MDCT in the diagnostic algorithm in patients with symptomatic atrial fibrillation

Anatomical variation of pulmonary venous ostium and its relationship with atrial arrhythmia in the Saudi population

PURPOSE

To assess the anatomical variation of the ostial pattern of pulmonary veins observed on coronary computed tomography (CT) angiogram and to estimate the relationship of atrial arrhythmia with similar ostial variants in the Saudi population.

MATERIALS AND METHODS

Thin-section (0.625 mm) contrast enhanced CT scans of 151 consecutive patients obtained over a span of a two-year period (January 2009-January 2011) for the diagnosis of ischemic heart disease, aortic regurgitation, infective endocarditis, aortic aneurysm, fibrosing mediastinitis, and pericardial defect. The retrospective study was focused on the identification of the number of venous ostia on either side of the left atrium and the drainage patterns of pulmonary veins. The frequency of each pattern was tabulated, and significance of their relationship with atrial arrhythmias was assessed with the X(2) and Fisher's exact tests.

RESULTS

Out of 151 patients analyzed, 26 patients (17.2%) had anatomical variation of the pulmonary venous ostia. Atrial arrhythmia was recorded in 16 of 26(61.5%) patients (p = 0.000). The association of higher anatomical variation of pulmonary venous ostia was recorded as higher (p = 0.034) in the female group (n = 15, 57.7%).

CONCLUSION

The association between anatomically varied venous ostia and atrial arrhythmia was significant (p = 0.000) with a significantly higher anatomical variation of pulmonary venous ostia in the female Saudi population (p = 0.034).

Left atrial volumetry from routine diagnostic work up prior to pulmonary vein ablation is a good predictor of freedom from atrial fibrillation

AIMS

This study aimed to identify whether left atrial (LA) volume assessed by multidetector computed tomography (MDCT) is related to the long-term success of pulmonary vein ablation (PVA). MDCT is used to guide PVA for the treatment of atrial fibrillation (AF). MDCT permits accurate sizing of LA dimensions.

METHODS AND RESULTS

We analysed data from 368 ablation procedures of 279 consecutive patients referred for PVA due to drug-refractory symptomatic AF (age 62 ± 10; 58% men; 71% paroxysmal AF). Prior to the procedure, all patients underwent ECG-gated 64-MDCT scan for assessment of LA and PV anatomy, LA thrombus evaluation, LA volume estimation, and electroanatomical mapping integration. Within a mean follow-up of 356 ± 128 days, 64% of the patients maintained sinus rhythm after the initial ablation, and 84% when including repeat PVA. LA diameter (P = 0.004), LA volume (P = 0.002), and type of AF (P = 0.001) were independent predictors of AF recurrence in univariate analysis. There was a relatively low correlation between the echocardiographic LA diameter and LA volume from MDCT (P = 0.01, r = 0.5). In multivariate analysis, paroxysmal AF (P < 0.006) and LA volume below the median value of 106 mL (P = 0.042) were significantly associated with the success of PVA, whereas LA diameter was not (P = 0.245). Analysing receiver-operator characteristics, the area under the curve for LA volume was 0.73 (P = 0.001) compared with 0.60 (P = 0.09) for LA diameter from echocardiography.

CONCLUSION

LA volume assessed by MDCT is a better predictor of AF recurrence after PVA than echocardiograpic LA diameter and can be derived from the pre-procedural imaging data set.