Systemic acid-base imbalances significantly influence the heart, both clinically and exper-imentally. Extensive knowledge exists regarding the impact of pH on cardiac function, yet the role of organic anions accumulating in acidosis is less explored. In severe metabolic acidosis cases, such as hereditary organic acidemias, these organic compounds can reach millimolar concentrations in blood and other body fluids, exerting significant physiologi-cal effects on the heart. Cardiomyopathies and arrhythmias are common in patients with organic acidemia, although the underlying pathophysiological processes remain unclear. Research into organic anion physiology, particularly concerning propionate – which accu-mulates in propionic acidemia (PA), a form of organic acidemia commonly associated with cardiac illness – has increased substantially in recent years. The purpose of this review is to provide an overview of the cardiac sequelae observed in PA patients who suffer from cardiac diseases.