The intervention group will be trained with inspiratory muscle training for 4 weeks. Inspiratory Muscle Training has been designed to enhance respiratory muscle function through targeted exercises, to strengthen the respiratory muscles, ,thereby improving overall respiratory efficiency

The control group will receive standard care

Participants will perform 20 sessions of respiratory muscle strengthening (20 minutes at 30-60% of MIP), using the Threshold Inspiratory Muscle Training device

Diaphragmatic thickness measured by ultrasound is a non-invasive, widely used method to assess diaphragm structure in patients with chronic heart failure. Thickness is measured between the pleural and peritoneal lines at end-expiration and end-inspiration

Dysfunctional breathing refers to abnormal breathing patterns that are often related to the heart's inability to supply blood effectively, affecting respiratory function. Dysfunctional breathing will be assessed with the Hi-Lo breathing test, an observational clinical test used to assess breathing pattern and diaphragm function. The clinician observes and palpates whether the movement is greater under the upper chest hand (Hi) or lower abdomen hand (Lo).The test is scored as "Yes" if upper chest (apical) breathing predominates and "No" if normal diaphragmatic breathing is present.

Functional ability refers to how well patients can perform daily activities and maintain independence despite their cardiac condition. It will be assessed with the 6-Minute Walk Test (6MWT), a simple and effective tool that evaluates the maximum distance a person can walk in six minutes. The outcome reflects the integrated response of the cardiovascular system mainly, and exercise tolerance.

It is a measure of the strength of inspiratory muscles, primarily the diaphragm. MIP is a reliable and reproducible measure that does not depend on the patient's respiratory flow.