Cardiac dysrhythmia following reversal of neuromuscular blocking agents in geriatric patients.

Ninety-three patients 65 years of age or older were studied to determine the incidence of dysrhymia following administration of 1 of 2 cholinesterase inhibitors, neostigmine or pyridostigmine. The ECG was then continuously monitored for 90 minutes. Neostigmine was associated with a higher incidence of dysrhythmia than was pyridostigmine. Neostigmine administered to patients with pre-existing coronary artery disease and/or conduction defects and to patients with hypertension was associated with a significantly higher incidence of dysrhythmia than was pyridostigmine when administered to patients with the same conditions. The incidence of dysrhythmia in patients who received a halogenated anesthetic was 5 times greater after neostigmine than after pyridostigmine.