What electrocardiographic changes occur during selective coronary artery injections of Hypaque-M 75%?
Selective coronary injections of Hypaque-M 75% cause predictable, transient shifts in QRS and T wave vectors that are minimized by coronary occlusion, providing useful information during angiography.
Examination was made of standard lead III of the electrocardiogram recorded during selective right and left coronary artery injections of Hypaque-M 75% in 107 patients. Left coronary artery injection caused the mean frontal plane QRS vector to shift transiently to the left and T wave vector to shift toward the right. Right coronary artery injection caused shifts of the QRS and T wave vectors in the opposite directions. Occlusion of one main coronary artery caused these ECG changes to be minimal or absent. Transient sinus bradycardia was common with injection of either coronary artery. Serious arrhythmias were rare. The electrocardiogram recorded during selective coronary arteriography can give information useful to the angiographer during the procedure itself as well as during the subsequent interpretation of the angiogram.
MacAlpin et al. (Sat,) studied this question.