Assessment of Exercise Capacity, Muscle Oxygenation and Aortic Stiffness in Patients With Mitral Stenosis

Overview

Heart valve diseases are the most common cause of mortality and morbidity after coronary artery disease, hypertension, and heart failure. In patients with mitral stenosis, the narrowed valve restricts blood flow, causing symptoms such as shortness of breath, fatigue, exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea. These patients may experience decreased exercise capacity and physical activity levels, deterioration in quality of life, and deterioration in respiratory function. When reviewing the literature, we see that the study groups evaluating these factors are generally not homogeneous, and most studies conducted in patients with mitral stenosis evaluate patients who have undergone percutaneous mitral balloon valvuloplasty.

In mitral valve stenosis, blood flow from the left atrium to the left ventricle is mechanically restricted, resulting in increased pressure in the left atrium, pulmonary vascular bed, and right chambers of the heart. The narrowed mitral valve obstructs the flow of blood from the lungs to the heart, causing shortness of breath in patients. Increased blood volume in the left atrium may cause palpitations. Other symptoms include fatigue, exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, chest pain, and dizziness. Patients with mitral stenosis are expected to have decreased exercise capacity due to restrictive lung function, chronotropic insufficiency, limited stroke volume, and the effects of peripheral factors. Studies evaluating the exercise capacity of patients who have undergone surgery for mitral stenosis are limited. After cardiac surgery, oxygen saturation decreases in the acute period, and hemodynamic and systemic oxygenation are often impaired. It has been suggested that muscle deoxygenation may also occur in patients with mitral stenosis due to these reasons. Studies investigating skeletal muscle oxygenation after mitral valve surgery are limited in the literature. While surgery for heart valve lesions improves cardiac function, changes in the thoracic compartment are major causes of mortality and morbidity. These changes reduce cardiorespiratory capacity, leading to physical inactivity, loss of muscle strength, and loss of fitness in patients. Inspiratory muscle performance is impaired in patients who have undergone valve replacement surgery. Better inspiratory muscle performance in these patients is associated with better physical function. This relationship between respiratory muscle strength and exercise capacity demonstrates the importance of assessing respiratory muscle strength. Mitral valve stenosis is associated with impaired aortic stiffness. In patients with heart failure, aortic stiffening plays a role in hemodynamic deterioration due to its adverse effect on left ventricular function and coronary artery perfusion. In conclusion, aortic stiffness has been shown to exacerbate the disease through multiple mechanisms. Inadequate physical activity after heart valve surgery is associated with a higher mortality rate, while adequate physical activity prevents cardiovascular events and reduces mortality in the long term. Physical activity is an important prognostic factor in patients who have undergone cardiac surgery. The quality of life of patients improves after heart valve surgery. The extent of improvement may vary depending on the surgical method used. The primary objective of the study is to compare exercise capacity, muscle oxygenation, aortic stiffness, and quality of life in patients who have undergone surgery for mitral stenosis with those in healthy individuals. The secondary objective of the study is to compare respiratory muscle strength and endurance, pulmonary function, and physical activity levels in patients who have undergone surgery for mitral stenosis with those in healthy individuals. Primary outcomes are exercise capacity, muscle oxygenation, aortic stiffness, and quality of life. Secondary outcomes are respiratory muscle strength, respiratory muscle endurance, pulmonary function and physical activity level.