Physiologic changes in mitral stenosis.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Between April 1986 and August 1987, eight children, 9 to 18 years old, with rheumatic mitral valve stenosis underwent a percutaneous balloon valvotomy. Immediate results were good. By echocardiographic measurements, mean transmitral gradients went from 23.7 +/- 7.1 mmHg to 5.8 +/- 4.7 mmHg (p less than 0.001), diastolic pressure half-times went from 299.0 +/- 15.6 msec to 123.3 +/- 42.3 msec (p less than 0.001) and mitral valve areas measured by planimetry went from 1.00 +/- 0.15 cm2/1.73 m2 to 2.68 +/- 0.71 cm2/1.73 m2 (p less than 0.001). Hemodynamic measurements showed a decrease in mean pulmonary artery pressure from 48.3 +/- 13.2 mmHg to 32.5 +/- 5.7 mmHg (p less than 0.01), a decrease in the mean left atrial pressure from 26.1 +/- 6.3 mmHg to 14.6 +/- 4.7 mmHg (p less than 0.02) and an increase in calculated mitral valve area (Gorlin formula) from 1.07 +/- 0.31 cm2/1.73 m2 to 2.73 +/- 1.17 cm2/1.73 m2 (p less than 0.02). The only complication observed was a grade III mitral insufficiency in a child with marked subvalvular fibrosis. Six patients had a very good result and one kept a moderate mitral stenosis. Percutaneous balloon valvotomy gives probably better results in children than in adults and obtains at least as good results as surgical closed mitral commissurotomy. Presently, this technique is the treatment of choice for rheumatic mitral stenosis in children. Contra-indications are intra-atrial thrombus and shortened, thickened subvalvular apparatus.
A 68 year old woman with chronic renal failure on long-term haemodialysis presented with progressive dyspnoea. Serial echocardiography showed a rapid reduction in mitral valve area from 2.18 to 0.92 cm2 over 18 months. In addition, the previously non-stenotic aortic valve was found to be severely stenotic with a valve area of 1.05 cm2. Cardiac catheterisation confirmed these findings. The patient had undergone subtotal parathyroidectomy more than 10 years before but had chemical and clinical evidence consistent with recurrent hyperparathyroidism. The patient underwent successful mitral and aortic valve replacement with relief of symptoms. Rapid progression of both aortic and mitral valve stenosis in the presence of secondary hyperparathyroidism is a rare finding.
Eight patients with mixed mitral stenosis and regurgitation underwent hemodynamic and angiographic study prior to mitral valve replacement. The stenotic orifice of the mitral valve was calculated employing the total left ventricular stroke volume by cineangiography as the numerator of the Gorlin Formula. Excellent agreement with the measured orifice of the mitral valve was obtained using a value of 37.9 (0.85 X 44.5) for the constant in the Gorlin formula as recommended by Cohen and Gorlin. Recalculation of this constant independently by our data yielded a value that was almost identical. Regurgitant flows and orifice sizes were calculated for each patient using the same constant as for calculation of the stenotic orifices.
BACKGROUND: This study compares the mitral valve area determined by Doppler color mapping of the proximal isovelocity surface area (PISA) and by Doppler pressure half-time with that obtained by two-dimensional planimetry in patients affected by mitral stenosis, with and without associated aortic regurgitation. Pressure half-time frequently overestimates the mitral valve area in patients with mitral stenosis and associated aortic regurgitation. PISA is an alternative method for determining mitral valve area in mitral stenosis and is not influenced by regurgitant lesions. METHODS: We studied 76 patients with mitral stenosis; aortic regurgitation > or = 2 was present in 24 patients. The PISA was recorded from the apex and the transmitral maximal flow rate, Q (ml/s), was calculated using the hemispheric equation Q = 2 pi R2 x AV x alpha/180, where R (cm) is the maximal radius of the PISA, AV (cm/s) is the aliasing velocity and alpha/180 is a correction factor accounting for the alpha inflow angle formed by the mitral leaflets. Mitral valve area, A (cm2), was calculated by continuity equation A = Q/V, where V (cm/s) is the peak transmitral flow velocity measured by continuous wave Doppler. RESULTS: The mitral valve area by two-dimensional planimetry (range 0.5-2.4 cm2; mean 1.33 +/- 0.41 cm2) was consistent with both PISA (r = 0.83; SEE 0.23 cm2) and pressure half-time (r = 0.79; SEE 0.25 cm2) methods. Similar agreement was found for the 36 patients with mitral regurgitation and for the 30 patients in atrial fibrillation. However, in patients with aortic regurgitation > or = 2, pressure half-time overestimated two-dimensional and PISA determined mitral valve areas by 0.24 +/- 0.25 cm2 (p < 0.01). CONCLUSIONS: In patients with mitral stenosis and significant aortic regurgitation, the PISA method is more accurate than pressure half-time in assessing mitral valve area. This method may be a reliable alternative when pressure half-time is affected by aortic regurgitation and two-dimensional planimetry images are unsuitable for anatomic evaluation.
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BACKGROUND AND AIM OF THE STUDY: The predictive value of chronic atrial fibrillation (AF) before percutaneous mitral balloon valvotomy (PMBV) is still under discussion. The effect of the duration of chronic AF on short- or long-term results is not known. Therefore, we analyzed the predictive value of pre-procedural chronic AF and the duration of this rhythm disturbance for short- and long-term outcome after PMBV in patients with mitral valve stenosis. METHODS: A total of 140 PMBV procedures was performed in 137 patients with severe mitral stenosis. Sixty-three patients (45%) were in chronic AF; in 40 patients (63%) the AF was of more than one year duration. A successful procedure is defined as PMBV achieved without acute mitral valve replacement, and a mitral valve area after PMBV of > or =1.5 cm2. RESULTS: Patients in chronic AF were significantly older, had a larger left atrial diameter and higher NYHA functional class, compared with patients in sinus rhythm (SR). The success rates of PMBV were 80.5% and 77.6% in patients with SR and AF, respectively (p = NS). Mean follow up was 4.2+/-2.6 years (n = 127). At four years' follow up the event-free survival was 86.5% in patients with SR, and 78.5% in those with chronic AF at baseline (p = 0.031). Multivariate analysis of the entire study population showed the presence of chronic AF to be the only pre-procedural independent predictor for severe mitral regurgitation after PMBV (p = 0.030), as well for an event (p = 0.039) and restenosis (p = 0.034) during follow up. The risk for an event or restenosis during follow up increased seven-fold when chronic AF at baseline was present for more than one year (p = 0.010). CONCLUSION: Pre-procedural chronic AF is an independent predictor for unfavorable outcome at short- and long-term follow up after PMBV. A longer duration of AF further increases the risk of an event or restenosis.
OBJECTIVE: To investigate the relation between plasma concentrations of immunoreactive endothelin and haemodynamic variables before and after percutaneous transvenous balloon dilatation of the mitral valve. DESIGN: Prospective study. SETTING: National cardiovascular centre. PATIENTS: 25 patients with mitral stenosis and 26 healthy volunteers. MAIN OUTCOME MEASURES: Plasma concentrations of immunoreactive endothelin were measured in the pulmonary artery, left atrium, ascending aorta, and femoral vein before and after balloon dilatation of the mitral valve. RESULTS: Peripheral venous concentrations (mean (SD)) of endothelin were higher in the patients with mitral stenosis than in the healthy volunteers (1.76 (0.51) v 1.37 (0.45) pg/ml, p < 0.05) and they correlated with the mean left atrial pressure (r = 0.74, p < 0.01). Balloon dilatation of the mitral valve reduced the mean left atrial pressure without changing the mean right atrial pressure, systemic arterial pressure, heart rate, or cardiac index. Concentrations of plasma endothelin in the femoral vein increased from 1.76 (0.51) to 3.39 (2.46) (p < 0.01), 4.82 (2.34) (p < 0.001), and 2.43 (0.52) pg/ml (p < 0.05) at 15 and 30 minutes and 24 hours after the procedure. The concentration of endothelin in the pulmonary artery also increased from 1.85 (0.85) to 4.32 (1.58) pg/ml (p < 0.01) 30 minutes after the dilatation, whereas there were no appreciable changes in endothelin concentration in the left atrium or ascending aorta. CONCLUSIONS: Plasma endothelin concentrations were higher in patients with mitral stenosis than in healthy volunteers and the increase was proportional to left atrial pressure. After balloon dilatation of the mitral valve there was an abrupt rise in endothelin in the femoral vein and pulmonary artery but no change in left atrial or aortic blood samples. These findings suggest that endothelin may be another vasoactive substance involved in congestive heart failure.
Twenty-eight patients with mitral stenosis underwent Doppler echocardiography at rest and during exercise to determine the accuracy of mitral valve area determination by the flow-convergence-region method during exercise-induced changing hemodynamic conditions. The mitral valve area calculated by using the flow-convergence-region method correlated strongly with that measured by the Gorlin formula both at rest (r = 0.85) and during exercise (r = 0.92) for all 28 patients studied. Although mitral valve area obtained by the flow-convergence-region method did not change (p = 0.1) in 16 patients with echocardiographic mitral scores > or = 12, it increased significantly during exercise (p = 0.0001) in 12 patients with echocardiographic mitral scores < 12. This study suggests that in mitral stenosis, the mitral valve area can be accurately estimated by the flow-convergence-region method both at rest and during changing hemodynamic conditions induced by supine bicycle exercise.
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To evaluate the pathoanatomic findings of mitral valve stenosis and changes after percutaneous balloon valvuloplasty (PBV), magnetic resonance (MR) imaging was performed in 23 patients. The patients were imaged with a 2.0-T system within 1 week before and 3-10 days after PBV. The angle of the interatrial septum was measured on the transverse image to facilitate a successful transseptal puncture. On MR images, the mean transverse and anteroposterior diameters of the left atrium at the level of the aortic root in the ventricular diastolic phase decreased significantly after PBV. Areas of flow-related intraluminal signal intensity detected in the left atrial cavity of 17 patients (74%) before the procedure disappeared in 15 patients after the procedure. Other MR imaging findings after PBV were the disappearance of intraluminal signal intensity in the pulmonary artery, normal curvature of the interatrial and interventricular septa, and pericardial effusion as a complication. MR imaging was thought to provide useful information before and after PBV in patients with mitral stenosis.