A Case of Reversible Atrioventricular Block Potentially Associated with Atenolol-Induced Hyperkalemia

Area of Science:

• Cardiology
• Nephrology
• Clinical Pharmacology

Background:

• Potassium is crucial for cardiac electrophysiology; abnormal levels, particularly hyperkalemia, can cause life-threatening arrhythmias.
• Drug-induced hyperkalemia is a significant clinical concern, often precipitated by medications in patients with underlying conditions.
• End-stage renal disease (ESRD) patients are particularly vulnerable to electrolyte imbalances due to impaired kidney function.

Observation:

• A case report details an ESRD patient experiencing hyperkalemia and type II second-degree atrioventricular (AV) block.
• The patient's condition emerged upon initiation of atenolol therapy.
• Hyperkalemia and AV block resolved after discontinuing atenolol and treating the electrolyte imbalance.

Findings:

• Atenolol, a beta-blocker, was identified as the likely cause of drug-induced hyperkalemia and subsequent AV block in this ESRD patient.
• The resolution of both hyperkalemia and heart block upon atenolol withdrawal strongly suggests a causal relationship.
• This case underscores the importance of monitoring potassium levels and cardiac function in patients with ESRD initiating beta-blocker therapy.

Implications:

• Clinicians should be vigilant for hyperkalemia and associated cardiac conduction abnormalities in ESRD patients prescribed atenolol.
• Discontinuation of the offending drug (atenolol) can effectively manage drug-induced hyperkalemia and related cardiac complications.
• This case emphasizes the need for careful medication review and monitoring in vulnerable patient populations to prevent adverse drug events.