<b id="quote">quote:</b id="quote"><table border="0" id="quote"><tr id="quote"><td class="quote" id="quote">Abnormal heart rhythm i.e. Tachycardia
Occasionally, electrical signals arise in areas of the heart away from the normal pacemaker (sino-atrial node). This may be in the atria (atrial ectopic beats or atrial fibrillation), atrioventricular node (AV nodal tachycardia) or ventricles (ventricular ectopic beats of ventricular tachycardia). They produce a heartbeat which comes earlier than expected that is called an ectopic beat. This alone is not dangerous and the effect on the heart is minimal.
Alternatively, a fast heartbeat that is persistent is called tachycardia. This is usually caused by abnormal activation of the heart in what is called a 're-entrant circuit'. If the heart rate is increased to 150-200 beats per minute, the heart tends not to work as effectively and the patient may feel unwell. The experience of palpitations in this form can often be frightening to the individual concerned.
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