and LV sensing 10Sinus tachycardia, Wenckebach and pro-arrhythmia 11Ventricular episodes in a CRT-P: what started them?12RA lead impedance alert in a paced CRT patient 13BiV markers with changing far-field morphology 14CRT drop and low-amplitude atrial events 15CRT loss at rest with sinus bradycardia

From Boston Scientific CRT — clinical cases by M. Strik. Published by Cardiocases. Every numbered marker on a recording is explained in the list beneath it; tap a marker on the trace or an entry in the list.