Discussion
The longitudinal and circumferential strain values of the LA were considerably lower in the patient group compared to the control group. In compared to healthy volunteers, individuals with PVC exhibited impaired LA function, according to our findings.
Increased PVC frequency (>10,000/day or >10/hour) might negatively impact the left atrial and left ventricular functions of a structurally normal heart. Frequent PVC may result in an aberrant LV filling pressure, leading in a change in LV shape and systolic dysfunction or PVC-induced cardiomyopathy. Depending on the degree and duration of the aberrant LV filling pressure, frequent PVC may lead to atrial overload and pathological alterations of the LA. These structural modifications to the LA have the potential to affect its functions and degrade longitudinal and circumferential strain values. In recent research analyzing patients with normal LVEF and frequent PVCs, individuals with PVCs had an elevated LA volume index. [14, 15] Prior research investigating the effect of PVC ablation on atrial and ventricular architecture demonstrated that effective PVC ablation can prevent LA dilatation. [15, 16] In our study, it was also shown that the LA volumes increased in patients with PVC.
The relationship between PVC and atrial arrhythmias is not clear. Age, hypertension, and diabetes are common risk factors for both PVC and atrial arrhythmias. PVC may generate retrograde ventriculo-atrial conduction and behave like atrial ectopic beats originating from the pulmonary vein. Consequently, PVC may enhance the incidence of atrial ectopies via retrograde ventriculo-atrial conduction [4-6].
As LA may contract against a closed mitral valve, PVC can result in atrioventricular dyssynchrony. This may raise LA pressure and atrial wall tension. Occasionally, PVC cannot conduct retrogradely to the LA, but it might render the AV node resistant to the subsequent sinus beat. Due to the postextrasystolic compensatory pause, the beat following a PVC may result in a LA volume overload. Depending on the cause of the PVC, the QRS duration and coupling interval may be lengthened and shortened, respectively. In this situation, atrioventricular dyssynchrony may increase. An increase in atrioventricular dyssynchrony may result in a deterioration of LA functions and strain levels. [15, 18-20] In our investigation, LA strain metrics were worse in patients with epicardial origin PVC whose QRS length was predicted to be longer. PVC coupling intervals were also shown to be closely associated with LASrc, LASr, LASct, LAScd, LAScdc and LAStc.
Del Cardipo et al. observed that PVCs originating from the right ventricle (RV) may result in a more serious reduce in LVEF than those coming from the left ventricle (LV). [21] A deteriorating LVEF will likewise have significant effects on LA functioning. LASrc, LASr, LASct, LAScd, LAScdc and LAStc were considerably lower in individuals with PVC coming from the right ventricle, according to our study. Our data indicate that PVCs affect the quantities and functioning of LA. Patients with PVC of epicardial and right ventricular origin and longer QRS durations have more significant alterations in LA characteristics.