Potassium and Cardiovascular Disease

Hyperkalemia (potassium levels >5.5 mEq/L) or hypokalemia (potassium < 3.5 mEq/L) may incur potentially serious cardiovascular (CV) complications. Hyperkalemia is most commonly encountered in renal failure, K+ oversupplementation for diuretic therapy, use of potassium-sparing diuretics, therapy with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in cardiorenal disease (chronic kidney disease [CKD] and/or heart failure-HF), digitalis toxicity, massive hemolysis, or muscle trauma. For patients with hyperkalemia, potassium binders (sodium zirconium cyclosilicate, patiromer, and sodium polystyrene) are guideline-recommended for patients with CKD. Importantly, proactive potassium control via routine use of potassium binders in hyperkalemia may incur cost reduction in acute care while simultaneously supporting optimization of medications for comorbid conditions. Hypokalemia can occur in response to diuretic therapy (7-56%), following renal dialysis, or during recovery from endurance exercise and can be equally detrimental as it may raise the risk of ventricular arrhythmias and cardiac arrest. Its diagnosis depends on the level of serum potassium. An ECG is useful in identifying the more severe consequences. Hypokalemia occurs in up to 20% of hospitalized patients and incurs an increased incidence of ventricular and atrial fibrillation. Importantly, "you cannot eat your way out of hypokalemia," i.e., by adding bananas and/or other potassium-providing fruit or juices, hence one needs to provide the patient with K+ supplements in tablet or liquid form or in more serious cases via slow (10 mmol/h) IV supplementation in highly controlled, strict hospital protocols and with continuous ECG monitoring. All these issues of serum potassium disturbances and their CV effects are herein reviewed.