Digoxin versus bisoprolol for left atrium reservoir function modulation in atrial fibrillation: A randomized controlled trial.

Digoxin (Dig) and beta blockers (BB) are the most used drugs to control heart rate in patients with atrial fibrillation (AF). Dig exerts its effect by increasing intracellular calcium whereas BB inhibits sympathetic receptors. Left atrium reservoir function is substantially decreased in AF patients and is predictive of major cardiovascular events in these patients. To assess how Dig and BB different mechanisms of action exerts their effects on left atrial mechanics. This is a bicentric randomized controlled trial. A total of 42 newly diagnosed AF patients with indication for frequency control were randomized to Dig group (n = 21) or BB group (n = 21). Patients in the Dig group received digoxin 0.25 mg once day for 30 days. Patients in the BB group received bisoprolol either 5 mg or 10 mg per day for 30 days. Left atrial reservoir (LAr) strain was measured at randomization before drug intake and after 30 days of Dig or BB therapy. Left atrial reservoir strain curves were obtained from the four chambers and the two chambers' views. The mean age of our patients was 65 ± 9 years. Sixteen patients (38.1%) were diabetics and 26 (61.9%) were hypertensive. At randomization, LAr strain from the four and the two chambers' views, indexed left atrial volume and cardiac frequency were comparable between the two groups. In the Dig group, there was a significant increase in the two chambers view LAr strain from day 0 to day 30 [6.5 (3.2–8.9) vs. 8.1 (6.4–10.8), P = 0.01] but not in the the BB group [6.5 (4.3–8.4) vs. 7 (5–9), P = 0.36]. The four chambers LAr strain did not change after 30 days of follow up in both the Dig group [7.1 (4.6–8.8) vs. 7.8 (4.7–11), P = 0.7) and the BB Group [6 (4.3–9.25) vs. 7 (4.3–8.5), P = 0.6]. The mean increase in two chamber LAr strain was significantly greater in the Dig group as compared the BB group (2.2 ± 3 vs. 0.2 ±2.5, P = 0.02). The use of digoxin in the treatment of atrial fibrillation leads to a significant improvement in the reservoir function of the left atrium compared to bisoprolol. [ABSTRACT FROM AUTHOR]