Correlation of abnormal Q waves, coronary pathology, and ventricular contractility

Area of Science:

• Cardiology
• Diagnostic Imaging
• Medical Electrography

Background:

• Coronary artery disease (CAD) diagnosis relies on correlating clinical findings with imaging and electrical activity.
• Electrocardiograms (ECG) provide insights into myocardial health, but their correlation with coronary pathology and ventricular function requires precise definition.

Purpose of the Study:

• To investigate the correlation between significant Q-waves on electrocardiograms (ECG) and critical coronary occlusions (≥75% obstruction).
• To assess the relationship between Q-waves, ventriculographic abnormalities, and ventricular contractility in patients with coronary artery disease.
• To evaluate the diagnostic value of normal and abnormal ECGs in predicting ventriculographic findings in the presence of critical coronary occlusions.

Main Methods:

• Analysis of electrocardiograms, coronary arteriograms, and ventriculograms from 492 patients with coronary artery disease.
• Correlation of significant Q-wave presence and location with the degree of coronary artery obstruction and ventricular contractility.
• Comparison of ECG findings with ventriculographic results in patients with both critical coronary occlusions and normal ECGs.

Main Results:

• Significant Q-waves demonstrated strong correlation (77-87%) with critical coronary occlusions and ventriculographic abnormalities, except in true posterior myocardial infarction (55%).
• Specific ECG lead combinations (II, III, aVF) showed varying degrees of accuracy in predicting ventriculographic abnormalities.
• In patients with critical coronary occlusions and normal ECGs, ventriculograms were normal in 71-78% of cases, indicating ECGs correlate better with ventricular function than coronary pathology.

Conclusions:

• Significant Q-waves on ECG are reliable indicators of critical coronary occlusions and associated ventricular dysfunction.
• The diagnostic accuracy of Q-waves varies by myocardial region, with true posterior infarction showing lower correlation.
• Normal ECGs in the context of significant coronary artery disease correlate more closely with normal ventricular function than with the extent of coronary pathology.