1. Trimetazidine is an antianginal agent which acts by inhibition of:

A. Beta oxidation of fatty acids

B. Anaerobic metabolism of glucose

C. Calicum channels

D. Beta adrenergic receptors

Answer:

A. Beta oxidation of fatty acids

Normal myocardium utilises more of fatty acids than glucose for energy production. Oxidation of fatty acids requires more of oxygen per ATP molecule generated. If beta oxidation of fatty acids is inhibited, the metabolism shifts to glucose utilisation which uses less oxygen per molecule of ATP generated, hence it is useful to the ischemic myocardium.

2. Nicorandil is a:

A. Calcium channel blocker

B. Potassium channel blocker

C. Sodium channel blocker

D. Potassium channel activator

Answer:

D. Potassium channel activator

Nicorandil is an anti anginal agent without any significant hemodynamic effect.

3. The important mechanism of action of ranolazine is:

A. Inhibits late sodium channel current

B. Inhibits beta receptors

C. Inhibits L – type calcium channels

D. Inhibits transient outward potassium current

Answer:

A. Inhibits normal and abnormal late Na+ channel current

Ranolazine also inhibits beta oxidation of fatty acids partially. It acts as an antianginal agent by both these mechanism.

4. The important structure seen in the triangle of Koch is:

A. Sinoatrial node

B. Suprascapular artery

C. Femoral artery

D. Atrioventricular node

Answer:

D. Atrioventricular node

Triangle of Koch is situated on the septal wall of the right atrium, bounded by the tricuspid valve, coronary sinus orifice and tendon of Todaro. Atrioventricular node is situated at the apex of the triangle.

5. Which of the following rhythms is taken as a marker of successful ablation of atrioventricular nodal re-entrant tachycardia (AVNRT)?

A. Ventricular tachycardia

B. Sinus rhythm

C. Juncation rhythm

D. Atrial fibrillation

Answer:

C. Juncation rhythm

Usually a short run of accelerated junctional rhythm occurs during successful radiofrequency catheter ablation of AVNRT. Non inducibility of tachycardia is an important criterion of success.