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Flashcards in Cardiac Rhythm Analysis 2 Deck (41)
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1

What are the features of ventricular rhythms?

1) WIDE QRS
Depolarization spreads abnormally along muscle cells and not proper conduction pathways

2) QRS, ST, T look BIZARRE
Conduction is abnormal, repolarization is also abnormal

2

What do abnormal ST and T waves indicate in ventricular rhythms?

Abnormal conduction, NOT ischemia or infarct

3

Premature Ventricular Complex: Criteria, types

Early beat, wide and bizarre QRS > 0.12 secs

Unifocal PVC
Multifocal PVC
R-on-T
(The R wave of the PVC falls on the preceding T wave)
Multiple PVCs in a row: 3 or more is a "run of V-Tach". Paired PVC are "couplets"
Ventricular bigeminy/trigeminy (every 2nd/3rd beat is a PVC)

4

What is it called when you have more than 3 PVC in a row?

Run of v-tach

5

Premature Ventricular Complex: Etiology, physiology

Ectopic site in the ventricles, reduces stroke volume by 30-60% due to early depolarization, impaired ventricular contraction and loss of atrial kick

Hypokalemia, dilated ventricles (CHF), myocardial ischemia or infarct

6

Premature Ventricular Complex: Treatment

Do not require treatment if isolated, treat underlying cause.
If pt symptomatic with increasing PVCs, amio may be given esp if underlying rhythm has a lengthened QT interval

7

Idioventricular escape rhythm: Criteria, physiology, etiology

QRS wide and bizarre, HR 20-40

Both SA and AV node failed, ventricles initiate impulses to try and sustain life. No atrial activity, very low CO. EMERGENCY

Expected- dying pt
Unexpected- hyperkalemia, severe acid base imbalance

8

Idioventricular escape rhythm: Treatment

If withdrawing care, no treatment. Otherwise investigate why other pacemakers failed, epinephrine for CO, atropine tried to increase SA node activity, pacing

DO NOT ADMINISTER VENTRICULAR ANTIARRYTHMICS

9

Can we give amio for Idioventricular escape rhythm?

NO do not administer ventricular antiarrythmics

10

Accelerated idoventricular escape rhythm: Criteriam, etiology, physiology

QRS wide and bizarre, HR 40-100

Common reperfusion arrythmia, transient, seen after inferior MI with SA/AV node involvement

An ectopic site in ventricles fire at 40-60bpm. Irritable focus usually secondary to ischemia or infarct

11

Accelerated idoventricular escape rhythm: Treatment

Give O2 if required to reperfuse cardiac tissue. In-between rhythm is hard to treat, usually self-limiting. If sustained HR is LOW and the pt becomes SYMPTOMATIC, then atropine may be trialed to increase SA function

Meds that speed up rhythm may cause more dangerous ventricular arrythmias, ventricular antiarrythmics may further slow down rhythm

12

Ventricular Tachycardia: Criteria, etiology

QRS wide and bizarre, monomorphic (uniform QRS), polymorphic (QRS shape varies)

Myocardial infarct or ischemia, electrolyte imbalance, acid base imbalance, anything that causes long QT

13

Ventricular Tachycardia: Physiology

Ectopic sites in the ventricles fire at fast rate, taking over pacemaker functioning. Treatment focuses on suppressing irritable ectopic site.

14

Torsades de Pointes: Etiology

Meds that lengthen QT interval (Haldol), electrolyte imbalances (hypo-mg, hypo-K)

15

Ventricular tachycardia: Treatment

Assess pt if stable, unstable, or pulseless

1) Stable (BP normal, pulse strong)
12 lead ECG and consider adenosine if monomorphic and regular for diagnostic purposes
Give antiarrhythmics (amiodarone)!!!

2) Unstable (BP dropping, pulse weak, symptomatic)
Synchronized cardioversion

3) Pulseless (No BP, no pulse)
Defibrillate immediately 120-200J
Continuous CPR with drugs administered during CPR
MD may defibrillate again as needed during session
Epi every 3-5 mins
Amio may be given

16

Ventricular fibrillation: Criteria, etiology, physiology

Chaotic irregular deflections, no pattern

Myocardial infarction, electrolyte imbalance, acid base imbalance, anything that causes long QT

Ectopic site in the ventricles fire but is not organized or uniform

17

Ventricular fibrillation: Treatment

Defibrillate immediately 120-200J,
Continuous CPR with drugs administered during CPR
Epi every 3-5 mins
MD may defibrillate again as needed during session
Amio may be given

18

Asystole: Criteria, etiology, physiology

Flat or wavy line, MAY HAVE P WAVES

Myocardial infarction, hypothermia, massive pulmonary embolism, cardiac tamponade

No electrical activity

19

Asystole: Treatment

Confirm tracing and leads
CPR
Epinephrine
DO ABOVE WHILE DETERMINING CAUSE

DEFIBRILLATION NOT APPROPRIATE BECAUSE NOTHING TO SHOCK

20

Pulseless electrical activity (PEA): Criteria, physiology

Electrical activity (excluding VT and VF) with no pulse

Heart has some electrical conduction functioning but little or no contractility and cannot generate cardiac output. May be due to severe hypovolemia due to loss of preload

21

PEA: Treatment

Prognosis is poor, initiate fluid bolus, investigate other causes while CPR and epinephrine

22

PEA: Etiologies and most common cause

Loss of preload and severe hypovolemia most common cause

Hypoxia, hypo/hyperthermia, tension pneumothorax, cardiac tamponade

23

What are the features of junctional rhythms?

Originate in the AV node, and conduction goes down to the ventricles or retrograde up to the SA node therefore resulting in different conduction patterns where P is inverted or absent prior to a narrow QRS:

Absent P before QRS (impulses originate in AV and conduct down to the ventricles. No atrial conduction)

Inverted P before QRS (Conduction first travels retrograde up to the SA node resulting in inverted P wave, then conduct down to ventricles)

Inverted P after QRS (Conduction first goes to ventricles then retrograde up to SA node)

Inverted P during QRS (Conduction goes down to ventricles and retrograde up to SA node at about the same time resulting in inverted P superimposed in the QRS. will make QRS look slightly wide)

24

Premature Junctional Complex: Criteria, etiology, physiology, treatment

Early beat with inverted or absent P prior to a narrow QRS

Inferior wall MI (affecting SA, AV node), congestive heart failure, electrolyte imbalance

Ectopic focus in the AV junction fires before SA node discharges next impulse

Treatment: Usually none other than to investigate cause

25

Junctional Escape Beat: Criteria, physiology

Late beat with inverted or absent P prior to a narrow QRS

Occur when SA node periodically fails to fire so AV node initiates beat

26

Junctional escape rhythm: Criteria, physiology, etiology

Inverted or absent P prior to a narrow QRS, rate 40-60, regular

SA node slows down, AV node tries to take over as pacemaker (40-60)

Severe sinus bradycardia, post cardiac surgery, meds (beta blocker, calcium channel blockers)

27

Junctional escape rhythm: Treatment

Cardiac output may be reduced. If asymptomatic, monitor and investigate cause

If unstable:
Atropine to increase HR
Dopamine or epinephrine to increase HR
Cardiac pacing

28

Accelerated Junctional Rhythm: Criteria, etiology, treatment

Inverted or absent P prior to a narrow QRS, HR 60-100, regular

Myocardial infarction, cardiac surgery, valvular heart disease

Irritable focus in AV junction fires impulses at an accelerated rate 60-100. Atrial kick is lost but pts usually asymptomatic due to HR 60-100. Monitor and investigate cause

29

Junctional Tachycardia: Criteria, physiology

Inverted or absent P prior to narrow QRS, HR > 100, regular

AV junction becomes irritable site and fires off impulses at a rapid rate

Myocardial infarction, cardiac surgery, valvular heart disease

30

Junctional Tachycardia: Treatment

The higher the HR the more likely pt is symptomatic e.g. HR > 150

Stable:
Vagal maneuvers, adenosine, beta blockers, calcium channel blockers, amiodarone

Unstable: Synchronized cardioversion