Hypercalcemic crisis and primary hyperparathyroidism: Cause of an unusual electrical storm

Area of Science:

• Cardiology
• Endocrinology
• Medical Case Reports

Background:

• Hypercalcemia is a known cause of cardiac rhythm disturbances.
• Ventricular arrhythmias associated with hypercalcemia are considered rare.
• Patients with dilated cardiomyopathy and reduced ejection fraction are at higher risk for arrhythmias.

Observation:

• A 53-year-old male with ischemic and alcoholic dilated cardiomyopathy, reduced ejection fraction, and implanted cardiac resynchronization therapy (CRT) with cardioverter defibrillator (ICD) presented with an electrical storm.
• The patient experienced multiple appropriate ICD shocks refractory to antiarrhythmic therapy.
• Diagnostic workup revealed severe hypercalcemia secondary to previously undiagnosed primary hyperparathyroidism.

Findings:

• Severe hypercalcemia was identified as the underlying cause of the refractory ventricular arrhythmias.
• Reduction of serum calcium levels led to the cessation of ventricular tachycardia and the electrical storm.

Implications:

• This case highlights the critical importance of investigating metabolic causes, such as hypercalcemia, in patients presenting with electrical storms, even those with known structural heart disease.
• Early diagnosis and management of primary hyperparathyroidism are crucial for preventing life-threatening cardiac events.
• Clinicians should consider screening for hypercalcemia in patients with unexplained ventricular arrhythmias or electrical storms.