It has been emphasized that as the procedure is changing, the results of various techniques should be reported separately. In comparison, reports using only the double-balloon technique have shown that the average mitral valve area before CBV ranged from 0.7 to 1.0 cm2 and increased up to 2.0 to 2.2 cm2 after CBV In both of these series the increases in valve areas were also demonstrated by Doppler echocardiography and confirmed by repeated cardiac catheterization six to 12 weeks after the procedure.
The larger increase in calculated valve area and the smaller residual gradients after double-balloon CBV suggest that this procedure, although more technically demanding, usually achieves wider opening of the mitral valve commissures. fully
These hemodynamic improvements are often associated with rapid improvement in the patients clinical condition. When CBV produces wide opening of the valve in patients with orthopnea and very high left atrial pressures, the left atrial pressures decrease immediately, and the orthopnea can resolve completely. After a 48-hour recovery period, patients are discharged from hospital and followed up on a program of progressive ambulation. Younger patients who are inactive mainly owing to the mitral stenosis are rapidly reconditioned over several weeks of progressive normal activity and may soon become asymptomatic, a finding also reported soon after surgical commissurotomy in these patients.
The changes in symptoms have also been associated with improvements in results of objective exercise treadmill tests and exercise hemodynamic values during repeat cardiac catheterization. The late clinical and hemodynamic results after CBY although promising, are not yet known and will be described by longterm studies and follow-up in centers with active investigational protocols.