Early time course of myocardial electrical impedance during acute coronary artery occlusion in pigs, dogs, and humans.

Changes in myocardial electrical impedance (MEI) and physiological end points have been correlated during acute ischemia. However, the importance of MEI's early time course is not clear. This study evaluates such significance, by comparing the temporal behavior of MEI during acute total occlusion of the left anterior descending coronary artery in anesthetized humans, dogs, and pigs. Here, interspecies differences in three MEI parameters (baseline, time to plateau onset, and plateau value normalized by baseline) were evaluated using Kruskal-Wallis ANOVA and post hoc tests (P < 0.05). Noteworthy differences in the MEI time to plateau onset were observed: In dogs, MEI ischemic plateau was reached after 46.3 min (SD 12.9) min of occlusion, a significantly longer period compared with that of pigs and humans [4.7 (SD 1.2) and 4.1 min (SD 1.9), respectively]. However, no differences could be observed between both animal species regarding the normalized MEI ischemic plateau value (15.3% (SD 4.7) in pigs, vs. 19.6% (SD 2.6) in dogs). For all studied MEI parameters, only swine values resembled those of humans. The severity of myocardial supply ischemia, resulting from coronary artery occlusion, is known to be dependent on collateral flow. Thus, because dogs possess a well-developed collateral system (unlike humans or pigs), they have shown superior resistance to occlusion of a coronary artery. Here, the early MEI time course after left anterior descending coronary artery occlusion, represented by the time required to reach ischemic plateau, was proven to reflect such interspecies differences.

[1]  K. Kamiya,et al.  ATP directly affects junctional conductance between paired ventricular myocytes isolated from guinea pig heart. , 1990, Circulation research.

[2]  A. van Oosterom,et al.  Intramural resistivity of cardiac tissue , 2006, Medical and Biological Engineering and Computing.

[3]  D. Hearse.  Myocardial ischaemia: can we agree on a definition for the 21st century? , 1994, Cardiovascular research.

[4]  Eung Je Woo,et al.  Dependence of apparent resistance of four-electrode probes on insertion depth , 2000, IEEE Transactions on Biomedical Engineering.

[5]  B. Rodríguez,et al.  Mechanistic investigation of extracellular K+ accumulation during acute myocardial ischemia: a simulation study. , 2002, American journal of physiology. Heart and circulatory physiology.

[6]  E. Michelson,et al.  Extracellular potassium dynamics in the border zone during acute myocardial ischemia in a canine model. , 1988, Journal of the American College of Cardiology.

[7]  J. Fleischhauer,et al.  Electrical resistances of interstitial and microvascular space as determinants of the extracellular electrical field and velocity of propagation in ventricular myocardium. , 1995, Circulation.

[8]  M. Matsuda,et al.  Infarct size and the protection of ischemic myocardium in pig, dog and human. , 1989, Japanese circulation journal.

[9]  C. Bollensdorff,et al.  Na(+) current through KATP channels: consequences for Na(+) and K(+) fluxes during early myocardial ischemia. , 2004, American journal of physiology. Heart and circulatory physiology.

[10]  J. Lowe,et al.  On-line detection of reversible myocardial ischemic injury by measurement of myocardial electrical impedance. , 1987, The Annals of thoracic surgery.

[11]  Reimer Ka,et al.  Factors involved in salvaging ischemic myocardium: effect of reperfusion of arterial blood. , 1983 .

[12]  E Gersing,et al.  Impedance Spectroscopy: a Method for Surveillance of Ischemia Tolerance of the Heart , 1987, The Thoracic and cardiovascular surgeon.

[13]  Pierre N. Robillard,et al.  Spatial Resolution of Four Electrode Array , 1979, IEEE Transactions on Biomedical Engineering.

[14]  Hong Cao,et al.  Error analysis of tissue resistivity measurement , 2002, IEEE Transactions on Biomedical Engineering.

[15]  P. Steendijk,et al.  Dependence of anisotropic myocardial electrical resistivity on cardiac phase and excitation frequency , 1994, Basic Research in Cardiology.

[16]  J. Haselgrove,et al.  Early ischemia after complete coronary ligation in the rabbit, dog, pig, and monkey. , 1981, The American journal of physiology.

[17]  J. Cinca,et al.  Changes in myocardial electrical impedance induced by coronary artery occlusion in pigs with and without preconditioning: correlation with local ST-segment potential and ventricular arrhythmias. , 1997, Circulation.

[18]  W. Cascio,et al.  Electrical Properties and Conduction in Reperfused Papillary Muscle , 2001, Circulation research.

[19]  W. Schaper,et al.  Influence of collateral flow on the ischemic tolerance of the heart following acute and subacute coronary occlusion. , 1976, Circulation.

[20]  W. Cascio,et al.  Correlation of ischemia-induced extracellular and intracellular ion changes to cell-to-cell electrical uncoupling in isolated blood-perfused rabbit hearts. Experimental Working Group. , 1996, Circulation.

[21]  M. Hori,et al.  Right coronary artery occlusion: its role in the mechanism of precordial ST segment depression. , 1989, Journal of the American College of Cardiology.

[22]  R. Jennings,et al.  Factors involved in salvaging ischemic myocardium: effect of reperfusion of arterial blood. , 1983, Circulation.

[23]  Carlos del-Rio,et al.  Myocardial electrical impedance responds to ischemia and reperfusion in humans , 2004, IEEE Transactions on Biomedical Engineering.

[24]  F. Eberli,et al.  Frequency distribution of collateral flow and factors influencing collateral channel development. Functional collateral channel measurement in 450 patients with coronary artery disease. , 2001, Journal of the American College of Cardiology.

[25]  Michiel J. Janse,et al.  Comparison of the Effect of the Regional Ischemia, Hypoxia, Hyperkalemia, and Acidosis on Intracellular and Extracellular Potentials and Metabolism in the Isolated Porcine Heart , 1980, Circulation research.

[26]  P. Steendijk,et al.  The four-electrode resistivity technique in anisotropic media: theoretical analysis and application on myocardial tissue in vivo , 1993, IEEE Transactions on Biomedical Engineering.

[27]  F. C. White,et al.  Coronary collateral circulation in the pig: correlation of collateral flow with coronary bed size , 1981, Basic Research in Cardiology.

[28]  W. Cascio,et al.  The Ib phase of ventricular arrhythmias in ischemic in situ porcine heart is related to changes in cell-to-cell electrical coupling. Experimental Cardiology Group, University of North Carolina. , 1995, Circulation.

[29]  Myocardial Electrical Impedance Responds to Ischemia and Reperfusion in Humans: [2002][A-494] , 2002 .

[30]  D. Beuckelmann,et al.  Cell swelling causes the action potential duration to shorten in guinea-pig ventricular myocytes by activating IKATP , 1998, Pflügers Archiv.

[31]  R. Jennings,et al.  Energy metabolism in the reversible and irreversible phases of severe myocardial ischemia. , 2009, Acta medica Scandinavica. Supplementum.

[32]  J. L. Hill,et al.  Effect of Acute Coronary Artery Occlusion on Local Myocardial Extracellular K+ Activity in Swine , 1980, Circulation.

[33]  R. Dzwonczyk,et al.  Use of myocardial electrical impedance to assess the efficacy of preconditioning , 2002, Computers in cardiology.

[34]  Roger Dzwonczyk,et al.  A new apparatus and method for measuring the myocardial electrical impedance spectrum , 1992, Proceedings Computers in Cardiology.

[35]  A. Kleber.  Extracellular potassium accumulation in acute myocardial ischemia. , 1984, Journal of molecular and cellular cardiology.

[36]  W. Cascio,et al.  Passive electrical properties, mechanical activity, and extracellular potassium in arterially perfused and ischemic rabbit ventricular muscle. Effects of calcium entry blockade or hypocalcemia. , 1990, Circulation research.

[37]  Roland Hetzer,et al.  Intramyocardial impedance measurements for diagnosis of acute cardiac allograft rejection , 2000 .

[38]  W. Schaper,et al.  Influence of collateral blood flow and of variations in MVO2 on tissue-ATP content in ischemic and infarcted myocardium. , 1987, Journal of molecular and cellular cardiology.

[39]  J. Lowe,et al.  Relation between high energy phosphate and lethal injury in myocardial ischemia in the dog. , 1978, The American journal of pathology.

[40]  A. Kleber,et al.  Electrical uncoupling and increase of extracellular resistance after induction of ischemia in isolated, arterially perfused rabbit papillary muscle. , 1987, Circulation research.

[41]  D. Yellon,et al.  Species variation in the coronary collateral circulation during regional myocardial ischaemia: a critical determinant of the rate of evolution and extent of myocardial infarction. , 1987, Cardiovascular research.

[42]  R Hetzer,et al.  Electric myocardial impedance registration in humoral rejection after heart transplantation. , 1996, The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation.

[43]  S. Rush,et al.  Resistivity of Body Tissues at Low Frequencies , 1963, Circulation research.

[44]  R. Jennings,et al.  Development of cell injury in sustained acute ischemia. , 1990, Circulation.

[45]  P B Corr,et al.  Contribution of shrinkage of extracellular space to extracellular K+ accumulation in myocardial ischaemia of the rabbit. , 1996, The Journal of physiology.

[46]  R. Ferrari.  Metabolic disturbances during myocardial ischemia and reperfusion. , 1995, The American journal of cardiology.

[47]  R Gorlin,et al.  Determinants of collateral filling observed during sudden controlled coronary artery occlusion in human subjects. , 1989, Journal of the American College of Cardiology.

[48]  R. Dzwonczyk,et al.  An Evaluation of a New Two-Electrode Myocardial Electrical Impedance Monitor for Detecting Myocardial Ischemia , 2001, Anesthesia and analgesia.