The heart is a muscular organ located behind the breastbone, slightly to the left. It is about the size of a fist. It is divided into four chambers:
The heart receives blood from various parts of the body through veins and pumps blood to the whole body through arteries. Blood flow through the heart is unidirectional: atria à ventricles à pulmonary artery and aorta. Two valves (AV valves) connect the atria to the ventricles. They prevent backflow of blood from ventricles to the atria. Oxygen-deficient blood enters the right atrium and passes to the right ventricle. The heart then pumps it into the lungs where it receives oxygen. Oxygenated-rich blood then returns to the left atrium and passes to the left ventricle. The heart pumps out this oxygen-rich blood to the whole body. Blood to the heart is supplied by coronary arteries.
Contraction and relaxation of heart muscles is initiated and coordinated by the electrical conduction system of the heart.At rest, the heart contracts in the ranges from 60-100 beats per minute.
There are more than 60 different forms of heart disease. The most common ones are:
• Coronary artery disease – affects or damages arteries that supply blood to the heart
• Angina pectoris – pain, tightness and discomfort in the chest region when the heart does not receive enough blood due to narrowed coronary arteries
• Cardiomyopathy – weakened heart muscle due to thickening and/or stiffening
• Congenital heart disease – defect present in the heart at the time of birth
• Congestive heart failure – heart is unable to pump blood throughout the body effectively
• Arrhythmia – irregular heartbeat due to improper conduction of electric impulses in the heart
• Myocardial infarction (heart attack): death of part of the heart muscle due to blocked blood supply
• Myocarditis and pericarditis: inflammation of heart tissue due to infection
• Heart valve disease – narrowing of heart valve or prevention of full closure of valve
Diseases of the heart are diagnosed with listening to the heart-sounds with a stethoscope, blood tests, X-ray, ECG, echocardiogram, stress test, catheterization, ultrasound, etc.
Lifestyle changes, diet and medication form a major part of treatment of heart disease. Other options are angioplasty, stenting, ablation, percutaneous coronary intervention, defibrillation, pacemaker and surgical interventions like bypass surgery, open heart surgery, heart transplant, etc.