CMR characterization of ablation lesions following pulmonary vein isolation.

Pulmonary vein isolation is the cornerstone of ablation therapy in patients
with atrial fibrillation. Index-guided radiofrequency ablation is a safe
technique for this purpose. However, the efficacy is limited by a high rate of
atrial fibrillation recurrence within the first year after pulmonary vein
isolation (20-50%).
Previous imaging and histopathological studies showed that ablation can result
in both permanent and reversible tissue injury (incomplete ablation), which may
explain the high recurrence rate of atrial fibrillation after pulmonary vein
isolation, due to pulmonary vein reconnection. Early identification of
incomplete ablation, suitable for additional ablation, is important to improve
pulmonary vein isolation techniques, leading to less redo procedures, and may
further pave the way for real-time CMR guidance of pulmonary vein isolation
procedures.

Using state of the art CMR imaging techniques, we will characterize ablation
lesions in the early phase after pulmonary vein isolation, and relate findings
to (1) the ablation scar at 3 months follow up and (2) atrial fibrillation-free
survival at 1 year.

Single center observational study.

All patients will receive standard medical care for pulmonary vein isolation,
including visits to the outpatient clinic and ambulatory monitoring. Additional
CMR using a contrast agent will be performed within 72 hours after pulmonary
vein isolation (preferable at the day of discharge) and at 3 months follow-up
to characterize the ablation lesions, which will take 60 minutes. The
additional risks associated with participation are minimal. Gadolinium is a
safe contrast agent, which is frequently used in clinical practice. Intravenous
gadolinium administration may cause minimal injection site reactions (e.g.
pain, cold or burning sensation). As with other contrast-agents,
anaphylactic-like reactions can occur, although this is very unusual. For
safety reasons a medical doctor will be present during the scanning sessions to
monitor the patient*s status. Patients with a known (suspected) allergic
reaction to gadolinium or severe kidney failure (GFR <45 ml/min/kg) will be
excluded. The results of the present study will be used for optimizing
pulmonary vein isolation techniques and may further pave the way for real-time
CMR guidance of pulmonary vein isolation procedures.