Quick version
The heart is a muscular organ that pumps blood through the body's circulatory system.
- Consists of four chambers: two atria and two ventricles
- Drives blood through two systems: the pulmonary and pulmonary circulation
- Controlled by an electrical signal system that regulates the heart's rhythm
- Common diseases include heart attack and heart failure
- Symptoms of heart problems can include chest pain, shortness of breath, and fatigue
- Regular exercise and a healthy diet strengthen heart function
What is the heart?
The heart is a muscular organ and is about the size of a clenched fist. It is located slightly to the left of the chest behind the breastbone. The heart consists of four chambers – two atria and two ventricles, which pump blood to the lungs and then out into the body. The heart works around the clock and is controlled by electrical signals that cause the heart muscle to contract in a regular pattern.
Anatomy of the heart
The four main parts of the heart are the right atrium, right ventricle, left atrium and left ventricle. There are also four valves that control blood flow in the right direction – these are called the tricuspid valve, the pulmonary valve, the mitral valve and the aortic valve.
How the heart pumps blood
The heart works like two pumps. The right side pumps oxygen-poor blood to the lungs, where the blood is oxygenated. The left side then pumps the oxygen-rich blood out to the rest of the body via the aorta.
Electrical signals and heart rhythm
The heart's rhythm is controlled by the sinus node, a natural pacemaker that sends electrical signals. These signals cause the heart muscle to contract and create the pulse we feel.
The heart's role in blood pressure
When the heart pumps blood, pressure is created in the blood vessels – blood pressure. This is crucial for oxygen and nutrients to reach the body's cells. High blood pressure can strain the heart and cause damage over time.
Common heart diseases and conditions
The heart can be affected by several different diseases and conditions. A heart attack is an acute disruption of blood flow to the heart. Heart failure means that the heart is unable to pump adequately. Atrial fibrillation is a common rhythm disorder that increases the risk of stroke. Vasospasm causes chest pain during exertion. Valves can affect blood flow and require surgery. Congenital heart defects also occur, especially in children.
Examinations and diagnoses
Several methods are used to assess the function of the heart. EKG (electrocardiogram) measures the electrical activity of the heart and can detect rhythm disorders. Ultrasound of the heart (echocardiography) shows the structure and pumping function of the heart. Exercise tests test the heart's capacity during physical exertion. Blood tests such as troponin are used to detect heart attacks. Cardiac catheterization may be done to see the status of the coronary arteries.
The heart and lifestyle
Physical activity, a healthy diet, quitting smoking, and stress management are important for heart health. A healthy lifestyle reduces the risk of heart diseases such as heart attack and heart failure.
Relevant symptoms
- Chest pain or pressure
- Shortness of breath with exertion or at rest
- Irregular heartbeat (arrhythmia)
- Dizziness or fainting
- Fatigue or weakness
- Swelling in the legs or feet
Related conditions and diagnoses
- Heart attack (myocardial infarction)
- Heart failure
- Atrial fibrillation
- High blood pressure (hypertension)
- Vascular spasm(angina pectoris)
- Valvular heart disease