Improvement in left ventricular deformational indices following radiofrequency ablation in patients with tachycardia: A comparative study between AVRT and AVNRT regarding left ventricular strain and strain rates

Background: Ablation will efficiently lead to sinus rhythm preservation, which consequently improves left ventricular function; however, the strain rate and its indices as functional systolic factors of the left ventricle have not been studied. Objectives: To assess the improvements in different patterns of radial, longitudinal, and circumferential strain rates separately. Methods: In this case series, 31 patients with symptomatic tachycardia who were candidates for ablation between october 2011 and March 2012 in our tertiary cardiovascular center in Iran were enrolled. Patients underwent trans-thoracic echocardiography 24 hours before and 24 hours and three months after ablation, and left ventricular ejection fraction deformation indices were assessed using the two-dimensional (2D) speckle tracking method during normal sinus rhythm. Results: Strain and strain rate indices in different aspects (radial and circumferential in the short axis view, and for longitudinal in the long axis view) improved remarkably during the three-month follow-up period (P< 0.05). The improvements in ventricular indices were usually between 24 hours to three months after ablation. The systolic strain rate (SR) and strain (SN) were significantly different at echocardiographic views before and 24 hours after ablation (P< 0.05), which revealed that myocardial function developed in the first 24 hours of ablation. Conclusions: Echocardiography and 2D speckle tracking strain imaging shows improvements in left ventricular deformation indices in atrioventricular reentrant tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) patients for the mean systolic strain and strain rate at 24 hours and the three-month follow-up. In spite of the normal LVEF, even during sinus rhythm, deformation indices maybe abnormal before and after ablation