Myocardial Scar on Surface ECG: Selvester Score, but Not Fragmentation, Predicts Response to CRT

Abstract

Purpose. Myocardial scar is directly related to the response to CRT after implantation. The extent of myocardial scar can be detected not only by cardiac magnetic resonance but also by two electrocardiographic scores: fragmented QRS (fQRS) and Selvester score (SSc). The aim of our study is to compare the role of baseline SSc and fQRS in predicting response to CRT in a cohort of heart failure patients with true left bundle branch block (LBBB). As a secondary endpoint, we assessed the association of both scores with overall and cardiac mortality, heart failure hospitalizations, ventricular arrhythmias requiring ICD intervention, and major adverse cardiovascular event (MACE). Methods. We evaluated fQRS and SSc of 178 consecutive HF patients with severe systolic dysfunction (LVEF ≤ 35%), NYHA class II-III despite optimal medical treatment, and true-LBBB. Response to CRT was defined as the improvement of LVEF of at least 10% or as the reduction of LVESV of at least 15% at a 6-month follow-up. Each endpoint was related to fQRS and SSc. Results. SSc ≥7 was significantly associated with the absence of echocardiographic response to CRT (OR: 0.327; 95% C.I. 0.155–0.689; p=0.003), while the presence of fQRS at baseline ECG was not (OR: 1.133; 95% C.I. 0.539–2.381; p=0.742). No correlation was found between SSc and overall mortality, cardiac death, ventricular arrhythmias, hospitalizations due to heart failure, or for MACE. Similar results were observed between fQRS and all secondary endpoints. Conclusion. In HF patients with true-LBBB and LVEF ≤35% eligible for CRT, myocardial scar assessed by calculating the SSc on preimplant ECG is an independent predictor of nonresponse after multiple adjustments. Neither SSc nor fQRS is associated with overall and cardiac death, ventricular arrhythmias, or hospitalization for heart failure at a 24-month follow-up.

O Escore de Selvester QRS é um Preditor de Mortalidade na Insuficiência Cardíaca com Fração de Ejeção Preservada

“… 35 No estudo de Chen et al, 36 que comparou a ressonância magnética (RM) cardíaca e o escore S-QRS em pacientes com cardiomiopatia hipertrófica , notou-se que o escore S-QRS indicou a presença e o tamanho da cicatriz com a mesma precisão da RM cardíaca. 36 Netsi et al, 37 por outro lado, mostraram que o escore S-QRS antes da implantação da terapia de ressincronização cardíaca (TRC) é um dos mais importantes indicadores de resposta ao tratamento TRC. 37 Muitos estudos revelaram que a fibrose cardíaca é um dos mecanismos fisiopatológicos mais importantes em pacientes com ICFEp.…”

“… 36 Netsi et al, 37 por outro lado, mostraram que o escore S-QRS antes da implantação da terapia de ressincronização cardíaca (TRC) é um dos mais importantes indicadores de resposta ao tratamento TRC. 37 Muitos estudos revelaram que a fibrose cardíaca é um dos mecanismos fisiopatológicos mais importantes em pacientes com ICFEp. O estudo da autópsia de Mohammed et al, 38 provou que doença arterial coronariana epicárdica, infartos microvasculares e cicatrizes macroscópicas e microscópicas eram mais prevalentes em pacientes com ICFEp em comparação com o grupo controle.…”

“… 35 In the study by Chen et al, 36 which compared cardiac MRI and the S-QRS score in patients with hypertrophic cardiomyopathy, it was noted that the S-QRS score indicated the presence and size of the scar as accurately as cardiac MRI. 36 Netsi et al 37 on the other hand, showed that the S-QRS score before implantation of cardiac resynchronization therapy (CRT) is one of the most important indicators of response to CRT treatment. 37 Many studies have revealed that cardiac fibrosis is one of the most important pathophysiological mechanisms in patients with HFpEF.…”

Left Ventricular Functions Assessment by Speckle Tracking in Comparison with The Two-Dimensional (2D) Echocardiography in Patients with Fragmented QRS

“…On the other side, exclusion criteria were: ischemic heart disease either by history or investigation; more than mild degree of valvular stenosis or regurgitation; poor quality echocardiographic views; patients with a history of cardiomyopathy and LV hypertrophy (LVH), pathological Q wave on electrocardiogram, typical left or right bundle blocks, incomplete right bundle block, or paced rhythm, previous cardiac surgery, diabetes mellitus, hypertension, chronic kidney disease, smoking and obesity. All subjects are submitted to full history taking, complete general and local examinations, twelve lead ECG searching for fQRS complex and exclude ischemia and arrhythmia (8) , and transthoracic echocardiography to assess left ventricular function as described in Nagueh et al (9) , El-Sebae et al (10) and Hung et al (11) Statistical Analysis: Quantitative normally distributed data were expressed as an average and standard deviation (SD). Frequency and percentage were the measures for qualitative data.…”

Value of q waves in lateral and left precordial leads in patients with left bundle branch block to predict the response to cardiac resynchronization therapy

“…The ECG features for CRT response majorly focus on whether strict Strauss LBBB criteria is fulfilled, as a strict LBBB morphology on surface ECG is suggested to indicate more serious in electrical disturbance rather than structural disturbance in HF 9 . QS or rS wave in V1, and R wave with notches in I, avL, V5, and V6 were proved to be associated with CRT response, 4 while high LBBB Selvester score (LBBB‐SSc), 10 fragmented QRS, 11 and S waves in V6, 12 were related to CRT non‐response.…”