The long-term effect of successful mitral balloon valvotomy on left atrialsize

Background and aim of the study: The study aim was to determine the extent of regression of left atrial (LA) enlargement following mitral balloon valv otomy (MBV) for mitral stenosis. Methods: Data obtained from 205 patients before, and at a mean of 31.0 +/- 21.1 months (range: 6 to 86.3 months) after successful MBV were analyzed re trospectively. Results: The invasively determined mitral valve area increased from 0.81 +/ - 0.27 cm(2) at baseline to 1.73 +/- 0.54 cm(2) immediately after valvotomy (p <0.0001), and the mean mitral gradient fell from 15.6 +/- 5.3 to 5.4 +/ - 2.5 mmHg (p <0.0001), Similar changes were noted in Doppler-determined mi tral valve area (0.89 +/- 0.16 to 1.97 +/- 0.29 cm(2); p <0.0001) and gradi ent (12.6 +/- 5.3 to 4.9 +/- 1.7 mmHg; p <0.0001). In comparison with basel ine, significant (p <0.0001) reductions were noted at follow up in the echo cardiographic anteroposterior (48.7 +/- 6.9 to 42.4 +/- 6.6 mm), superior-i nferior (68.5 +/- 8.1 to 59.6 +/- 8.2 mm) and medial-lateral LA dimension ( 51.2 +/- 6.7 to 44.1 +/- 7.7 mm) and calculated LA volume (91.6 +/- 29.1 to 60.7 +/- 23.8 cm(3)) Patients in atrial fibrillation had larger LA dimensi ons, but substantially smaller absolute and relative reduction in LA size a t follow up than patients in sinus rhythm. Among patients with prevalvotomy LA enlargement, normalization of LA dimension at follow up was seen in 29. 2% of patients in sinus rhythm, but in none of the 32 with atrial fibrillat ion. Conclusions: Successful MBV results in significant long-term reduction in L A size in most patients, but normalization of LA size is unusual.