Med Chem - Arrhythmias

Question 1

Define an arrhythmia

Answer 1

an abnormal heart RHYTHM

Question 2

true or false

an arrhythmia is defined as an abnormal heart rate

Answer 2

FALSE - ABNORMAL RHYTHM

but faulty electrical signaling can cause heart rate issues like tachycardia, bradycardia, or erratic, irregular beats

Question 3

define tachycardia and bradycardia

Answer 3

tachycardia - over 100bpm

bradycardia - under 60 bpm

Question 4

what are supraventricular arrhythmias?

give an example

Answer 4

arrhythmias that begin in the atria

ie - atrial fibrillation

Question 5

true or false

ventricular arrhythmias begin in the ventricles

Answer 5

true

Question 6

what are bradyarrhythmias and why do they occur

Answer 6

abnormally slow and irregular heartbeats

happens bc of issues in the heart’s conduction (AV/SA node_ or His-purkinje fibers

Question 7

what is the general target of antiarrhythmic drugs

Answer 7

the flow of ions that controls the electrical current in the heart

Question 8

in what part of the heart is the SA node (pacemaker) located

Answer 8

the right atrium

Question 9

explain–

gain of function sodium channel genes

loss of function sodium channel genes

Answer 9

gain of function - QT will be prolonged and the patient will have fast, chaotic heart beats

loss - irregular heartbeats that can cause sudden cardiac death. called “brugada syndrome”

Question 10

*differentiate between T type vs L type calcium channels

Answer 10

T type have a LOW THERSHOLD, meaning that they only require a weak depolarization to activate. they start working 1st

L type calcium channels have a high threshold, meaning they need a STRONG depolarization to operate

Question 11

*compare which work faster - sodium channels or calcium channels?

explain which types of action potentials they’re involved in

Answer 11

sodium channels work MUCH FASTER than calcium channels

ONLY calcium channels are involved in atrial depolarization.

SODIUM is the major depolarizing ion in ventricular depolarization - therefore, it happens MUCH FASTER – like a completely straight line up to 30mv from -90

Question 12

*true or false

L-type calcium channels will start to operate before T-Type

Answer 12

FALSE

T-Type work first because they have a lower threshold

Question 13

the __________ of the _____ defines how long the refractory period is for the next ventricular depolarization

Answer 13

the conformational state of sodium channels