What is QT prolongation and torsade de pointes?

As a medical professional with expertise in cardiology, I can provide you with an explanation of QT prolongation and Torsades de Pointes. QT Prolongation is a condition that affects the heart's electrical activity, which can be seen on an electrocardiogram (ECG). The QT interval represents the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. It reflects the time taken for the ventricles to depolarize and then repolarize, which is crucial for the proper timing of the heartbeat. When the QT interval is longer than normal, it is referred to as QT prolongation. This can lead to a potentially life-threatening heart rhythm disturbance known as Torsades de Pointes. Torsades de Pointes is a specific type of ventricular tachycardia, which is a rapid and irregular heart rhythm that originates in the ventricles of the heart. The name "Torsades de Pointes" translates to "twisting of the points" in French, which is a descriptive term for the pattern seen on the ECG. This condition is characterized by a series of rapid, irregular beats that can lead to a sudden loss of consciousness and even death if not treated promptly. QT prolongation can be congenital (present from birth) or acquired (developed later in life). Acquired QT prolongation is often due to medications, electrolyte imbalances, or certain medical conditions. It's important for healthcare providers to be aware of the medications that can cause QT prolongation because they can lead to Torsades de Pointes.

If TdP is rapid or prolonged, it can lead to ventricular fibrillation and sudden cardiac death (fig 1?). Essentially, TdP may be caused by either congenital or acquired long QT syndrome (LQTS). ... (A) Self limiting torsades de pointes (TdP). (B) TdP leading to ventricular fibrillation.