Alteration of ventricular repolarization by intracoronary infusion of normal saline in patients with variant angina.

Background And Objectives: During coronary angiography and interventional procedures, catheters that are engaged in a coronary ostium are routinely flushed, typically with normal saline, to expel blood from the catheter or to inject a pharmacologic agent. Saline contains sodium and chloride ions. Such injections may affect the electrophysiologic properties of the myocardium; however, the effect of normal saline on ventricular repolarization has not been established in patients with variant angina.

Subjects And Methods: We studied 51 consecutive patients with variant angina. Five mL of normal saline (NS) or 5% dextrose solution (DW) were infused into the left coronary artery in random order. We measured the heart rate, QT interval, and T-wave amplitude using Mac-Lac 5.2.

Results: The baseline clinical characteristics were not different between the NS {n=30 (14 males); mean age, 56+/-10 years} and the 5% DW groups {n=21 (7 males); mean age, 59+/-10 years}. The changes in the mean corrected QT (QTc) interval were significantly increased at the time of infusion of NS compared to 5% DW (45.1+/-30.3 vs. 20.9+/-23.3 ms, p=0.004). There was a T-wave amplitude change >0.2 mV in at least one-lead in 27 patients (90.0%) during NS infusion compared to 7 patients (33.3%) during 5% DW infusions (p=0.001). No significant changes in heart rate and blood pressure were noted during of the infusions.

Conclusion: NS was associated with prolongation of ventricular repolarization in patients with variant angina.