Loss of biventricular pacing due to a prolonged episode of atrial arrhythmias

Tracing
N° 25
Manufacturer Medtronic Device CRT Field Management of atrial arrhythmias
Patient

72-year-old man implanted with a triple-chamber defibrillator Viva XT CRT-D for ischemic cardiomyopathy with atypical bundle branch block and episodes of atrial fibrillation; device interrogation performed a few days after implant. 

Graph and trace
  1. probable atrial arrhythmia with a 2:1 atrioventricular conduction and conducted ventricular activities, acceleration of the atrial arrhythmia;
  2. termination of the atrial arrhythmia;
  3. commutation (MS) to DDD mode with recovery of atrioventricular synchronization;
  4. recurrence of the arrhythmia rapidly conducted;
  5. atrial tachycardia followed by a 2:1 atrioventricular response;
    Interruption of the recording
  6. degradation of the atrial arrhythmia into atrial fibrillation with persistence of an irregular spontaneous ventricular response;
  7. spontaneous termination of the atrial arrhythmia;
  8. commutation (MS) to DDD mode;
  9. recovery of biventricular pacing;
  10. the episode summary indicates that the episode lasted 8 hours (plot in the range  > 220/min);
  11. plot of atrial rate indicating episodes of atrial fibrillation rapidly conducted to the ventricles;
  12. except for the episodes of atrial arrhythmia, the biventricular pacing is nearly permanent.
Comments

Atrial fibrillation is probably the most common cause of prolonged loss of biventricular pacing in CRT patients with a preserved atrioventricular conduction. These episodes are regularly associated with a rapid deterioration of hemodynamics through several combined mechanisms: increased heart rate, irregular ventricular rhythm with short diastole and LV filling disorder, loss of atrial systole and loss of biventricular resynchronization... This patient had multiple episodes of paroxysmal atrial arrhythmias that were not effectively controlled by the antiarrhythmic treatment. He was successfully treated by a pulmonary vein isolation procedure. The combined effect of ablation and resynchronization resulted in a significant improvement of the patient's symptomatology and in a reduction of ventricular volumes.