Effect of Various Concentrations of Lignocaine & Adrenaline Combination as Local Anesthetic on ECG Parameters of Patients Undergoing Dental Procedures

Background: Systemic absorption of local anesthetics occurs due to its local vasodilator effects. This leads to inhibitory action on the heart which is represented in the form of a decrease in conduction rate, the excitability of myocardium and force of contraction. The aim of the present study was to evaluate the effects of Lignocaine and adrenaline combinations on electrocardiogram undergoing dental procedures. Methods: This was a prospective, observational clinical study done in collaboration with the Department of Oral & Maxillofacial Surgery. All patients scheduled for oral surgeries under local anesthesia with Lignocaine 2% and adrenaline (1:80000 or 1:200000) combination of age 18 years or above 150 patients were included in the study. Patients with a history of hepatic, renal, cardiovascular and thyroid disorders were excluded from the study. A standard 12-lead ECG (25 mm/s) was recorded for each patient before administration of drugs (Basal), during the dental procedure (Intraoperative) and immediately after completion of surgical procedure. Results: There was no statistically significant difference seen between the Group A (Lignocaine 2% with 1:80000 adrenaline) and B (Lignocaine 2% with 1:200000 adrenaline) when the age, gender, PR interval, RR interval, mean QT & QTc dispersion, and heart rate were compared. Statistically significant difference was seen in comparing the mean QT & QTc interval, which was higher in Group A. ECG parameters in Group A and B showed a statistically significant decrease in PR interval, RR interval, QT interval, QTc interval, QT dispersion and QTc dispersion, with the basal, was compared with intraoperative and postoperative findings. The increase in heart rate although was statistically significant in both the groups, it was always within normal limits suggestive of no clinical significance. There was a statistically significant decrease in QT and QTc interval, QT and QTc dispersion. The change in all these parameters was within the physiologic range. All these relevant parameters for cardiac arrhythmias did not show any arrhythmogenic potential of lignocaine-adrenaline combination in both the groups. Both the combinations are comparable with each other in terms of ECG parameters with changes more with group A suggesting the effect of increased concentration of adrenaline. The change in the heart rate and ECG parameters in both the study group might be attributed to the presence of adrenaline in the combination. No cardiovascular morbidities were observed except palpitation. Conclusion: Thus it can be very well concluded that the effects of lignocaine-adrenaline combinations on electrocardiographic parameters are minimal and clinically irrelevant. Both the combination appears to be safe to use in healthy individuals.