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Purpose: The purpose of this project is to observe the different parts of the (right ventricular apex, left ventricular posterior wall) absolute refractory period of electrical stimulation to further explore its mechanism of action of cardiac function, normal rabbit cardiac function. Methods: 24 healthy New Zealand white rabbits were randomly divided into three groups: (1) sham-operated group: line thoracotomy, opening of the pericardium, but did not give any part of the stimulus; (2) right ventricular stimulation group: line thoracotomy, children with temporary pacing electrodes sutured to the right ventricular apex, and then give the absolute refractory period of stimulation. Provisions of RS stimulation of the absolute refractory period of stimulation, triggered by the R wave of the ECG in sinus rhythm stimulator issuing absolute refractory period of stimulation, the delay of 30 ms, the the pacing voltage of 2 times the diastolic threshold, pulse width 2ms , lasted 6 hours; (3) the posterior wall of the left ventricular stimulation group, the line thoracotomy, children with temporary pacing electrode sutured to the posterior wall of the left ventricle, then give absolute refractory period stimulation (as above). Left ventricular end-diastolic diameter measurements before and after stimulation (left ventricular end-diastolic dimension, LVEDD), left ventricular end systolic diameter (left ventricular end-systolic dimension, LVESD), ejection fraction (left ventricular ejection fraction, LVEF) values. By double antibody sandwich ABC-ELISA method detected before and after stimulation animal blood B-type natriuretic peptide (BNP) concentrations. Results: BNP results 1.1 between the results before stimulation sham, stimulation of the right ventricular apex, left ventricular posterior wall stimulation group BNP levels between the three groups were not statistically different (P gt; 0.05). Stimulation of the right ventricular apex stimulation group, the posterior wall of the left ventricular stimulation group BNP water on average higher than the sham-operated group, a statistically significant difference (P lt; 0.05), but the stimulation of the right ventricular apex and left ventricular posterior wall stimulation group between BNP levels was no significant difference (P gt; 0.05) 1.2 compare the results before and after stimulation of the sham-operated group BNP level was no significant difference (P gt; 0.05) after stimulation of the right ventricular apex stimulation of the posterior wall of the left ventricular stimulation group BNP water was higher than that stimulate statistically difference (P lt; 0.05) (see Table 1, Fig.1). 2 cardiac ultrasound results 2.1 between the result of the comparison stimuli before and after stimulation with sham operation group, stimulation of the right ventricular apex, left ventricular posterior wall stimulation between the three groups LVEDD, LVESD, LVEF data showed no significant difference (P gt; 0.05). 2.2 compare the results before stimulation and after stimulation with sham operation group, stimulation of the right ventricular apex, left ventricular posterior wall stimulation group were group LVEDD, LVESD, LVEF data were not statistically different (P GT; 0.05) ( See Table2, Fig.2). ARPES Conclusion: The short-term impact on systolic and diastolic function of the normal heart is not obvious, and there is no difference between different parts of the impact, but after stimulation of BNP may be prompted to enhance myocardial contractility, heart function improved.
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