Falling after CABG.

Sir, Pituitary infarction following Coronary Artery Bypass Grafting (CABG) is rare but may have serious debilitating effects. We present two cases of panhypopituitarism after CABG. BR, 56 years man who presented with repeated falls following CABG done eight months back. Of late he was pleasantly surprised to see wonderfully good glycaemic control, which he was struggling to get before. His BMI was 23, heart was in sinus rhythm (74/min), systolic blood pressure dropped from 110 to 90 mm Hg on standing. Systemic examination was unremarkable. Routine blood check including complete haemogram, liver and renal function, calcium profile and lipid were normal. He had hyponatraemia [serum Sodium 127 (normal 135-144) mmol/L] with normal serum Potassium [4.1 (3.8-5.2) mmol/L]. This led us to look for serum Cortisol [8am 90 (N-240 -510) nmol/L] and Thyroid function {TSH-0.1 (N-0.5-4.5) mIU/L, free T4-0.7 (N0.8-2.1) ng/dL}. Further endocrine work up showed low Testosterone {1.1 (N3-10) ng/ml} and disproportionately low LH {2.3 (N1-8) miu/ml} with normal Prolactin and failure of Cortisol to rise with ACTH stimulation. MR scan of the Pituitary showed atrophic gland making the diagnosis of complete anterior hypopituitarism with empty sella (Fig. 1). He was started on oral Hydrocortisone (initially 80, later reduced to 20 mg/d in three divided doses), Thyroxine (50 later to 100 mcg/d) and monthly injection of 250 mg Testosterone Undecanoate. In view of good improvement of quality of life, Growth Hormone therapy was not being considered. Our second patient was a 60-year-old man presented one month after CABG with repeated falls and sternal wound infection. Physical examination revealed postural hypotension. After CABG his insulin requirements were coming down. Investigations revealed low Sodium, normal Potassium (115meq/L and 4.3 meq/L respectively) and low 8am serum Cortisol (113nmol/ L). Further endocrine workup revealed features of secondary hypothyroidism and hypogonadism (TSH 5.1miu/lt, free T4 1.2 ng/dl , LH 10.7miu/lt and Testosterone 2.4ng/dl). MR scan of pituitary revealed small pituitary. He was started with Hydrocortisone, Thyroxine (50mcg/day) orally and monthly injection of Testosterone with wonderful subjective and objective improvement. Pituitary infarction, apoplexy and hypopituitarism following cardiac surgery, although rare have been reported earlier.1-3 Pituitary infarction probably arises secondary to the major haemodynamic changes, which occur during CABG with extracorporeal circulation. These include ischaemia, haemorrhage, edema and positive pressure ventilation. Both our cases our a subtle presentation of anterior hypopituitarism (feature of secondary hypocortisolism, secondary hypothyroidism and secondary hypogonadism). Increased awareness of hypopituitarism after CABG will lead to endocrine