Department of Pediatric Cardiology, University of Health Sciences Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Education and Research Hospital, Istanbul, Turkey.
Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey.
Pacing Clin Electrophysiol. 2022 Sep;45(9):1165-1171. doi: 10.1111/pace.14568. Epub 2022 Aug 9.
Fasciculoventricular fiber (FVF) that does not cause tachyarrhythmia is a rare form of ventricular preexcitation, which is important to distinguish from Kent fibers. Although, adenosine and some electrocardiographic features are important in the differentiation of Wolff Parkinson White (WPW) than FVF, a clear distinction may not always be possible without an electrophysiological study (EPS). In this study, we aimed to present the clinical and electrophysiological features of our pediatric patients with fasciculoventricular fiber.
Between October 2013 and September 2021, 565 patients who underwent electrophysiological studies due to ventricular preexcitation in our clinic were screened in the study, and 27 (4.7%) patients with fasciculoventricular fiber were included. The data of the patients were obtained from the file records using the electronic internet database system Filemaker . Electrophysiological study age, weight, gender, symptom, and presence of congenital heart disease of the patients were obtained from the file records. Accessory pathway localization was evaluated according to the modified Arruda algorithm in pre-procedural electrocardiography. In addition, delta wave amplitudes were measured in the first 40 ms from the surface ECG. PR interval, QRS interval, and delta wave amplitude were recorded before and after ablation in patients with additional accessory pathways. Post-procedure values were included in the FVF group.
The mean age of the patients was 11.47 ± 4.25 years. All 70.4% of the reasons for admission were symptoms such as palpitations and syncope. Two patients had hypertrophic cardiomyopathy and 1 patient had ccTGA. In the electrophysiological study, additional manifest WPW was found in 9 (33%) patients (3 patients with high risk, 6 patients with orthodromic supraventricular tachycardia), focal atrial tachycardia in a patient, and atrioventricular nodal reentry tachycardia in a patient. While the delta wave amplitude was found to be 2.56 ± 1.38(1-5.5) mm in the first 40 ms in surface electrocardiography in 9 patients with additional accessory pathway, it was found to be 1.64 ± 0.67(0.5-3) mm in the FVF group. There was no statistically significant difference between the 2 groups (p = .398). Delta wave amplitude > 3.5 mm was not detected in any patient with isolated FVF. Interestingly, delta wave amplitude was < 3.5 mm in 7 (78%) of 9 patients who were identified and ablated with an additional accessory pathway. Total 19 of the patients (59.3%) were adenosine-responsive (18 isolated FVF, 1 manifest AP+FVF adenosine-responsive. 8 patients with other manifest AP + FVF had no pre-procedural adenosine-asystole response, and all of them QRS were expanded).
Although, the fasciculoventricular fibers themselves are not the cause of tachyarrhythmia, the accessory pathway and other tachyarrhythmia substrate frequency accompanying these cases are quite high (approximately 40%) in EPS. The delta wave characteristics of ablated patients are very similar to FVF patients. While all patients with isolated FVF were adenosine responsive, most of those with additional manifest WPW were unresponsive. Therefore, performing EPS in patients with suspected FVF based on surface ECG features seems to be important for the detection of additional tachyarrhythmias and risky accessory pathways.
不引起心动过速的束支-心室纤维是一种罕见的心室预激形式，与 Kent 纤维相比，这一点很重要。虽然腺苷和一些心电图特征在鉴别 WPW 与 FVF 方面很重要，但如果不进行电生理研究（EPS），可能并不总能明确区分。本研究旨在介绍我们儿科患者束支-心室纤维的临床和电生理特征。
2013 年 10 月至 2021 年 9 月，我们对因心室预激在我院进行电生理研究的 565 例患者进行了筛选，其中 27 例（4.7%）患者存在束支-心室纤维。通过电子互联网数据库系统 Filemaker 从档案记录中获取患者的数据。从档案记录中获取患者的电生理研究年龄、体重、性别、症状和先天性心脏病情况。根据改良 Arruda 算法评估附加旁路的定位。此外，还在体表心电图的前 40ms 内测量 delta 波振幅。在存在附加旁路的患者中，记录消融前后的 PR 间期、QRS 间期和 delta 波振幅。将术后值纳入束支-心室纤维组。
患者的平均年龄为 11.47±4.25 岁。所有患者（70.4%）入院的原因均为心悸和晕厥等症状。两名患者患有肥厚型心肌病，1 名患者患有 ccTGA。在电生理研究中，9 名（33%）患者发现附加显性 WPW（3 名高危患者，6 名顺向型房室结折返性心动过速）、1 名患者发现局灶性房性心动过速、1 名患者发现房室结折返性心动过速。在 9 名附加旁路的患者中，体表心电图前 40ms 的 delta 波振幅为 2.56±1.38（1-5.5）mm，而在束支-心室纤维组中为 1.64±0.67（0.5-3）mm。两组间无统计学差异（p=0.398）。在任何孤立性束支-心室纤维患者中均未检测到 delta 波振幅>3.5mm。有趣的是，在 9 名伴有附加旁路的患者中，有 7 名（78%）患者的 delta 波振幅<3.5mm。共有 19 名患者（59.3%）对腺苷有反应（18 名孤立性束支-心室纤维患者，1 名显性 AP+束支-心室纤维患者腺苷有反应。8 名其他显性 AP+束支-心室纤维患者无术前腺苷停搏反应，且所有患者的 QRS 波均扩张）。
虽然束支-心室纤维本身不会引起心动过速，但在 EPS 中，这些病例伴随的附加旁路和其他心动过速基质的频率相当高（约 40%）。消融患者的 delta 波特征与束支-心室纤维患者非常相似。虽然所有孤立性束支-心室纤维患者均对腺苷有反应，但大多数伴有显性 WPW 的患者对腺苷无反应。因此，根据体表心电图特征在疑似束支-心室纤维患者中进行 EPS 似乎对于发现附加性心动过速和高危旁路很重要。
