Evaluation of the Mitral Valve Resistance as a Hemodynamic Parameter in Mitral Stenosis

ABSTRACT

BACKGROUND: Mitral stenosis is charcterized by decrease in mitral valve area anatomically and increase in transmitral pressure gradient hemodynamically. And these changes have been used to quantify the severity of mitral stenosis clinically. To evaluate the clinical usefulness of mitral valve resistance as a hemodynamic parameter in patients with mitral stenosis, we compared the mitral valve resistance to the clinical status of the patient with mitral stenosis, the other hemodynamic parameters and static parameter. METHODS: We analyzed and reviewed the data obtained from the consecutive 27 patients with mitral stenosis(7 male, 20 female mean age 38+/-9 years) who had been underwent percutaneous mitral valvuloplasty(PMV). RESULTS: Befor PMV, the mitral valve resistance was significantly correlated with exercise capacity on treadmill test(r=-0.37, p<0.05), mitral valve area(r=-0.72, p<0.01), transmitral mean pressure gradient(r=0.83, p<0.01),not with cardiac output, mixed venous oxygen saturation. After PMV, the mitral valve resistance was significantly correlated with mitral valve area (r=-0.72, p<0.01), transmitral mean pressure gradient(r=0.90, p<0.01).According to the results summerizing and comparing the values of before and after percutaneous mitral valvuloplasty, the mitral valve resistance had good relationship with preexisting paramerters of severity such as mitral valve area(r=-0.82, p<0.01), transmitral mean pressure gradient (r=0.92, p<0.01). CONCLUSION: This results indicate that the mitral valve resistance is a useful hemodynamic parameter in patients with mitral valve stenosis and reflects the exercise capacity during the treadmill test which was the objective parameter of practical and clinical status of the patient well than the other hemodynamic parameters in case of remarkably reduced transmitral valve blood flow due to severe mitral valve stenosis, because the degree of change in the mitral valve resistance in relagion to the degree of change in transmitral valve blood flow is relatively more constant than the other hemodynamic parameters.