Lung Function Impairment Tied to Increased Risk of Heart Failure

Introduction

The impairment of lung function that is observed during rest or physical activity can affect the heart due to various underlying causes. Respiratory failure can cause an increase in blood pressure of the pulmonary (lung) artery, leading to pulmonary hypertension. This directly affects the capacity of the heart and causes overload on the right side of the heart. Thereby, the pumping ability of the heart is reduced, resulting in oxygen deficiency. Also, the body tries to produce more red blood cells to compensate for the oxygen deficiency to improve oxygen diffusion to various organs. This condition is called erythrocytosis. An increase in red blood cells produces arteriosclerosis in the pulmonary blood vessels leading to loss of elasticity and respiratory disturbance.

What Are the Causes of Lung Function Impairment Tied to Increased Risk of Heart Failure?

The lung metabolism varies depending on the severity of heart failure. The causes are as follows:

• Restrictive Lung Disease - The stiffness of the lungs and congestion of interstitial space influences the cardiac output and shows a restrictive respiratory pattern. Also, the excess fiber deposition in the lungs makes the condition worse.

• Pleural Effusion - An increase in lung fluids along with enlargement of the heart causes cardiopulmonary issues. The failure of the lungs to clear the fluids causes interstitial edema. This leads to chronic heart failure. However, this condition is reversible after treatment.

• Chronic Obstructive Lung Disease - Lung damage that occurs due to increased smoking causes emphysema. It also destroys the walls of air sacs, thereby inducing lung impairment. The airway inflammation produces mucus and causes bronchitis. It decreases the volume of blood pumped per minute by the lungs.

• Pulmonary Hypertension - The narrowing or damage of blood vessels increases pulmonary arterial hypertension in the lungs. The extra effort produced by cardiac muscle makes the heart weak and causes cardiac failure.

What Are the Symptoms Associated With Lung Dysfunction and Heart Failure?

The symptoms are co-related to lung dysfunction and heart failure that include:

• Breathing Difficulty - The abnormality in lung capillaries and parenchymal tissue of the lungs causes breathing problems like shortness of breath.

• Rapid Respiratory Rate - An individual with both systemic failures has an exaggerated respiratory rate.

• Fatigue - There is an increased effort exhibited by the breathing muscles causing fatigue in the patient.

• Breathlessness - The quality of life is severely affected due to reduced inspiration and expiration.

• Dizziness - A negative respiratory mechanism causes dizziness.

• Cough - The lung function impairment due to smoking induces cough with sputum production.

• Wheezing (High Pitched Noise) - The severe respiratory illness causes wheezing frequently.

• Chest Pain - A restrictive lung function causes tightness in the chest during exertion.

How Is the Correlation Between Lung Dysfunction and Heart Failure Diagnosed Using Different Diagnostic Procedures?

The diagnostic procedures are as follows:

• Chest X-Ray - Chest X-rays are helpful in determining the size of the lungs and heart in a single radiographic image. The increased size of the heart is measured using the cardiothoracic index, which is done with the help of a radiographic image. The change in thoracic (rib space) volume can also be observed in the X-rays.

• Lung Function Test - The carbon dioxide is not eliminated due to reduced ventilatory deficiency. It is diagnosed using a lung function test. Lung dysfunction causes an increase in tidal volume during exercise and also signifies heart failure. The diffusion mechanism, particularly carbon monoxide in the lung, is measured to evaluate cardiac function. A hemoglobin resistance to carbon monoxide is also calculated using this test.

• Cardiopulmonary Exercise Test - It is the gold standard test for cardiac patients. An altered respiratory mechanism causes impairment in the alveolar gas exchange between the capillaries and the lung parenchyma. This makes the individual intolerant to exercise. There is a frequent reduction in ventilation during exercise, which causes an increase in carbon dioxide and remains a specific marker that indicates pulmonary abnormalities.

• Echocardiogram (ECG) - An ultrasound scan that is used by cardiologists to observe the heart chambers, heart valves, and pumping ability of the heart is called an ECG. The monitor displays the waves. It is used to determine the severity of cardiac disease.

• Enzyme Test - There is an increase in brain natriuretic peptide (BNP) hormone for patients with lung impairment and heart failure. The alterations in the cardiac enzymes present in the blood help to diagnose heart attack at an earlier stage.

What Are the Various Types of Treatment Methods for the Recovery of Lung Function and Cardiac Function?

• Medications - Heart failure therapy should focus on improving the efficiency of heart function. So ACE (angiotensin-converting enzyme) inhibitors are used to improve the diffusion in the lungs and heart function. Beta-blockers are used to treat the symptoms of heart failure. Carvedilol is commonly used in patients with dyspnea (shortness of breath). Bronchodilators are the main therapy for opening the airways. Medicines are provided through an intravenous (IV) route to reduce heart strain. Anticoagulants are prescribed along with other medications to ease the blood flow.

• Supplemental Oxygen Therapy - Oxygen is necessary for improving heart functioning, So an artificial supply of oxygen is given. This is machine-assisted breathing to support life. Breathing tubes are provided for patients in case of severe restrictive lung disease.

• Surgery - The pulmonologist recommends lung transplantation to increase life expectancy, especially for younger patients. There are several factors associated with replacing the lungs, like the rejection of transplantation organs, proper follow-up with medications and diagnostic procedures, infections, and other systemic conditions. However, immunosuppressants are prescribed for a lifetime to prevent rejection. A surgical procedure corrects the septal defect in cardiac dysfunction. It helps in relieving the pressure present in heart chambers. However, there are complications associated with these surgeries.

Conclusion

The patient with both lung dysfunction and heart failure has polycythemia, a condition in which there is an abnormal increase in hemoglobin. This results in circulatory failure. An increase in heart size greatly impacts pulmonary function. The oxygen diffusion varies depending on the position of the body. It becomes worse, especially when the patient is lying on the lateral side. It commonly affects middle-aged men, who are unaware of the symptoms unless there is an emergency condition. It is the top most common cause of death. Chronic obstructive lung disease (COPD) with cardiac failure occurs in individuals with a family history. Each patient differs because some patients have mild lung disease with severe cardiac failure. In comparison, others have severe lung impairment with mild heart dysfunctions.