Myocardial perfusion in nonischemic dilated cardiomyopathy with and without atrial fibrillation.
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 (H(2)(15)O 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.


CONCLUSIONS
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.
Range
Felix T
FT
Department of Nuclear Medicine, University of Münster, Münster, Germany.
Paul
Matthias
M
Schäfers
Klaus P
KP
Acil
Tayfun
T
Kies
Peter
P
Hermann
Sven
S
Schober
Otmar
O
Breithardt
Günter
G
Wichter
Thomas
T
Schäfers
Michael A
MA
D000241:Adenosine; D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003326:Coronary Circulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014867:Water
D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water; D000241:Adenosine