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Prolongation of the QTc interval is seen uniformly during early transmural ischemia

David N Kenigsberg1, Sanjaya Khanal, Marcin Kowalski

  • 1Henry Ford Heart and Vascular Institute, Henry Ford Hospital, Detroit, Michigan, USA.

Journal of the American College of Cardiology
|March 31, 2007
PubMed

Insights

The QTc interval consistently prolongs in patients experiencing early transmural ischemia, preceding other electrocardiogram abnormalities like ST-segment elevation or depression.

Area of Science:

  • Cardiology
  • Electrocardiography
  • Ischemic Heart Disease

Background:

  • Acute myocardial infarction treatment decisions rely on ECGs, but have limitations.
  • ST-segment changes appear late in the ischemic cascade.
  • Early electrocardiographic manifestations of transmural ischemia require further understanding.

Purpose of the Study:

  • To investigate electrocardiogram (ECG) changes during early transmural ischemia.
  • To identify the earliest ECG indicators of myocardial ischemia.

Main Methods:

  • Prospective analysis of ECGs from 74 patients undergoing balloon angioplasty.
  • Utilized automated (MUSE, Interval Editor) and manual ECG analysis.
  • Measured ST-segment, T-wave, and QT-interval changes at 20-s intervals.

Main Results:

  • QTc interval prolongation occurred in 100% of patients with transmural ischemia.
  • Mean QTc interval increased significantly (p < 0.001) in all analyzed groups.
  • QTc prolongation (22s) preceded T-wave changes (24s), ST-segment elevation (29s), and ST-segment depression (35s).

Conclusions:

  • QTc interval prolongation is a universal finding in early transmural ischemia.
  • QTc interval prolongation is the earliest detectable ECG abnormality.
  • This finding may improve early diagnosis and management of myocardial ischemia.
Abstract

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