[Bronchial hyperresponsiveness and relaxability in patients with mitral stenosis]

Area of Science:

• Pulmonary Medicine
• Cardiology
• Respiratory Physiology

Background:

• Mitral valve disease (MVD) can affect respiratory function.
• Bronchial asthma (BA) is characterized by airway hyperresponsiveness.
• The relationship between MVD and bronchial hyperresponsiveness is not fully understood.

Purpose of the Study:

• To compare bronchial responsiveness and airway relaxability between patients with mitral stenosis (MS) and bronchial asthma (BA).
• To investigate the characteristics of bronchial hyperresponsiveness in MS patients.

Main Methods:

• Bronchial provocation tests with methacholine and salbutamol were performed using an Astograph.
• Pulmonary function tests, including FEV/FVC and V25, were conducted.
• An index of airway relaxability (SGrs-d) was derived from salbutamol response after methacholine precontraction.

Main Results:

• 72% of MS patients demonstrated bronchial hyperresponsiveness (BHR) to methacholine.
• MS patients with BHR showed reduced FEV/FVC and V25 compared to MS patients without BHR.
• MS patients with BHR had significantly higher Dmin and PD35Grs values than BA patients, indicating greater hyperresponsiveness.
• Indices of airway relaxability (SGrs-d, SCrs-d/Grs-d) were significantly lower in MS patients with BHR compared to BA patients.

Conclusions:

• Patients with mitral stenosis exhibit significant bronchial hyperresponsiveness and reduced airway relaxability.
• The airway dysfunction observed in MS patients shares similarities with that seen in bronchial asthma.
• These findings suggest potential common pathophysiological mechanisms affecting airway function in both conditions.