GTN

Question 1

What is the mechanism of action of GTN?

Answer 1

Nitrite –> NO –> increased cGMP –> Smooth muscle relaxation.

Question 2

What are the clinical effects of GTN?

Answer 2

1. Beneficial effects: venodilation, reduced VR, decreased ventricular pre-load, reduced LVEDV, reduced LV wall tension, reduced myocardial oxygen consumption. Vasodilation of epicardial coronary arteries, increased coronary collateral flow. Decreased systemic BP.
2. Adverse effects: hypotension, tachycardia, headache.

Question 3

What are the indications for GTN use in the ED?

Answer 3

Angina

Acute coronary syndrome

Hypertensive urgencies / emergencies

APO

Aortic dissection (with beta-blockade)