Exercise test to assess adequate percentage ventricular pacing in patients with heart failure and atrial fibrillation treated with CRT

Abstract

Objective Especially in patients with atrial fibrillation it is of great importance to assure that a sufficient degree (>90%) of ventricular pacing is achieved. Methods 10 patients with chronic atrial fibrillation and heart failure, NYHA class III-IV, LVEF<35% and QRS duration≥150ms and optimal pharmacological treatment were included. The percentage of ventricular pacing during 1 month was calculated from the Holter function in the pacemaker (InSync III, Medtronic) and from the ECG during bi-cycle test with increasing workload in steps of 10 W for every minute. Results. Mean HR at rest before the exercise-test was 75±7.6 (69-94). The percentages of ventricular pacing from the pacemaker Holter and from the bi-cycle test at each workload are shown in the table below. View this table: The degree of ventricular pacing was acceptable in 9/10 patients during rest, but non-optimal in 7/10 during exercise. The Holter did not consistently reflect the pacing pattern during exercise in 6/7 patients with non-optimal degree of ventricular pacing. 5 patients were subsequently treated with AV-junctional ablation. Conclusion To assess the percentage of pacing in CRT treatment of patients with atrial fibrillation an exercise test should be done.