ANP and BNP in atrial fibrillation before and after cardioversion--and their relationship to cardiac volume and function.

The role of atrial (ANP) and B-type (BNP) natriuretic peptide in atrial fibrillation (AF) is not clear. Our aim was to describe ANP and BNP in AF, and their changes following cardioversion in persistent AF. Furthermore, we wanted to assess the association between ANP and BNP and cardiac volume and function evaluated by magnetic resonance imaging. ANP and BNP decreased significantly following cardioversion. After 180 days of sinus rhythm, ANP and BNP were still significantly elevated. Same results were seen in patients with lone AF. Left and right atrial volumes correlated positively with ANP and BNP. Changes in left atrial volume were predictive of changes in ANP and BNP following cardioversion. AF may cause enduringly elevated ANP and BNP and atrial volume seems to be an important determinant of ANP and BNP in AF.

Atrial and ventricular volume and function evaluated by magnetic resonance imaging in patients with persistent atrial fibrillation before and after cardioversion.

Atrial fibrillation (AF) is the most common cardiac arrhythmia and 25% of those >40 years old will experience AF. Left atrial size and left ventricular function are independently related to cardiovascular morbidity and mortality. Our aim was to evaluate cardiac volume and function using magnetic resonance imaging in patients with persistent AF and to describe the changes after cardioversion (CV). Sixty consecutive patients with persistent AF and 19 healthy volunteers had cardiac volumes evaluated by cinematographic breath-hold magnetic resonance imaging. Patients with AF were evaluated before CV and at 1, 30, and 180 days after CV, if still in sinus rhythm. All atrial and ventricular volumes and left ventricular mass decreased and ejection fractions increased significantly after CV (p <0.0001 for all variables). Atrial and ventricular diastolic volumes increased significantly the day after CV. The atrial diastolic volumes had decreased significantly at 30 days and ventricular volumes at 180 days. The atrial systolic volumes decreased significantly the day after CV, but the ventricular systolic volumes remained constant the day after CV and decreased thereafter. Only the right atrial volumes were normalized 180 days after CV. The same results were found in a subgroup of patients with lone AF. In conclusion, reversal of atrial dimensions and function happened earlier than ventricular reversal after CV in persistent AF. Atrial reversal began immediately and ventricular reversal was not seen before 30 days after CV. Our results suggest that the changes to the left atrium and both ventricles caused by AF could be permanent and that CV of AF may be preferable.

Atrial and ventricular volume and function in persistent and permanent atrial fibrillation, a magnetic resonance imaging study.

Left atrial size is independently related to cardiovascular morbidity and mortality, and atrial fibrillation (AF) is strongly associated with atrial size. Our aims were to report atrial and ventricular dimensions in patients with AF evaluated with magnetic resonance imaging (MRI), and to assess the inter-study reproducibility of the measurements. Nineteen healthy volunteers, 19 patients with permanent AF, and 58 patients with persistent AF had cardiac dimensions evaluated by 6-mm cinematographic breath-hold MRI scans using a 1.5 Tesla Siemens Vision Magnetom scanner with a phased array chest coil. Intraobserver variability and inter-study reproducibility of the cardiac volumes and ejection fractions (EF) gave acceptable Bland-Altman plots, good correlations (R2: 0.80-0.99), and low reproducibility coefficients. The mean atrial volumes were similar in the two groups with AF [systolic vol. index (SVI): 75.9-80.3 mL/m2; diastolic vol. index (DVI): 77.4-82.1 mL/m2] and significantly different from the healthy volunteers (SVI: 30.3 mL/m2; DVI: 62.3 mL/m2; p < 0.0001). Mean left ventricular (LV) volumes and EF were significantly different in permanent AF (SVI: 34.2 mL/m2; DVI: 68.3 mL/m2; EF: 50.8%) compared to persistent AF [SVI: 44.0 mL/m2 (p = 0.02); DVI: 77.2 mL/m2 (p = 0.03); EF: 44.9% (p = 0.02)], and closer to the normal values (SVI: 22.4 mL/m2; DVI: 66.5 mL/m2; EF: 67.0%). MRI is a highly reproducible method for measurement of atrial and ventricular dimensions in healthy volunteers and in patients with AF. Our results suggest that atrial dilatation appears within the first months of AF and stays more or less unchanged thereafter. The LV appears to dilate early as a response to AF, but later seems to adapt.