Iron Deficiency and Cardiac Palpitations

Mechanisms and Clinical Significance

Iron deficiency can directly cause cardiac palpitations through multiple mechanisms, including compensatory cardiac response, direct myocardial effects, and hyperdynamic circulation, even in the absence of anemia 1, 2
The European Society of Cardiology recommends evaluating iron status in all newly diagnosed heart failure patients, as iron deficiency affects 40-70% of chronic heart failure patients and is recognized as an important comorbidity independent of anemia 4
Iron deficiency in heart failure patients is associated with worse symptoms, reduced exercise capacity, and increased hospitalizations 5

Iron deficiency is defined as ferritin <100 μg/L OR ferritin 100-299 μg/L with transferrin saturation <20% in heart failure patients, and should be evaluated using ferritin and transferrin saturation simultaneously 4

Intravenous iron is preferred over oral supplementation in heart failure patients with iron deficiency, as it bypasses hepcidin-mediated blockade of intestinal absorption, and improves exercise capacity, quality of life, and reduces hospitalizations 5, 6
The European Society of Cardiology gives a Class IIa recommendation for IV iron therapy in heart failure patients with reduced ejection fraction and iron deficiency 6
Oral iron supplementation is first-line for patients without cardiovascular disease, with ferrous sulfate 324 mg (65 mg elemental iron) daily or twice daily between meals, and treatment should continue for 2-3 months after hemoglobin normalization to replenish iron stores 6

Erythropoiesis-stimulating agents should be avoided in patients with mild to moderate anemia and heart disease, as harms outweigh benefits 7, 2
Patients with pre-existing cardiac conditions should be monitored more closely when starting iron supplementation 3
IV iron should be withheld during active infections, as these patients were excluded from clinical trials 8