Cyclic sinus node dysfunction in a patient with hyperthyroidism.

In a 54-year-old woman with hyperthyroidism, episodic sinus node dysfunction (SND) recurred in a cyclic fashion. The SND occurred suddenly during normal sinus rhythm and progressed to marked sinus bradycardia; occasionally, sinus arrest developed with or without ventricular escape beats. A 1-mg dose of intravenous atropine sulfate suppressed the occurrence transiently. After a 200-mg dose of propylthiouracil and a 20-mg dose of prednisolone every six hours, the SND was completely abolished within 21 hours. It is probable that, together with a pathologic process induced by hyperthyroidism, the autonomic nervous system participated in our patient's episodic SND.

[1]  T. Cheng,et al.  Coronary artery spasm with sinus node dysfunction and syncope. , 1982, Archives of internal medicine.

[2]  R. Wolfe,et al.  Rapid fluctuations in plasma catecholamines in monkeys under undisturbed conditions. , 1982, The American journal of physiology.

[3]  R. Peters,et al.  Clinical and Electrophysiologic Findings in Patients with Paroxysmal Slowing of the Sinus Rate and Apparent Mobitz Type II Atrioventricular Block , 1978, Circulation.

[4]  D. Dighton.  Sinoatrial block. Autonomic influences and clinical assessment. , 1975, British heart journal.

[5]  T F Gallagher,et al.  ACTH and cortisol secretory patterns in man. , 1973, The Journal of clinical endocrinology and metabolism.

[6]  C. Toh,et al.  The sick sinus syndrome. A study of 15 cases. , 1972, British heart journal.

[7]  J. Han,et al.  A-V conduction in hyper- and hypothyroid dogs. , 1972, American heart journal.

[8]  D. Heimbach,et al.  Effect of atropine on the tachycardia of hyperthyroidism. , 1972, Archives of internal medicine.

[9]  M. Stjernholm,et al.  Complete heart block with thyrotoxic myocarditis. Report of a case. , 1970, The New England journal of medicine.

[10]  L. Sataline,et al.  Hypercalcemia, heart-block, and hyperthyroidism. , 1970, JAMA.

[11]  L. Papadaki,et al.  Cardiovascular effects of thyroxine. , 1969, Cardiovascular research.

[12]  J. Crout,et al.  Role of the autonomic nervous system in the resting tachycardia of experimental hyperthyroidism. , 1967, The Journal of pharmacology and experimental therapeutics.

[13]  R. Lowrey,et al.  The electrocardiogram in thyrotoxicosis. , 1960, The American journal of cardiology.

[14]  J. Rupp,et al.  Prolongation of the P-R interval as a manifestation of thyrotoxicosis. , 1960, JAMA.

[15]  Harry L. Smith,et al.  Complete heart-block in hyperthyroidism following acute infections: A report of six cases with necropsy findings in one case , 1933 .