In-vivo measurement of swine myocardial resistivity

• Published in: IEEE transactions on biomedical engineering Vol. 49; no. 5; pp. 472 - 483
• Main Authors: Jang-Zern Tsai, Will, J.A., Hubbard-Van Stelle, S., Hong Cao, Tungjitkusolmun, S., Young Bin Choy, Haemmerich, D., Vorperian, V.R., Webster, J.G.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2002; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Animals; Anisotropy; Biological and medical sciences; Biomedical engineering; Biomedical measurements; Conductivity; Electric Impedance; Electrocardiography - instrumentation; Electrocardiography - methods; Electrocardiography. Vectocardiography; Electrodes; Electrodiagnosis. Electric activity recording; Frequency; Fundamental and applied biological sciences. Psychology; Heart; Heart - physiology; Hogs; Impedance; Investigative techniques, diagnostic techniques (general aspects); Materials Testing; Medical sciences; Myocardium; Probes; Reproducibility of Results; Swine; Ventricular Fibrillation - physiopathology; Ventricular Fibrillation - prevention & control; Vertebrates: cardiovascular system; Voltage; Heart; Animal model; Epicardium; Experimental study; Stray current; Electrodes; In vivo; Vertebrata; Mammalia; Swine; Measurement technique; Animal; Calipering; Myocardium; Electric resistivity; Capacitance; Leakage current; Circulatory system; Artiodactyla; Ungulata
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/10.995686

We used a four-terminal plunge probe to measure myocardial resistivity in two directions at three sites from the epicardial surface of eight open-chest pigs in-vivo at eight frequencies ranging from 1 Hz to 1 MHz. We calibrated the plunge probe to minimize the error due to stray capacitance between the measured subject and ground. We calibrated the probe in saline solutions contained in a metal cup situated near the heart that had an electrical connection to the pig's heart. The mean of the measured myocardial resistivity was 319 /spl Omega//spl middot/cm at 1 Hz down to 166 /spl Omega//spl middot/cm at 1 MHz. Statistical analysis showed the measured myocardial resistivity of two out of eight pigs was significantly different from that of other pigs. The myocardial resistivity measured with the resistivity probe oriented along and across the epicardial fiber direction was significantly different at only one out of the eight frequencies. There was no significant difference in the myocardial resistivity measured at different sites.