The rhythm of the heart is dictated by a fascinating electrical, chemical and muscular timekeeping mechanism. This too can go wrong, producing disorders of rhythm or arrhythmias. The pathways along which the signal from the pacemaker cells is sent must be kept open and clear, since otherwise the message may become garbled. If the route is diseased this is exactly what happens: the muscle cells receive instructions to beat either too quickly (tachycardia) or too slowly (bradycardia). In addition, irregularities such as extra beats and atrial fibrillation can occur. Some can be controlled by a regime of drugs, while others benefit from an artificial pacemaker – still others can be prevented altogether.
If, for some reason, the sino-atrial node fails, any other part of the heart can take over its function and keep the heart contracting – albeit at a slower rate. This is seen dramatically in a condition called atrio-ventricular block where, although the heartbeat originates normally in the right atrium, it cannot be conducted down the Bundle of His and so the ventricles produce their own ‘node’. The condition stabilizes with the atria beating at their usual 60 to 70 beats per minute and the ventricles beating at a much slower rate, say 40 to 50 beats per minute. Since the ventricular contractions produce the pulse which is felt at the wrist or neck, this condition can be detected by a slowing of the pulse-rate. If the slowing is severe enough to cause symptoms such as blackouts, the ventricles will require help to speed them up a little, and a pacemaker will probably be inserted.
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The absence of symptoms is one of the major problems in identifying high blood pressure and getting treatment under way. The condition offers no warnings. It works its damage slowly and quietly while you feel fine.
Many hypertensive people don’t realize anything is wrong with them, and all too often, the first indication of trouble is a stroke or heart attack that might have been prevented had the condition been diagnosed and treated. United States statistics show the highest death rate from these ailments, with about 42 deaths per 100,000 population. The figure is growing.
Symptoms of trouble are not reliable clues. Headaches may be caused by hypertension, or they may simply indicate the need for new glasses. There may be dizziness, fatigue, heart palpitations or flushing of the face. But the only certain, typical change is in the blood pressure itself.
Headaches are the most common incapacitating symptom. They often are present on waking from sleep, but they may occur at any time of day. They do not signify that a hemorrhage in the brain is in the making; nor do they indicate that the blood pressure is exceptionally high. It may be exceptionally low! But consistent headaches are considered clues to increased blood pressure.
Dizziness, or lightheadedness, accompanies a feeling of fullness in the head and tightness over the scalp, and may signal hypertension. Numbness and tingling in the arms and fingers are also associated with elevated blood pressure. Vertigo, a sensation that the world is moving about you, or that you are moving in space, is a more definite symptom. These are warning conditions.
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HOW DOES HIGH BLOOD CHOLESTEROL AFFECT ME?
High blood cholesterol is one of the three major risk factors for coronary artery disease (the other two being cigarette smoking and high blood pressure). High blood cholesterol can significantly increase the risk of your having a heart attack. Fortunately, all these risk factors are modifiable. You can take steps to lower your cholesterol levels and thereby lower your risk for coronary heart disease.
WHO SHOULD HAVE BLOOD CHOLESTEROL MEASURED AND WHEN?
Everyone should have their blood cholesterol checked at least once after the age of 30. If your cholesterol is ‘desirable’ it can be checked every 5 years. If it is borderline it should be checked every 2-3 years. But if your cholesterol is high, or you have some other risk factors for heart disease, you will need to have it checked more frequently.
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CONTROL YOUR CHOLESTEROL: HOW DOES HIGH BLOOD CHOLESTEROL AFFECT ME? WHO SHOULD HAVE BLOOD CHOLESTEROL MEASURED AND WHEN?HOW DOES HIGH BLOOD CHOLESTEROL AFFECT ME?High blood cholesterol is one of the three major risk factors for coronary artery disease (the other two being cigarette smoking and high blood pressure). High blood cholesterol can significantly increase the risk of your having a heart attack. Fortunately, all these risk factors are modifiable. You can take steps to lower your cholesterol levels and thereby lower your risk for coronary heart disease.WHO SHOULD HAVE BLOOD CHOLESTEROL MEASURED AND WHEN?Everyone should have their blood cholesterol checked at least once after the age of 30. If your cholesterol is ‘desirable’ it can be checked every 5 years. If it is borderline it should be checked every 2-3 years. But if your cholesterol is high, or you have some other risk factors for heart disease, you will need to have it checked more frequently.*79\254\8*