Heart Diseases and treatments

Important diseases of the heart include:

• Coronary heart disease is the lack of oxygen supply to the heart muscle; it can cause severe pain and discomfort known as Angina.
• A heart attack occurs when heart muscle cells die because blood circulation to a part of the heart is interrupted.
• Congestive heart failure is the gradual loss of pumping power of the heart.
• Cardiac arrhythmia is an irregularity in the heartbeat. It is sometimes treated by implanting an artificial pacemaker
• Congenital heart defects.

If a coronary artery is blocked or narrowed, the problem spot can be bypassed with coronary artery bypass surgery or it can be widened with angioplasty.

Beta blockers are drugs that lower the heart rate and blood pressure and reduce the heart's oxygen requirements.

See also: Cardiology diagnostic tests and procedures

Interesting Extras which are not in the syllabus

First Aid

See cardiac arrest for emergencies involving the heart

If a person is encountered in cardiac arrest (no heartbeat), cardio-pulmonary resuscitation (i.e., CPR) should be started.

The hearts of other animals

Structure

The structure of the heart of other mammals is quite similar to that of humans, with four chambers. Birds also have a four-chambered heart, however it is thought that this evolved independently of that of mammals. Amphibians have a three-chambered heart. Reptilia also have a three-chambered heart, except from crocodylians, which have four. Fish have a single circulation system and a heart with two chambers. The hearts of arthropods and mollusks have a single chamber.

Heartbeat

Smaller animals have faster heartbeat. This is evident within a species as well, as the young beat their hearts faster than the adults. Gray Whale beats 9 times per minute, Harbour Seal 10 when diving, 140 when on land, elephant 25, human 70, sparrow 500, shrew 600, and hummingbird 1,200 when hovering.

The earthworm has a series of multiple primitive hearts.