Diagnostic and Prognostic Value of Arterial Blood Gas and Electrolyte Analyses in Heart Failure

: Heart failure (HF) is a multifaceted clinical syndrome that frequently precipitates disturbances in perfusion, ventilation, and metabolic regulation, all of which are rapidly detectable through arterial blood gas (ABG) analysis. Meanwhile, clinical markers such as lactate, arterial pH, arterial partial pressure of carbon dioxide (PaCO2), arterial partial pressure of oxygen (PaO2), bicarbonate, and electrolyte concentrations provide dynamic insight into the pathophysiologic status of patients and can serve as early indicators of decompensation. This review evaluates the clinical significance of key ABG and electrolyte parameters in both acute and chronic HF, emphasizing the prognostic value of the analyses, contribution to risk stratification, and utility in guiding therapy. In acute HF and cardiogenic shock, hyperlactatemia and acidosis are associated with increased mortality and the need for hemodynamic or ventilatory support. Furthermore, electrolyte abnormalities, particularly those involving sodium and potassium, are common and driven by neurohormonal activation, pharmacological therapies, and volume shifts. Therefore, integrating ABG and electrolyte monitoring into routine HF management can enhance diagnostic precision and support timely, targeted interventions. This narrative review synthesizes current evidence and proposes a practical framework for interpreting ABG results in the context of contemporary HF care.