Cardio/Renal Lab 1 Flashcards
1
Q
Depolarization
A
- Na, Ca, K move into the cell
2
Q
Repolarization
A
K moves out of the cell
3
Q
Resting potential (Phase 0)
A
-90 mV
4
Q
Atrial and ventricular cardomyocyte depolarization
A
- Systole (contraction)
5
Q
Resting membrane potentional corresponds to?
A
Diastole (relaxation)
6
Q
Phase 0
A
- Na channels open
- influx of Na
- cell rapidly depolarizes and trigger muscle contraction
7
Q
Phase 1
A
- Na channel closes
- K channels open to removed K+ out of the cells
- Partially repolarized
8
Q
Phase 2
A
- calcium channels open and Ca+ flows into the cell
- cells remains depolarized for 0.3 seconds
- Plateau segment of action potential
9
Q
Phase 3
A
- cell repolarizes
- Potassium channel opens and K+ flows out
- cell returns to resting potential
10
Q
Absolute refractory period
A
- cariomyocytes are unable to generate, propogate or respons to the arriving action potential
11
Q
Relative refractory period
A
- the cell is only able to respons when there is a strong enough stimulus from action potential
12
Q
Electrocardiogram
A
- recording of the electrical activity of the heart
- currents generated can reach to the surface of the chest
- recorded by electrodes
13
Q
P wave
A
- first wave of the ECG
- represents the depolarization of the atrium
- before atrial contraction
- short period after (straight line) allows for ventricular filling
14
Q
QRS complex
A
- depolarization of the ventricles
- Q = depolarization from V septum (left to right)
- R = largest wave, depolarization of the V
- S = final stage of V depolarization
15
Q
T wave
A
- ventricular repolarization
- before the end of ventricular contraction
16
Q
ST segment
A
- zero potential between depolarization and repolarization
17
Q
PQ interval
A
- time between the beginning of the P wave and the beggining of the QRS complex
18
Q
QT interval
A
- ventricular contraction
- begins at Q wave until the end of T wave
19
Q
Atrial fibrillation
A
- no P waves
- irregular narrow QRD complex at random irregular intervals
20
Q
Atrial flutter
A
- sawtooth P wave form
21
Q
Bradycardia
A
- sinus node dysfunction caused by coronary artery disease
- hypothyroidism
22
Q
Tachycardia
A
- abnormal impulse formation / conduction
23
Q
Sinus
tachycardia
A
- caused by drug toxicity or disease
24
Q
Triggered activity
A
- when depolarization occurs before the cell is fully repolarized
- not related to SA node firing
25
Q
Re-entry arrhythmias
A
- abnormal conduction
- retrograde conduction is blocked as the cells originating the stimuli are still in refractory period
- antrograde conduction is blocked in one of the paths and impulse travels through the paths which are not blocked
26
Q
Class 1
A
- block inward Na (slow conduction velocity)
- block outward K channels (prolong APD)
27
Q
Class 1B
A
- shorten APD (shorten rate of depolarization)
28
Q
Class 1C
A
- slows conduction
- sympatholytic drugs
29
Q
Class 2
A
- B-blockers
- slow heart rate, reduced the influx of calcium ions
30
Q
Class 3
A
- potassium channel blockers
- slow down electrical impulses
31
Q
Class 4
A
- calcium channel blockers
- decrease HR and contraction
32
Q
Inverted T-wave
A
- due to mild ischemia in the apex of the ventricle
33
Q
causes of cardiac arrhythmias
A
- damage to heart muscle leads to alterations to conduction and heart rhythm
34
Q
Sinoatrial Block
A
- sudden stop of P waves, atrium is at standstill
- ventricles pick up rhythm
35
Q
Atrioventricular block
A
- Prolonged PR or PQ interval
- P wave is present but conduction is slowed
- ventricle beats drop but still generate impulses
37
Q
Ventricular Fibrillation
A
- Coarse contraction of ventricles disappear
- irregular spasmodic waves
38
Q
Class 1A drugs – Sodium Channel Blocker
A
- quinidine
- procainamide
- dispyramide
39
Q
Class 1B drugs
A
- lidocaine
- mexiletine
- tocainide
40
Q
Class 1C drugs
A
- flecainide
- encainide
- propafenone
41
Q
Class 2 – BB
A
- propranolol
- esmolol
- metoprolol
- atenolol
- timolol
42
Q
Class 3 - K channel blocker
A
- Sotalol
- ibutilide
- bretylium
- dofetilide
- amiodarone
43
Q
Class 4 – CCB
A
- diltiazem
- verapamil
