Anti-Arrhythmic Drugs--Nordgren

Question 1

Atrial, Purkinjie, and Ventricular cells depends on what ion to depolarize?

Answer 1

Na⁺

Question 2

SA and AV nodal cells depend on which ion to depolarize?

Answer 2

Ca²⁺

Question 3

What ion is responsible for phase 3 (repolarization) of all cardiac cells?

Answer 3

K⁺ (increase in permeability)

Question 4

Hypokalemia does what to membrane conductance in pacemaker?

Answer 4

increases K+ conductance

decreases duration of phases 3 and 4

increases HR

Question 5

Hyperkalemia does what to membrane conductance in pacemaker?

Answer 5

decreases K+ conductance

increases length of phases 3 and 4

decrease HR

Question 6

Early Afterdepolarization

Answer 6

opening of Ca2⁺ channels

inhibition of K⁺ channels

during phase 2 or 3 (when not normally expected)

Question 7

Delayed Afterpolarization

Answer 7

elevated Ca2+ cytoplasmic levels

occur AFTER AP

Question 8

Early afterdepolzarizations occur in what type of heart beats?

Answer 8

slow HR

Question 9

Delayed afterdepolarizations occur in what type of heart beat?

Answer 9

fast HR

Question 10

Reentry of impulses

Answer 10

impulses reenter excited areas of the heart more than once

large or small areas

Question 11

Reentry is most dependent on this factor

Answer 11

timing

has to be unidirectional block

not bidirectional block

Question 12

What is the goal of anti-arrhythmic drug therapy?

Answer 12

affect pathological cells

without affecting normally polarized cells