Coupling Interval Variability Differentiates Ventricular Ectopic Complexes Arising in the Aortic Sinus of Valsalva and Great Cardiac Vein From Other Sources

Abstract

Objectives The objective of this study was to determine whether premature ventricular contractions (PVCs) arising from the aortic sinuses of Valsalva (SOV) and great cardiac vein (GCV) have coupling interval (CI) characteristics that differentiate them from other ectopic foci. Background PVCs occur at relatively fixed CI from the preceding normal QRS complex in most patients. However, we observed patients with PVCs originating in unusual areas (SOV and GCV) in whom the PVC CI was highly variable. We hypothesized that PVCs from these areas occur seemingly randomly because of the lack of electrotonic effects of the surrounding myocardium. Methods Seventy-three consecutive patients referred for PVC ablation were assessed. Twelve consecutive PVC CIs were recorded. The ΔCI (maximum – minimum CI) was measured. Results We studied 73 patients (age 50 ± 16 years, 47% male). The PVC origin was right ventricular (RV) in 29 (40%), left ventricular (LV) in 17 (23%), SOV in 21 (29%), and GCV in 6 (8%). There was a significant difference between the mean ΔCI of RV/LV PVCs compared with SOV/GCV PVCs (33 ± 15 ms vs. 116 ± 52 ms, p < 0.0001). A ΔCI of >60 ms demonstrated a sensitivity of 89%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 94%. Cardiac events were more common in the SOV/GCV group versus the RV/LV group (7 of 27 [26%] vs. 2 of 46 [4%], p < 0.02). Conclusions ΔCI is more pronounced in PVCs originating from the SOV or GCV. A ΔCI of 60 ms helps discriminate the origin of PVCs before diagnostic electrophysiological study and may be associated with increased frequency of cardiac events.

Sites of Successful Ventricular Fibrillation Ablation in Bileaflet Mitral Valve Prolapse Syndrome

“…Both short-coupled (245±28, 42 302±52, 43 297±41 ms 44 ) and long-coupled (409±62 ms 45 ) VEs have been previously reported with idiopathic VE-induced VF, and whether this group is a spectrum of these populations or a separate entity in view of electrogram evidence of localized fascicular or myocardial disease is unknown. Previous studies have reported an association between increased variability in VE coupling intervals and risk of malignant VA, with similar coupling interval variability 46,47 to our population, although no differences were seen between the groups with and without previous cardiac arrest. One possible mechanism of this variability is electrotonic modulation by surrounding myocardium of a protected parasystolic focus, 48,49 such as a Purkinje fiber, which was the tissue target tissue in 11 of the 14 patients.…”

Premature Ventricular Contraction Coupling Interval Variability Destabilizes Cardiac Neuronal and Electrophysiological Control

“…aortic cusps, epicardial) are associated with worse outcomes. 4, 5, 7 Finally, variable CI PVCs increased PES-SB dispersion as compared to fixed CI PVCs, despite comparisons following similar CI. Therefore, impact of variable CI on neuronal stability was the last potential mechanistic component of the increase in PES-SB dispersion that we could identify in the present study.…”

“…However, cardiac events are known to occur with “benign” PVCs, 2, 3, 5 and we have yet to decipher the mechanism behind this small, but very real risk. This study provides important mechanistic insights into mechano-electrical feedback (mediated through cardiac neurons) that have the potential to contribute to a new avenue of investigation and allow more precise risk stratification in the future.…”

“…Particularly, patients with PVCs showing high coupling interval (CI) variability are at a greater risk for cardiac events such as left ventricular (LV) dysfunction 4 and sudden cardiac death. 5, 6 …”

Ablating Premature Ventricular Complexes: Justification, Techniques, and Outcomes

“…14 A variable coupling interval might be related to variability in conduction across the fibrous annuli related to reentrant PVCs targeted near the semilunar valves or at the GCV-AIV junction, 26 although reentrant PVCs can certainly occur with a fixed coupling interval. As opposed to relatively benign long-coupled PVCs, short-coupled PVCs can induce rapid and unstable ventricular tachyarrhythmias.…”