Background: Dyspnea is a common symptom in a patient with valvular heart disease. The mechanism underlying this is still uncertain.
Methods: We prospectively studied 20 patients with rheumatic mitral valve stenosis who were candidates for percutaneous balloon mitral valvotomy. Assessment of airway hyper-reactivity by histamine challenge test was done on all patients at baseline and at 1 week after the procedure. The provocative concentration of histamine solution required producing a 20% fall in forced expiratory volume in 1 second (FEV(1)) (PC20) was recorded as a measure of airway hyper-reactivity. The severity of dyspnea in study subjects was also studied by the 6-minute-walk test and visual analog scale.
Results: After balloon valvotomy, a significant improvement was seen in the six minute walking distance (219+/-30.15 to 237.55+/-32.25; p < 0.001), visual analog scale as a measure of dyspnea (60.95+/-12.16 to 44.4+/-13.71; p < 0.001) and airway hyper-reactivity (PC20; 5.69+/-6.01 mg/ml to 10.16+/-7.93; p < 0.001).
Conclusions: Improvement in dyspnea in mitral stenosis after balloon valvotomy is associated with significant improvement in airway hyper-reactivity.