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Atrial fibrillation and Wolf-Parkinson-White in a 68 year old patient with Tuberous Sclerosis
Urbano Gálvez J.M.; López-Minguez J.R.
Infanta Cristina Hospital
Background: Tuberous sclerosis (TS) is an autosomal-dominant disease with a variable involvement of organs such as skin, brain, lung, kidney, heart, pancreas, etc. Although family case history may exist (affectation in chromosome 9), over half of the cases are new mutations with an incidence calculated at approximately 1 in 10.000. The most frequent cardiac affectation is due to its association with rhabdomyomas, a type of tumour, which can appear in multiple, intracavitary or intramural forms. These rhabdomyomas are at times asymptomatic; at other times they can produce symptoms related to obstruction of the exit and entrance of the ventricles, or may be responsible for arrhythmias which are occasionally dangerous and difficult to control, sometimes requiring surgery. On the other hand, the association with Wolf-Parkinson-White syndrome (WPW) accompanied at times by supraventricular arrhythmias has been described as being of more than normal frequency. Almost all of the series and follow-ups reported as such in the literature are in children, with occasional cases described in young patients. It is not frequent, however, to find reports of patients presenting arrhythmias in the context of associated WPW at an advanced age.
Case: Here we present the case of a 68 year old man diagnosed many years previously as having TS, with multiple subungual fibromas present on his feet and hands since his youth (figure 1).
He also bore other signs of the disease such as shagreen plates in the lumbar region, a certain degree of mental retardation, osseous lesions appearing on radiographs of the skull and phalanges. The patient had been a heavy smoker although he had recently stopped. He experienced dyspnea and loss of weight in recent months. He visited emergency services complaining of rapid palpitations and feeling weak and dizzy. The electrocardiogram showed a somewhat irregular rapid tachycardia at 200 beats per minute with QRS width of 0.16 sec. with right bundle branch block image (figure 2). Atrial fibrillation in WPW context was suspected and treatment with procainamyde (400 mg) commenced, however because of the lack of response and bad tolerance an electric discharge of 100 W. was applied restoring sinus rhythm, showing the presence of WPW with positive delta wave in V1 and V5 (figure 2).
The patient was subsequently put on a treatment with propafenone at 450 mg per day and became asymptomatic. A 24 hour Holter (figure 3) revealed the presence of asymptomatic runs of atrial fibrillation with preexcitation.
The dose of propafenone was increased to 900 mg. A new Holter was repeated after some days which registered occasional, though asymptomatic runs of preexcited atrial fibrillation and supraventricular tachycardia. Indication was set for an electrophysiologic study (EPS). A bidimensional echocardiogram was completely normal, without the presence of tumoral images. In the meantime, due to the appearance in the thorax X-ray of a pulmonary mass, a fybroscopy was carried out displaying an infiltrative peribronchial mass which at the byopsy turned out to be epidermoid cancer. For this reason we decided finally not to perform the EPS.
Discussion: WPW has been described in association
with TS regardless of the presence or not of rhabdomyoma in echocardiography examination.
Jayakar et al. has reported that in a period of nine years 7 children were diagnosed as
having TS, 2 of which had WPW with supraventricular tachycardia (28.5%) with the
identification in one of them of a rhabdomyoma. Farokki et al. described a case of one
child in five with rhabdomyoma, as having WPW (20%). Amiran et al. found WPW in 2 to 3
children of 23 with rhabdomyoma, a frequency of 9 to 13%. Finally Sosi et al. reported a
frequency of 6 out of 33 children (the majority, 30 had rhabdomyomas) i.e. 18%. These
values are clearly higher than those given for the general population, estimated at
between 0.15 and 0.50% depending on whether or not cardiac illness is associated. It is
important to note that the most numerous series for which this association is reported are
in children and generally with rhabdomyomas, although in these same series a reduction is
observed in the size and number of the rhabdomyomas with time, especially in children
under four years old. It has been suggested that the mechanism of WPW and TS could be due
to the presence of rhabdomyoma cells in the atrioventricular groove; it is known that they
have a structure similar to that of giant Purkinje cells and may act as accessory pathway.
It is worth remembering that, although the pathogenesis of TS is unknown, it is considered
a disorder of cellular migration, proliferation and differentiation. The fact that with
time these tuners diminish in size or disappear, together with the fact that at times they
are not visible on echocardiography examination since they exist as small intramural
tumors, leaves this possibility open
Due to the frequent affectation of various organs or intercurrent processes, life expectancy does not appear to be very high in these patients in general. Our case is , therefore, unique in showing that patients with TS who reach adult or senile ages can suffer supraventricular arrhythmias with narrow or wide QRS (preexcited atrial fibrillation), and that the first mechanism to be considered should be the existence of an accessory pathway when selecting treatment.
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