Serial monitoring of reverse left-atrial remodeling after pulmonary vein isolation in patients with atrial fibrillation: A magnetic resonance imaging study

PURPOSE: To prospectively determine the impact of sinus rhythm restoration on left-atrial (LA) volumes and function assessed by cardiac magnetic resonance (CMR) imaging within the first year after pulmonary vein isolation (PVI). METHODS: Forty-one patients (28 men; age: 57±10years) with paroxysmal or non-paroxysmal atrial fibrillation were studied serially using CMR at baseline and at 1-, 3-, 6- and 12-month intervals following PVI. LA diastolic and systolic volumes were determined by cine imaging with full gapless LA coverage applying Simpson's rule. Successful PVI was defined by a persisting sinus rhythm during the 12-month follow-up after a 3-month blanking period; patients with a relapse of atrial fibrillation after the blanking period were censored (4 patients at 6-month follow-up and additional 6 patients at 12-month follow-up). RESULTS: In all patients, LA diastolic and systolic volumes decreased significantly and progressively during the 12-month follow-up (p<0.001 and p=0.001, respectively). At baseline patients with successful PVI demonstrated a significantly smaller LA diastolic volume compared to patients with relapsed atrial fibrillation (p=0.009). During the 3-month blanking period, patients with successful PVI showed a significant decrease of LA diastolic and systolic volumes (p=0.026 and p=0.006, respectively) and a significant increase of LA ejection fraction (p=0.028); patients with subsequent relapse of atrial fibrillation, however, exhibited no significant change of LA diastolic and systolic volumes or LA ejection fraction. CONCLUSION: Restoration of sinus rhythm led to a significant and progressive decrease of left-atrial diastolic and systolic volumes during one year following pulmonary vein isolation

Image-Based View-Angle Independent Cardiorespiratory Motion Gating for X-ray-Guided Interventional Electrophysiology Procedures

Cardiorespiratory phase determination has numerous applications during cardiac imaging. We propose a novel view-angle independent prospective cardiorespiratory motion gating technique for X-ray fluoroscopy images that are used to guide cardiac electrophysiology procedures. The method is based on learning coronary sinus catheter motion using principal component analysis and then applying the derived motion model to unseen images taken at arbitrary projections. We validated our technique on 7 sequential biplane sequences in normal and very low dose scenarios and on 5 rotational sequences in normal dose. For the normal dose images we established average systole, end-inspiration and end-expiration gating success rates of 100 %, 97.4 % and 95.2 %, respectively. For very low dose applications, the method was tested on images with added noise. Average gating success rates were 93.4 %, 90 % and 93.4 % even at the low SNR value of 5–√, representing a dose reduction of more than 10 times. This technique can extract clinically useful motion information whilst minimising exposure to ionising radiation