propylthiouracil and Coronary-Disease

We describe an unusual case of acute myocardial infarction (AMI) and cardiogenic shock in a 25-year-old woman. After coronary revascularization, a thyrotoxic storm developed and the patient's cardiac failure changed into a hyperdynamic circulation without obvious changes in the patient's vital signs. This report will focus on three issues: (1) the benefit of advanced hemodynamic monitoring in circulatory unstable patients, (2) the confounding effects of untreated hyperthyroidism on the circulation, and (3) previous cancer treatment as a cause of AMI in young persons.

Topics: Acute Disease; Adrenal Cortex Hormones; Adult; Antithyroid Agents; Catheterization, Swan-Ganz; Coma; Coronary Disease; Electric Countershock; Female; Hemodynamics; Humans; Myocardial Infarction; Myocardial Revascularization; Postoperative Complications; Propylthiouracil; Pulmonary Edema; Thyroid Crisis; Thyroxine

1. The severity of ventricular arrhythmias induced by coronary artery occlusion and reperfusion has been examined in control rats and animals made hypothyroid by pretreatment with 6-propylthiouracil (PTU). The maximal driving frequency and sensitivity of isolated left atria and papillary muscles to isoprenaline and to phenylephrine in the presence of propranolol, were also examined in tissues from control and hypothyroid animals. 2. Pretreatment with PTU resulted in a potentiation of responses to the alpha-adrenoceptor agonist phenylephrine in both left atria and papillary muscles, while responses to isoprenaline were depressed in left atria but unaltered in papillary muscles from hypothyroid animals. 3. In rats subject to coronary artery occlusion, PTU pretreatment reduced the incidence of ventricular fibrillation during acute myocardial ischaemia and abolished reperfusion-induced ventricular fibrillation. Mortality during myocardial ischaemia and reperfusion was also abolished. Diastolic blood pressure was similar in hypothyroid and control animals, but there was a small reduction in systolic blood pressure and a marked decrease in heart rate in PTU pretreated animals. 4. These results demonstrate that PTU-induced hypothyroidism represents a condition where cardiac alpha-adrenoceptor-mediated responses are enhanced but the severity of ischaemia- and reperfusion-induced arrhythmias is reduced.

Topics: Anesthesia; Animals; Coronary Disease; Hypothyroidism; Isoproterenol; Male; Myocardial Reperfusion Injury; Myocardium; Papillary Muscles; Phenylephrine; Propylthiouracil; Rats; Rats, Inbred Strains; Receptors, Adrenergic, alpha; Ventricular Fibrillation

Topics: Animals; Body Weight; Cholesterol; Coronary Disease; Coronary Vessels; Death, Sudden; Diet, Atherogenic; Disease Models, Animal; Electrocardiography; Male; Myocardial Infarction; Myocardium; Propylthiouracil; Radiation Injuries, Experimental; Swine

Topics: Animals; Bile Acids and Salts; Coronary Disease; Hypercholesterolemia; Hyperlipidemias; Myocardial Infarction; Propylthiouracil; Rats; Salts; Thrombosis