| Your heart beats 100,000 times a day. It may never miss a beat. But what happens when it does, and the heart rhythm is disturbed?���. What makes the heart beat? Your heart is made of muscle and normally beats regularly around seventy times each minute, but can accelerate and decelerate depending on your level of activity, emotion and arousal. When taking exercise, the heart beats harder and faster to pump more blood to meet the demand of the working muscles. Pumping of the heart is controlled by the electrical activity that flows rhythmically through the muscle of the heart, causing it to contract. What disturbs the heart beat? When the electrical activity of the heart is disturbed, the resulting extra or missed beats cause an abnormal rhythm, or arrhythmia, of the heart. Extra beats may occur in continuous rapid runs which may last for just a few seconds or up to several hours incessantly. Depending on the site of the abnormally irritable bit of heart muscle that is firing off erratically and acting as the source of the electrical disturbance, the particular arrhythmia may be regular or irregular and may be completely benign or potentially life threatening. Atrial fibrillation, for example, is the name given to the commonest heart rhythm disturbance which occurs in about 1 in 10 of the over 70s, and which results from chaotic electrical activity originating in the atria, the small collecting chambers at the top of the heart. Many with this totally irregular rhythm disturbance are not even aware of it, and the heart may be otherwise normal and continue to function well as a pump. Ventricular fibrillation, on the other hand, is similarly chaotic electrical activity, but arising in the ventricles, the large pumping chambers of the heart, making the heart �wriggle� ineffectively instead of pumping. This rhythm disturbance, which fortunately tends to occur only in otherwise diseased hearts, is the principal cause of sudden death, killing about 100,000 people each year in UK (~400,000 in USA). The other types of arrhythmia all cause different levels of awareness and potential threat to the affected person. What does a disturbed heart beat feel like? If you are aware of having an arrhythmia, the usual symptom is the feeling of the heart beating abnormally within the chest, so called palpitations. This may be associated with some chest tightness and shortness of breath, dizziness and even possible collapse with loss of consciousness. On experiencing such symptoms, medical advice should be sought. How will doctors investigate symptoms suggesting disturbed heart beat? An electrical recording of the heart through patches stuck to the skin (an ECG) during the arrhythmia is key to making the diagnosis. An interested doctor will investigate further with tests such as an ultrasound scan of the heart (echocardiogram), a continuous 24-hour electrical recording of the heart by a machine mounted on a belt, and possibly other special X-ray investigations such as a coronary angiogram. How will doctors treat a disturbed heart beat? Treatment is dependent on the type and location of the source of the arrhythmia, and the level of symptoms and threat to life. A number of potential treatment options include drugs, implantable devices such as pacemakers that keep the heart beating in a reguilar and orderly fashion, or possible cure by localised treatment of the irritable source of the arrhythmia by passing fine wires from an area locally anaesthetised at the top of the leg, into the heart and steering one of the wires under x-ray vision to treat the target. Treatment should be at a specialist centre that has particular interest in heart rhythm disturbances, and has the full range of options and expertise. |