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Evaluation of precordial electrocardiographic mapping as a means of assessing changes in myocardial ischemic injury

, : Evaluation of precordial electrocardiographic mapping as a means of assessing changes in myocardial ischemic injury. Circulation 52(1): 16-27

Precordial electrocardiographic mapping has been proposed as a method for evaluating the extent of myocardial injury in patients with acute myocardial infarction. To assess the relationship between direct measures of myocardial cell damage and findings obtained by precordial mapping, the left anterior descending coronary artery (LAD) was occluded in dogs instrumented for simultaneous recording of epicardial and precordial electrocardiograms. The sum in millivolts of ST-segment elevation recorded from 30 electrodes placed in a Silastic grid sutured to the epicardium (EPIsigmaST) was compared to that recorded from 30 precordial electrodes (PresigmaST). While ischemic injury was: 1) maintained constant with a fixed occlusion; 2) reduced by partial reperfusion; 3) increased by addition of a second occlusion; or 4) increased repeatedly by intermittent infusions of isoproterenol, EPIsigmaST and PresigmaST were always closely correlated in each of the 16 dogs studied: r equal 0.92 plus or minus 0.01 (SEM). In seven control dogs, 30 minutes after coronary occlusion, PresigmaST had fallen to 77.4 plus or minus 6.6% of its value 15 minutes postocclusion. In seven experimental dogs, two branches of the LAD were occluded. Fifteen minutes after double occlusion, one occlusion was released; 30 min after the initial occlusion PresigmaST had fallen significantly more than control, to 43.1 plus or minus 13.1% of its value 15 minutes postocclusion. Simultaneously, epicardial sites in the reperfused area also showed normalization of ST segments and 24 hours later exhibited normal myocardial creatine phosphokinase activity and normal histologic appearance. During the same experiment, the mean precordial R wave voltage of sites with ST-segment elevations exceeding 0.15 mV 15 minutes following occlusion fell significantly (P less than 0.05) more in the control group (from 1.14 plus or minus 0.15 to 0.75 plus or minus 0.06 mV) than in the reperfused group (from 1.06 plus or minus 0.09 to 0.96 plus or minus 0.17 mV) during the ensuing 45 minutes. Thus, more rapid normalization of PresigmaST or preservation of precordial R wave voltage reflected the actual prevention of myocardial necrosis by reperfusion. These findings demonstrate the usefulness of precordial electrocardiographic mapping for evaluation changes in myocardial ischemic injury. Sites at which appearance of epicardial ST segment is not a reliable index of ischemic injury were associated with the development of intraventricular conduction blocks with Q to intrinsic deflection intervals exceeding 40 mesc or QRS durations exceeding 65 msec; these changes were associated with precordial RSR' configurations. Such sites, whether recorded from precordial or epicardial leads, should be excluded from ST-segment measurements used in the assessment of myocardial ischemia.


PMID: 1132119

Other references

Kovalev V.G., 1981: The most ancient representatives of brachycera from the jurassic in siberia russian sfsr ussr. PALAEOBRACHYCERON handlirschi gen. et sp. nov., P. hennigi sp. nov., P. rohdendorfi sp. nov., P. nagatomii sp. nov., P. steyskali sp. nov., JURABRACHYCERON abbreviatum gen. et sp. nov. and IJA problematica gen. et sp. nov. from the Liassic-Dogger...

Potapov A.A., 1971: The problem of the use of solid repellents. Meditsinskaya Parazitologiya i Parazitarnye Bolezni 40(1): 32-36

Reaban M.E.; Griffin J.A., 1990: Induction of rna stabilized dna conformers by transcription of an immunoglobulin switch region. Nature (London) 348(6299): 342-344

Monowar Hossain, S.M., 1996: Peri-urban and urban vegetable production. Methods of growing vegetables in uran areas in addition to the current system of intensive vegetable production in peri-urban areas of Bangladesh are examined. The potential for integrating vegetable, fish, poultry, and dairy farming is explored.

Geyer, C.R.nald; Sen, D., 1997: Evidence for the metal-cofactor independence of an RNA phosphodiester-cleaving DNA enzyme. Background: RNA and DNA are polymers that lack the diversity of chemical functionalities that make proteins so suited to biological catalysis. All naturally occurring ribozymes (RNA catalysts) that catalyze the formation, transfer and hydrolysis o...

Adler, G.K.; Bonyhay, I.; Failing, H.; Waring, E.; Dotson, S.; Freeman, R., 2009: Antecedent hypoglycemia impairs autonomic cardiovascular function: implications for rigorous glycemic control. Glycemic control decreases the incidence and progression of diabetic complications but increases the incidence of hypoglycemia. Hypoglycemia can impair hormonal and autonomic responses to subsequent hypoglycemia. Intensive glycemic control may inc...

West, N.J.; Courtney, E.D.J.; Poullis, A.P.; Leicester, R.J., 2009: Apoptosis in the colonic crypt, colorectal adenomata, and manipulation by chemoprevention. This review discusses the biology and the methods of assessment of apoptosis, of which, the monoclonal antibody M30 would seem to be the most useful; the role of apoptosis in the etiology of colorectal cancer; and its use as a marker to monitor th...

Frostell, G., 1970: A method for evaluation of acid potentialities of foods. Acta Odontologica Scandinavica 28(5): 599-622

Koch, H., 1970: Removal of noise in tin. Zentralblatt für Arbeitsmedizin und Arbeitsschutz 20(9): 261-262

Simroth, H., 1883: Anatomie der Elisa bella. Jahrbuch der Malakozoologischen Gesellschaft, X 289-312