An Investigation on the Probability of Spontaneous Conversion to Sinus Rhythm in Patients with Atrial Fibrillation after Cardiac Surgery

Objectives: Atrial fibrillation (AF) can occur in up to 33% of patients after cardiac surgery. Using data from continuous monitoring devices we investigate the probability of spontaneous conversion in sinus rhythm (SR).

Methods: In 320 patients with history of cardiac surgery (245 males, 73 ± 9 years old) continuous rhythm monitoring of an average duration of 349 ± 49 days could identify AF recurrence. No patient received any obvious AF therapies (cardioversion, AF ablation) which enabled us to investigate the natural history of AF recurrence in these patients and the probability of spontaneous conversion to SR.

Result: High-density low-burden AF could be observed in the majority of patients, with most episodes (61%) terminating spontaneously within 24 hours. Using curve fitting and logistic regression methods, we observed that the more time a patient spends in AF the less likely the patient will spontaneously convert to SR. On day 1 of AF recurrence the probability of spontaneous conversion is high (61%) (p < 0.001) but progressively declines (p < 0.001) the more time the patient spends in AF reaching a plateau after 5 to 7 days of 8% probability of spontaneous SR conversion per day thereafter.

Conclusion: Short, asymptomatic AF episodes are common in patients after cardiac surgery. The probability of spontaneous conversion to SR declines significantly the more time a patient spends in AF. These results highlight the need for closer monitoring of these patients to prevent and interrupt AF episodes before they become long duration which may require significant therapeutic decisions such as the need to initiate anticoagulation therapy

Publication History

Article published online:
19 February 2021