Congenital long QT syndrome can lead to?
**Core Concept**
Congenital long QT syndrome is a genetic disorder affecting the heart's electrical system, characterized by a prolonged QT interval on the electrocardiogram (ECG). This condition is associated with an increased risk of life-threatening arrhythmias, particularly torsades de pointes.
**Why the Correct Answer is Right**
The prolonged QT interval is due to abnormalities in the genes encoding cardiac ion channels, such as potassium (K+) and sodium (Na+) channels. These genetic mutations disrupt the normal repolarization process of the heart, leading to a prolonged action potential duration. This increases the risk of torsades de pointes, a polymorphic ventricular tachycardia that can degenerate into ventricular fibrillation and sudden cardiac death.
**Why Each Wrong Option is Incorrect**
**Option A:** Sudden hearing loss - This is incorrect because congenital long QT syndrome is primarily associated with cardiac arrhythmias, not auditory symptoms.
**Option B:** Wolff-Parkinson-White syndrome - While both conditions are cardiac arrhythmias, they are distinct entities with different underlying mechanisms. WPW syndrome is characterized by a pre-excitation pathway, whereas long QT syndrome is associated with abnormal repolarization.
**Option C:** Hypokalemia - This is incorrect because while potassium imbalances can affect the QT interval, congenital long QT syndrome is a genetic disorder affecting the underlying ion channels, not a result of electrolyte imbalances.
**Clinical Pearl / High-Yield Fact**
Remember that congenital long QT syndrome is a genetic condition that can be inherited in an autosomal dominant pattern, and affected individuals may be asymptomatic until a life-threatening arrhythmia occurs.
**Correct Answer: D. Torsades de pointes**