The Incidence of Cardiac Arrhythmias is Lower in Isoflurane than Enflurane.

Lee,  Soo II; Lee,  Chang Yeol; Kim,  Seung Su; Lee,  Na Kyung; Kim,  Sang Bum; Kim,  Chong Sung

doi:1997.32.3.370

Clinical Research Article

Korean Journal of Anesthesiology 1997;32(3):370-376.
DOI: https://doi.org/10.4097/kjae.1997.32.3.370

The Incidence of Cardiac Arrhythmias is Lower in Isoflurane than Enflurane.

Soo II Lee, Chang Yeol Lee, Seung Su Kim, Na Kyung Lee, Sang Bum Kim, Chong Sung Kim

¹Department of Anesthesiology, College of Medicine, Dong-A University, Pusan, Korea.
²Department of Internal Medicine, College of Medicine, Dong-A University, Pusan, Korea.
³Department of Anesthesiology, Seoul National University College of Medicine, Seoul, Korea.

Abstract

BACKGROUND
There is difference between isoflurane and enflurane in the myocardial sensitization to catecholamines, and their actions on the heart. Enflurane reduces cytoplasmic calcium more than isoflurane. The hypothesis could be suggested that these two volatile anesthetics might cause the different incidences and natures of cardiac arrhythmias.
METHODS
The anesthesia was induced by the intravenous injection of thiopental(6 mg, kg-1) and pipecuronium(0.1 mg, kg-1). Two groups were randomly allocated to the patients(n=80) in the maintenance: Group I inhaled isoflurane(1~2%), O2(2 L), and N2O(2 L), Group II, enflurane (1.5~2.5%). Continuous electrocardiographic recordings with Holter monitor were made of those undergoing tympanoplasty during anesthesia. The tapes recorded were scanned using analyzer, and we read out ECG complexes on the screen.
Results
were categorized as induction, maintenance, and emergence, and inferred from unpaired t-test, and X2-test with p<0.05 considered significant.
RESULTS
The results were as follows: 1) The total incidence of cardiac arrhythmias was 65.0%. Isoflurane(52.5%) was lower than enflurane(77.5%) in the incidence. 2) During maintenance and emergence, isoflurane was lower than enflurane in the frequency of supraventicular arrhythmias. 3) Ventricular arrhythmias most frequently occurred in induction. 4) The frequency of supraventricular arrhythmias was more than two times that of ventricular ones. The arrhythmias at the AV junction were the most common, and VPC's the second.
CONCLUSIONS
Greatest caution should be paid during peri-induction. It could be suggested that compared to enflurane, isoflurane better be administered for those to whom arrhythmias could be harmful.

Key Words: Anesthetics; volatile; enflurane; isoflurane; Arrhythmias; Holter monitor; incidence; nature