HEART PROBLEMS
Heart Attack
A heart attack is due to a near complete or total blockage of one or more of the coronary arteries. The blockage results as a result of arteriosclerosis which has generally taken years to develop. The blockage in the lining of a coronary artery ruptures, causing platelets in the blood to adhere to it. This then forms a large clot in the artery past which the blood cannot flow.
There are interchangeable names for a heart attack, such as myocardial infarction, unstable angina and acute coronary syndrome. Myocardial infarction describes the loss of muscle resulting from little or no blood flow to a particular area of the heart muscle. When that specific area of the heart has used up its oxygen supply, it ceases to function. The symptom of this is chest pain ranging from mild discomfort to severe crushing pain. The pain is generally felt in the centre of the chest, which can radiate up the through the jaw and down the left arm. An acute coronary syndrome is a collective term for a heart attack or unstable angina. People with stable angina have a good knowledge of when the angina pain will come on, such as during exercise or walking up a flight of stairs. Unstable angina is generally regarded as angina that was previously stable but has changed recently.
A heart attack is very painful and very serious. It can result in difficulty in breathing, sweating, nausea and vomiting and dizziness. This is a medical emergency, and should result in an emergency call to the ambulance service.
During a heart attack, the heart is still beating, but it is being damaged by the lack of oxygen. The next step following a heart attack is cardiac arrest. As the name implies, cardiac arrest is a complete cessation of heart activity. There are several heart rhythms associated with cardiac arrest. The most common rhythm is called ventricular fibrillation. Approximately 70% of people who suffer a cardiac arrest are in this particular rhythm. In VF, there is no coordinated activity between the filling chambers (the atria) and the pumping chambers (the ventricles). The heart cannot fill adequately and is unable to eject blood out into the aorta. The treatment is by defibrillating the heart using an electric shock to stop the heart momentarily in the hope that the normal pacing system will take control again.