Universal Algorithm for Diagnosis of Biventricular Capture in Patients with Cardiac Resynchronization Therapy

Abstract

LV capture leaves diagnostic hallmarks in the fused BiV QRS related to different vectors of depolarization and more rapid depolarization of the ventricles. An accurate two-step ECG algorithm for BiV capture diagnosis was developed and validated. This algorithm is universally applicable to all CRT patients, regardless of the positions of the pacing leads.

Reappraisal of ECG Lead V1 in the Assessment of Cardiac Resynchronization

“…Jastrzebski et al studied a large number of patients with biventricular (BiV) pacing and found a dominant R wave in lead V1 in 33.3% (80/240) patients when all RV sites were included. With BiV and RV apical pacing, a dominant R wave in lead V1 occurred in 48.8% (39/80), which is similar to the early data of Sweeney et al With BiV and RV outflow tract pacing, 22.8% (21/92) of the patients developed a tall R wave in lead V1, while BiV and RV septal pacing produced a tall R wave in lead V1 in 29.4% (20/68) of the patients.…”

“…There are many causes of a negative lead V1 during CRT and this pattern is more common in association with nonapical RV pacing . It would be unwise to attribute a negative QRS in lead V1 automatically to the participation of nonapical RV pacing without further investigation.…”

“…Such a positive R wave occurs in 10–20% of cases of uncomplicated RV apical pacing . In contrast, a dominant R wave in lead V1 is virtually unknown during nonapical RV pacing . A tracing with a dominant R wave in lead V1 during RV apical pacing should be displayed prominently in the patient's record and communicated to all involved in the follow‐up.…”

“…The 2012 EHRA/HRS (European Heart Rhythm Association/Heart Rhythm Society) Expert Consensus has stated that “a dominant R wave in V1 is almost invariably present in successful cardiac resynchronization therapy. It follows that a negative paced QRS complex in V1 should prompt full investigation.” Many workers have used an R/S > 1 with or without an equiphasic QRS complex (R/S = 1) to define a dominant R wave in lead V1 . A dominant R wave in lead V1 has also been called a right bundle branch block (RBBB), though it is caused by anterior displacement of the QRS forces rather than a right‐sided conduction delay .…”

“…A dominant R wave in lead V1 has also been called a right bundle branch block (RBBB), though it is caused by anterior displacement of the QRS forces rather than a right‐sided conduction delay . Lead V1 provides useful information about the timing between left ventricular (LV) and right ventricular (RV) electrical activity, and it constitutes an integral part of some algorithms for the detection of successful LV capture . Yet, studies focusing on the dominant R wave in V1 during cardiac resynchronization therapy (CRT) have reported an incidence of a dominant R wave in 25–100% for LV leads implanted predominantly in the posterior or posterolateral cardiac veins .…”