Background: Atrial cardiomyopathy is characterized by disordered myofibrils and fibrosis resulting in tachyarrhythmia and conduction block. Bi-atrial pacing improves hemodynamic markers with inter-atrial conduction (IAC) delay, but the use of four-chamber pacing for resynchronization has not been described. We describe a novel treatment for a patient with atrial cardiomyopathy, complete heart block (CHB), and pacemaker syndrome due to severe IAC delay.
Objective: To show an RA-synchronous LA-LV-RV pacing system can improve functional status with severe IAC delay and CHB.
Results: A 46 year-old female with familial atrial cardiomyopathy marked by IAC delay and CHB status post dual chamber pacemaker presented with dyspnea. Her symptoms drove multiple hospital admissions and loss of employment. EPS showed IAC delay of >300ms. A quadriopolar pacing lead was positioned with the proximal two electrodes in the coronary sinus capturing the LA and distal two electrodes capturing LV from a posterolateral branch, with the lead secured at this position via a coronary sinus stent. Multipoint pacing was enabled and the delays programmed so as to pace the LA 25ms after RA sensing, followed by a 95ms delay before LV and RV pacing (see figure). LA pressure is 6mmHg lower with LA capture than without. Symptoms improved, employment resumed, and hospital readmissions for pacemaker syndrome abated.
Conclusion: Quad-chamber pacing was effective for marked IAC delay causing pacemaker syndrome. This may offer a better solution than closure to those patients with left atrial appendage isolation. Studies are needed to define the indications and outcomes of this approach.