Spike and Dome pattern is seen in: March 2007
## **Core Concept**
The "spike and dome" pattern is a characteristic electrocardiographic (ECG) finding. It is primarily associated with a specific abnormality in cardiac electrophysiology, particularly related to **Torsades de Pointes**, a type of polymorphic ventricular tachycardia.
## **Why the Correct Answer is Right**
The spike and dome pattern, often referred to in the context of a "spike-and-dome" or "tented" appearance, is seen in the ECG in conditions that affect the cardiac action potential, specifically prolonging the QT interval. This pattern is a hallmark of **Long QT Syndrome (LQTS)**, which predisposes individuals to Torsades de Pointes. The "spike" refers to the early rapid depolarization, and the "dome" refers to the late repolarization phase of the T wave. This abnormal T wave morphology is a critical indicator of the abnormal repolarization that underlies LQTS.
## **Why Each Wrong Option is Incorrect**
- **Option A:** Incorrect because, although it could potentially represent a cardiac condition, the specific association with a "spike and dome" pattern is not as directly related as Option .
- **Option B:** Incorrect because it does not directly correlate with the characteristic ECG findings of a "spike and dome" pattern.
- **Option C:** Incorrect because the details of this option are not provided, but based on the context, it is less directly related to the spike and dome pattern compared to the correct answer.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the "spike and dome" pattern on an ECG is highly suggestive of **Long QT Syndrome**. This condition can be congenital or acquired and significantly increases the risk of life-threatening arrhythmias like Torsades de Pointes. Recognizing this pattern is crucial for immediate intervention to prevent cardiac catastrophes.
## **Correct Answer: D. Long QT Syndrome.**