ng cells(spotaneous AP, diastolic depolarization) ? Automaticity increases from high to low as follows: ? Physiological status : SN 、 AVN 、 HIS 、 Purkinje ? pathological : diseased myocardial and conductive tissue, etc. Property of normal rhythm ? Impulse from SN ? Heart rate is within 60 ~ 100/min ? Regular rhythm , P interval < 0.12s ? PR interval is between 0.12 ~ 0.20s , plex duration < 0.10s ? Frontal axis within -30 ~ 90 ° It is considered as arrhythmia if any item above is not matched Classification of cardiac arrhythmias ? Classified on property of electrical activity ? Abnormality of impulse and conduction ? Classified on heart rate, rapid or slow ? Rapid or slow arrhythmias ? Classified on clinical manifestation, mild or sever ? Fatal or nonfatal ? High risk or low risk
全文预览
