1. Tasneem Z. Naqvi JIMG 2010;3:1168-1180
Evaluation of Surface QRS to Determine Biv Pacing Surface QRS on the ultrasound monitor from lead III in response to atrioventricular delay (AVD) changes are shown. A was obtained during transition from native rhythm at an AVD of 200 ms to a short AVD of 50 ms. Note the complete change in QRS pattern (A) during biventricular (Biv) pacing (transition). (B) QRS at 140 ms shows morphology in-between native and Biv-paced rhythm representing fusion complexes. C shows transition from an AVD of 130 ms to 80 ms (white arrow). The QRS morphology changes back to that shown in A, indicating complete Biv pacing at an AVD of 80 ms. D shows transition from an AVD of 130 ms to 100 ms (white arrow) and QRS morphology similar to that in A, suggesting complete Biv pacing.
Tasneem Z. Naqvi JIMG 2010;3:
American College of Cardiology Foundation