Click on image to view larger version.

Figure 5 Left atrial fibrillation, induced by left atrial appendage (LAA) burst pacing. Note that during electrocardiographic atrial fibrillation (AF), the right atrial activation rate is markedly less than the left atrial activation rate. The AF terminates (arrow), after which interatrial conduction is intact. Note also that the ventricular activation rate is significantly faster than the right atrial activation rate, consistent with activation of the atrioventricular node by a route other than the right atrium. RAA = right atrial appendage.