Premature atrial contraction (premature atrial beat / complex): ECG & clinical implications
Premature atrial contraction (premature atrial beat / complex) It is caused by an impulse discharged from an ectopic focus which may be located anywhere in the atria. In most cases, the premature atrial impulse is conducted to the ventricles, which results in ventricular depolarization and the appearance of a QRS complex . Because the impulse originates in the atria it will pass through the bundle of His and thereby produce a normal QRS complex (provided that intraventricular conduction is normal). A premature atrial contraction induces a delay to the next sinus beat (the RR interval is prolonged after a premature beat). This yields more time to fill the ventricles with blood (increased ventricular filling). Persons with premature beats might perceive this as palpitations, because of the stronger ventricular contractions caused by the increased filling. Frequent premature beats can also be perceived as having an irregular heart rhythm (despite the underlying sinus rhythm ). Although atrial…
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Cuộc đời thì ngắn, mà nghề thì miên man;cơn bệnh phập phù;kinh nghiệm hiểm nguy, còn quyết định thì thật khó.Người thầy thuốc không phải chỉ chuẩn bị để tự mình làm đúng, mà còn khiến cho bệnh nhân, người đi theo và các yếu tố xung quanh hợp tác hài…