**Question:** Spoked wheel appearance is seen in

A. Angiography
B. Chest X-ray
C. Electrocardiogram (ECG)
D. Ultrasound

**Correct Answer:** C. Electrocardiogram (ECG)

**Core Concept:** Spoked wheel appearance in an electrocardiogram refers to a specific pattern observed during the QRS complex, which is a crucial part of the cardiac cycle. It represents the depolarisation and repolarisation of cardiac muscle cells.

**Why the Correct Answer is Right:** The spoked wheel appearance is associated with the presence of right bundle branch block (RBBB). RBBB is a type of conduction system abnormality that occurs when the electrical impulse fails to pass properly through the right bundle branch of the heart, leading to delays in the depolarisation and repolarisation of the right ventricle. This results in a characteristic pattern on the ECG, resembling a spoked wheel.

**Why Each Wrong Option is Incorrect:**

A. Angiography (A): Angiography is an imaging technique that visualises the heart's blood vessels, not the cardiac muscle. It is unrelated to the QRS complex and does not demonstrate spoked wheel appearance.

B. Chest X-ray (B): Chest X-rays provide information about the heart size, position, and lung parenchyma but do not display the QRS complex or demonstrate the spoked wheel appearance.

D. Ultrasound (D): Ultrasound is an imaging modality used to visualise internal structures, including the heart. While it can show the heart's size, position, and motion, it does not display the QRS complex or reveal the spoked wheel appearance.

**Clinical Pearl:** Understanding the spoked wheel appearance on an ECG and its association with right bundle branch block is crucial for medical professionals, particularly cardiologists, to accurately diagnose and manage patients with cardiac conditions.

**Core Concept:** The spoked wheel appearance in the QRS complex is a clinical sign, which indicates right bundle branch block (RBBB). RBBB is a type of electrical conduction disorder, where the electrical impulse fails to propagate effectively through the right bundle branch of the heart, leading to a delay in depolarization and repolarization of the right ventricle. This results in a characteristic pattern on the electrocardiography (ECG) tracing, which resembles a spoked wheel.

Understanding the spoked wheel appearance on an ECG helps in diagnosing cardiac conditions, such as right ventricular hypertrophy, myocardial infarction, or right ventricular ischemia, among others. This can aid in formulating an appropriate treatment plan and monitoring the patient's response to therapy.

**Why Each Wrong Option is Incorrect:**

A. Angiography: Angiography is an imaging technique that visualizes the heart's blood vessels, not the heart's electrical activity or QRS complex. Therefore, it is unrelated to the spoked wheel appearance in ECGs.

B. Chest X-ray: Chest X-rays provide information on heart size, position,