What causes Torsades de Pointes?

As a medical professional with expertise in cardiology, I can provide you with an explanation of what causes Torsades de Pointes (TdP), a type of life-threatening ventricular arrhythmia. Torsades de Pointes is a specific type of polymorphic ventricular tachycardia that is characterized by rapid, irregular heart beats. It is typically associated with a particular disturbance in the heart's electrical activity known as the long QT syndrome (LQTS). The "QT" refers to the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle, which is measured on an electrocardiogram (ECG). A prolonged QT interval is a risk factor for TdP. Several factors can contribute to the development of Torsades de Pointes: 1. Genetic Mutations: Some people have a genetic predisposition to LQTS, which can lead to TdP. 2. Electrolyte Imbalances: Abnormal levels of electrolytes such as potassium, magnesium, and calcium can affect the heart's electrical activity and increase the risk of TdP. 3. Certain Medications: A number of drugs, particularly those that affect the heart's electrical activity, can prolong the QT interval and provoke TdP. These are often referred to as "QT-prolonging drugs." 4. Underlying Heart Conditions: Conditions that affect the heart's structure or function can increase the risk of TdP. 5. Bradycardia: An abnormally slow heart rate can also lead to a longer QT interval and TdP. 6. Acute Myocardial Infarction: A heart attack can cause changes in the heart's electrical activity that increase the risk of TdP. It's important to note that TdP is a serious condition that requires immediate medical attention, as it can degenerate into ventricular fibrillation or asystole, leading to sudden cardiac death.

Risk factors for torsade include the following: Congenital long QT syndrome. Female gender. Acquired long QT syndrome (causes of which include medications and electrolyte disorders such as hypokalemia and hypomagnesemia)