Chloroquine terminates stretch-induced atrial fibrillation more effectively than flecainide in the sheep heart.

Background: Blockade of inward-rectifier K+ channels by chloroquine terminates reentry in cholinergic atrial fibrillation (AF). However, it is unknown whether inward-rectifier K+ channels and reentry are also important in maintaining stretch-induced AF (SAF). We surmised that reentry underlies SAF, and that abolishing reentry with chloroquine terminates SAF more effectively than traditional Na+-channel blockade by flecainide.

Time- and frequency-domain analyses of atrial fibrillation activation rate: the optical mapping reference.

Background: Time- and frequency-domain estimates of activation rate have been proposed to guide atrial fibrillation (AF) ablation in patients, but their electrophysiological correlates are unclear.

Objective: This study sought to examine the relative correlation of average electrical cycle length (CL) and dominant frequency (DF) during AF with reference optical mapping measures.

Methods: Eight sheep hearts were Langendorff-perfused and superfused with oxygenated Tyrode solution inside a tank representing the human thorax.