W008
An unusual case of Autoimmune Hypoparathyroidism: presenting as Congestive cardiac failure and Myocardial Infacrction
Neelam Khalid, Hadleigh Cuthbert, Adie Viljoen, Peter Winocour, Sagen Zac-Varghese, Kanchana Rajaguru, Lister Hospital, Stevenage
66 year old lady was admitted to the A&E department with shortness of breath and chest tightness. She had a background of hypertension and migraine. There was no significant family history and no past medical history, in particular no previous neck irradiation or surgery. Her admission blood tests revealed low corrected calcium of 1.35 mmol/L. She denied any symptoms of hypocalcemia. Clinical examination was normal, there was no paraethesia, tetany or other neurological findings and she had a negative Trousseau and Chvostek’s sign. The lack of signs and symptoms pointed to a chronic cause for the hypocalcaemia. She was of normal height and had normal bone development. She had 2 children and had no problems during pregnancy. Her children did not have any known medical conditions and were of normal height and had developed normally. Her PTH was undetectable at a level of <0.0 pmol/L (repeated three times and discussed with the biochemistry department to exclude assay interference). 25-HydroxyVitamin D3 was sufficient at 63.6 nmol/L.
Electrolytes showed marginally raised phosphate 2.52 mmol/L, normal Magnesium 0.82mmol/L and normal renal function. Her thyroid function tests and serum cortisol were normal. She was commenced on Calcium infusion, 10% calcium gluconate at 50ml/hr and this was titrated according to response. She remained on Calcium infusion for 72 hrs. Following this her adjusted calcium was 2.20 mmol/L. She was commenced on oral Calcium carbonate 1g BD and 0.5 mcg Alpha calcidol daily to maintain her calcium levels. Whole body CT was performed and it ruled out any infiltrative/malignant process.
Her initial ECG showed QTC prolongation 487 and ST depression in V4-V6. She had a raised troponin and was treated for acute coronary syndrome. An echo showed severe left ventricular systolic dysfunction. An angiogram was performed which showed severe multivessel atherosclerosis and she was referred for a CABG.
Learning point: This was a rare case of likely Autoimmune Hypoparathyroidism, presenting following an acute coronary syndrome. Autoimmune Hypoparathyroidism can occur as two main etiologies, either as an isolated enzyme deficiency of PTH or in connection with other endocrine enzyme deficiencies. In cases of hypoparathyridism, where there is no history of thyroid or neck surgery, it is also important to rule out infiltrative process.