Pulmonary venous stenosis on ventilation-perfusion scintigraphy: a correlation with dynamic magnetic resonance pulmonary angiography

Clinical characteristics of patients with atrial fibrillation suffering from pulmonary vein stenosis after radiofrequency ablation

OBJECTIVE

Pulmonary vein stenosis (PVS) is a serious complication in patients with atrial fibrillation (AF) receiving radiofrequency catheter ablation (RFCA). We therefore examined these patients' clinical characteristics in relation to PVS occurrence.

METHOD

We retrospectively analyzed the clinical symptoms, diagnostic procedures, and treatment strategies in patients with AF who developed PVS after RFCA.

RESULTS

Among 205 patients with AF who underwent RFCA, five (2.44%) developed PVS (all men; age 44-64 years; AF history 12-60 months; 2 paroxysmal AF, 3 persistent AF). One patient underwent two RFCA sessions and the others received one. The time to PVS diagnosed by pulmonary vein computed tomography angiography (CTA) was 3 to 21 months. PVS symptoms included dyspnea and hemoptysis. Nine pulmonary veins developed PVS. Single mild PVS occurred in two asymptomatic patients and multiple PVS or single severe PVS in three symptomatic patients who underwent pulmonary vein angiography and stent placement. Symptoms in the three patients significantly improved after stent implantation; however, stent restenosis occurred 1 year later in one case.

CONCLUSION

PVS is a rare complication of RFCA for AF that can be diagnosed by CTA. Pulmonary vein stent implantation can remarkably improve the symptoms, but stent restenosis may occur.

Update on MR imaging of the pulmonary vasculature

Magnetic resonance imaging (MRI) plays an increasingly important role in the non-invasive evaluation of the pulmonary vasculature. MR angiographic (MRA) techniques provide morphological information, while MR perfusion techniques provide functional information of the pulmonary vasculature. Contrast-enhanced MRA can be performed at high spatial resolution using 3D T1-weighted spoiled gradient echo sequence or at high temporal resolution using time-resolved techniques. Non-contrast MRA can be performed using 3D steady state free precession, double inversion fast spin echo, time of flight or phase contrast sequences. MR perfusion can be done using dynamic contrast-enhanced technique or using non-contrast techniques such as arterial spin labelling and time-resolved imaging of lungs during free breathing with Fourier decomposition analysis. MRI is used in the evaluation of acute and chronic pulmonary embolism, pulmonary hypertension and other vascular abnormalities, congenital anomalies and neoplasms. In this article, we review the different MR techniques used in the evaluation of pulmonary vasculature and its clinical applications.