In vivo experiments of screwing the electrode of canine hearts and assigning external excitation on the lead-myocardium interface was carried out to evaluate the lead/myocardium adherence safety.The electrode is specially designed to host a measurement unit of strain gauges. We obtained the lead/heart interactions data from 12 dogs under natural heart beating and beating with external excitations.The data recorded from the acute phase and the chronic phase of pulling out pacing leads were compared with each other.The electrode/heart interaction is caused by the heart beat and influenced by the lung breath.This process induced tolerable damage to the lead or myocardium.The interaction decreases as the frequency of external excitations increases.The lead is more likely to be detached from myocardium under higher excitation frequency.At the same implanting sites,safer pacing lead/myocardium attachment can be realized in the chronic tests than in the acute tests. In vivo experiments of screwing the electrode of canine hearts and assigning external excitation on the lead-myocardium interface was carried out to evaluate the lead / myocardium adherence safety. The electrode is specially designed to host a measurement unit of strain gauges. We obtained the lead / heart interactions data from 12 dogs under natural heart beating and beating with external excitations. The data recorded from the acute phase and the chronic phase of pulling out pacing leads were compared with each other. The electrode / heart interaction is caused by the heart beat and influenced by the lung breath. This process induced tolerable damage to the lead or myocardium. The interaction decreases as the frequency of external excitations increases. The lead is more likely to be detached from the myocardium under higher excitation frequency. At the same implanting sites, safer pacing lead / myocardium attachment can be realized in the chronic tests than in the acute tests.