Sajeer Kalathingathodika, Haridasan Vellani, Rajesh Gopalan Nair
BACKGROUND Cardioembolic episodes are reported in patients with rheumatic mitral stenosis. Impaired function of left atrial appendage secondary to left atrial pressure and volume overload facilitates thrombus formation inside. Beta blockers used for symptom relief can worsen the left atrial appendage function further. Ivabradine, a selective rate reducing drug is unlikely to have such an effect and may be a better alternative. Objective of the study was to compare the effects of these two drugs on left atrial appendage velocities. MATERIALS AND METHODS This study is a sub study of a trial which compared the effectiveness of atenolol and ivabradine for rate control. Out of 82 patients randomised to atenolol (50 mg once daily) or ivabradine (5 mg twice daily) in the original study, 20 patients were selected (9 in the atenolol group and 11 in the ivabradine group). RESULTS These patients underwent transoesophageal echo at baseline and 6 weeks after treatment with assigned drug and left atrial appendage emptying velocities (LAAEV) and left atrial appendage filling velocities (LAAFV) were estimated. Baseline velocities were comparable in both groups. Peak LAAEV were 29.224 (5.678) cm/s and 24.557 (5.103) cm/s (p value 0.069), early LAAEV were 15.778 (3.002) cm/s and 16.410 (1.750) cm/s (p value 0.564) and LAAFV were 34.265 (6.605) cm/s and 30.031 (6.606) cm/s (p value 0.206) in atenolol group and ivabradine group respectively. Post drug treatment, peak LAAEV and LAAFV decreased significantly while early LAAEV did not change significantly in the atenolol group (29.224(5.678) cm/s v/s 27.771 (5.774) p value 0.018 for peak LAAEV and 34.265 (6.605) cm/s v/s 32.382 (5.789) cm/s with p value 0.009 for LAAFV). None of the three velocities changed significantly in the ivabradine group. CONCLUSION Atenolol significantly reduced peak LAAEV and LAAFV in patients with rheumatic mitral stenosis in sinus rhythm. Ivabradine did not have such an effect.
