As suggestive as the title seems, “Heart Diseases” is a term given to address any problem related to the heart or the blood vessels that supply blood to the heart (called major arteries or blood vessels). This term is used under the pretext of a common understanding to everyone as – any problem related to the heart.
Cardiovascular Diseases is another term that is often used interchangeably with Heart Diseases. While the former includes any defects related to the major arteries only, the latter covers a wider spectrum of diseases that could be anything related to the heart and blood vessels together.
Atherosclerosis or deposition of fat as plaques in the major blood vessels is the most common cause of Cardiovascular Disease. This deposition of fats interrupts the continuous circulation of blood to the heart to function and thus causes severe complications. Understand Atherosclerosis better with Dr Subramanian Kannan, Senior Endocrinologist and Diabetologist from Narayana Hrudayalaya, Bengaluru as he anecdotes his explanation.
Under the Umbrella of Heart Diseases
Coronary arteries are one of the major arteries that nurture the heart muscles by supplying oxygen and nutrients to them. Thus if these arteries are affected either due to blockage (i.e. Atherosclerosis) or infections, it is classified as a Coronary Artery Disease (CAD). Also, if the heart suddenly stops working or in common called a heart attack, the medical term for it is Myocardial Infarction. This happens when there is a blood clot in the same coronary arteries and blocks blood flow.
The red blood vessels running over the heart are the Coronary arteries that supply blood to the heart muscle
Apart from the issues with the blood vessels of the heart, there could be other complications in the heart itself. If the electrical impulses of the heart that cause the heart to beat are irregular, that by itself is a serious condition call Arrhythmia. There are variations in this condition depending on how fast (Tachycardia), slow (Brachycardia) or irregular (abnormal beats, fibrillation) the beats are.
The third component that holds the most significance is the heart muscle itself, after the blood vessels of the heart and the electrical impulse. Since the heart is entirely a muscle, any defects of the muscle are called Cardiomyopathies (meaning defects of the heart muscle). The usual cause of Cardiomyopathy is a weak heart either due to ageing or any Coronary Artery Disease condition. Here again, there are a few types of cardiomyopathies.
If the muscle is just weak and cannot pump blood because of improper supply of oxygen (mostly because of Coronary Artery Disease), it is called Dilated Cardiomyopathy. If the heart muscle thickens and is not flexible enough to pump blood, it is called Hypertrophic Cardiomyopathy. Due to these conditions and sometimes coupled with Coronary Artery Disease, if the heart fails to pump blood to all parts of the body, it is called Heart Failure.
Conditions of the heart usually occur in adults due to many factors such as an unhealthy diet, lifestyle irregularities and habits such as excessive smoking and alcoholism, etc. All these are environmental or external factors that influence the condition. But, a category of heart diseases called the Congenital Heart Diseases is classified when a newborn has a heart defect. This set of complication is mostly due to inherited factors from either or both the parents. The baby is born with heart defects such as a hole in between two chambers (septal defects), obstruction of blood flow or a condition that causes the improper supply of oxygen to the body (cyanotic heart defects).
A graphic representation of the Human Heart in cross-section
Apart from the above major conditions, there are few other conditions of the heart that are not often fatal. They include conditions of the valves that are present between the upper and lower chambers of the heart and at the origin of major arteries. The pulmonary valve that is at the beginning of the pulmonary artery originating from the ventricle might sometimes cause a condition when it closes very tightly (Pulmonary stenosis) and does not allow blood to flow from the ventricle to atrium. The mitral valve is between the left atrium and left ventricle. Conditions concerning this valve could be the incomplete closure (Mitral valve prolapse) and thus allow the blood to flow backwards (Mitral valve regurgitation) instead of pushing it out of the heart. These mitral valve defects are not life-threatening and usually do not need any treatment, unlike the above-mentioned conditions that require timely attention.
