Segmentation and registration of three-dimensional rotational angiogram on live fluoroscopy to guide atrial fibrillation ablation: a new online imaging tool.

BACKGROUND: Three-dimensional rotational atriography (3DATG) was developed to supplement two-dimensional fluoroscopy with 3D volume reconstruction of the left atrium (LA), pulmonary veins (PV), and other structures. Until recently, 3DATG images could only be viewed separately and were not suitable to directly guide atrial fibrillation (AF) ablation. OBJECTIVE: The purpose of this study was to evaluate the feasibility and accuracy of intraprocedural 3DATG. METHODS: Three-dimensional rotational atriography with right atrial contrast injection was obtained using a Philips Allura Xper FD10 system in 30 patients with symptomatic AF who also underwent preprocedural computed tomographic (CT) scan. RESULTS: The majority (93%) of 3DATG image reconstructions were useful for guidance of catheter ablation. Nearly all PVs (94%), LA appendage (89%), and esophagus (100%) were successfully segmented. Measured PV ostial diameters compared using 3DATG and CT showed close concordance. Registration and re-registration of 3DATG overlay image was easily achieved with thoracic landmarks and validated by catheter placement demonstrating minimal discrepancy. Endoscopic views allowed for improved visualization of ostial position, dimensions, and navigation within the antrum. Lesion tagging on 3DATG overlay enhanced ablation guidance. Radiation exposure with 3DATG was significantly reduced compared with preprocedural CT scan (2.1 +/- 0.3 mSv vs 13.8 +/- 2.4 mSv, P <.001). CONCLUSION: Intraprocedural 3DATG imaging during AF ablation with online segmentation and superimposition on live fluoroscopy is feasible. Overlay provides valuable and accurate information on 3D surface outline and endoscopic PV location. Three-dimensional rotational atriography overlay is a new imaging method with reduced radiation exposure that may replace preprocedural CT scan for catheter navigation and ablation of AF.

Pulmonary hypertension and thyroid disease.

BACKGROUND: The association between thyroid dysfunction and pulmonary hypertension (PH) has not been well characterized. METHODS: This retrospective study comprised 356 consecutive PH patients seen at Mayo Clinic Jacksonville Pulmonary Hypertension Center from 1992 to 2006 and 698 sex-matched control subjects without PH. Thyroid disease was defined as an abnormal thyroid-stimulating hormone level, with or without an abnormal free or total thyroxine level, a history of thyroid disease on replacement, or an elevated thyroperoxidase antibody level. The main outcome measure was prevalence of thyroid disease in each group. RESULTS: Median age of the 356 PH patients was 65 years; 230 patients (65%) were female. The control group of 698 patients had the same sex ratio and median age of 68 years. Most PH patients had severe PH, as categorized by World Health Organization (WHO) class (74% class 3-4) and pulmonary artery systolic pressure. Among those with PH, 85 patients (24%) had thyroid disease vs 107 control patients (15%). After adjusting for age and sex, the prevalence of thyroid disease was increased in PH patients compared with control patients. Increased prevalence was most prominent in WHO group 1, pulmonary artery hypertension confirmed by right-heart catheterization (odds ratio, 2.53; 95% confidence interval, 1.55 to 4.08; p < 0.001). Most patients had mild thyroid disease and were hypothyroid. Only 14 of 85 patients (16%) had previously undiagnosed thyroid disease. CONCLUSIONS: Patients with PH have a higher prevalence of thyroid disease than other pulmonary patients. Evaluation of thyroid function in PH patients may be warranted to detect and assess coexisting thyroid disease.