Electrocardiographic changes in precordial leads during selective coronary angiography

Area of Science:

• Cardiology
• Diagnostic Imaging
• Electrophysiology

Background:

• Coronary angiography is a key diagnostic tool for evaluating coronary artery disease.
• Electrocardiogram (ECG) changes can occur during invasive cardiac procedures.
• Understanding these transient ECG alterations is crucial for accurate interpretation during angiography.

Purpose of the Study:

• To investigate the electrocardiographic (ECG) changes induced by contrast media injection during coronary angiography.
• To compare ECG patterns between patients with obstructive coronary disease and those with normal coronary arteries.
• To analyze the effects of contrast injection in the right and left coronary arteries on ECG parameters.

Main Methods:

• Simultaneous recording of precordial (V1, V2, V5, V6) and limb (I, II) leads during coronary angiography.
• Inclusion of 35 patients with obstructive coronary disease and 17 subjects with normal coronary angiograms.
• Analysis of ECG changes following contrast material injection into the right or left coronary artery.

Main Results:

• Contrast injection into the left coronary artery caused a leftward shift of the QRS complex.
• Right coronary artery injections also induced a leftward QRS shift and a more consistent inferior direction.
• Repolarization changes included increased T wave amplitude and transient U waves, with T wave polarity opposite to QRS; these findings were consistent across patient groups.

Conclusions:

• Electrocardiographic changes during coronary angiography are transient and similar in patients with and without obstructive coronary disease.
• Contrast injection elicits predictable shifts in QRS forces and repolarization abnormalities.
• No significant differences in ECG patterns were observed based on coronary dominance or disease presence.