Evaluation of long-term pituitary functions in patients with severe ventricular arrhythmia: a pilot study.

Abstract

Traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), stroke and cerebrovascular disease (CVD) are identified as risk factors for hypopituitarism. Pituitary dysfunction after TBI, SAH, and CVD may present in the acute phase or later in the course of the event. Chronic hypopituitarism, particularly growth hormone (GH) deficiency is related to the increased cardiovascular morbidity and mortality. In patients with serious ventricular arrhythmias, who need cardiopulmonary resuscitation, brain tissue is exposed to short-term severe ischemia and hypoxia. However, there are no data in the literature regarding pituitary dysfunction after ventricular arrhythmias. Forty-four patients with ventricular arrhythmias [ventricular tachycardia (VT), ventricular fibrillation (VF)] (mean age, 55.6 ± 1.8 years; 37 men, 7 women) were included in the study. The patients were evaluated after mean period of 21.2 ± 0.8 months from VT-VF. Basal hormone levels, including serum free triiodothyronine (fT3), free thyroxine (fT4), TSH, ACTH, prolactin, FSH, LH, total testosterone, estradiol, IGF-1, and cortisol levels were measured in all patients. To assess (GH)-insulin like growth factor-1 (IGF-1) axis, glucagon stimulation test was performed and 1 µg ACTH stimulation test was used for assessing hypothalamic-pituitary-adrenal (HPA) axis. The frequencies of GH, gonadotropin and TSH deficiency were 27.2, 9.0, 2.2%, respectively. Mean IGF-1 levels were lower in GH deficiency group, but it was not statistically significant. The present preliminary study showed that ventricular arrhythmias may result in hypopituitarism, particularly in growth hormone deficiency. Unrecognized hypopituitarism may be responsible for some of the cardiovascular problems at least in some patients.