PTH and cardiac arrhythmia: Primary hyperparathyroidism (pHPT) is the third most common endocrine disorder worldwide, characterized by the overproduction of parathyroid hormone (PTH), which often leads to hypercalcemia and a range of systemic complications.1,2,3 Among the most serious complications are the cardiovascular risks associated with pHPT, including hypertension,4 arrhythmias, and vascular calcification, which impair patient well-being and quality of life.