ACE (angiotensin converting enzyme) gene genotypes have been shown to
be a risk factor for development of left ventricular hypertrophy and c
ardiomyopathy, upon the assumption that the DD genotype is linked to h
igher cellular ACE activity leading to myocardial fibrosis. To test an
analogous hypothesis that the DD genotype favors myocardial fibrosis
in the atrium and thus promotes atrial fibrillation without any struct
ural heart diseases, we determined the distribution of the ACE gene ge
notypes in 77 patients with lone atrial fibrillation and investigated
the effects of the ACE genotypes on the clinical characteristics of at
rial fibrillation. The distribution of ACE genotypes was not significa
ntly different between the patients and healthy volunteers. Also, the
ACE gene genotypes did not affect the types of atrial fibrillation and
the age at the onset of atrial fibrillation. Thus, these results refu
ted the hypothesis of possible relationships between ACE genotypes and
lone atrial fibrillation through myocardial fibrosis, and indicated s
ome unknown differences between the atrium and ventricle.