The QT interval is the time from the beginning of the QRS complex (ventricular depolarization) to the end of the T wave (ventricular repolarization). The normal QT interval is controversial and ...

As more consumer-facing devices add features to measure the heart’s electrical activity, companies are looking for new ways to turn this data into valuable health information. AliveCor, a startup that ...

QT prolongation occurs when the heart muscle takes longer to contract and relax than usual. It can affect heart rhythms and lead to sudden cardiac arrest. The heart is a muscle that contracts and ...

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center. COVID-19 infection is associated with a significant increase in the corrected QT interval (QTc) in ...

Long QT interval is a condition that affects the heart’s electrical rhythm, which can lead to potentially life threatening arrhythmia. Behind the pumping action of the heart is an electrical ...

This cohort study assessed ECG parameters in transgender men and women before and after use of gender-affirming hormone therapies. Testosterone use in transgender men was associated with shorter ...