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[Influence of the angiocardiographic severity of ischemic heart disease on QTc duration]
Insights
Coronary artery disease severity did not affect corrected electrical systole (QTc) duration. However, impaired left ventricular wall motion, indicative of more severe disease, was linked to longer QTc intervals in stable angina patients.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Coronary artery disease (CAD) is a leading cause of mortality.
- The corrected electrical systole (QTc) interval is a marker of ventricular repolarization.
- Assessing QTc's prognostic value in CAD is crucial for risk stratification.
Purpose of the Study:
- To evaluate the relationship between CAD severity and QTc duration.
- To determine the prognostic value of QTc for predicting sudden death in patients with stable angina.
Main Methods:
- Retrospective analysis of 123 patients with stable angina undergoing cardiac catheterization.
- Categorization of patients based on CAD severity (0-vessel, 1-vessel, 2-vessel, 3-vessel disease) and left ventricular (LV) wall motion abnormalities.
- Measurement of QTc interval from 12-lead resting electrocardiograms.
Main Results:
- No significant difference in QTc duration was observed across different CAD severity groups (0-V, 1-V, 2-V, 3-V).
- Patients with three or more areas of LV asynergy or aneurysm (Group C) had significantly longer QTc intervals compared to those with normal LV wall motion (Group A).
Conclusions:
- CAD severity, by itself, does not significantly alter QTc duration in stable angina patients.
- Abnormal LV wall motion, reflecting more advanced cardiac damage, is associated with prolonged QTc intervals, suggesting potential prognostic implications.
Abstract:
The influence of severity of coronary artery disease (CAD) on the duration of corrected electrical systole (QTc) and the prognostic value to predict sudden death of this index were retrospectively evaluated in 123 non-consecutive patients with history of stable angina who underwent cardiac catheterization. Fifteen patients had no angiographic evidence of CAD (O-V group). The 108 patients with a greater than or equal to 70% luminal diameter narrowing of a major coronary artery were further subdivided: 23 patients had 1-vessel (1-V group), 40 patients had 2-vessel (2-V group) and 45 had 3-vessel (3-V group) coronary artery disease; 26 patients showed normal left ventricular (LV) wall motion (A group), 57 patients showed asynergic contraction of 1 or 2 LV areas (B group) and 25 patients showed 3 or more areas of asynergy and/or aneurysm. Sixty-one patients had a previous myocardial infarction (MI). QT interval, calculated in the lead where it was longer, on 12-lead resting electrocardiograms recorded at a paper speed of 25 mm/sec, was corrected by the formula: QTc = QT/square root R-R. The follow-up was performed by telephone. At the time of angiography there was no significant difference in QTc duration between the different groups according to the severity of CAD (O-V, 1-V, 2-V and 3-V groups). Patients showing three or more areas of abnormal segmental wall motion and/or aneurysm (C group) had a significantly longer QTc (p less than 0.05) than patients with normal LV wall motion (A group).(ABSTRACT TRUNCATED AT 250 WORDS)