Morphology of the thoracic veins and left atrium in paroxysmal atrial fibrillation initiated by superior caval vein ectopy.
BACKGROUND
The structural changes of the superior caval vein, pulmonary veins, and left atrium in atrial fibrillation initiated by superior caval vein ectopy have not been reported.


RESULTS
Nine patients with atrial fibrillation initiated by superior caval vein ectopic beats (male = 5, 54 +/- 10 years) and 15 control (n = 15, male = 10, 52 +/- 8 years) without any cardiac arrhythmias were included in this study. Using gadolinium-enhanced magnetic resonant angiography with three-dimensional reconstruction, the parameters of the superior caval vein morphology (length, various diameters, area, eccentricity, and volume) were measured. The morphological parameters of the four pulmonary veins (diameter, ostial area, and eccentricity) were also measured at the pulmonary vein-left atrial junction in an oblique sagittal section from the multiple-plane reconstruction images. The left atrial diameters and volume were measured. The different morphological parameters were compared between the two groups. The patients with atrial fibrillation initiated by superior caval vein ectopic beats exhibited a more eccentric structure of the second part of the superior caval vein as compared to the control group. All the ectopic beats initiating atrial fibrillation were located in the second part of the superior caval vein. Furthermore, the patients with atrial fibrillation initiated by superior caval vein ectopic beats had a larger superior caval vein volume, left atrial volume, and pulmonary vein size, and more eccentric pulmonary vein ostia than the controls.


CONCLUSIONS
Structural changes of the superior caval vein were demonstrated in the patients with atrial fibrillation initiated by superior caval vein ectopic beats. These findings might explain the arrhythmogenic mechanism of atrial fibrillation initiated by superior caval vein ectopy.
Huang
Bien-Hsien
BH
Kuang Tien General Hospital, Taichung, Taiwan.
Wu
Mei-Han
MH
Tsao
Hsuan-Ming
HM
Tai
Ching-Tai
CT
Lee
Kun-Tai
KT
Lin
Yenn-Jiang
YJ
Hsieh
Ming-Hsiung
MH
Lee
Shih-Huang
SH
Chen
Yi-Jen
YJ
Kuo
Jen-Yuan
JY
Chen
Shih-Ann
SA
D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology*; D005117:Cardiac Complexes, Premature / Q000150:complications* / Q000175:diagnosis; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000473:pathology*; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis / Q000209:etiology*; D014683:Vena Cava, Superior / Q000473:pathology*