Objectives: To compare the time course of resumption of
mechanical performance of the left and right atrium after the novel
method of internal low-energy cardioversion (CV) and conventional
external CV of atrial fibrillation (AF).
Right atrial performance has been shown to normalize before the left
atrium after external CV. However, no data on atrial function after
internal CV are available.
Patients and interventions:
Sixty-three patients with chronic AF were randomized to participate in
either external or internal CV.
Echocardiographic examinations were carried out before as well as
immediately after CV (day 0), and at days 1, 7, and 28 thereafter for
the determination of cardiac dimensions, volumes, and transvalvular
Results: After randomized internal CV
or external CV, stable sinus rhythm was restored in 59 patients.
Irrespective of the mode of CV, the right atrium resumed its mechanical
function immediately after CV, whereas the left atrium was stunned
beyond day 7. The mode of CV, internal or external, had no influence on
the recovery of atrial mechanical function.
Conclusions: The right atrium resumes its normal function
immediately after internal as well as external CV, whereas left atrium
function is delayed. In contrast to the assumption that low-energy
internal CV would impact less on atrial mechanical recovery, the type
of method of CV used has no effect on such