Glossary

Arrhythmia: a group of conditions associated with irregular electrical activity in the heart which leads to abnormal heart rhythm.

COVID-19: coronavirus disease 2019

hERG: human Ether-à-go-go-Related Gene, a gene that codes for a protein known as Kv11.1, the alpha subunit of a potassium ion channel. This channel mediates the repolarizing (reset) current in the cardiac action potential, which helps coordinate the heart's beating. For simplicity, the term “hERG” is frequently used to describe the entire potassium channel.

QTc: heart rate corrected QT interval.

QT interval: a measurement made on an electrocardiogram used to assess some of the electrical properties of the heart. It approximates the time taken from when the cardiac ventricles start to contract to when they finish relaxing. An abnormally long or abnormally short QT interval is associated with an increased risk of developing abnormal heart rhythms and sudden cardiac death.

QT prolongation: an electrocardiographic measure of delayed ventricular repolarization, meaning the heart muscle takes longer than normal to “reset” between beats.

SARS-CoV-2: severe acute respiratory syndrome coronavirus 2

Cardiac arrest (sudden cardiac death): rapid loss of blood flow resulting from the failure of the heart to pump effectively. If not treated within minutes, it typically leads to death.

Torsade de Pointes (TdP): a specific type of arrhythmia that can lead to sudden cardiac death (French: translated as "twisting of peaks")