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Background: The electrophysiologic effects of acute atrial dilatation and dedilatation in humans with chronic atrial fibrillation remains to be elucidated., Objective: To study the electrophysiological effects of acute atrial dedilatation and subsequent dilatation in patients with long-standing persistent atrial fibrillation (AF) with structural heart disease undergoing elective cardiac surgery., Methods: Nine patients were studied. Mean age was 71 ± 10 years, and left ventricular ejection was 46% ± 6%. Patients had at least moderate mitral valve regurgitation and dilated atria. After sternotomy and during extracorporal circulation, mapping was performed on the beating heart with 2 multielectrode arrays (60 electrodes each, interelectrode distance 1.5 mm) positioned on the lateral wall of the right atrium (RA) and left atrium (LA). Atrial pressure and size were altered by modifying extracorporal circulation. AF electrograms were recorded at baseline after dedilation and after dilatation of the atria afterward., Results: At baseline, the median AF cycle length (mAFCL) was 184 ± 27 ms in the RA and 180 ± 17 ms in the LA. After dedilatation, the mAFCL shortened significantly to 168 ± 13 ms in the RA and to 168 ± 20 ms in the LA. Dilatation lengthened mAFCL significantly to 189 ± 17 ms in the RA and to 185 ± 23 ms in the LA. Conduction block (CB) at baseline was 14.3% ± 3.6% in the RA and 17.3% ± 5.5% in the LA. CB decreased significantly with dedilatation to 7.4% ± 2.9% in the RA and to 7.9% ± 6.3% in the LA. CB increased significantly with dilatation afterward to 15.0% ± 8.3% in the RA and to 18.5% ± 16.0% in the LA., Conclusions: Acute dedilatation of the atria in patients with long-standing persistent AF causes a decrease in the mAFCL in both atria. Subsequent dilatation increased the mAFCL. The amount of CB decreased with dedilatation and increased with dilatation afterward in both atria., (Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Hypoxemic patients with Chronic Obstructive Pulmonary Disease (COPD) have impaired cognitive performance. These neuropsychological impairments are related to the degree of hypoxemia. So far, cognitive performance has not been tested in non-hypoxemic patients with COPD., Methods: We recruited patients with stable COPD and PaO2 > 8.0 kPa (60 mmHg), as well as healthy subjects, who were matched for age, intelligence quotient (IQ), and level of education. Cognitive performance was studied by Stroop Colour Word Test, Trailmaking, digit-symbol of the Wechsler Adult Intelligence Scale, addition subtest of the Groningen Intelligence Test, and Story Recall., Results: Thirty patients with COPD (FEV1 49.8% pred, mean age 64.8 yr) and 20 healthy volunteers (65.6 yr) were enrolled. COPD patients performed significantly worse on trailmaking B, the digit-symbol test, and on the addition subtest. There was no significant correlation between the tests of cognitive performance and disease specific health status (Chronic Respiratory Questionnaire)., Conclusions: We conclude that even non-hypoxemic patients with COPD show significant impairments in cognitive performance. These impairments are not associated with deteriorations in health related quality of life. Prospective evaluation of the impact of treatment on cognitive performance in non-hypoxemic patients with COPD would be a logical subsequent study.