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

Abstract

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.