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A prolonged QRS duration on surface electrocardiogram is a specific indicator of left ventricular dysfunction [see
R L Murkofsky1, G Dangas, J A Diamond
1Zena & Michael A. Wiener Cardiovascular Institute, and the Department of Medicine, Mount Sinai School of Medicine, New York, New York 10029, USA.
Journal of the American College of Cardiology
|August 26, 1998
Summary
A prolonged QRS duration on an electrocardiogram (ECG) is a specific indicator of reduced left ventricular (LV) systolic function. Further QRS prolongation increases specificity for predicting abnormal LV ejection fraction (EF).
Area of Science:
- Cardiology
- Diagnostic Imaging
- Electrophysiology
Background:
- The 12-lead electrocardiogram (ECG) is a standard tool for cardiac assessment.
- Existing LV systolic function scoring systems lack direct correlation with QRS duration alone.
Purpose of the Study:
- To investigate the association between prolonged QRS duration and diminished left ventricular (LV) systolic function.
- To determine if QRS duration is an independent predictor of reduced LV systolic function.
Main Methods:
- Analysis of 12-lead ECGs and radionuclide ventriculography in 226 patients.
- Exclusion of patients with confounding cardiac conditions or medications.
- Correlation of QRS duration with LV ejection fraction (EF) and volume indices.
- Multivariate analysis incorporating QRS duration, R-wave score, and clinical variables.
Main Results:
- Significantly longer QRS duration in patients with abnormal EF (0.102s vs. 0.091s, p < 0.0001).
- QRS duration >0.10s showed high specificity (83.6%) but moderate sensitivity (43.8%) for abnormal EF.
- Increased QRS duration thresholds (e.g., >0.12s) enhanced specificity and positive likelihood ratios for predicting decreased LV function.
- Prolonged QRS duration and low R-wave score were independent predictors of reduced LV systolic function.
Conclusions:
- Prolonged QRS duration (>0.10s) on a standard ECG is a specific, though not highly sensitive, marker for decreased LV systolic function.
- Increasing QRS duration thresholds improve predictive specificity for abnormal LV EF.
- QRS duration is a valuable, independent predictor of LV systolic dysfunction.