The impact of atrial fibrillation and stroke risk factors on left atrial blood flow characteristics

Figures

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  Figure 1. Patients at moderate-to-high stroke risk display altered LA 4D flow characteristics in SR, regardless of a history of atrial fibrillation. LA 4D flow maps in a patient with persistent AF and CHADS2-VA2Sc = 4 (Group 1, A) show uniformly low peak velocities (0.16 m/s) and flow vorticity (11.6 rad) compared with those obtained in the same patient forty days after successful cardioversion (peak velocity = 0.24 m/s, vorticity = 20.9 rad, B). Post-cardioversion 4D flow parameters in patients with a history of AF were similar to those obtained in patients with SR and no history of AF but with comparable risk factor profile (Group 2, C). By contrast, low-risk individuals (CHADS2-VA2Sc = 0; Group 3) in SR had a significantly higher LA peak flow velocity and vorticity compared with moderate-to-high risk patients in SR with or without a history of AF (D, mean data in Figure 2). Velocity vectors (arrows) were obtained during mid-ventricular systole. AF, atrial fibrillation; SR, sinus rhythm.

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  Figure 2. LA flow characteristics at baseline. LA mean velocity (A), LA peak velocity (B), LA vorticity (C), and LA vortex volume ratio (D) in Group 1 patients before cardioversion (in AF, in red), Group 2 patients (in SR, in green), and Group 3 low-risk individuals (in SR, in grey). Data are shown as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001.

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  Figure 3. LV and LA CMR parameters in patients with persistent AF before and after cardioversion. Changes in LVEF (A), LA volume (B), LAEF (C), LA reservoir strain (D), LA mean velocity (E), LA peak velocity (F), LA vorticity (G), and LA vortex volume ratio (H) are reported in AF patients after successful restoration of SR (AF-SR subgroup, in blue) and in those with early AF relapse or failed cardioversion (AF-AF subgroup, in red). Data are presented as mean ± SE. *P < 0.05. CV, cardioversion.

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  Figure 4. LV and LA parameters in the three groups in SR. LVEF (A), LV longitudinal strain (B), LV early diastolic strain rate (GLSR-E, C), LA volume (D), LAEF (E), LA reservoir strain (F), LA mean velocity (G), LA peak velocity (H), LA vorticity (I), and LA vortex volume ratio (J) in Group 1 patients after successful restoration of SR (AF-SR subgroup, in blue), Group 2 patients (in green) and Group 3 low-risk individuals (in grey). Data are shown as mean ± SD, with the exception of LA volume which is shown as median (IQR). *P < 0.05; **P < 0.01; ***P < 0.001.

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  Figure 5. Relationships between LA emptying fraction, LV diastolic function, and LA flow Bar charts illustrate mean (SE) values of LA peak velocity (A), mean velocity (B), vorticity (C), and vortex/LA volume ratio (D), stratified by higher and lower levels of LA emptying fraction (LAEF) and LV early diastolic strain rate (GLSR-E), defined by the top 50%/bottom 50% of the distribution in SR. *P < 0.05.