cardiovascular-agents and Hyperthyroidism

The arrhythmogenic hazard of adenosine treatment in an emergency room (ER) has not been established. Thus, in this study, we set out to prospectively determine the prevalence and clinical consequences of the arrhythmogenic effects associated with urgent adenosine treatment in the ER. One hundred and sixty consecutive patients treated with adenosine for regular wide or narrow complex tachyarrhythmias at our ER were included in the study. An initial bolus of 3 mg of adenosine was used, up to a maximum dose of 18 mg (mode 6 mg). Proarrhythmia was defined as the new appearance of any brady- or tachyarrhythmia within 1 minute from the bolus administration of adenosine. Of the 160 study patients, 84% had narrow complex tachycardia and 16% had wide complex tachycardia. Adenosine was effective in the diagnosis and/or treatment of the underlying arrhythmia in 92%. The overall prevalence of adenosine-induced proarrhythmia was 13%, including prolonged AV block inducing asystole > 4 seconds (7%), paroxysmal atrial fibrillation (1%) and non-sustained ventricular tachycardia (5%). All adenosine-induced arrhythmias were transient and subsided spontaneously. It is concluded, firstly, that adenosine-induced proarrhythmia proved to be frequent in a consecutive ER series, and included potentially dangerous arrhythmias. Secondly, nevertheless, all adenosine-induced arrhythmias subsided spontaneously and did not require treatment. Therefore, urgent adenosine treatment is safe and can be recommended in an emergency setting, provided a strict protocol of administration under close monitoring by highly trained personnel.

Topics: Adenosine; Adult; Age Distribution; Aged; Aged, 80 and over; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Cardiovascular Agents; Comorbidity; Diabetes Mellitus; Drug Therapy, Combination; Drug Tolerance; Electrocardiography; Emergency Service, Hospital; Female; Humans; Hypertension; Hyperthyroidism; Italy; Logistic Models; Male; Middle Aged; Prevalence; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Sex Distribution; Tachycardia; Treatment Outcome

Hyperthyroidism was induced by subcutaneous injections of L-thyroxine (T(4)) (500 mg/kg/day) for 3 days in order to study whether adrenergic and muscarinic receptor-mediated vascular responses alter at an early stage of the disease. T(4) treatment was sufficient to induce a significant degree of thyroid weight loss, tachycardia, cardiac hypertrophy, and an elevation in serum T(4) levels. The tension of aortic ring preparations isolated from rats was measured isometrically to investigate the influence of acute hyperthyroidism. The contractions induced by norepinephrine (NE) were significantly suppressed in aortic rings from rats treated with T(4) compared with control rats. N(G)-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthase (NOS), significantly enhanced NE-induced contraction in aortic rings from both control and T(4)-treated rats, and the enhancement was greater in rats treated with T(4) than control rats. The relaxations induced by either acetylcholine (ACh) or sodium nitroprusside (SNP) were also significantly enhanced by T(4) treatment. L-NOARG abolished the relaxation induced by ACh in aortic rings from both control and T(4)-treated rats. L-NOARG shifted SNP-induced relaxation curves of aortic rings from those of control rats to the left, but not with rats treated with T(4). T(4) treatment showed no influence on the amount of endothelial NOS (eNOS) protein. These results suggest that vascular responses alter at an early stage of hyperthyroidism and that it may be due to a modification in the NO system which is independent from the amount of eNOS protein.

Topics: Acetylcholine; Acute Disease; Animals; Aorta; Blood Pressure; Blotting, Western; Body Weight; Cardiovascular Agents; Disease Models, Animal; Dose-Response Relationship, Drug; Heart Rate; Hyperthyroidism; Male; Muscle Relaxation; Myocardial Contraction; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Nitroprusside; Norepinephrine; Rats; Rats, Wistar; Stimulation, Chemical; Thyroxine; Triiodothyronine; Vasoconstriction

A 52-year-old woman developed hyperthyroidism due to the alternative Vascu-Vitaal pills. She was suffering from nephrotic syndrome due to membranoproliferative glomerulonephritis and subclinical hypothyroidism, possibly due to renal loss of thyroid hormone. For peripheral vascular disease she took the non-registered Vascu-Vitaal pills on her own initiative. According to the product information, these pills contain multiple vitamins, minerals, amino acids and tissue extracts of bovine adrenals, hypophysis and thymus. The patient developed hyperthyroidism after starting on a new batch of the preparation; it subsided after stopping the treatment. A technetium thyroid scan showed decreased uptake and subsequently the Vascu-Vitaal pills were found to contain both thyroxine and triiodothyronine. The thyroid hormone contamination was probably caused by bovine thyroid tissue. It is suggested to require a health warning statement on the package of alternative therapeutics stating that production and contents are not subject to governmental supervision.

Topics: Animals; Cardiovascular Agents; Cattle; Complementary Therapies; Drug Contamination; Female; Humans; Hyperthyroidism; Intermittent Claudication; Middle Aged; Nonprescription Drugs; Thyroid Gland; Tissue Extracts

Topics: Adrenal Cortex Hormones; Calcium; Cardiovascular Agents; Cortisone; Glucocorticoids; Humans; Hypercalcemia; Hyperthyroidism; Prednisone; Thyrotoxicosis

Topics: Cardiovascular Agents; Dihydroergotamine; Ergot Alkaloids; Headache; Hyperthyroidism; Hypothyroidism; Oxytocics

Topics: Cardiovascular Agents; Hydroxypropiophenone; Hyperthyroidism; Muscle Relaxants, Central; Pituitary Gland; Thiouracil

Topics: Cardiovascular Agents; Hydroxypropiophenone; Hyperthyroidism; Muscle Relaxants, Central; Pituitary Diseases; Pituitary Gland; Thiouracil

Topics: Cardiovascular Agents; Ergot Alkaloids; Hydrogenation; Hyperthyroidism

Topics: Animals; Cardiovascular Agents; Ergolines; Ergot Alkaloids; Guinea Pigs; Hydrogenation; Hyperthyroidism

Topics: Cardiovascular Agents; Ergot Alkaloids; Goiter; Humans; Hyperthyroidism; Oxytocics; Postoperative Period