Stricter criteria for left bundle branch block diagnosis do not improve response to CRT

Abstract

Stricter definition of LBBB did not improve response to CRT in comparison to the current AHA definition.

Contrast‐induced nephropathy after cardiac resynchronization therapy implant impairs the recovery of ejection fraction in responders

“…Balloonocclusive contrast angiography of the coronary sinus tributaries is therefore recommended to guide electrode positioning. 16 Tester et al 7 reported for the same amount of contrast lower incidence; however, differently from us, they considered the increase of Creatinine ≥48 h and not within. Iodinated contrast causes direct cellular injury to kidney tubular cells that undergo swelling, blebbing, and apoptosis 12 resulting in contrast nephropathy.…”

“…3 However, up to 30-60% 4 of them do not benefit from this therapy, and so far, many efforts have been done to find the determinants of this lack of response to CRT, which are related [5][6][7][8] to either patients' and procedural characteristics and in addition to the post-procedural management. Furthermore, CRT improves symptoms, quality of life, and prolongs survival in patients with interventricular conduction delay (QRS complex width > 130 ms), LV ejection fraction (EF) ≤ 35%, and New York Heart Association (NYHA) Class II-IV symptoms.…”

Comparison of four LBBB definitions for predicting mortality in patients receiving cardiac resynchronization therapy

“…This might be interpreted as meaning that four slurred/notched leads are necessary to diagnose LBBB. However, interpretations present in the literature include the need for one notch/slur (Bertaglia et al, ), the need for three notched/slurred leads (Strauss, ), and a nonobligatory notch/slur (Perrotta et al, ; Zareba et al, ). In the current study, the presence of at least one lead with a notch/slur was deemed sufficient to fulfill the WHO/AHA definition criteria.…”

“…Similar results were seen in the only other study that compared mortality in patients with LBBB according to the Strauss and conventional definitions, a retrospective study involving 111 patients (Mascioli et al, ). Moreover, patients with Strauss‐defined LBBB had a better echocardiographic response to CRT than patients with conventionally defined LBBB (Tian et al, ), although not those with WHO/AHA defined LBBB (Bertaglia et al, ). The latter finding was similar to our results showing the smallest difference in long‐term mortality between these two definitions, a finding that may be due to both definitions requiring a QRS notch.…”

“…A meta‐analysis of four large trials showed that CRT had no clinical benefits in patients with non‐LBBB QRS morphology (Sipahi et al, ). However, several substantially different electrocardiographic criteria for LBBB have been used (Bertaglia et al, ; Hsing et al, ; Surawicz, Childers, Deal, & Gettes, ; Wagner, ; Willems et al, ; Zareba et al, ). Recently, on the basis of pathophysiological considerations, endocardial mapping and computer simulations, a new definition of LBBB including longer QRS duration (≥130 ms in women and ≥140 ms in men) and the presence of at least two mid‐QRS notches/slurs in leads I, aVL, V1, V2, V5, and V6 was proposed (Strauss, Selvester, & Wagner, ).…”