Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine(416 views) Biondi B, Fazio S, Cuocolo A, Sabatini D, Nicolai E, Lombardi G, Salvatore M, Sacca L
Affiliations: Depts. Int. Med., Endocrinol., N., Univ. Federico II Medical School, Naples, Italy
Medicina Interna, Via Pansini 5, 80131 Naples, Italy
References: Not available.
Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine
To assess cardiac function and exercise tolerance in patients receiving long term TSH-suppressive therapy with levothyroxine (L-T4), we studied maximal exercise capacity with a bicycle ergometer and left ventricular function at rest and during physical exercise by radionuclide angiography. The evaluation was performed in 10 patients receiving L-T4 therapy (2.31 ± 0.13 μg/kg) for 5-9 yr, presenting with effort dyspnea and symptoms of adrenergic overactivity, and 10 matched control subjects. The patients were reassessed after 4 months of administration of the selective β-adrenergic blocker bisoprolol (4.25 ± 0.4 mg/day); L-T4 therapy remained unchanged. The results showed that at rest, left ventricular diastolic filling was impaired in the patients (P < 0.05), whereas systolic function was unaltered. During submaximal physical exercise, left ventricular ejection fraction increased in the controls from 58 ± 2% to 65 ± 2% (P < 0.001), whereas in the patients it fell from 63 ± 2% to 53 ± 2% (P < 0.01), mainly because of increased end-systolic left ventricular volume (P < 0.05). Exercise capacity was markedly reduced in the patients in terms of both peak workload (P < 0.001) and exercise duration (P < 0.001). β-Adrenergic blockade prevented both the fall in ejection fraction and the increase in end-systolic volume during exercise, and improved exercise tolerance. In conclusion, our data show that long term TSH-suppressive therapy with L-T4 is not as harmless as believed, because it may cause marked impairment of cardiac functional reserve and physical exercise capacity. Administration of a β-blocking drug for 4 months caused significant improvement of cardiac performance and exercise tolerance.
Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine
No results.
Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine
Hesse B, Tagil K, Cuocolo A, Anagnostopoulos C, Bardies M, Bax J, Bengel F, Busemann Sokole E, Davies G, Dondi M, Edenbrandt L, Franken P, Kjaer A, Knuuti J, Lassmann M, Ljungberg M, Marcassa C, Marie PY, Mckiddie F, O'connor M, Prvuolovich E, Underwood R * 3. 0 T perfusion MR imaging(878 views) Rivista Di Neuroradiologia (ISSN: 1120-9976), 2004; 17(6): 807-812. Impact Factor:0.023 ViewExport to BibTeXExport to EndNote