ECG Cardiac Anatomy 3

Question 1

The fossa ovalis is a remnant of which fetal structure?

Accepted Answer

Foramen ovale

Answer

After birth, the foramen ovale closes and becomes the fossa ovalis, a thin depression in the interatrial septum.

Question 2

Which ECG lead best reflects the lateral wall of the left ventricle supplied by the left circumflex artery?

Accepted Answer

I, aVL, V5–V6

Answer

Leads I, aVL, V5, and V6 face the lateral wall, making them most sensitive to lateral ischemia from circumflex disease.

Question 3

How many pulmonary veins typically drain into the left atrium?

Accepted Answer

Four

Answer

Normally four pulmonary veins (two from each lung) return oxygenated blood to the left atrium.

Question 4

The moderator band (septomarginal trabecula) is found in which cardiac chamber?

Accepted Answer

Right ventricle

Answer

The moderator band crosses the right ventricular cavity and carries part of the right bundle branch to the anterior papillary muscle.

Question 5

Which artery is the most common culprit in anterior ST-elevation MI?

Accepted Answer

Left anterior descending artery

Answer

The LAD supplies the anterior left ventricular wall and septum; its occlusion causes anterior STEMI seen in V1–V4.

ECG Certification Practice Test