Predictors of positive electrophysiological study in patients with syncope and bundle branch block: PR interval and type of conduction disturbance

Abstract

Background Electrophysiological study (EPS) is indicated in patients with syncope and bundle branch block (BBB). Data about predictors of positive EPS in these patients is scarce. Objective To assess clinical and electrocardiographic (ECG) predictors of positive EPS in patients with syncope and BBB. Methods Observational single‐center study that included all consecutive patients with syncope and BBB that underwent EPS from January 2011 to June 2017. Results of EPS were considered positive according to current ESC syncope guidelines. Results During study period, 271 patients were included (64.9% male, age: 73.9 ± 12.2 years, number of syncopal episodes: 2.4 ± 2.5, LVEF: 56.1 ± 9.9%). Type of BBB: RBBB + LAFB/LPFB in 39.8%, isolated LBBB in 38.7% and isolated RBBB in 18.5% of the patients. Duration of QRS and PR interval were 141.9 ± 16.7 and 182.8 ± 52.2 milliseconds. EPS was positive in 41.7% of the patients. In multivariate analysis, conduction disturbance pattern and long PR interval (OR 8.6; 2.9‐25; P < 0.0001) were predictors of positive EPS. Conduction disturbance patterns related with positive EPS were: BBB different than isolated RBBB (OR 15.2; 2.2‐23.4; P = 0.005), LBBB or RBBB+long PR + left fascicular block (OR 4.5; 1.06‐20.01; P < 0.042), and RBBB+left fascicular block compared with LBBB (OR 4.8; 1.2‐16.7; P = 0.025). Clinical factors and syncope characteristics were not related with EPS result. Conclusions Diagnostic yield of EPS in patients with syncope and BBB is moderate (41%). Type of conduction disturbance pattern and PR interval are associated with the electrophysiological (EP) test result. Patients with LBBB or bifascicular block have the highest rate of positive EP test. Long PR interval increases the proportion of positive EPS in all conduction disturbance patterns.

Sex-Related Differences in Patients With Unexplained Syncope and Bundle Branch Block: Lower Risk of AV Block and Lesser Need for Cardiac Pacing in Women

“…Moreover, RBBB was more frequent in men while LBBB morphology was more frequent in women. These findings in baseline characteristics are consistent with data previously published (3,5,7,(26)(27)(28), which suggests that patients included in the present study are likely representative of the population with syncope and BBB.…”

“…In a recent national population-based cohort study that included more than 2.5 million participants, Fedorowsky et al (21) found that 62% of the patients with syncope were women. However, this proportion is reversed when a cohort of patients with structural heart disease (6,24,25) or abnormal ECG (3,5,7,26) is selected, probably because men have a higher prevalence of cardiovascular risk factors and other comorbidities. In our study, which included consecutive patients, 63% were men.…”

“…A Abbreviations: aAVB, Advanced atrioventricular block; sCD, Severe conduction disturbances; BBB, Bundle branch block; EPS, electrophysiological study; ICM, Implantable cardiac monitor; SND, Sinus node dysfunction. systematic diagnostic approach based on clinical evaluation, electrophysiological study (EPS), and the Implantable cardiac monitor (ICM) has shown to be safe and provide a high rate of etiological diagnosis (3,(5)(6)(7). However, due to the low predictive value of EPS, some investigators suggest that a pacemaker should be implanted on an empirical basis (2,8), therefore, the best way to manage these patients remains controversial.…”

Bedside Carotid Sinus Massage for Syncope Evaluation With Bifascicular Block and First-Degree Atrioventricular Block

“…Although BFB, including LBBB and right bundle branch block (RBBB) with a left anterior or posterior fascicular block (LAFB/LPFP), is usually asymptomatic, the presence of first-degree AVB heralds the risk of complete AVB, with 13% complete AVB at a 5.4-year follow-up in one study [7]. The complete AVB risk in BFB patients warrants diagnostic evaluation; however, electrophysiologic (EP) evaluation yield is modest at 41% positivity [8] due to which implantable loop recorder (ILR) is indicated in undiagnosed cases [9]. Ischemic evaluation should also be considered part of the syncope workup due to the relationship between coronary artery disease, arrhythmia, and recurrent syncope [10].…”

Cardiac monitoring for patients with palpitations

“…In addition to allowing for a precise diagnosis of certain arrhythmias (such as paroxysmal supraventricular tachycardias), it is possible to treat the arrhythmia with ablation during the procedure in those cases where it is indicated[ 91 - 93 ]. It also allows to evaluate other causes of syncope if present[ 9 , 10 , 94 , 95 ], and performing risk stratification in patients with structural heart disease[ 14 , 71 ]. Since it is an invasive test, it tends to be considered at the end of the diagnostic process, either in patients with a high probability of significant arrhythmia when the monitoring methods have not allowed for it to be documented, or in patients where, after documenting the clinical arrhythmia, ablation treatment is planned.…”