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.