Evaluation of Mean Mitral Gradient in Exercise Doppler Echocardiography in Mitral Stenosis
Abstract
Saleha Lehachi, Fadila Daimellah, Djohar Hannoun, Youcef Laid, Rachid Mechmeche and Mohand Said Issad
Background: In mitral stenosis (MS), the international recommendations are favor the mitral dilation if mean transmitral gradient reaches 15 mmHg or greater at the peak exercise Doppler echocardiography (grade C).
Objective: Study of the transmitral gradient during exercise Echocardiography in patient with mitral valve area (MVA) of ≤ 2 cm2.
Results: 300 patients were included. The mean age was 42.7 ± 1.3 years, the sex ratio of 0.23. According to the MVA, three groups were defined. G1 (severe MS): MVA ≤ 1cm2 (n =72), G2 (moderate MS): 1cm2 < MVA < 1.5cm2 (n = 128) and G3 (mild MS): MVA ≥ 1.5 cm2 (n = 100). The mean MVA was 0.8 ± 0.1 cm2 (G1), 1.3 ± 0.1 cm2 (G2) and 1.7 ± 0.1 cm2 (G3) (p < 10-6). At rest, from the 1st to the 3rd group, mean heart rate/min was respectively 71.5 ± 2.7, 76.3 ± 1.7 and 73.6 ± 2.1, and means transmitral gradient were respectively to 11.6 ± 0.8 mmHg, 8.8 ± 0.5mmHg and 5.1 ± 0.3mmHg (p < 10-6). At peak exercise, mean heart rate/min was 152.3 ± 2.9 (G1), 150.7 ± 2.2 (G2), 148.7 ± 2.4 (G3) (p = 0.20), and means transmitral gradient 39.2 ± 2.1 mmHg (G1), 31.5 ± 1.3 mm Hg (G2) and 22.8±1.0 mm Hg (G3) (p < 10-6). At maximum of exercise, the mean transmitral gradient was above 15 mm Hg in 95 patients (95%) in group 3 despite MVA ≥ 1.5 cm2. All patients of group 1 and group 2 increased their mitral gradient above 15 mm Hg at peak stress.
Conclusion: At maximum exercise, most of our patients have increased their transmitral gradient beyond 15 mm Hg, even those who had mild MS (MVA ≥ 1.5 cm2). Therefore, in stress echo-Doppler, the mean mitral gradient at peak exercise justifying percutaneous valvulotomy is probably greater than 15 mm Hg.