Electrocardiographic measurement of infarct size after thrombolytic therapy.

Abstract

OBJECTIVES:

We examined the utility of the 32-point QRS score from the 12-lead electrocardiogram (ECG) for measurement of the ischemic risk region and infarct size in patients receiving thrombolytic therapy.

BACKGROUND:

The QRS score offers a means of evaluating the therapeutic benefit of thrombolytic therapy by comparing final infarct size with the initial extent of ischemic myocardium.

METHODS:

The study included 38 patients (34 men, 4 women; mean [+/-SD] age 54 +/- 10 years) with a first infarction (18 anterior, 20 inferior). The maximal potential QRS score (QRS0) was assigned to all leads with >/= 100-microV ST elevation on the initial ECG. The QRS scores were calculated at 7 and 30 days after infarction. Left ventricular ejection fraction was measured by radionuclide ventriculography at 1 month. Twenty-eight patients had thallium (Tl)-201 and technetium (Tc)-99m pyrophosphate tomographic measurement of the ischemic region and infarct size.

RESULTS:

The QRS0 was 10.3 +/- 3.1 (mean +/- SD) for anterior and 10.4 +/- 3.5 for inferior infarcts. The QRS scores were similar at 7 and 30 days for both anterior (5.6 +/- 3.4 vs. 5.5 +/- 3.4) and inferior infarcts (3.7 +/- 2.6 vs. 2.9 +/- 2.2). The day 7 QRS score and ejection fraction at 1 month were inversely correlated (r = -0.74, p < 0.01). The Tl-201 perfusion defect was 34 +/- 11% of the left ventricle for anterior and 32 +/- 7% for inferior infarcts. Subsequent Tc-99m pyrophosphate infarct size was 15 +/- 9% of the left ventricle for anterior and 17 +/- 9% for inferior infarcts. The QRS0 was correlated with the extent of the Tl-201 perfusion defect (r = 0.79, p < 0.001), and the day 7 QRS score was correlated with Tc-99m pyrophosphate infarct size (r = 0.79, p < 0.005).

CONCLUSIONS:

The 32-point QRS score can provide useful immediate measurements of the ischemic risk region and subsequent infarct size.

• Authors: C P Juergens, C Fernandes, E T Hasche, S Meikle, G Bautovich, C A Currie, S B Freedman, R W Jeremy
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 27 Issue 3 Pg. 617-24 (Mar 01 1996) ISSN: 0735-1097 [Print] United States
• PMID: 8606273 (Publication Type: Clinical Trial, Controlled Clinical Trial, Journal Article)

Topics

• Aged
• Drug Monitoring
• Electrocardiography
• Female
• Humans
• Male
• Middle Aged
• Myocardial Infarction (diagnosis, drug therapy)
• Prognosis
• Prospective Studies
• Radionuclide Ventriculography
• Reproducibility of Results
• Risk Factors
• Severity of Illness Index
• Stroke Volume
• Thrombolytic Therapy
• Time Factors
• Tomography, Emission-Computed, Single-Photon