How acidity interferes with the heart beat

Modulation of hERG potassium channel function by extracellular acidosis: single channel effects and underlying basis

The heart’s ability to pump blood round the body depends on co-ordinated electrical activity generated by small proteins in heart cells called ‘ion channels’. When blood flow to the heart is blocked off, for example, because of coronary heart disease or a heart attack, the blood becomes acidic. This acidity alters cardiac ion channel function and can predispose the heart to develop an irregular heartbeat or arrhythmia. An ion channel called hERG is central to normal cardiac activity. There is evidence that acidity (acidosis) impairs hERG function in ways that increase arrhythmia risk but the underlying mechanisms are incompletely understood. This project aims to provide, for the first time, detailed insight into how acidosis alters the electrical activity of individual hERG channel proteins. Genetic methods will be used to investigate which parts of the ion channel protein are affected by acidosis to modify hERG function. The results of this study could explain how acidosis could interfere with the effectiveness of drugs used to treat arrhythmia.