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Horm Metab Res 1987; 19(2): 71-75
DOI: 10.1055/s-2007-1011742
Clinical

© Georg Thieme Verlag, Stuttgart · New York

Abnormalities in Pituitary Thyroid Axis Function Tests in Patients with Paroxysmal Supraventricular Arrhythmias

F. Vermiglio, S. Benvenga, A. Granata, G. Sobbrio, C. Melluso, S. Carerj, F. Arrigo1 , F. Consolo, F. Trimarchi2
  • Istituto Pluridisciplinare di Clinica Medica e Terapia Medica Generale e Speciale, University of Messina, Messina, Italy
  • 1Cattedra di Cardiologia, University of Messina, Messina, Italy
  • 2Cattedra di Semeiotica Medica I, University of Messina, Messina, Italy
Further Information

Publication History

1985

1986

Publication Date:
14 March 2008 (online)

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Summary

The study was carried out on 60 consecutive patients (23 males and 37 females) aged between 20 and 83 years (x ± SD, 40.7 ± 16) who arrived at our Cardiologic Unit with paroxysmal Supraventricular arrhythmias (PSVA) including junctional paroxysmal tachycardia (n = 32), atrial fibrillation (n = 13), atrial flutter (n = 1), premature beats (n = 13) and with no obvious cardiovascular causes.

Serum thyroxine and triiodothyronine were normal in all patients and thyroid scintiscan revealed normal shape and size thyroids without autonomously functioning nodule(s). Thyrotropin (TSH) response to thyrotropin releasing hormone (TRH) was normal in 44 subjects in whom normal serum free T4(FT4) and free T3 (FT3) levels were measured. Six patients with normal FT4 and FT3 levels did not respond to TRH. Abnormalities in thyrotropin response to TRH were observed in 10 patients all exhibiting increased FT4 or also FT3 levels. Among these, 5 patients did not respond to TRH, whereas the remaining 5 exhibited a blunted TSH response to TRH.

These results suggest that only in a small proportion (5/60) of consecutive patients with PSVA it is possible to recognize a status of “occult thyrotoxicosis” on the basis of the combined evaluation of free thyroid hormones and TSH response to TRH.

Key-Words

FT4 - TRH Test - Paroxysmal Supraventricular Arrhythmias - Occult Thyrotoxicosis

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