Deceleration capacity as a predictor of vasovagal syncope subtypes

Area of Science:

• Cardiology
• Autonomic Neuroscience
• Medical Diagnostics

Background:

• Autonomic dysfunction is implicated in vasovagal syncope (VVS) pathogenesis.
• Understanding autonomic function across VVS subtypes is crucial.
• Deceleration capacity (DC) is a novel vagal indicator with potential for improved VVS subtype discrimination.

Purpose of the Study:

• To assess the efficacy of DC in distinguishing between various VVS subtypes.
• To compare the discriminatory power of DC against traditional heart rate variability (HRV) indices.

Main Methods:

• Included 141 VVS patients confirmed by head-up tilt test.
• Analyzed 24-hour Holter data for HRV and DC across VVS subtypes.
• Employed ANOVA, logistic regression, and ROC analyses to develop a DC-based prediction model.

Main Results:

• Significant differences in autonomic parameters, including DC, were found across VVS subtypes (p < 0.05).
• DC demonstrated superior ability in differentiating cardioinhibitory VVS from vasodepressor VVS compared to HRV indices (p < 0.05).
• A DC-based model achieved an AUC of 0.811, with increased daytime DC correlating with higher odds of cardioinhibitory response.

Conclusions:

• Baseline autonomic function varies significantly among VVS subtypes.
• Deceleration capacity (DC) shows potential as a predictive biomarker for VVS patient stratification.
• DC may aid in clinical decision-making for VVS management.