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Electrophysiological study in chagasics with syncope and conduction disorder
Alexia Hallack Dreicon1, Luciana Armaganijan1, Dalmo Antonio Ribeiro Moreira1
1Dante Pazzanese Institute of Cardiology, Electrophysiology and Clinical Arrhythmias - São Paulo (SP), Brazil.
Insights
Electrophysiological study in Chagas disease patients with syncope and conduction disorder frequently induces malignant ventricular arrhythmias. Risk factors include wide QRS, prolonged HV interval, reduced ejection fraction, and higher Rassi score.
Area of Science:
- Cardiology
- Electrophysiology
- Infectious Diseases
Background:
- Syncope evaluation often utilizes electrophysiological study (EPS) for cardiac conduction disorders.
- Conflicting evidence exists regarding the utility of EPS in Chagas disease patients.
Purpose of the Study:
- To assess electrophysiological study findings in Chagas disease patients with syncope and conduction abnormalities.
- To identify predictors of malignant ventricular arrhythmias in this population.
Main Methods:
- Retrospective analysis of 45 Chagas disease patients undergoing EPS for syncope (2017-2021).
- Exclusion of patients with non-interpretable ECG, coronary artery disease, or other cardiomyopathies.
- Analysis of HV interval and EPS-induced ventricular arrhythmias.
Main Results:
- Over half (57.8%) of patients had inducible malignant ventricular arrhythmias.
- Mean HV interval was 58.37 ms, with 22.2% having prolonged intervals (≥70 ms).
- Beta-blockers, amiodarone, NYHA class ≥II, wide QRS, prolonged HV interval, high Rassi score, and reduced ejection fraction predicted inducible arrhythmias.
Conclusions:
- Inducible malignant ventricular arrhythmias are common in Chagas disease patients with syncope and conduction disorder.
- Prolonged HV interval is less common than anticipated but remains a risk factor.
- Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score are associated with increased arrhythmia risk.
Background:
Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease.
Objective:
The objective of this study was to evaluate the electrophysiological study findings in patients with Chagas disease and bundle branch block and/or divisional block presenting with syncope.
Methods:
This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed.
Results:
A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias.
Conclusion:
More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.
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