The Effect of Pharmacologic Doses of Steroids on Atrioventricular Conduction in Man

Abstract

His bundle electrograms were performed in ten patients with organic heart disease. Recordings were made at various rates using right atrial pacing. Two grams of methylprednisolone were infused intravenously over a 20-minute period. The PI-A, A-H, H-Q, and H-S intervals were obtained before and up to 1 hour after the infusion of the steroid. The maximum effect was seen at 1 hour. All patients showed a significant prolongation in the A-H interval with negligible effects on other intervals. At the atrial pacing rate of 120 beats/minute, the average A-H interval increased from control of 119 milliseconds to 159 milliseconds after steroids (P smaller than 0.01). Second-degree heart block occurred at lower pacing rates after steroids in six patients as compared with the control state. The postsuppressive sinoatrial node recovery time was increased in seven cases after steroid infusion. Pharmacologic doses of steroids can impair conduction through the atrioventricular node.

Is immune‐mediated complete fetal atrioventricular block reversible by transplacental dexamethasone therapy?

“…At an early stage, CAVB appears to result from AV nodal tissue edema and inflammation that resolves with anti‐inflammatory medication. Dexamethasone is unlikely to directly improve AV conduction, as it has been shown to prolong the A–H (atrium–His) interval in electrophysiological studies12. However, despite the initial success with near‐normalization of the AV conduction time (145 ms at 27 weeks) in the present case, dexamethasone did not prevent the emergence of left atrial and AV nodal fibrosis followed by stepwise deterioration of the AV conduction.…”

Assessment of Atrial Conduction Time in Patients with Systemic Lupus Erythematosus

“…Gould at al. 39 reported that a significant prolongation in the A-H interval was determined after infusion of 2 g of methylprednisolone intravenously over a 20-minute period, and the maximum effect was seen at 1 hour in 10 male subjects. However, all of patients' disease was in an inactive phase, so our patients had been using low doses of oral corticosteroids, but none of them had been taking intravenous therapy.…”