Left atrial and left ventricular conduction delay by transesophageal electrocardiography with hemispherical electrodes in sinus rhythm cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy in approximately two-thirds of symptomatic heart failure (HF) patients (P) with left bundle branch block (LBBB). The aim of this study was to evaluate left atrial (LA) conduction delay (LACD) and left ventricular (LV) conduction delay (LVCD) using pre-implantational transesophageal electrocardiography (ECG) in sinus rhythm (SR) CRT responder (R) and non-responder (NR). Methods: SR HF P (n=52, age 63.6 +/- 10.4 years; 6 females, 46 males) with New York Heart Association (NYHA) class 3.0 +/- 0.2, 24.4 +/- 7.1 % LV ejection fraction and 171.2 +/- 37.6 ms QRS duration (QRSD) were measured by bipolar filtered transesophageal LA and LV ECG recording with hemispherical electrodes (HE) TO catheter (Osypka AG, Rheinfelden, Germany). LACD was measured between onset of P-wave in the surface ECG and onset of LA deflection in the LA ECG. LVCD was measured between onset of QRS in the surface ECG and onset of LV deflection in the LV ECG. Results: There were 78.8 % SR CRT R (n=41) with 171.2 +/- 36.9 ms QRSD, 73.3 +/- 25.7 ms LACD, 80.0 +/- 24.0 ms LVCD and 2.3 +/- 0.5 QRSD-LVCD-ratio. SR CRT R QRSD correlated with LACD (r=0.688, P<0.001) and LVCD (r=0.699, P<0.001). There were 21.2 % SR CRT NR (n=11) with 153.4 +/- 22.4 ms QRSD (P=0.133), 69.8 +/- 24.8 ms LACD (n=6, P=0.767), 54.2 +/- 31.0 ms LVCD (P<0.0046) and 3.9 +/- 2.5 QRSD-LVCD-ratio (P<0.001). SR CRT NR QRSD not correlated with IACD (r=-0.218, P=0.678) and IVCD (r=0.042, P=0.903). During a 22.8 +/- 21.3 month CRT follow-up, the CRT R NYHA class improved from 3.1 +/- 0.3 to 1.9 +/- 0.3 (P<0.001). In CRT NR, NYHA class not improved (2.9 +/- 0.4 to 2.9 +/- 0.2, P=1) during 11.2 +/- 9.8 months BV pacing. Conclusions: Transesophageal LA and LV ECG with HE can be utilized to analyse LACD and LVCD in HF P. Pre-implantational LVCD and QRSD-LVCD-ratio may be additional useful parameters to improve P selection for SR CRT.