Choosing the anesthetic and sedative drugs for supraventricular tachycardia ablations: A focused review

Abstract

This study provides a review of the contemporary literature for the effects of most commonly used anesthetic drugs for sedation and anesthesia during adult electrophysiologic (EP) studies where supraventricular tachycardias (SVT) need to be induced for diagnostic purposes and/or catheter ablation. Some medications may affect cardiac electrophysiology and conduction, altering the ability to induce the arrhythmia, and may have negative impact on mapping and ablation treatment. The objective of the study is to determine the best sedative choice during SVT ablations. The authors searched MEDLINE, PubMed, and Google Scholar databases for published articles within the past 20 years (1998‐2018) that have evaluated the effects of common anesthetic drugs during SVT ablations. Further articles were identified through crossreferencing, discussion with electrophysiologists, and hand‐searching key electrophysiology and anesthesia journals. Eight review articles, two randomized control trials, six prospective observational studies, one retrospective observational study, and two case reports were included in this review. Seven of the studies focused on the pediatric population. The findings about the effects of the commonly used anesthetics are discussed further in detail. Sevoflurane had no clinically important effects on sinoatrial (SA) node activity, or the normal atrioventricular (AV), or accessory pathway. Midazolam and fentanyl, alone or in combination, neither alter the inducibility of reentrant tachycardia nor have they shown to affect the SA node, refractory periods of AV conduction, or accessory pathways. Similar findings were reported by investigators with propofol, except for ectopic atrial tachycardia in children, which remained un‐inducible in one of the studies. Remifentanil and dexmedetomidine lengthened both sinus cycle and AV conduction. Dexmedetomidine increased the atrial refractory period and diminished atrial excitability. Ketamine shortened atrial conduction and successfully returned prolongation of sinus node conduction due to dexmedetomidine. In conclusion, the current literature regarding sedation for SVT studies in the adult population is sparse. Midazolam, propofol, fentanyl, and remifentanil can be used safely in patients undergoing EP studies without significant interference with electrophysiological variables or the inducibility of reentrant tachycardias in usual clinical doses. Low‐dose ketamine has potential use as an adjunctive medication in the EP lab and additional studies would be beneficial. The effects of dexmedetomidine on conduction and arrhythmia inducibility during SVT ablation is not as clear as studies have yielded conflicting results, and may not be the best choice for sedation in this patient population.

Effects of anesthetic and sedative agents on sympathetic nerve activity

“…34 In contrast, midazolam, which does not suppress SKNA, does not alter the inducibility of reentrant tachycardia nor has it be shown to affect the sinoatrial node, refractory periods of atrioventricular conduction, or accessory pathways. 35 We propose that the SNA suppression effects might play a role in the mechanism by which anesthetic/sedative agents suppress cardiac arrhythmias.…”

Treatment of supraventricular tachycardias in patients with non-cardiac surgery by dexmedetomidine during the perioperative period

“…However, only two patients are eventually improved, other patients failed to respond in group M. The sedation degree in group M was deeper than group D (Table 3), and midazolam caused three patients SpO2 drop at T2 (>92% , Table 4), which got better after oxygen inhalation. Earlier studies have shown that intravenous infusion of midazolam 5 mg did not alter the reentrant tachycardia [3].…”

“…Although anesthetic drugs have not been used widespreadly to prevent cardiovascular event, many anesthetic drugs, such as propofol, sevo urane, have shown the ability of cardiac protection. Meanwhile, many anesthetic drugs with cardiovascular protection is a common adjuvant method for the treatment of perioperative SVTs [3]. Dexmedetomidine (DEXm) exerts anti-stress, sedative, and analgesic roles by selectively acting on the α-2 receptors of the central and peripheral nervous systems.…”

Incidence and predictors of postoperative nausea and vomiting in children undergoing electrophysiology ablation procedures

“…An important consideration is the effect of propofol on the cardiac conduction system. A recent review suggested that propofol, volatile anesthetics, and midazolam have no significant known effect on the induction of supraventricular tachyarrhythmias . Other anesthetic agents have various effects.…”

“…Other anesthetic agents have various effects. Remifentanil, a common agent in total intravenous anesthesia, slows both sinus and atrioventricular function . Opioids such as fentanyl or morphine have little effect, but may cause bradycardia due to enhanced vagal tone.…”