Cardiology Division, Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, Brazil.
Department of Radiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
J Electrocardiol. 2022 May-Jun;72:66-71. doi: 10.1016/j.jelectrocard.2022.03.005. Epub 2022 Mar 21.
Electrocardiographic (ECG) abnormalities are frequently identified in Chronic Chagas cardiomyopathy (CCC) patients and advanced abnormalities are related to a worse prognosis. Cardiac Magnetic Resonance (CMR) can precisely assess ventricular systolic dysfunction and quantify myocardial fibrosis (MF), both identified as prognostic factors. We sought to investigate if ECG abnormalities in CCC patients were associated with more severe myocardial involvement as evaluated by CMR.
CCC patients with 12‑lead ECG and CMR closely obtained were included. ECG analysis evaluated rhythm, presence, and type of intraventricular conduction disturbances (IVCD) and, ventricular premature beats (VPB). CMR short-axis cine and late gadolinium enhancement images were evaluated to obtain left and right ventricular ejection fractions and MF mass, respectively. Statistical significance was set in 5%.
194 CCC patients (98 women, 56 ± 14 years) were evaluated, and no IVCD was detected in 71. The most common IVCD was the association of right bundle branch block and left anterior fascicular block (RBBB+LAFB) in 58 patients, followed by isolated RBBB in 34, isolated LAFB in 17, and left bundle branch block (LBBB) in 14 patients. Of patients with no IVCD, 63% had MF and the burden of fibrosis (no IVCD - 7.4 ± 8.6%; RBBB - 6.6 ± 6.5%; p = 1.00), as well as left ventricular ejection fraction (LVEF) (no IVCD - 52 ± 14%; RBBB - 55 ± 10%; p = 1.00) were similar to patients with isolated RBBB. Left conduction system impairment was associated with lower LVEF (LAFB - 39 ± 15%; RBBB+LAFB- 41 ± 15%; and LBBB - 35 ± 15%; p < 0.001) and more MF (RBBB+LAFB - 12.2 ± 10.4%; LBBB - 10.6 ± 7.5%; and LAFB - 12.0 ± 7.0%; p < 0.001). The univariable model showed that the presence of MF was related to RBBB+LAFB (OR 5.0; p = 0.001) and VPB (OR 6.3; p = 0.014). After adjustment for age, gender, and different risk factors in a multivariable model, the same findings were still significantly related to CMR myocardial fibrosis (RBBB+LAFB OR 5.0; p = 0.002 / VPB OR 6.9; p = 0.015).
ECG without IVCD does not exclude serious cardiac abnormalities in CCC, and isolated RBBB seems to have a benign course. The presence of VPB and left branch conduction impairment, especially LAFB associated with RBBB, indicate a more severe cardiac involvement.
研究慢性恰加斯病（CCC）患者心电图（ECG）异常与心脏磁共振（CMR）评估的心室收缩功能障碍和心肌纤维化（MF）之间的关系。
入选 194 例接受 12 导联心电图和 CMR 检查的 CCC 患者。分析心电图评估节律、是否存在室内传导障碍（IVCD）和室性早搏（VPB），以及类型。CMR 短轴电影和晚期钆增强图像用于获得左、右心室射血分数和 MF 质量。
194 例 CCC 患者（女性 98 例，56±14 岁）中，71 例无 IVCD。最常见的 IVCD 是右束支阻滞合并左前分支阻滞（RBBB+LAFB），共 58 例，其次是孤立性 RBBB 34 例，孤立性 LAFB 17 例，左束支阻滞（LBBB）14 例。无 IVCD 的患者中 63%有 MF，纤维化负荷（无 IVCD：7.4±8.6%；RBBB：6.6±6.5%；p=1.00）和左心室射血分数（LVEF）（无 IVCD：52±14%；RBBB：55±10%；p=1.00）与孤立性 RBBB 患者相似。左束支传导系统损伤与较低的 LVEF（LAFB：39±15%；RBBB+LAFB：41±15%和 LBBB：35±15%；p<0.001）和更多的 MF（RBBB+LAFB：12.2±10.4%；LBBB：10.6±7.5%和 LAFB：12.0±7.0%；p<0.001）相关。单变量模型显示 MF 与 RBBB+LAFB（OR 5.0；p=0.001）和 VPB（OR 6.3；p=0.014）有关。多变量模型调整年龄、性别和不同危险因素后，相同的发现仍与 CMR 心肌纤维化显著相关（RBBB+LAFB OR 5.0；p=0.002/VPB OR 6.9；p=0.015）。
心电图无 IVCD 不能排除 CCC 患者存在严重的心脏异常，孤立性 RBBB 似乎具有良性病程。VPB 和左束支传导损伤的存在，特别是 RBBB 合并 LAFB，提示心脏受累更严重。
