Coughing is basically an instinctive reflex action or a defense mechanism that our body employs for expelling the foreign substances that may be irritating the airways. When the sensory receptors in the windpipe and the airways detect irritants or any foreign particles, the diaphragm and the muscles located within the ribs contract. This is followed by inhalation of air. When the inhaled air moves into the lungs, the epiglottis (the cartilage flap that covers the windpipe) and the larynx close so as to trap the inhaled air within the lungs. The abdominal muscles and the innermost intercostal muscles contract. As a result, pressure in the lungs increase. The vocal cords relax and the larynx opens. This is followed by the expulsion of air from the lungs at a high velocity. The air that is forced out clears the foreign particles or irritants from the airways. Though coughing is not really a disease in itself, chronic cough is often a sign of respiratory tract infections. There may be a connection between cough and heart diseases. Let's find out if there is a cause-and-effect relationship between the two.
Can Coughing be Caused due to a Heart Disease?
More often than not, persistent cough is a symptom of upper or lower respiratory tract infections. Before the lungs can actually carry out the exchange of oxygen and carbon dioxide, the air that we inhale passes through the nasal passages, pharynx, larynx, windpipe and the bronchial tubes. These respiratory organs could get inflamed if we inhale irritants such as dust, chemicals, fumes or disease causing microbes. When that happens, the irritants are expelled out with this natural reflex action.
So, what does coughing have to do with the functioning of the heart? Well, the organ systems of the body work collectively. The respiratory system does work in tandem with the circulatory system, of which the heart is definitely a key organ. The heart is the pumping organ that supplies deoxygenated blood to the lungs. The oxygen-enriched blood from the lungs is then carried by the blood vessels to various parts of the body. If the heart's pumping capacity is affected by any ailment, the lungs may become congested. Fluid buildup in the lungs and the heart may give rise to symptoms such as cough, shortness of breath or wheezing.
Coughing and Heart Failure
To understand how cough and heart conditions may be linked, one must first understand how the heart works. The human heart is divided into four chambers. The upper and lower chambers on the right and left side of the heart are referred to as the right atrium, right ventricle, left atrium and the left ventricle. The left atrium receives the oxygen-rich blood through the pulmonary veins. This is followed by opening of the mitral valve. When the mitral valve opens, blood is carried into the left ventricle. It is through the left ventricle that the oxygenated blood is carried to various parts of the body. On the other hand, deoxygenated blood is carried by the inferior vena cava and superior vena cava to the right atrium. The tricuspid valve opens to facilitate the passage of blood into the right ventricle. The pulmonary artery carries the blood into the lungs, wherein it gets oxygenated and is again carried to the left side of the heart. When the chambers of the heart fail to pump the blood properly, one is said to suffer from a congestive heart failure.
Weakening of the myocardium (heart muscle) due to coronary artery disease is one of the most common causes of congestive heart failure. Coronary heart disease is characterized by limited flow of blood to the heart due to the accumulation of arterial plaque. This causes the heart muscle to weaken, thereby increasing the risk of congestive heart failure. Thickening of the heart muscle due to high blood pressure can also cause the same effect. Coronary artery disease also increases the risk of a heart attack. A heart attack is a life-threatening condition wherein the blockage of a coronary artery causes damage to a part of the heart muscle. Shortness of breath, persistent cough, chest pain, wheezing and edema are the characteristic symptoms of congestive heart failure.
Left-sided heart failure is a type of congestive heart failure in which pulmonary congestion occurs due to the inability of the left ventricle to pump blood properly. This causes blood to flow back into the left atrium. Blood is then carried by the pulmonary veins into the lungs. This causes fluid buildup in the lungs. When the alveolar sacs get filled with fluid, lung function is adversely affected. Cough, wheezing and shortness of breath are the common symptoms of pulmonary congestion. The use of ACE inhibitors, which are a class of drugs that are used for the treatment of hypertension and congestive heart failure, can also cause persistent cough.
Though cough is one of the common symptoms of respiratory tract infections, at times it may be caused by congestive heart failure. Those who do suffer from persistent cough along with the other aforementioned cardiac symptoms must therefore get a thorough medical checkup done.
Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.