Two Different Cycle Lengths During Left Ventricular Pacing: What Is the Mechanism?

The article discusses the case of a male patient whose surface electrograms showed two different cycle lengths during left ventricular pacing. The patient has ischemic cardiomyopathy. The electrograms showed pacing cycle of two different cycle lengths and different pacing morphologies. Pacing was predominantly at a longer cycle length with intermittent pacing at a shorter cycle length.