[Hemodynamic assessment before and after PTMC by using cardiac blood pool scintigraphy]

Rest and exercise cardiac blood pool scintigraphy with 99mTc-RBC were performed in 12 patients with symptomatic mitral stenosis before percutaneous transvenous mitral commissurotomy (PTMC) and at one week, one month after PTMC. Comparison of hemodynamic parameters before and one month after PTMC showed that LVEDV (97.4 +/- 8.9 vs. 111.4 +/- 12.1 ml; p less than 0.01) and diastolic indices (1/3FF: 23.6 +/- 6.5 vs. 30.9 +/- 4.1%; p less than 0.01) both increased, while there was no significant change in LVEF and RVEF. Comparison of symptom-limited bicycle exercise before and one month after PTMC showed that the duration of exercise time (7.6 +/- 1.6 vs. 8.6 +/- 1.4 min; p less than 0.02) and anaerobic threshold (10.6 +/- 3.0 vs. 15.4 +/- 3.2 ml/min/kg; p less than 0.01) increased. In comparison of hemodynamic response before and one month after PTMC, there were significant increases in cardiac output (CO) at the same workload (15 W: 3.9 +/- 0.7 vs. 4.8 +/- 0.8 l/min; p less than 0.05, 30 W: 3.9 +/- 0.7 vs. 5.2 +/- 1.2 l/min; p less than 0.05) despite similar CO at rest (3.5 +/- 0.8 vs. 3.9 +/- 0.7 l/min; NS). We conclude that cardiac blood pool scintigraphy is useful to evaluate improvement of hemodynamic parameters and exercise capacity after PTMC non-invasively.