Pulmonary Vein Dimensions and Variation of Branching Pattern in Patients With Paroxysmal Atrial Fibrillation Using Magnetic Resonance Angiography

Abstract

SUMMARYPulmonary veins are the most frequent origin of focal and paroxysmal atrial fibrillation. Although radiofrequency ablation has been attempted for the treatment of focal and paroxysmal atrial fibrillation, the anatomy of the pulmonary vein is still not fully understood. To investigate the dimensions and anatomical variation of the pulmonary vein in patients with paroxysmal atrial fibrillation, we performed breath-hold gadolinium enhanced magnetic resonance (MR) angiography using a 1.5 T cardiac MR imager (GE CV/i) in 32 patients with paroxysmal atrial fibrillation (61 ± 8 years old), 11 patients with chronic atrial fibrillation (64 ± 9 years old), and 26 patients with normal sinus rhythm (55 ± 15 years old). Three dimensional images of the pulmonary veins were thus obtained, and the diameters of the most proximal portion of the left or right superior pulmonary vein and left or right inferior pulmonary vein were measured. Pulmonary vein branching variations were determined by a visual qualitative analysis by two separate readers' agreements, who were blinded to any clinical information. We focused on the existence of a complex-branching pattern draining into the orifice of four pulmonary veins. Patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation showed larger superior pulmonary veins than those with normal sinus rhythm (mean ± SD; in the left superior pulmonary vein, 20 ± 3 mm, 23 ± 3 mm vs 16 ± 3 mm, P <0.05; in right superior pulmonary vein, 19 ± 4 mm, 19 ± 2 mm vs 16 ± 2 mm, P < 0.05). Complex-branching pattern was frequently observed in inferior pulmonary veins in patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation; 25/32 patients with paroxysmal atrial fibrillation, 11/11 patients with chronic atrial fibrillation, compared to 7/26 patients with normal sinus rhythm. Complex-branching patterns were not observed in superior pulmonary veins in any patients in this cohort. Conclusion; In patients with paroxysmal atrial fibrillation or chronic atrial fibrillation, significant pulmonary vein dilation occurred mainly in the superior pulmonary veins, while a complex-branching pattern was frequently observed in the inferior pulmonary veins. These MR angiographic findings might be useful when From the

Evaluation of pulmonary vein variations and anomalies with 64 slice multi detector computed tomography

“…Recently, it has been shown that ectopic electrical activity in the sleeves of atrial myocardium extending 1-2 cm into the pulmonary veins (PVs) plays a central role in generating AF [4][5][6]. Th us, since the discovery that ectopic foci can originate in PVs and can be responsible for AF, pulmonary veins themselves became the targets of catheter directed radiofrequency ablation [7,8]. Electrical mapping for radiofrequency ablation in the pulmonary vein requires a clarifi cation of pulmonary vein anatomy, especially the pulmonary vein diameter and branching pattern and the characteristics of the left atrium to the pulmonary vein junction [7].…”

“…Th us, since the discovery that ectopic foci can originate in PVs and can be responsible for AF, pulmonary veins themselves became the targets of catheter directed radiofrequency ablation [7,8]. Electrical mapping for radiofrequency ablation in the pulmonary vein requires a clarifi cation of pulmonary vein anatomy, especially the pulmonary vein diameter and branching pattern and the characteristics of the left atrium to the pulmonary vein junction [7]. A variety of cardiac imaging modalities including conventional fl uoroscopy/ angiography, transesophageal or transthoracic echocardiography, intra-cardiac echocardiogram [9], multi-detector computed tomography (MDCT) and magnetic resonance imaging (MRI) have been used for catheter navigation during ablation procedures [10].…”

Pulmonary Venous Flow Pattern and Atrial Fibrillation: Fact and Controversy

“…6C). Four PV diameters are reported to be greater in the order of patients with permanent AF > those with paroxysmal AF > those with sinus rhythm (Takase et al, 2004). Moreover, PV branching pattern observed in AF patients is complicated compared with that of patients with sinus rhythm.…”

“…PV orifice morphologies in conjunction with AF progression have been investigated over the years by various modalities such as TEE (Knackstedt et al, 2003), magnetic resonance (MR) imaging (Tsao et al, 2001;Takase et al, 2004) and multislice computed tomography (Scharf et al, 2003). These investigations have been conducted under the uniform hypothesis that largest PV is the main source of ectopic electrical activities triggering and sustaining AF.…”

Focalized Contractile Impairment at Hypertrophied Myocardium Proven in Consideration of Wall Stress in Patients With Hypertrophic Cardiomyopathy

“…No subject had either mitral regurgitation or aortic stenosis. MR imaging: MR [30][31][32][33] examination was performed using a Magnetom Vision (Siemens, Erlangen, Germany) instrument with a 1.5 Tesla superconducting magnet. A cine loop of LV short-axis images was obtained using an ECG trigger gradient refocused sequence (turbo-fast low angle shots).…”