M-Complex: The Electrocardiographic Sign of Impending Cardiac Rupture following Myocardial Infarction

1972 ◽  
Vol 17 (10) ◽  
pp. 319-325 ◽  
Author(s):  
M. Afzal Mir
Keyword(s):  
Myocardial Infarction ◽  
Chest Pain ◽  
Coronary Care Unit ◽  
Progressive Increase ◽  
Injury Pattern ◽  
Cardiac Rupture ◽  
Time Of Death ◽  
St Segment ◽  
Coronary Care ◽  
Electrocardiogram Ecg

Out of 284 patients admitted to the Coronary-Care Unit, 60 patients showed an acute monophasic injury pattern (M-Complex) on their initial electrocardiogram (ECG). There were 13 fatalities on the first day of myocardial infarction; 6 from the M-complex group. Three of these 6 patients died with cardiac rupture. The ECG features of these 3 patients were compared with the 3 non-rupture patients. A progressive increase in the elevated R-ST segment of the M-complex with an upward ‘pull’ of the R-ST junction, proved to be an ominous ECG sign of impending cardiac rupture in patients with protracted chest pain and persistent hypertenison. The 3 non-rupture patients remained in a hypotensive state from admission to the time of death. Atrioventricular block and A-V junctional tachycardia were the commonest rhythm disturbances in patients dying with cardiac rupture.

Peak time of occurrence of myocardial ischemia in the coronary care unit

1998 ◽  
Vol 7 (6) ◽  
pp. 411-417 ◽  
Author(s):  
MM Pelter ◽  
MG Adams ◽  
SF Wung ◽  
SM Paul ◽  
BJ Drew
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Chest Pain ◽  
Myocardial Ischemia ◽  
Coronary Care Unit ◽  
Circadian Variation ◽  
Transient Ischemia ◽  
St Segment ◽  
Coronary Care ◽  
Ischemic Events

BACKGROUND: The onset of acute myocardial infarction and sudden cardiac death has a circadian variation, with the peak occurrence between 6 AM and 12 noon. OBJECTIVES: To determine if a circadian variation exists for transient myocardial ischemia in patients admitted to the coronary care unit with unstable coronary syndromes. METHODS: The sample was selected from patients enrolled in a prospective clinical trial who had had ST-segment monitoring for at least 24 hours and had had at least one episode of transient ischemia. The 24-hour day was divided into 6-hour periods, and comparisons were made between the 4 periods. RESULTS: In 99 patients, 61 with acute myocardial infarction and 38 with unstable angina, a total of 264 (mean +/- SD, 3 +/- 2) ischemic events occurred. Patients were more likely to have ischemic events between 6 AM and noon than at other times. A greater proportion of patients complained of chest pain between 6 AM and noon than during the other 3 periods. However, more than half the patients never complained of chest pain during ischemia between 6 AM and noon. CONCLUSION: Transient ischemia occurs throughout the 24-hour day; however, ischemia occurs more often between 6 AM and noon. An important nursing intervention for detecting ischemia is continuous electrocardiographic monitoring of the ST segment, even during routine nursing care activities, which are often at a peak during the vulnerable morning hours.

Association of Transient Myocardial Ischemia With Adverse In-Hospital Outcomes for Angina Patients Treated in a Telemetry Unit or a Coronary Care Unit

2002 ◽  
Vol 11 (4) ◽  
pp. 318-325 ◽  
Author(s):  
Michele M. Pelter ◽  
Mary G. Adams ◽  
Barbara J. Drew
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Ischemia ◽  
Coronary Care Unit ◽  
Similar Group ◽  
Hospital Outcomes ◽  
Hospital Unit ◽  
Telemetry Unit ◽  
St Segment ◽  
Transient Myocardial Ischemia ◽  
Coronary Care

• Background Little is known about the frequency or consequences of transient myocardial ischemia in patients admitted to a telemetry unit for treatment of angina. • Objectives To compare the rate of transient myocardial ischemia in a group of patients with angina treated in a telemetry unit with the rate in a similar group treated in a coronary care unit and to determine if transient myocardial ischemia is associated with adverse in-hospital outcomes. • Methods Continuous 12-lead electrocardiography was used to monitor changes in the ST segment in 186 patients in the coronary care unit (1994–1996) and 186 patients in the telemetry unit (1997–2000). Transient myocardial ischemia was defined as a change from baseline of 100 μV or more in the ST segment in 1 or more leads lasting 60 seconds or longer. • Results The rate of transient myocardial ischemia was 15% for patients in the telemetry unit and 19% for patients in the coronary care unit. Regardless of hospital unit, patients with transient myocardial ischemia were more likely than those without this complication to experience death or acute myocardial infarction after hospital admission. Most patients did not experience signs or symptoms during transient myocardial ischemia: 71% of patients in the telemetry unit versus 58% of patients in the coronary care unit (P = .28). • Conclusions Transient myocardial ischemia is common among patients with angina treated in a telemetry unit. ST-segment monitoring may be useful for detecting patients with ischemia who may benefit from more aggressive therapies aimed at abolishing ongoing ischemia.

Early Diagnosis of Myocardial Infarction by Timed Sequential Enzyme Measurements

1988 ◽  
Vol 25 (4) ◽  
pp. 376-382 ◽  
Author(s):  
P O Collinson ◽  
S B Rosalki ◽  
M Flather ◽  
R Wolman ◽  
T Evans
Keyword(s):  
Myocardial Infarction ◽  
Chest Pain ◽  
Lactate Dehydrogenase ◽  
Coronary Care Unit ◽  
Acute Chest Pain ◽  
Serum Samples ◽  
Cardiac Enzymes ◽  
History Of ◽  
Coronary Care ◽  
Lactate Dehydrogenase Isoenzymes

Serum samples from patients admitted to a coronary care unit with a history of acute chest pain suggestive of myocardial infarction in the previous 12 h were obtained on admission and at 6 and 12 h, thereafter. Creatine kinase (CK), CK-MB isoenzyme, CK-MM sub-bands, myoglobin, and lactate dehydrogenase (LD) isoenzymes were examined. Changes were evaluated in relation to the diagnosis obtained from clinical examination, serial electrocardiography and ‘routine’ cardiac enzymes (CK, aspartate transaminase and alpha-hydroxy butyrate dehydrogenase daily for 3 days following admission). The slope of the logarithms of CK, CK-MB activity and CK-MB concentration in the early post infarct period fully distinguished between infarct and non-infarct patients. Measurement of myoglobin and lactate dehydrogenase isoenzymes was less sensitive. Serial estimation of CK-MM sub-band patterns allowed the time from infarction to be estimated. Serial estimation of CK in the 12 h following admission can be substituted for conventional daily enzyme estimations for the diagnosis of acute myocardial infarction in patients with onset of chest pain within the previous 12 h. This could reduce laboratory and in-patient costs.

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