Pseudohypoparathyroidism and Cardiomyopathy: A Case Report with a New Perspective on the Cardiovascular-Endocrine Axis with Respect to Calcium Homeostasis

Pseudohypoparathyroidism encompasses a group of heterogeneous disorders defined by targeted organ unresponsiveness to parathyroid hormone (PTH). With an estimated prevalence of approximately 0.79 per 100,000, this is an extremely rare group of genetic disorders. The documented phenotypic manifestations and complications of this condition include skeletal abnormalities, thyroid-stimulating hormone (TSH) resistance, growth hormone deficiencies and abnormalities in gonadotropic hormones. However, the cardiovascular effects of this condition have never been studied. To the knowledge of the writer, this is the first report of pseudohypoparathyroidism resulting in profound hypocalcaemia leading to heart failure in a previously healthy 22-year-old man with no known cardiac history. Following treatment with calcium replacement therapy, the patient’s cardiac function improved dramatically, demonstrating the seminal role played by serum calcium in myocardial contractility and its influence on cardiac function. LEARNING POINTS: In patients with heart failure, serum calcium must be measured, especially if the underlying aetiology of heart failure is unclear. In patients with heart failure, correction of calcium levels is an important aspect of management. Patients with pseudohypoparathyroidism should undergo cardiac evaluation, especially in the presence of symptoms such as peripheral oedema and dyspnoea on exertion.