Atrioventricular block secondary to transient causes and long-term recurrence after an index event

Background: Atrioventricular block (AVB) secondary to transient causes can recover with its correction. However, studies assessing predictors of recovery and long-term recurrence are lacking. Methods: Patients with advanced or complete AVB who had a reversible cause admitted in a single expert center were retrospectively studied. Patients with AVB secondary to acute coronary syndromes were excluded from analysis. Results: In a population of 162 patients, the main factors associated with recovery of rhythm without a permanent pacemaker (PPM) implantation were the presence of chronic kidney disease (CKD) on dialysis (OR 7.6; CI 95% 1.2-47.5 (p = .03)); greater serum potassium levels (OR 2.3; CI 95% 1.28-4.0 (p < .01)), higher dosage of bradycardic drugs (OR 2.2; CI 95% 1.13-4.4 (p = .02)), the association between different bradycardic drugs (OR 9.0; CI 95% 2.02-40.3 (p < .01)) and between drug therapy and hyperkaliemia (OR 5.2; CI 95% 1.8-15.1 (p < .01)). There was an overall high burden of conductions abnormalities which did not correlate with recovery of rhythm (OR 0.5; CI 95% 0.19-1.5 (p = .23)). In 29 patients (17.9%) there was a correction of the AVB. During a maximum follow-up of 130 months, 24 patients (82.8%) had a recurrence which warranted a PPM. In the overall cohort only five patients (3%) had sustained recovery of rhythm. Conclusions: Recovery of AVB was mainly observed with higher doses of drug therapy, higher serum potassium levels or a combination of factors and regardless of baseline conduction abnormalities. The high rate of recurrence during follow-up warrants a close follow-up or PPM implantation at index admission.