Your heart is a powerful pump that moves blood around the body via blood vessels, in order to deliver oxygen and nutrients to the cells.5 As with all muscles in the body the heart muscle needs a constant supply of oxygen and nutrients in order to function properly, which is supplied via blood flowing through the coronary arteries.1 Coronary arteries branch off from the aorta - the main artery that carries oxygen rich blood away from the heart to the rest of the body.1
If one of the coronary arteries becomes constricted due to a clot or a spasm, blood stops flowing to a section of the heart. This is known as a heart attack.2 If this blood supply to the heart isn’t quickly resumed the section of the heart muscle that’s been cut off from oxygen becomes damaged and begins to die. 4 Depending on the size of the blocked coronary artery, the damage that occurs can be more or less significant: if it’s one of the main coronary arteries, a large part of the heart muscle will be damaged, while if only a smaller artery is blocked, less of the heart muscle will be affected.1
The part of the heart muscle that’s been damaged is then replaced by scar tissue, which itself can cause severe long-term complications. 4
Heart attacks usually occur as a result of a pre-existing condition such as heart failure or coronary heart disease where there is a build up of fatty deposits on the walls of your coronary arteries. These fatty deposits are called ‘atheroma’.1
When a heart attack happens, the heart rhythm becomes disturbed. In the most serious cases, the electrical impulses that form the heartbeat become so erratic that the heart stops beating altogether, and quivers or ‘fibrillates’ instead. This condition is known as ventricular fibrillation, and results in cardiac arrest, in which blood circulation around the body stops abruptly. When this happens, the person loses consciousness and stops breathing almost immediately.5
In many cases, if ventricular fibrillation is treated quickly enough, the heart can be restored to produce a regular heartbeat again. This is done via a large electric shock administered through the chest wall by a device called a defibrillator. If this process is successful the heart will beat normally afterwards, and the person will start breathing again.5
If a person has a cardiac arrest they will lose consciousness and there are also no other signs of life such as breathing.
This is the most extreme emergency. Unless someone starts cardiopulmonary resuscitation (CPR) within three to four minutes, the person may suffer permanent damage to the brain and other organs. CPR means:
© 2007 LES LABORATOIRES SERVIER, an incorporated company of SERVIER. All Rights Reserved - Terms of Use
SERVIER does not sell its products over the Internet - More information
Last Updated 15/06/2011 12:14:14
Best viewed in Internet Explorer 6.0 or later, at 1024x768 resolution.
