CRT in patients with His-ablation due to LV dysfunction and fast conducted AF has become an important treatment. Studies have been so positive that it now enjoys a class I recommendation in the 2021 ESC guidelines. Loss of CRT due to AV conduction (supraventricular arrhythmias or sinus tachycardia) is impossible in these patients but ventricular arrhythmia may very well be a cause, such as in this patient.

Statistics show low %CRT in the past few weeks due to 25-50% sensed events.

The V pacing rate curves show that since a few months, there has been a progressive decrease in %CRT.

The management of PVCs includes identification of structural triggers such as ischemia or valvular disease. Most of the times, a treatment with beta-blockers or other arrhythmic drugs suffices but sometimes radiofrequency ablation of the PVCs may be required.

You prescribed the patient with 10 mg Bisoprolol daily and see him back a few months later. He feels much better now. The EGM during interrogation shows no more premature ventricular complexes.

The following programmer screens confirm the dramatic lowering of PVCs, restoring %CRT to 100%.

Soon after the initiation of béta-blockers, the V sensed (green) bar diminishes.

The effect is sustainted during follow-up.

The %CRT curve (V pacing graph) recovers to near 100%.