Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Myocardial fibrosis is a known prognostic factor in patients with systemic right ventricle (SRV). In these patients fixed ...myocardial perfusion defects are a common finding and are thought to represent areas of myocardial infarction and fibrosis. However, no study has yet correlated myocardial perfusion imaging findings with cardiac magnetic resonance (CMR) imaging, which is the imaging gold standard for detecting myocardial fibrosis.
Purpose
Our aim was to evaluate whether fixed myocardial perfusion defects in adult patients with SRV represent myocardial fibrosis.
Methods
Patients with SRV followed at our outpatient clinic for congenital heart disease were prospectively included. Myocardial perfusion was evaluated with a two-day stress/rest single-photon emission computed tomography (SPECT) protocol, focal myocardial fibrosis with late gadolinium enhancement (LGE) and diffuse myocardial fibrosis with T1 mapping by CMR. The 12-segment model of the right ventricle was used to report segments with myocardial perfusion defects and fibrosis (Figure 1).
Results
Fifteen patients with SRV (12 patients with transposition of the great arteries following atrial switch procedure and 3 patients with congenitally corrected transposition of the great arteries; 4 (26.7%) females; mean age 34.6 ± 10.0 years) were included. Myocardial perfusion defects were present in 14 patients (93%), with predominate fixed perfusion defects (73%) and less common reversible perfusion defects (27%). Fixed myocardial perfusion defects were most frequent in anterior RV segments (figure 1), with multiple segments affected in 11 patients (median number of affected segments – 2 segments). CMR was possible in 11 (73%) patients, others had a permanent pacemaker. LGE indicating focal myocardial fibrosis was detected in only 1 (9%) patient, while increased T1 values indicating diffuse myocardial fibrosis were present in 7 (64%) patients. There was no matching between areas of fixed myocardial perfusion defects and focal myocardial fibrosis in individual patients.
Conclusions
In our study, fixed myocardial perfusion defects detected on SPECT in patients with SRV did not represent areas of focal myocardial fibrosis on CMR. Other causes than scar may explain the frequently reported fixed perfusion defects, such as SRV anatomy with anterior position of the outflow tract and aorta, SRV morphology with variable degree of wall thickness and hypertrophy that influences tracer accumulation and image quality, or difficulties due to complex image acquisition and interpretation. To improve the diagnostic accuracy, the use of fused imaging modalities (SPECT-CT or PET-CT) is recommended in patients with SRV.
Figure 1. Bull`s eye 12-segment plots of the right ventricle (RV) representing the number of segments with fixed myocardial perfusion defects detected by SPECT (1A) and LGE by CMR (1B) in patients with SRV. ANT – anterior, FW – free wall, INF – inferior, SEP – septal wall of RV.
Abstract Figure.
Reduced expression and activity of the peroxisome proliferator-activated receptor gamma (PPARG) have been measured in cells of bronchoalveolar lavage fluid in sarcoidosis patients. PPARG, together ...with its transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A), has important modulating effects on immune response and apoptosis. In the present study, we investigated whether the polymorphisms Pro12Ala (rs1805192) in the PPARG gene and Gly482Ser (rs8192678) in the PPARGC1A gene, which affect transcriptional activities, are associated with sarcoidosis.
We performed an integrative "omic" approach and identified the PPARG gene as a suitable candidate. Polymerase chain reaction was performed followed by restriction fragment length polymorphism to determine PPARG/Pro12Ala and PPARGC1A/Gly482Ser genotypes of 104 sarcoidosis patients and 112 healthy control subjects.
A higher frequency of the Ala allele (p=0.0101, OR=1.84, CI 1.18-2.88), as well as a significantly higher frequency of Pro/Ala heterozygotes and Ala/Ala homozygotes at the Pro12Ala/PPARG polymorphism (p=0.0020, OR=2.45, CI 1.42-4.25) were found in patients with sarcoidosis. In addition, a higher frequency of the Ser allele (p=0.013, OR=1.69, CI 1.13-2.53) and Gly/Ser heterozygotes and Ser/Ser homozygotes (p=0.0470, OR=1.80, CI 1.04-3.10) at the Gly482Ser/PPARGC1A polymorphism were found in patients with sarcoidosis as compared to healthy control subjects.
Our results indicate that the presence of the Ala allele at the PPARG/Pro12Ala polymorphism and the Ser allele at the PPARGC1A/Gly482Ser polymorphism may be a predisposing factor for sarcoidosis.
We describe a case of a 45-y-old woman with a left atrial myxoma, mild to moderate constitutional symptoms and systemic embolisms. Increased levels of antiphospholipid antibodies were detected at ...admission to the hospital and were graduallynormalized after the surgical removal of the tumor. It is known that myxomas have the peculiar ability to induce a systemic inflammatory state with constitutional symptoms, probably mediated by the production of inflammatory mediators in the tumor. This case suggests that myxomas might have also been implicated in the production of antiphospholipid antibodies. Antiphospholipid antibodies could be just a by-product of the systemic inflammatory response. However, theycould also have a role in the thrombosis on the myxoma surface and systemic embolisms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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