Improving an automatic stress test analysis protocol as a problem solution for sympatho-dependent arrhythmias identification

Sympathetic-dependent ventricular arrhythmias (VA) are prognostically more adverse than resting VA. They are hard to diagnose, though they are present in patients with life-threatening conditions. The current challenge with finding sympathetic-dependent VA obstructs the study of arrhythmia characteristics that are crucial for preventing arrhythmic threats and identifying individuals at elevated risk for cardiovascular complications, including sudden cardiac death. Objective of the Study. To update the automatic exercise test analysis protocol, improve sympathetic-dependent ventricular arrhythmia diagnostics, and identify patients requiring additional in-depth examination. Material and methods. The study involved 167 patients who exhibited VA during wakefulness according to Holter monitoring and had no contraindications for the exercise test. All patients underwent a treadmill test, the results of which were assessed using the step-by-step protocol and the advanced minute-by-minute protocol. Results. The sequential step-by-step and minute-by-minute interpretation of the treadmill test revealed sympathetic VA in 65/167 (39%) and 80/167 (48%) patients, respectively. The advanced protocol with minute-by-minute stress test analysis decreases the post-processing analysis duration by 50% compared to the step-by-step method (7 min vs. 14 min). Coronary artery disease (15 patients, 19%), hypertension (25 patients, 31%), mild cardiac anomalies (21 patients, 26%), arrhythmogenic cardiomyopathy/right ventricular dysplasia (5 patients, 6%), catecholaminergic polymorphic ventricular tachycardia (1 patient, 1%) were found in patients with registered sympathetic-dependent VA. No underlying etiology for arrhythmogenesis was found in 13 individuals. Conclusion. The advanced automatic minute-by-minute stress test analysis protocol improves sympathetic-dependent VA diagnostics and helps identify individuals with prognostically adverse conditions. Their early detection will facilitate the prevention of chronic heart failure and sudden cardiac death.