Assessment Of Subtle Cardiac Dysfunction In Patients With Frequent Premature Ventricular Complexes By Real-time 3D Speckle Tracking Imaging Technology

Background and Objective:Premature ventricular complexes (PVCs) are among the most common forms of arrhythmia encountered in clinical practice. In recent years more and more studies have shown that frequent PVCs may lead to deterioration of cardiac function, even to PVCs-induced cardiomyopathy. Current clinical traditional methods could not detect subtle and early forms of PVC-induced left ventricular impairment, besides, most patients with frequent PVCs have a normal LVEF. Real-time 3D Speckle Tracking Imaging Technology, as a novel convenient and non-invasive method, provides a new way to achieve precise quantitative evaluation of myocardial changes.Our study is aimed at evaluating subtle and early forms of PVC-induced ventricular impairment in PVCs patients without structural heart diseases by Real-time 3D Speckle Tracking Imaging Technology. It could help us detect subtle PVC-induced cardiac dysfunction in early time and make a risk classification.Methods:1.40 patients (22 male) with a single source of frequent PVCs (burden 22.8±9.7%) and 40 healthy controls (24 male) were enrolled in this study. Through the routine examinations (physical and laboratory), there were no clear structural heart disease and cardiac dysfunction found in all subjects.2. Subjects were performed standard 12-lead electrocardiogram, recorded QRS duration, morphology. The PVC burden was calculated by dividing the number of PVCs by the total number of beats on Holter recording.3. Subjects were performed using conventional two-dimensional echocardiography:aortic root diameters, left atrial diameters, LV end-diastolic diameters and end-systolic diameters, inter-ventricular septum and posterior wall thickness were measured.4. Subjects were performed using Real-time 3D Speckle Tracking Imaging Technology (RT3D-STI):4D mode was switched after showing the apex four-chamber view, real-time 3D images of volume imaging were recorded. Left ventricular end-diastolic and end-systolic volumes(LVEDV and LVESV), left ventricular ejection fraction(LVEF), and global longitudinal strain(GLS), global circumferential strain (GCS), global radial strain (GRS), global area strain(GAS) and every segment strain were calculated on off-line analysis software. The variables were compared between the two groups.Results:1. Baseline characteristics were comparable between PVCs group and healthy controls. Age, gender, body surface area and other factors were no obvious-differences(P>0.05).2. All variables from conventional two-dimensional echocardiography, including aortic root diameters, left atrial diameters, LV end-diastolic diameters and end-systolic diameters, inter-ventricular septum and posterior wall thickness and left ventricular ejection fraction, were no obvious differences between PVCs group and healthy controls(P>0.05).3. Variables from RT3D-STI, including global mean peak systolic longitudinal, circumferential, area and radial strain in PVCs group were lower than control group (GLS:-13.50±3.00% vs-18.31±3.12%, GCS:-13.21 ±4.52% vs-19.49±2.60%, GAS:-22.43±5.02% vs-29.86±4.81% and GRS: 36.31±8.81% vs 49.61±10.12%, respectively), the differences were statistically significant(P<0.05).4. Strains from 3D-STI, including LS, CS, AS, RS from basal segment, middle segment and apical segment in PVCs group were lower than control group (P<0.05).5. Patients with a high PVC burden(≥20%) tended to have a lower LVEF and larger LV end-diastolic volume and LV end-systolic volume than patients with a moderate PVC burden, but these differences were not significant(P>0.05)6. All strain values by 3D-STI had strong correlations with assessment of LV function determined by LVEF. GCS was the best marker of LV function (r=-0.84, P=0.020). Good intra-observer, inter-observer, and test-retest agreements were seen with 3D-STI.Conclusions:1. Frequent premature ventricular complexes patients with normal left ventricular ejection fraction have lower global and regional strain value than healthy controls.2.3D Speckle Tracking Imaging Technology could assess subtle left ventricular dysfunction in PVCs patients.3.3D Speckle Tracking Imaging Technology could be a novel, feasible and reproducible method to quantitatively assess left ventricular function.