S. Yonesaka et al., CLINICAL AND HISTOPATHOLOGICAL STUDIES IN CHILDREN WITH SUPRAVENTRICULAR TACHYCARDIA, Japanese Circulation Journal, 60(8), 1996, pp. 560-566
To determine whether myocardial changes in patients with supraventricu
lar tachycardia (SVT) are primary or secondary to persistent tachycard
ia, 11 patients with SVT were studied. These patients were divided int
o 2 groups with respect to the type of SVT. Group I consisted of 5 pat
ients with incessant SVT and one with multifocal atrial tachycardia, w
hile group II consisted of 4 patients with paroxysmal supraventricular
tachycardia and one with short-run supraventricular premature contrac
tion. All of the patients underwent electrophysiological study and end
omyocardial biopsy from the right ventricle following routine cardiac
catheterization. In group II, there were no significant abnormalities
in the clinical and hemodynamic parameters. In group I, 3 patients had
clinical features of dilated cardiomyopathy including abnormal EGG, c
hest X-ray and hypokinesis on left ventriculography. Induction and ter
mination of SVT were possible in 2 patients in group I and in 4 of the
5 patients in group II. The only significant histologic difference be
tween group I and group II was fibrosis. A high incidence of histopath
ological abnormalities, such as hypertrophy, degeneration, interstitia
l fibrosis and disarray was observed in both groups. The incidence of
significant pathology was higher in group I than in group II. Almost a
ll of the patients were given antiarrhythmic drugs. One patient underw
ent a successful surgical procedure and normal cardiac function return
ed after resection of the foci of the right atrium. Our present result
s suggest that patients with SVT who have incessant or recurrent SVT s
hould undergo not only intracardiac electrophysiologic study but also
endomyocardial biopsy for the evaluation of myocardial damage, since S
VT might be the initial sign of cardiomyopathy.