Cardiac Pharmacology

Question 1

Describe the ECG in a mildly hyperkalemic patient. 5.5-6.5

Answer 1

Peaked T waves, Prolonged PR segment

Question 2

Describe the ECG in a Moderately hyperkalemic patient. 6.5-8

Answer 2

No P wave, Prolonged QRS

ST-segment elevation

Question 3

Describe the ECG in a severely hyperkalemic patient. > 8.0

Answer 3

Sine wave

Progressive widening of QRS

Question 4

Describe the ECG in a hypokalemic patient

Answer 4

Wide PR and QRS
ST depression
Flat T wave

Question 5

Discuss the clinical application of Digoxin

Answer 5

Prolongs the refractory period of the AV node in patients with supraventricular arrythmias

Question 6

Discuss Class 1A antiarrhythmic agents. Blocks Na and K

Answer 6

1. Slows conduction velocity and decreased pacemaker rate;
2. Increases QRS and QT intervals secondary to decrease in AV conductions
3. Prolongs AP and increases refractory period

Question 7

What are the side effects of Procainamide and Quinidine? (Class 1A)

Answer 7

Procainamide- SLE

Quinidine- Torsades and GI

Question 8

Discuss Lidocaine. Class 1B; Blocks Na

Answer 8

1. Blocks activated and inactivated channels with FAST kinetics.
2. Does NOT prolong action potential; decreases conduction
3. Shortens refractory period and shortens AP

Question 9

What is Lidocaine used for?

Answer 9

ONLY ventricular arrhrythmias

Question 10

Discuss Class 1C. Blocks Na (Flecainide or propafenone)

Answer 10

1. slows conduction velocity
2. prolongs PR interval and lengthens QRS duration.
3. Prolongs refractory period of AV Node

Question 11

What is the clinical application of Flecainide/Propafenone?

Answer 11

1. Supraventricular arrhythmias in pts with normal heart.

DO NOT use in ischemic conditions.