Percutaneous RFA has been widely used as the firstline
therapy for symptomatic patients with AF.[
1]
Serious complications, including thromboembolic
events, are likely to be seen in 1 to 5% of RFA
cases.[
2] Left atrial masses after the procedure should
be considered in the differential diagnosis of thrombi,
infective endocarditis, and myxomas.[
4] Prothrombotic
markers with other inflammatory mediators typically
increase within first week and most thromboembolic
events occur within two weeks after RFA.[
5] Therefore, procedure-related late thrombus formation in cardiac
chambers is not expected, unless AF recurs.
In addition, RFA produces myocardial necrosis
to prevent signal transmission through the accessory
pathways and, precisely, pulmonary vein isolation is
the main target.[1] Some inflammatory cytokines have
been studied to determine RFA-induced myocardial
injuries and baseline procedural high-sensitivity CRP
values are proposed to be independently predictive of
AF recurrences.[5] Myxomas have been also reported
to be seen after instances causing endocardial injuries,
including percutaneous mitral balloon valvuloplasty
and repair of atrial septal defects.[3] However, based
on a very few number of cases in the literature, it
is difficult to establish a conclusion that whether
myxomas are related to inflammatory responses to RFA
or are coincidences. To the best of our knowledge, the
appearance of an atrial myxoma after RFA has been
reported only twice.[4,6] In our case, its atypical site of
attachment close to the left superior pulmonary vein
and rapid growing process make us more suspicious
on its coincident nature with RFA-related myocardial
changes.
Furthermore, dyspnea is thought to occur when the
tumor mass intermittently obstructs the flow across
the atrioventricular valves and its severity correlates
the size of the myxoma.[7] Although possible effect of
the tumor size on hemolysis seems to be reasonable,
the evidences related to mechanical red blood cell
injuries are still unclear. In a study, Kanda et al.[8]
reported an increased expression of IL-6 in 12 of 15 myxomas (80%). Moreover, increased IL-6 in a wide
range of patients was found to be inversely related to
the hematopoietic activity.[9] As a result, the authors
concluded that; IL-6 level plays a major role for the
development of anemia'. Interleukin-6 measurement
for the diagnosis of myxomas would provide us
improved interpretation on the inverse relationship
between increased expression of IL-6 and anemia.
In conclusion, although further cases are required
to elucidate the relationship between myxoma
development and local inflammation of endocardium
after radiofrequency ablation, it should be kept in mind
that myxomas may cause anemia via interleukin 6
production.
Declaration of conflicting interests
The authors declared no conflicts of interest with
respect to the authorship and/or publication of this
article.
Funding
The authors received no financial support for the
research and/or authorship of this article.