[The atrial contribution to ventricular filling in mitral stenosis. An evaluation by Doppler echocardiography].

Using Doppler echocardiography, we have quantified the atrial contribution to ventricular filling in 22 patients with mitral stenosis in sinus rhythm without or with minimal mitral and/or aortic regurgitation. With continuous wave Doppler from apex we obtained the ventricular filling flow from which the valvular area was calculated. The product of the integrated ventricular filling waves multiplying by the valvular area was called total volume (TV). Assuming that the deceleration of the ventricular filling flow is linear and remain constant, we integrated the transmitral flow, this time without considering the atrial filling wave as if the patient was entering into atrial fibrillation. Multiplying this integration by the valvular area we obtained a second volume, atrial fibrillation volume (AFV). The atrial contribution was calculated by: 1) absolute value: TV-AFV and in 2) percent value or fraction: (TV-AFV/TV) x 100. When we correlate absolute and percent values with mitral valve area, the results were statistically significant in both cases (p less than 0.001), with an excellent regression factor both with absolute value r = 0.90 and the percent one r = 0.72. In mitral stenosis the atrial contribution to ventricular filling has an inverse relation with the grade of severity, being very low in the more severe lesions. This is why it would be doubtful that its lost (atrial contribution) is the only cause of hemodynamic deterioration that has been observed in patients who suddenly present atrial fibrillation.