More than meets the eye: Atrial fibrillation conversion pause with a twist

Figures

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  Figure 1. Graphic illustration of Cox-maze lesions that were done at the time of mitral valve surgery for patient’s atrial fibrillation.

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  Figure 2. A: Presenting electrocardiogram in the outpatient clinic that showed likely atrial tachycardia with 3:1 ventricular conduction. B: An example of a “conversion pause” that was frequently captured by the patient’s wearable monitor (tracing transmitted from outside hospital). The initial rhythm in this tracing is atrial fibrillation (AF) with irregular ventricular response. However, there appear to be superimposed, dissociated sinus p waves (solid and dashed red arrows point to directly observed p waves or to their expected location when extrapolated using a fixed sinus cycle length, respectively). Following a spontaneous AF conversion (fourth strip), the sinus p waves continue, but they fail to conduct to the ventricle. A junctional escape rhythm eventually ensures. Similar episodes were observed multiple times during the monitored period.

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  Figure 3. A: Intracardiac electrograms collected by the right atrial (RA) lead before active fixation. The septum is in atrial fibrillation and conducts to the ventricle. While the lateral wall is in sinus rhythm, it fails to conduct to the ventricle (pseudo-AV block). B: Posteroanterior chest radiograph was obtained after permanent pacemaker implant, detailing the septal position of the RA lead.