Evaluation of the Relationship Between Electrocardiographic Changes and the Calcium/Potassium Ratio in Patients with Acute and Chronic Renal Failure

The aim of this study was to investigate the relationship between serum calcium and potassium levels, as well as the calcium/potassium ratio, and electrocardiographic (ECG) changes in patients presenting to the emergency department with both renal failure and hyperkalemia. This cross-sectional study was conducted retrospectively by reviewing the medical records of patients diagnosed with renal failure and concomitant hyperkalemia (serum potassium>5.5 mEq/L) who presented to the emergency departments of a university hospital and a training and research hospital between November 1, 2022, and October 31, 2023. 55.4% of the patients were male, with a mean age of 68.31 ± 13.56 years. ECG abnormalities were detected in 69.5% of the cases. The most frequently observed ECG abnormalities were atrial fibrillation (22.0%) and peaked T waves (20.3%). Hemodialysis was performed in 52.5% of patients, 23.2% were admitted to the intensive care unit (ICU), and 15.8% died within 30 days of hospital presentation. Patients with T wave inversion had significantly lower potassium levels (6.42 ± 0.77 vs. 6.03 ± 0.71, p=0.018). In patients with any ECG abnormality, calcium levels (8.69 ± 0.87 vs. 8.36 ± 0.85, p=0.037) and calcium/potassium ratios (1.39 ± 0.19 vs. 1.32 ± 0.20, p=0.036) were significantly lower. The calcium/potassium ratio was also significantly lower in patients with peaked T waves (1.36 ± 0.20 vs. 1.27 ± 0.20, p=0.016). Among patients who died in-hospital or within 30 days, calcium/potassium ratios were significantly lower and potassium levels were significantly higher (p