Diagnosis of acute myocardial infarction (MI) and unstable angina in the emergency department (ED) is important because the current standard of care is immediate thrombolytic therapy or coronary angioplasty for patients with acute MI, and intravenous heparin for patients with unstable angina. In addition to early reperfusion of ischemic myocardium, sustained patency of the infarct artery is an important determinant of survival in patients with acute MI. Thus, even when early treatment ifn the ED is initially successful in achieving reperfusion, subsequent reocclusion of the infarct artery following admission to the hospital may negate the entire beneficial effects of these early treatments. Therefore, it is imperative to find better ways to monitor a patient for ischemia in the ED as well as throughout a patient's hospitalization in critical care and """"""""step-down"""""""" telemetry units. Reports suggest that continuous ST segment monitoring of the standard 12-lead ECG may improve detection of ischemia; however, such monitoring is difficult to accomplish because it requires multiple electrodes placed in locations that interfere with patient care and that create a noisy signal with body movement. The goal of this research is to test whether continuous ST segment monitoring using a simple lead system (derived 12-lead ECG) is comparable to the currently-accepted """"""""gold standard"""""""" lead system (standard 12-lead ECG) for detecting ischemia and MI. The experimental method involves mathematically deriving 121 ECG leads from 3 base signals recorded from the patient. A prospective, comparative, """"""""within-subjects"""""""" design will be used in which 685 patients with acute MI or unstable angina will undergo continuous 12-lead ST segment monitoring of both experimental and standard ECGs from the time they arrive in the ED until they are discharged from the hospital. Experimental and standard ECG methods will be compared for diagnostic accuracy for presence-absence of MI, infarct location, magnitude of ischemia (""""""""total ischemic burden""""""""), detection of delayed- onset ischemia in initially non-diagnostic ECGs, and recurrent ischemia during hospitalization for MI or unstable angina. Cardiac enzymes, echocardiographic, angiographic, and myocardial perfusion imaging data will be used as an independent standard relative to a correct diagnosis. Statistical analysis will include calculation of the sensitivity, specificity, and predictive accuracy of the experimental method, which will be compared to the standard ECG method.

Agency
National Institute of Health (NIH)
Institute
National Institute of Nursing Research (NINR)
Type
Research Project (R01)
Project #
5R01NR003436-06
Application #
6126047
Study Section
Nursing Research Study Section (NURS)
Program Officer
Armstrong, Nell
Project Start
1993-09-30
Project End
2001-07-31
Budget Start
1999-12-01
Budget End
2001-07-31
Support Year
6
Fiscal Year
2000
Total Cost
$226,645
Indirect Cost
Name
University of California San Francisco
Department
Other Health Professions
Type
Schools of Nursing
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Pelter, Michele M; Adams, Mary G; Drew, Barbara J (2003) Transient myocardial ischemia is an independent predictor of adverse in-hospital outcomes in patients with acute coronary syndromes treated in the telemetry unit. Heart Lung 32:71-8
Adams-Hamoda, Mary G; Caldwell, Mary A; Stotts, Nancy A et al. (2003) Factors to consider when analyzing 12-lead electrocardiograms for evidence of acute myocardial ischemia. Am J Crit Care 12:9-16; quiz 17-8
Pelter, Michele M; Adams, Mary G; Drew, Barbara J (2002) Association of transient myocardial ischemia with adverse in-hospital outcomes for angina patients treated in a telemetry unit or a coronary care unit. Am J Crit Care 11:318-25
Drew, B J; Pelter, M M; Adams, M G (2002) Frequency, characteristics, and clinical significance of transient ST segment elevation in patients with acute coronary syndromes. Eur Heart J 23:941-7
Adams, Mary G; Drew, Barbara J (2002) Efficacy of 2 strategies to detect body position ST-segment changes during continuous 12-lead electrocardiographic monitoring. J Electrocardiol 35 Suppl:193-200
Drew, Barbara J; Pelter, Michele M; Brodnick, Donald E et al. (2002) Comparison of a new reduced lead set ECG with the standard ECG for diagnosing cardiac arrhythmias and myocardial ischemia. J Electrocardiol 35 Suppl:13-21
Drew, Barbara J (2002) Celebrating the 100th birthday of the electrocardiogram: lessons learned from research in cardiac monitoring. Am J Crit Care 11:378-86; quiz 387-8
Drew, B J; Adams, M G (2001) Clinical consequences of ST-segment changes caused by body position mimicking transient myocardial ischemia: hazards of ST-segment monitoring? J Electrocardiol 34:261-4
Wung, S F; Drew, B J (2001) New electrocardiographic criteria for posterior wall acute myocardial ischemia validated by a percutaneous transluminal coronary angioplasty model of acute myocardial infarction. Am J Cardiol 87:970-4; A4
Wung, S F; Lux, R L; Drew, B J (2000) Thoracic location of the lead with maximal ST-segment deviation during posterior and right ventricular ischemia: comparison of 18-lead ECG with 192 estimated body surface leads. J Electrocardiol 33 Suppl:167-74

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