Flashcards in Conduction disorders Deck (89)
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1
What do the PQRST of an ECG represent
P: atrial depolarization
PR: AV node delay
QRS: Ventricular depolarization
ST: beginning of repolarization
T: Ventricular repolarization
2
"How to read a rhythm strip"
Assess rate
Regular or irregular
Wide or narrow QRS
P wave to QRS relationship
3
What is the big box method for counting HR
300
150
100
75
60
50
(5 boxes= 1 second)
4
What is bradycardia due to
defect in impulse formation (SA) or impulse conduction (heart block)
5
What constitutes "NSR"
rate 60-100
one P for every QRS, one QRS for every P
P waves have same morphology
QRS (in same leads) have same morphology
6
What are symptoms of rhythm disorders
fatigue, palpitations, syncope, dizzy spells
7
Whats important to check on PE
thyroid exam; hypothyroid can cause bradycardia
Hyperthyroid can cause arrhythmia
8
What must you fix in order to correct chronic hypokalemia
Mg levels
9
What is the initial survey of ACLS
Circulation
Airway
Breathing
10
What are the class I anti-arrhythmic drugs
Na channel blockers;
1a: Mod Na block, some K & Ca. Prolong QRS
1b: weak Na block. Min ECG changes. used for Ventricular arrhythmias
*1c: Strong Na block. wide QRS, SA node depression. NOT for CAD
11
What are the Class II anti-arrhythmic drugs
Beta blockers: decrease sinus rate, prolong PR
12
What are the Class III anti-arrhythmic drugs
K channel blockers: prolong QT
*amiodarone prolongs QT but side effects aren't as bad
13
What are the class IV anti-arrhythmic drugs
Ca channel blocker: decrease sinus rate, prolong PR
decrease contractility and cause edema
14
What are other anti-arrhythmic drugs
Digoxin: increase vagal tone/ AV block
Adenosine: AV node blocker (half life 10 seconds)
15
What is sick sinus syndrome
chronic SA node dysfunction diagnosed by symptoms (brady, sinus arrest, tacky-brady) plus ECG findings)
-Usually d/t fibrosis form aging
16
What is sinus bradycardia
Normal rate and rhythm but HR under 60
Caused by fibrosis, acute injury, or med s/e
17
What are symptoms of bradycardia
fatigue, SOB, syncope
18
When would you place a pacemaker in a bradycardia patient
If symptomatic and d/t irreversible cause
19
How do you treat sick sinus syndrome
Treat tacky if sx
stop offending agents if brady
Permanent pacemaker to control tachy-brady
20
What is sinus arrest
failure of sinus node to initiate impulse causing pause >2 seconds
21
When would you pace a sinus arrest patient
if pause is > 6 seconds
22
What is tachy-brady syndrome
intermittent fast and slow rates from SA node or atria (<60, >100)
-periods of AFib,
23
When would you pace a tachy-brady patient
If Afib is present as well
24
What is first degree AV block
PR interval >200 sec (one big box)
(patient asymptomatic, no treatment)
25
What is second degree AV block, Mobitz I
Wenkeback! progressive prolongation until failure to conduct and ventricular beat dropped
site of block is in AV node
26
How do you treat Wenkebach
Not dangerous, so no treatment
usually asymptomatic
27
What is second degree AV block, Mobitz II
Fixed PR interval, but dropped QRS
Block is in the HIS (below AV)
EMERGENCY! can lead to complete heart block
28
What is complete heart block
no conduction from atria to ventricles
P wave independent form QRS with ventricular escape rhythm
EMERGENCY! must pace
29
What are symptoms of complete heart block
syncope, SOB, HF, fatigue
30
