Relationship between the reduction in coronary flow and the appearance of electrocardiographic changes

Wégria, René; Segers, M; Keating, Richard P.; Ward, Henry P.

doi:10.1016/0002-8703(49)90795-4

Cited by 91 publications

(17 citation statements)

References 6 publications

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“…As shown in previous studies, epicardial S-T segment elevation reflects ischemia of the myocardial cells (19,20) and correlates with a diminution of myocardial oxygen tension and an asynergistic myocardial contraction in experimental animals subjected to coronary artery occlusion (21). Prinzmetal and associates (22) found close correspondence during hypoxia between elevation of S-T segments in epicardial electrocardiograms and changes in myocardial membrane potentials which occurred in the underlying myocardium.…”

Section: Resultsmentioning

confidence: 54%

Effect of Inhibition of Lipolysis on Infarct Size After Experimental Coronary Artery Occlusion

Kjekshus¹,

Mjøs²

1973

J. Clin. Invest.

115

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A B S T R A C T Recent studies have demonstrated a depressant effect of increased delivery of FFA to the hypoxic heart. Because catecholamines are released in acute myocardial infarction, it is likely that lipolytic activity is increased. The purpose of this study was to determine whether inhibition of hormone-sensitive lipases influence the extent and severity of myocardial ischemic injury produced by coronary occlusion. Myocardial infarction was produced by occlusion of the left anterior descending coronary artery in open-chest dogs. 15 min later a surface map of S-T segments was obtained with the use of 10-14 epicardial leads in the distribution area of the occluded artery. Average S-T segment elevation of all sites was used as an index of myocardial ischemic injury. Before coronary occlusion, the average S-T segment elevation was 0.340.2, which increased to 4.1+0.7 mV (SEM, 12 dogs) after occlusion. Inhibition of lipolytic activity by P-pyridyl-carbinol before repeated coronary occlusion reduced the occlusion-induced S-T segment elevation to 2.1+0.6 mV (P <0.001). When arterial concentrations of FFA were raised by i.v. infusion of a triglyceride emulsion and heparin, average S-T segment elevation after coronary occlusion increased from 1.2±0.7 to 2.2±0.8 mV (P < 0.05) in animals treated with P-pyridyl-carbinol, which suggests an unfavorable effect of circulating FFA in this setting. Isoproterenol given before a repeated occlusion increased the severity and extent of the ischemic injury. The effect of isoproterenol on the occlusion-induced S-T segment elevation was reduced, however, when the lipolytic effect of the drug was inhibited by P-pyridyl-carbinol.Our study suggests that P-pyridyl-carbinol during acute coronary artery occlusion may be of importance in reducing the extent and severity of myocardial ischemic injury.

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Section: Resultsmentioning

confidence: 54%

Effect of Inhibition of Lipolysis on Infarct Size After Experimental Coronary Artery Occlusion

Kjekshus¹,

Mjøs²

1973

J. Clin. Invest.

115

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“…In extensive anterior or anterolateral MIs all columns frequently showed +ST 25 patients is shown in figure 3.…”

Section: Methodsmentioning

confidence: 87%

Precordial ST-segment mapping 1. Clinical studies in the coronary care unit.

Madias¹,

Venkataraman²,

Hodd³

1975

Circulation

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SUMMARYPrecordial ST-segment mapping was applied serially in the coronary care unit for the study of 46 patients with myocardial infarction (MI), using a 49-lead system. Data from the maps were compared with clinical status of patients, conventional ECGs obtained simultaneously, and serum enzyme levels. Stability of the maps over a one hour period was noted in the early phase of admission. However, a The present study reports on the results of serial precordial mapping applied in patients treated in the CCU and discusses the advantages of this modality over the conventional ECG. Material and MethodsForty-six patients (33 males and 13 females) age 55.3 ± 1.7 (SEM, range 31 to 79) years who were admitted to the CCU of Boston City Hospital with the presumptive clinical diagnosis of MI were studied. All patients had ST elevation in their 12-lead ECG and chest pain of over one hour's duration within the 24 hours before admission,1 except for one patient who was studied 48 hours after onset of pain. Excluded were patients with left and right bundle branch block (LBBB, RBBB), and patients who had a pacemaker implanted. All ECGs were recorded using a Hewlett-Packard 1511A electrocardiograph. A Welsh selfretaining ECG electrode (HP Part No. 9301-0122) with a contact diameter of 15 mm, attached to the "V" lead was used for precordial mapping. Studies were not done during an episode of chest pain, save for the initial ones on admission. Paper speed was 25 mm/sec and the standardization was 0.1 mV/mm. Patients were studied in the supine position following marking of a grid on the anterior chest wall, consisting of 49 recording sites, arranged in seven horizontal rows, each including seven marks ( fig. 1). The seven horizontal rows were designated by letters A to G and the vertical columns by numbers 1 to 7. The top right mark (Al) was made at the second intercostal space to the right of the sternum, A2 was made at the second intercostal space to the left of the sternum. A6 was placed at the same horizontal level on the anterior axillary line, A, and A4 marks were spaced evenly between A2 and A,, and A,, and A7 were made at the same horizontal level on the mid-and posterior ax-

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“…The degree of ischemic injury produced during brief coronary artery occlusion is reflected by changes in the magnitude of ST-segment elevation as well as the overall duration. Several investigators have demonstrated that ST-segment elevation measured early after coronary artery occlusion correlates with reductions in myocardial blood flow (Heng et al 1976;Irvin and Cobb 1977;Kjekshus et al 1972;Wégria et al 1949) and cellular damage as estimated by myocardial creatine phosphokinase activity (Heng et al 1976;Maroko et al 1971). It is now postulated that ST-segment changes are caused by intracellular electrical potential differences between normal and ischemic myocytes during different phases of the cardiac cycle.…”

Section: Discussionmentioning

confidence: 99%

“…Experimental coronary artery occlusion has been used in canine models for decades to explore the myriad factors that determine the extent of ischemic injury (e.g., Wégria et al 1949). This model is particularly suitable if the interruption of blood flow is of sufficiently short duration to avoid irreversible myocardial damage.…”

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confidence: 99%

Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs.

Wellenius

Coull

Godleski

et al. 2003

Environ Health Perspect

147

108

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Short-term increases in ambient air pollution have been associated with an increased incidence of acute cardiac events. We assessed the effect of inhalation exposure to concentrated ambient particles (CAPs) on myocardial ischemia in a canine model of coronary artery occlusion. Six mongrel dogs underwent thoracotomy for implantation of a vascular occluder around the left anterior descending coronary artery and tracheostomy to facilitate particulate exposure. After recovery (5-13 weeks), pairs of subjects were exposed for 6 hr/day on 3 or 4 consecutive days. Within each pair, one subject was randomly assigned to breathe CAPs on the second exposure day and filtered air at other times. The second subject breathed CAPs on the third exposure day and filtered air at other times. Immediately after each exposure, subjects underwent 5-min coronary artery occlusion. We determined ST-segment elevation, a measure of myocardial ischemia heart rate, and arrhythmia incidence during occlusion from continuous electrocardiograms. Exposure to CAPs (median, 285.7; range, 161.3-957.3 microg/m3) significantly (p = 0.007) enhanced occlusion-induced peak ST-segment elevation in precordial leads V4 (9.4 +/- 1.7 vs. 6.2 +/- 0.9 mm, CAPs vs. filtered air, respectively) and V5 (9.2 +/- 1.3 vs. 7.5 +/- 0.9 mm). ST-segment elevation was significantly correlated with the silicon concentration of the particles and other crustal elements possibly associated with urban street dust (p = 0.003 for Si). No associations were found with CAPs mass or number concentrations. Heart rate was not affected by CAPs exposure. These results suggest that exacerbation of myocardial ischemia during coronary artery occlusion may be an important mechanism of environmentally related acute cardiac events.

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Relationship between the reduction in coronary flow and the appearance of electrocardiographic changes

Cited by 91 publications

References 6 publications

Effect of Inhibition of Lipolysis on Infarct Size After Experimental Coronary Artery Occlusion

Effect of Inhibition of Lipolysis on Infarct Size After Experimental Coronary Artery Occlusion

Precordial ST-segment mapping 1. Clinical studies in the coronary care unit.

Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs.

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