[Atropine in intraoperative isorhythmic AV dissociation]

Area of Science:

• Anesthesiology
• Cardiology
• Pharmacology

Background:

• Isorhythmic AV dissociation can occur during inhalation anesthesia with halothane or enflurane.
• This condition affects patients within ASA physical status groups I and II.
• Understanding the management of this intraoperative complication is crucial.

Purpose of the Study:

• To evaluate the efficacy of atropine sulfate in restoring sinus rhythm during isorhythmic AV dissociation.
• To assess the impact of atropine on heart rate and arterial blood pressure in this context.
• To investigate the role of vagal tone in the pathogenesis of isorhythmic AV dissociation.

Main Methods:

• A randomized study involving 40 patients with ASA groups I and II.
• Patients experienced intraoperative isorhythmic AV dissociation under halothane or enflurane anesthesia.
• Comparison between spontaneous rhythm return and atropine administration (0.01 mg/kg IV).

Main Results:

• Spontaneous return to sinus rhythm occurred in 20% of patients within 15 minutes.
• Intravenous atropine sulfate significantly increased the return rate to 80% within the same period.
• Atropine administration increased heart rate by 32% but had no significant effect on arterial blood pressure.

Conclusions:

• Atropine sulfate is effective in accelerating the return to sinus rhythm during isorhythmic AV dissociation.
• The findings suggest a significant pathogenetic role for vagal tone in depressing the sinus node.
• The increase in heart rate is a notable drawback of atropine treatment in this scenario.