[Chronotropic changes and cardiac arrhythmias during anesthetic induction and intubation in patients undergoing heart surgery. Study of 79 patients using Holter monitoring].

OBJECTIVES

To assess changes in heart rate and cardiac arrhythmias during anaesthetic induction and tracheal intubation in patients undergoing cardiac surgery.

MATERIAL AND METHODS

79 patients scheduled for cardiac surgery were divided into three groups: group I, 36 valvular diseases with a good ventricular function, group II, 22 valvular diseases with an ejection fraction less than 0.5, and group III, included 21 patients with coronary artery disease. All patients had a Holter monitoring. Anesthesia was performed with diazepam and morphine in patients with valvular disease and with diazepam and fentanyl in those with coronary artery disease.

RESULTS

During anesthesia induction there were no significant increases in heart rate in the two groups of patients with valvular diseases: in group I (n = 36, with good ventricular function) heart rate increased by about 5.4 +/- 23% and in group II (n = 22, with ejection fraction less than 0.5) by 7.5 +/- 33%. In patients with coronary artery disease (n = 21) we did not observe significant decreases in heart rate (-4.28 +/- 17%). During tracheal intubation the heart rate increased by 15.9 +/- 30% in group I (p < 0.002), by 13.6 +/- 30% in group II (p < 0.02), but decreased by 1.19 +/- 23% (p = NS) in patients with coronary artery disease. During anesthetic induction we observed frequent premature beats (single forms) in 13.8% of patients in group I, 13.6% in group II, and 9.5% in group III. The incidence of this arrhythmia during tracheal intubation was 16.6%, 9%, and 14%, respectively for the three groups. Sustained ventricular tachycardia was only observed in one patient.

CONCLUSIONS

Changes in heart rate and ventricular arrhythmias occurring during anesthetic induction and tracheal intubation in patients undergoing valvular and coronary surgery were infrequent and not severe.