RT Journal Article SR Electronic T1 Myocardial Perfusion in Nonischemic Dilated Cardiomyopathy With and Without Atrial Fibrillation JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 390 OP 396 DO 10.2967/jnumed.108.055665 VO 50 IS 3 A1 Range, Felix T. A1 Paul, Matthias A1 Schäfers, Klaus P. A1 Acil, Tayfun A1 Kies, Peter A1 Hermann, Sven A1 Schober, Otmar A1 Breithardt, Günter A1 Wichter, Thomas A1 Schäfers, Michael A. YR 2009 UL http://jnm.snmjournals.org/content/50/3/390.abstract AB Recent studies have shown that idiopathic atrial fibrillation (AF) is associated with diminished myocardial perfusion and perfusion reserve, which are also impaired in various forms of cardiomyopathies. In many cases, AF develops during progression of dilated cardiomyopathy (DCM) and may aggravate heart failure. This study compared myocardial perfusion between patients with nonischemic DCM with and without AF. Methods: Twelve men (age ± SD, 55 ± 12 y) who had DCM and persistent AF were compared with a group of 18 men (mean age, 43 ± 15 y, P = not statistically significant) who had DCM and sinus rhythm and with 22 healthy controls (mean age, 47 ± 13 y, P = not statistically significant). Myocardial blood flow (MBF) was noninvasively quantified at rest and during adenosine infusion using PET and radioactive-labeled water (H215O PET). Results: Compared with controls, DCM patients without AF showed impaired hyperemic perfusion (2.52 ± 1.29 vs. 3.57 ± 0.88 mL/min/mL, P = 0.014) and perfusion reserve (2.10 ± 1.01 vs. 3.37 ± 0.97, P = 0.003). However, compared with DCM patients without AF, DCM patients with AF showed an additional impairment in resting perfusion (0.82 ± 0.31 mL/min/mL, P = 0.010) and hyperemic perfusion (1.32 ± 0.93 mL/min/mL, P = 0.022), and compared with controls, DCM patients with AF showed a further diminishment of perfusion reserve (1.68 ± 0.94 vs. 3.37 ± 0.97, P < 0.001) accompanied by the highest coronary vascular resistance of all groups. Conclusion: Compared with patients with sinus rhythm, patients with AF have significantly reduced myocardial perfusion reserve and increased coronary resistance in nonischemic DCM. Further studies on the underlying pathomechanisms are warranted.