Can QRS morphology be used to differentiate between true septal vs. apparently septal lead placement? An analysis of ECG of real mid-septal, apparent mid-septal, and apical pacing

Abstract

The location of the pacemaker lead is based on the shape of the lead on fluoroscopy only, typically in the left and right anterior oblique positions. However, these fluoroscopy criteria are insufficient and many leads apparently considered to be in septum are in fact anchored in anterior wall. Periprocedural ECG could determine the correct lead location. The aim of the current analysis is to characterize ECG criteria associated with a correct position of the right ventricular (RV) lead in the mid-septum. Patients with indications for a pacemaker had the RV lead implanted in the apex (Group A) or mid-septum using the standard fluoroscopic criteria. The exact position of the RV lead was verified using computed tomography. Based on the findings, the mid-septal group was divided into two subgroups: (i) true septum, i.e. lead was found in the mid-septum, and (ii) false septum, i.e. lead was in the adjacent areas (anterior wall, anteroseptal groove). Paced ECGs were acquired from all patients and multiple criteria were analysed. Paced ECGs from 106 patients were analysed (27 in A, 36 in true septum, and 43 in false septum group). Group A had a significantly wider QRS, more left-deviated axis and later transition zone compared with the true septum and false septum groups. There were no differences in presence of q in lead I, or notching in inferior or lateral leads between the three groups. QRS patterns of true septum and false septum groups were similar with only one exception of the transition zone. In the multivariate model, the only ECG parameters associated with correct lead placement in the septum was an earlier transition zone (odds ratio (OR) 2.53, P = 0.001). ECGs can be easily used to differentiate apical pacing from septal or septum-close pacing. The only ECG characteristic that could help to identify true septum lead position was the transition zone in the precordial leads. ClinicalTrials.gov identifier: NCT02412176.

Intracardiac Echocardiography–Guided Implantation for Proximal Left Bundle Branch Pacing

“…The potentials of the His bundle and LBB were mapped using a saline-irrigated catheter on the left ventricular septum and marked in the ventricular model developed using ICE (Figure 1 ). The classification of the pacing site was based on the previously described ECG characteristics of the left bundle fascicular block and fascicular originated ventricular arrhythmia, 7 , 8 and the paced ECG met the criteria of LBB capture. 9 , 10 Proximal LBB (PLBB) pacing involves LBB trunk pacing, 10 proximal left anterior fascicle pacing, and proximal left posterior fascicle pacing.…”

Differences in Electrical Delay Between the Mid-septum and Apex with the Right Ventricular Lead: Novel Implications for Pacemaker Sensing

“…The mid-septal position was verified by combined fluoroscopy views and characteristic ECG of the early transition zone in the precordial paced QRS, as demonstrated in Figure 1 . 11 …”

Sincronia Ventricular na Estimulação Cardíaca Parahissiana: Alternativa por Ativação Cardíaca Fisiológica (Estimulação Indireta do Feixe de His)?

“…Para a determinação do eixo elétrico dos QRS do ECG pós-implante, considerou-se fisiológica a presença de ativação ventricular da direita para esquerda (QRS positivo nas derivações D1 e AVL) e de cima para baixo (QRS positivo em DII, DIII e AVF), assim como transição (onda R ≥ S) até V3-V4 nas derivações precordiais. 25 A presença de todos os três critérios categoriza um eixo fisiológico, a presença de dois critérios categoriza um eixo possivelmente fisiológico e a observação de somente um ou nenhum critério categoriza o eixo cardíaco como não fisiológico.…”

“…Variação mediana do IimeS no grupo DDD-Var = -74). Todavia, reforçando ainda mais as semelhanças entre a ECA PHP e a NS-HBP, o sentido da ativação elétrica ventricular produzida na totalidade dos casos para ambos os grupos se enquadrou nas categorias de eixo fisiológico, na verificação integral dos critérios de Mala et al 25 e eixo provavelmente fisiológico, na falta de um dos critérios.…”