Systolic blood pressure increases in patients with atrial fibrillation regaining sinus rhythm after electrical cardioversion

Direct current (DC) cardioversion is used to convert persistent atrial fibrillation (AF) to sinus rhythm (SR), but there is limited knowledge about how blood pressure (BP) is affected by conversion to SR. We sought to evaluate how BP changed in AF patients who converted to SR, compared to patients still in AF. In this retrospective registry analysis, we included a total of 487 patients, treated with DC cardioversion for persistent AF. We obtained data regarding medical history, medication, BP, and electrocardiogram the day before and 7 days after cardioversion. Systolic BP increased by 9 (±16) mm Hg (P < 0.01) and diastolic BP decreased by 3 (±9) mm Hg (P < 0.01) after conversion to SR. In the group of patients with restored SR, there was a 40% increase in the proportion of patients with a hypertensive BP level (≥140/90 mm Hg) after DC cardioversion compared to before. Patients still in AF had no significant change in BP. Systolic BP increases and diastolic BP slightly decreases when persistent AF is converted to SR. The underlying mechanisms explaining these findings are not known, but may involve either hemodynamic changes that occur when SR is restored, an underestimation of systolic BP in AF, or a combination of both. Our findings suggest that an increased attention to BP levels after a successful cardioversion is warranted.