Comparison Of Head-Chest Lead And Routine Lead ECGs In Normal, Right Ventricular Pacing And Myocardial Necrosis New Zealand Rabbits

Objective: To observe the difference of ECGs in New Zealand rabbits in the situation of normal .right ventricular pacing and myocardial necrosis recorded by Head-Chest lead and Routine leads. We summarize their changes and explore their mechanism .Methods: 1. After successful anaesthesia, the thorax of the rabbit was opened. A self-made pacing lead of endocardium was inserted via right ventricular tip to pace the right ventricle. 2. A self-made double deck cannula was used to attach on the anterior wall of left or right ventricle. Some pure ice acetic acid were injected into the anterior wall to make a regional myocardial necrosis. 3.We use the ML 2000 ECG instrument in whole synchronization of 24 leads (made in Cardiac Research Center of The First Military Medical University) to record two different kinds of ECGs and to analyze the results in normaK right ventricular pacing or myocardial necrosis rabbits.Result: 1. In normal rabbits ,the amplitude of the wave P, R, T, S recorded by Head Chest leads are larger than those recorded by Routin leads, but the quantities of wave Q in the former are less than those in the latter. In left or right ventricle myocardial necrosis rabbits ,the amplitude of the wave R and S of Head Chest leads are larger than those of Routin leads 2.The amplitude of the wave R and S of Head Chest leads are larger than those of Routin leads before right ventricle pacing . The amplitude of the Q wave of Head Chest leads are larger than those of Routin leads in right ventricle pacing rabbits,The amplitude of the most of wave R of Head Chest leads are less than those of Routin leads at the same time.3. The most of left ventricular myocardial necrosis are subepicardium necrosis which is limited in the half of the ventricular wall. The amounts of leads with necrosis wave Q recorded by Head Chest leads are less than those recorded by Routin leads.The former accord with pathology examination.4. The most of right ventricular myocardial necrosis are penetrated necrosis.The waves in ECGs of Head Chest leads can be seen clearly and regularly,but no wave Q can be seen at the same time. The waves recorded by Routin leads in right chest are small and unstable and wave Q can be seen in some leads . S.The similar changes of the ST segment elevation and wave R decrease in the two kinds of ECGs at both of ventricle necrosis rabbits are observeded. The extents of the ST segment elevation and wave R decrease in Head Chest leads are larger than those in Routin leads.6. In different condition ,wave Q in two differdnt kinds of ECGs did not appear at same time.Conclusion:1.The amplitude of the postive waves recorded by Head Chest leads are larger than those recorded by Routin leads in normal and myocardial necrosis rabbits. 2. The amplitude of the wave Q of Head Chest leads are larger than those of Routin leads in right ventricle pacing rabbits . The amplitude of the most of wave R recorded by Head Chest leads arelarger than those recorded by Routin leads at the same time which may be caused by the decrease of electricity potential in the reference point. 3. In the left ventricular subepicardium necrosis rabbits ,the amounts of necrosis wave Q recorded by Head Chest leads are less than those recorded by Routin leads.The former accords with pathology examination. Head Chest leads indicate a more limited necrosis region. 4.The amounts of necrosis waves Q of Head Chest leads are less than those of Routin leads in right ventricle penetrated necrosis rabbits. It may be related to electricity potential of the ventricle interval.5. The extents of the ST segment elevation and R wave decrease recorded by Head Chest leads at both ventricular necrosis are larger than those recorded by Routin leads , which is benefit for identifying myocardial necrosis.6 In different condition ,wave Q in two differdnt kinds of ECGs did not appear at same time,which indicate different causes to produce different wave Q .