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.