Ventricular tachycardia exit site location within myocardial reinnervation zones predicts hemodynamic stability in ischemic cardiomyopathy
摘要
Hemodynamic stability during ischemic ventricular tachycardia (VT) critically influences mapping strategies and ablation outcomes. This study investigated whether VT exit site location within distinct myocardial scar zones affects hemodynamic stability.
MethodsWe analyzed 51 VTs in 27 patients with ischemic scar-mediated VT who underwent electroanatomic mapping and catheter ablation (2014–2017). Exit sites were categorized by voltage mapping as adjacent to central scar zone (CSZ, bipolar voltage < 0.5 mV) or peri-infarct border zone (PIBZ, voltage 0.5–1.5 mV). Hemodynamic stability was defined as sustained VT without precipitous blood pressure drop requiring cardioversion. Multivariate logistic regression identified independent predictors of instability.
ResultsOf 51 VTs, 30 (58.8%) were hemodynamically unstable. Among stable VTs, 81% had PIBZ exit sites versus 19% CSZ exits (P = 0.01). CSZ exit site location independently predicted hemodynamic instability (OR 6.8, 95% CI 1.3–35.8; P = 0.02) after adjusting for cycle length and ejection fraction. Unstable VTs had lower ejection fraction (28.7 ± 10.5% vs. 35.7 ± 11.4%, P = 0.03) and shorter cycle length (330.5 ± 78.5 ms vs. 403.2 ± 107.7 ms, P = 0.007).
ConclusionsVT exit site location adjacent to distinct scar zones independently predicts hemodynamic stability. CSZ exits are associated with instability, while PIBZ exits maintain stability. These findings may reflect differential post-infarction reinnervation patterns and mechanical forces between scar zones, enhancing risk stratification and guiding ablation strategy selection in ischemic VT.
Graphical Abstract