[Usefulness of exercise Doppler in the diagnosis of severe mitral stenosis].
BACKGROUND
Exercise in mitral stenosis produces an increase in cardiac output and heart rate which determines the increment in the transmitral gradient. However, it has not yet been established what level is reached by the gradients on exercise in severe mitral stenosis nor whether the rise in the gradient during such exercise is different to that occurring in non-severe stenosis.


OBJECTIVE
To evaluate the effect of exercise in patients with severe mitral stenosis on the mitral valve gradients in absolute values and on the increment with respect to base values.


METHODS
Forty-eight mitral stenosis patients (mean age: 48.8 +/- 11 years) underwent 50 exercise Doppler echocardiographic studies using supine bicycle ergometry in two stages with increases of 25 W every 3 minutes; from each of these we obtained the peak and mean mitral gradient using a non-imaging continuous-wave Doppler probe. We also conducted this procedure on 14 patients with a mean age of 50 +/- 6 who had Bjork mitral prostheses which were functioning normally.


RESULTS
We defined a hemodynamic profile of severity based on the data from 18 patients whose basal mitral valve areas was < 1.2 cm2 (group I), and compared them with the data from the 32 studies of mitral stenosis patients with an area > 1.1 cm2 (group II) and with the patients with mitral prostheses (group III). The mean mitral gradient (mmHg) in group I was greater than in group II at rest (9.3 +/- 3.2 and 6.6 +/- 2.7; p < 0.001), at 25 W (20.6 +/- 4.8 and 14.1 +/- 5; p < 0.001) and at 50 W (25.9 +/- 5.4 and 17.3 +/- 5.8; p < 0.001). The increase in mean mitral gradient from the baseline to 50 watts was 16.7 +/- 4.5 mmHg in group I, which was greater than in group II and III (11.1 +/- 4.1 and 6.8 +/- 2.6 mmHg; p < 0.001).


CONCLUSIONS
Exercise Doppler echocardiography enabled us to define a differential hemodynamic profile in patients with severe mitral stenosis which can be used in isolation as an indicator of severity in this condition.
Alonso Gómez
A M
AM
Servicio de Cardiología, Hospital Txagorritxu, Vitoria-Gasteiz.
Belló Mora
M C
MC
Arós Borau
F
F
Torres Bosco
A
A
Martínez Ferrer
J B
JB
Camacho Azcargorta
I
I
D000328:Adult; D000368:Aged; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005082:Physical Exertion
Valor del Doppler de esfuerzo para el diagnóstico de la estenosis mitral severa.