Question

What is the most common cardiac defect caused due to lithium?

• A. Ebstein's anomaly
• B. HOCM
• C. Aortic aneurysm
• D. Eisenmenger syndrome

Hint:

This drug is classically linked to Ebstein's anomaly in the fetus.

Answer 1

The Correct Option is A

Step 1: Recall the drug in question.
Lithium is a mood stabilizer used mainly in bipolar disorder. When taken during the first trimester of pregnancy, it carries a risk to the developing heart of the fetus.

Step 2: Recall the classic cardiac defect linked with lithium.
Lithium exposure in early pregnancy is classically linked with Ebstein's anomaly, a defect where the tricuspid valve is displaced downward into the right ventricle, making part of the right ventricle act like an extension of the right atrium.

Step 3: Rule out the other choices.
Hypertrophic obstructive cardiomyopathy (HOCM) is usually inherited through gene mutations affecting heart muscle proteins, not linked to lithium exposure.
Aortic aneurysm is linked with connective tissue disorders such as Marfan syndrome, not with lithium.
Eisenmenger syndrome is a late complication of an untreated left to right shunt, not a direct drug induced defect.

Step 4: Add a note on current evidence.
Newer, larger studies have shown the absolute risk of Ebstein's anomaly with lithium is lower than older teaching suggested, but it remains the cardiac defect most specifically and classically tied to lithium exposure among the choices given here.

Final Answer:
\[ \boxed{\text{Ebstein's anomaly}} \]