ECG Pattern of Hyperkalemia in Acute versus Chronic Kidney Disease

Background: Hyperkalemia is a life-threatening complication of kidney disease, but its electrocardiographic (ECG) manifestations may differ between acute Kidney Disease (AKD) and chronic kidney disease (CKD), particularly in pediatric patients. Aim of the work: to compare ECG changes in hyperkalemic children with AKD and CKD and to correlate these findings with biochemical and clinical parameters. Patients and Methods: A cross-sectional study was conducted on 89 children with hyperkalemia, including 40 with AKD and 49 with CKD, at the Pediatric Nephrology Unit, Menoufia University. All patients underwent detailed history, anthropometric and clinical examination, laboratory investigations (serum electrolytes, urea, creatinine), and standard 12-lead ECG. Results: Children with CKD were older than those with AKD. Serum potassium was significantly higher in AKD, whereas urea and creatinine were markedly higher in CKD. QRS prolongation occurred more often in AKD than CKD. QTc prolongation was more frequent in AKD, with abnormal T waves also significantly higher. Small or flat P-waves were strikingly more prevalent in AKD (97.5%) compared with CKD (28.6%, p < 0.001). Logistic regression confirmed that AKD independently predicted P-wave abnormalities, while low calcium was also associated (OR = 0.54, p = 0.017). The Tp–e interval was significantly shorter in AKD than in CKD. Conclusion: Hyperkalemia in children presents with distinct ECG abnormalities that differ between AKD and CKD. Acute cases were more frequently associated with abnormal P-waves, abnormal T-waves, QRS widening, and QTc prolongation, reflecting rapid and unstable potassium shifts. In contrast, CKD patients demonstrated more chronic adaptive changes. These findings highlight the importance of careful ECG monitoring in hyperkalemic children, particularly those with AKD, to enable timely detection of life-threatening arrhythmias and guide condition-specific management strategies.