Cardiac function in hypothyroid children: effect of replacement therapy.
OBJECTIVE
To evaluate prospectively cardiac function in children with primary hypothyroidism before and after replacement therapy with L-thyroxine.


METHODS
Prospective clinical and laboratory cardiac evaluation of children with hypothyroidism before and after therapy.


METHODS
Hospital based.


METHODS
20 consecutive children aged 6 months - 14 years with primary hypothyroidism.


METHODS
Assessment of cardiac status by clinical, radiological, ECG, echocardiography, M-mode and 2 dimensional echo-Doppler study and phonocardiography for systolic and diastolic functions and structural anomalies.


RESULTS
Indices of myocardial contractility like ejection fraction (EF), velocity of circumferential fibre shortening (VCF) did not change with therapy. However, systolic time intervals, both left ventricular (before therapy 0.32+/-0.03 msec; after therapy 0.25+/-0.03 msec; p <0.001) showed a significant change. In diastolic functions, isovolumic relaxation time fell from 62+/-9 msec before therapy to 50+/-5 msec after therapy (p <0.001). Pericardial effusion was found in 10 children before treatment which disappeared in 7 following therapy.


CONCLUSIONS
Subtle evidence of alteration of myocardial function is thus seen in children with primary hypothyroidism which reverses with treatment.
Bhupathi
R
R
Department of Pediatrics, All India Institute of Medical Sciences, New Delhi 110 029, India.
Kothari
S S
SS
Gupta
A K
AK
Menon
P S
PS
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy* / Q000503:physiopathology*; D007223:Infant; D008297:Male; D011446:Prospective Studies; D013974:Thyroxine / Q000627:therapeutic use*; D016276:Ventricular Function
D013974:Thyroxine