Author + information
- Dan-Andrei Radu,
- Corneliu Nicolae Iorgulescu,
- Stefan Nicolae Bogdan,
- Elena Ene,
- Alexandrina Nastasa,
- Georgiana Gratiela Malaescu and
- Radu-Gabriel Vatasescu
Background: In patients with HF and systolic LV dysfunction, LBBB is very often presumed to be complete, with septal activation occurring from the right-side of the apex through the RB. However, ECG aspects of most LBBB patients still suggest left-sided septal activation (r waves in V1 and q waves in DI and aVL). Therefore we wanted to evaluate how often left-sided septal activation is preserved in HF patients with systolic LV dysfunction and LBBB.
Methods: ECGs were obtained from 33 HF patients with systolic LV dysfunction and LBBB (∼ 65.5 ± 10.7 years old, 10 females, 12 with IHD) with preserved A-V conduction (PR<240 ms) who met the guideline criteria for either CRT-P or CRT-D implantation. During device implantation measurements of the interval between intrinsic QRS onset to RV EGM were obtained, with the right ventricular lead in apical and midseptal positions. The values of the delays (msec) were analyzed and compared by means of a paired samples T-test.
Results: The mean QRS width was 163.94 msec (±15.799; CI 95% 158.34-169.54). In the apical position the RV EGM was significantly more delayed than in the mid-septal position: 73.79 msec ±15.763 (CI 95% 68.20-9.38) vs. 51.67 msec ±8.985 (CI 95% 48.48-54.85). The mean difference during the apical-midseptal paired-samples T-test was 22.121 msec ±16.058 (CI 95% 16.427-27.815; p < 0.000). Out of 33 patients, the midseptal delay was longer in only two patients whose ECG directly suggested complete LBBB (absence of the mentioned waves).
Conclusions: In most patients with HF and systolic LV dysfunction, the LBBB is “incomplete”, with preserved left-sided septal activation. Loss of normal septal vectors on ECG is associated with “complete” LBBB.
Poster Hall, Hall C
Friday, March 17, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Arrhythmias and Clinical EP: Devices 2
Abstract Category: 5. Arrhythmias and Clinical EP: Devices
Presentation Number: 1149-081
- 2017 American College of Cardiology Foundation