Grade 3 ischemia on the admission electrocardiogram predicts rapid progression of necrosis over time and less myocardial salvage by primary angioplasty

J Electrocardiol. 2005 Jul;38(3):187-94. doi: 10.1016/j.jelectrocard.2005.03.010.

Abstract

Background: Among patients with ST-elevation acute myocardial infarction, those with terminal QRS distortion (grade 3 ischemia) have higher mortality and larger infarct size (IS) than patients without QRS distortion (grade 2 ischemia).

Methods: We assessed the relation of baseline electrocardiographic ischemia grades to area at risk (AR) and myocardial salvage [100 (AR-IS)/AR] in 79 patients who underwent primary angioplasty for first ST-elevation acute myocardial infarction and had technetium Tc 99m sestamibi single-photon emission computed tomography before angioplasty (AR) and at predischarge (IS). Patients were classified as having grade 2 ischemia (ST elevation without terminal QRS distortion in any of the leads, n = 48), grade 2.5 ischemia (ST elevation with terminal QRS distortion in 1 lead, n = 16), or grade 3 ischemia (ST elevation with terminal QRS distortion in >2 adjacent leads, n = 15).

Results: Time to treatment was comparable among groups. AR was comparable among groups (38% +/- 20%, 33% +/- 23%, and 34% +/- 23%, respectively; P = .70). There were no differences among groups in residual myocardial perfusion (severity index 0.28 +/- 0.12, 0.29 +/- 0.16, and 0.30 +/- 0.15 in grades 2, 2.5, and 3 ischemia, respectively; P = .97). In contrast, there was a trend toward lower myocardial salvage (45% +/- 32%) in the grade 3 group than in the grade 2 (65% +/- 33%) and grade 2.5 (65% +/- 40%) groups ( P = .16). Salvage was dependent on time only in the grade 3 group. Spearman rank correlation coefficients between time to treatment and percentage salvage were 0.003 ( P = .99), -0.24 ( P = .38), and -0.63 ( P = .022) for grades 2, 2.5, and 3, respectively.

Conclusions: Patients with grade 3 ischemia have rapid progression of necrosis over time and less myocardial salvage. This admission pattern is a predictor of myocardial salvage by primary angioplasty.

MeSH terms

  • Angioplasty, Balloon, Coronary*
  • Cohort Studies
  • Coronary Circulation / physiology
  • Disease Progression
  • Electrocardiography*
  • Female
  • Follow-Up Studies
  • Forecasting
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnostic imaging
  • Myocardial Infarction / pathology*
  • Myocardial Ischemia / classification*
  • Myocardial Ischemia / diagnostic imaging
  • Myocardial Ischemia / therapy
  • Myocardium / pathology*
  • Necrosis
  • Patient Admission
  • Radiopharmaceuticals
  • Retrospective Studies
  • Technetium Tc 99m Sestamibi
  • Tomography, Emission-Computed, Single-Photon

Substances

  • Radiopharmaceuticals
  • Technetium Tc 99m Sestamibi