Abstract
BACKGROUND: Frequent premature ventricular contractions (PVCs) can induce cardiomyopathy; however, there is a lack of early indicators to assess the cardiac functional impact of PVCs originating from different sites. This study employed three-dimensional speckle-tracking imaging (3D-STI) to compare myocardial torsion and deformation characteristics of PVCs from varying origins during sinus beats, PVC beats, and compensatory beats, with the aim of examining the early indicators of cardiac function. METHODS: Ninety-one patients (28 males, 63 females) with single-source PVCs who underwent successful radiofrequency ablation were enrolled. Preoperative echocardiographic parameters were collected, including mitral inflow velocity (E/A), tissue Doppler indices (EmS, EmL, and E/e'), and left ventricular ejection fraction (LVEF). We used 3D-STI to measure parameters such as peak left ventricular torsion angle, basal/apical rotation time-to-peak difference, and global longitudinal strain, radial strain, and circumferential strain to compare myocardial mechanical features of PVCs from different origins. RESULTS: Left/right ventricular systolic function during PVC beats was significantly lower than during sinus beats (P<0.05), whereas compensatory beats exhibited superior function as compared to sinus rhythm. PVCs of different origins primarily affected apical rotation angle (RotA) (P=0.021) and global rotation angle (P=0.043) during sinus beats. During PVC beats, significant differences were observed in basal radial strain (P<0.001) and right ventricular longitudinal strain (P=0.013). Coupling interval showed a strong positive correlation with left ventricular global longitudinal strain (r=0.732; P<0.001). CONCLUSIONS: 3D-STI enables the quantitative assessment of PVC-related myocardial motion. (I) PVC beats exhibited the worst systolic function, while compensatory beats demonstrated enhanced compensatory function. (II) Left ventricular global longitudinal peak strain, basal radial peak strain, and strain time-to-peak difference may serve as sensitive indicators for early cardiac dysfunction. (III) Shortening of the coupling interval is a critical risk factor for cardiac functional deterioration. This study provides novel imaging-based evidence for the early identification of and clinical intervention in PVC-induced myocardial damage.