Monophasic action potentials were reproducibly recorded from epicardial and endocardial locations with no significant differences in waveform morphology or duration between in situ and in vitro models.
Can monophasic action potentials be reproducibly recorded from multiple anatomic locations in situ and in vitro in a swine heart model?
The study validates the use of the Visible Heart in vitro model for reproducibly recording cardiac monophasic action potentials, supporting its utility for preclinical testing of cardiac mapping catheters.
p-value: p=ns
OBJECTIVE: For cardiac arrhythmia mapping and ablation procedures, the ability to record focal cardiac action potentials could aid in precisely identifying lesions, scarred tissue, and/or arrhythmic foci. Our study objective was to validate the electrophysiologic properties of a routinely employed large mammalian in vitro working heart model. METHODS: Monophasic action potentials (MAPs) were recorded from 18 swine hearts during viable hemodynamic function both in situ (postmedian sternotomy) and in vitro (using Visible Heart methodologies). We placed specially designed mapping catheters in epicardial and endocardial locations. High-quality MAP signals were recorded for up to 2 h, and MATLAB was utilized to evaluate relative duration and temporal/regional changes in waveform morphology. RESULTS: MAPs were reproducibly recorded from both epicardial and endocardial locations in situ and in vitro. No significant differences were noted in right atrial endocardial, right ventricular endocardial, right ventricular epicardial, or left atrial epicardial waveforms, when baseline recordings were compared to all other in situ and in vitro time points. Furthermore, MAP duration between right ventricular endocardial and epicardial waveforms was not significantly different, in situ or in vitro. CONCLUSION: The use of in vitro models like the Visible Heart is considered invaluable for the study of cardiac arrhythmias, the development of novel therapies, and/or preclinical testing of future cardiac mapping catheters and systems. SIGNIFICANCE: Preclinical studies assessing in situ and/or in vitro recorded cardiac monophasic action potentials could be critical for the future development and validation of cardiac devices.
Schmidt et al. (Fri,) conducted a other in Cardiac arrhythmia mapping (preclinical model) (n=18). In vitro working heart model (Visible Heart methodologies) vs. In situ (postmedian sternotomy) was evaluated on Monophasic action potentials (MAPs) duration and waveform morphology (p=ns). Monophasic action potentials were reproducibly recorded from epicardial and endocardial locations with no significant differences in waveform morphology or duration between in situ and in vitro models.