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Published on: April 13, 2015

Effect of slow coronary flow on electrocardiographic parameters reflecting ventricular heterogeneity

Alpay Turan Sezgin1, Irfan Barutcu, Ramazan Ozdemir

  • 1Department of Cardiology, Baskent University, Practice and Research Hospital, Adana, Turkey.

Angiology
|July 14, 2007
PubMed

Insights

Slow coronary flow (SCF) is linked to prolonged QT intervals and increased QT dispersion, indicating potential cardiac electrical instability. This suggests microvascular ischemia or altered autonomic regulation may be involved in SCF patients.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Coronary Artery Disease

Background:

  • QT interval dispersion (QTd) signifies regional ventricular repolarization variations and cardiac electrical instability.
  • QTd changes during myocardial ischemia, but its association with slow coronary flow (SCF) is unestablished.

Purpose of the Study:

  • To investigate electrocardiographic (ECG) changes in patients with angiographically proven SCF compared to those with normal coronary flow.
  • To determine if SCF is associated with abnormalities in QT interval dispersion and corrected QT (QTc).

Main Methods:

  • A comparative study involving 24 patients with SCF (Group I) and 25 controls without coronary artery disease (Group II).
  • Standard 12-lead surface ECGs were recorded at rest, and QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated.
  • Demographic data, cardiac risk factors, heart rate, and QRS duration were analyzed for comparability between groups.

Main Results:

  • Demographics, cardiac risk factors, heart rate, and QRS duration were similar between SCF and control groups.
  • Patients with SCF exhibited significantly higher QTd, QTcd, and QTc values compared to the control group.
  • Specifically, mean QTd was 73 ±14 ms in SCF vs. 40 ±14 ms in controls; mean QTcd was 71 ±15 ms vs. 42 ±9 ms; and mean QTc was 414 ±14 ms vs. 388 ±13 ms (all p < 0.05).

Conclusions:

  • Slow coronary flow is associated with a prolonged QT interval and increased QT dispersion.
  • Potential underlying mechanisms include microvascular ischemia and/or altered autonomic regulation of the heart.
  • These findings highlight potential electrical abnormalities in patients with SCF that warrant further investigation.

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