Efficacy and safety of morphine during thermal catheter ablation of atrial fibrillation

Aim The distinctive feature of the analgesia induced by morphine is the profound pain relieving combined with the lack of loss of consciousness. We evaluated the impact of the use of morphine as the first anesthetic drug during the thermal atrial fibrillation (AF) ablation procedure. Methods One hundred and nine patients undergoing radiofrequency (RF) or cryoballoon (Cryo) pulmonary vein (PV) isolation using sedation by means of morphine were enrolled (Group 1) and compared with the last consecutive 109 patients treated with thermal ablation using a conscious sedation protocol with midazolam as the first drug used (Group 2). Pain was assessed by means of a numerical rating scale. Results No statistically significant differences were observed between the two study groups. All PVs were isolated. No patients required general anesthesia or deep sedation. In Group 1, ablation was carried out under morphine alone in 78 patients with a mean morphine dose/patient of 8.5 ± 2.3 mg. Midazolam was used in 31 (28%, 21 RF, 10 Cryo) patients, and Fentanyl in 2 RF patients. In Group 2, ablation was carried out without any anesthetic drug in 35 (32%) patients. Midazolam was required in 74 (68%) patients with a mean dose/patient of 3.3 ± 1.5 mg. Fentanyl was required in five (5%) patients. There was no difference in the overall pain experience between the two study groups (4.7 ± 1.6 vs. 4.8 ± 1.5, P = 0.58). Conclusions Thermal catheter ablation for AF can be performed under conscious sedation using only morphine in most patients without impacting the patient's pain experience.