# QT Prolongation and Torsades De Pointes Due to Undiagnosed Sheehan Syndrome: A Rare Cause of Lethal Arrhythmia

## TL;DR

A rare case of lethal arrhythmia caused by undiagnosed Sheehan syndrome was successfully treated with hormone replacement.

## Contribution

Highlights Sheehan syndrome as a rare but treatable cause of long QT syndrome and torsades de pointes.

## Key findings

- The patient's LQTS and TdP were linked to undiagnosed Sheehan syndrome.
- Hormone replacement therapy normalized the QTc interval within two weeks.
- Delayed diagnosis was due to gradual symptom onset and lack of medical checkups.

## Abstract

We report a case of long QT syndrome (LQTS) associated with torsades de pointes (TdP) in a 57-year-old female patient transferred to our cardiac care unit/intensive care unit with septic shock secondary to urinary tract infection (UTI) from an adjacent hospital. The patient had no notable medications or electrolyte abnormalities that could have contributed to acquired LQTS, with normal potassium and only slightly reduced calcium (1.06 mmol/L) and magnesium (1.8 mg/dL). After detailed history taking and exploration, the patient was diagnosed with Sheehan syndrome secondary to a complicated delivery she experienced 20 years before. The diagnosis was confirmed by a combination of clinical history (poor lactation after delivery, progressive lethargy), laboratory findings showing anterior pituitary hormone deficiencies, and imaging evidence of empty sella on pituitary MRI. The diagnosis had been missed for two decades due to a lack of regular medical checkups and the gradual onset of symptoms that went unrecognized. Hypothyroidism and adrenal crisis precipitated by sepsis were considered as the underlying etiology for her LQTS-associated TdP. Concurrent supplementation with levothyroxine and hydrocortisone for two weeks successfully shortened the QTc interval from 722 msec to 434 msec, with sustained normalization thereafter.