EKG/Sinus & Atrial Dysrythmias Flashcards
Cardiac Probs
5 Leads ECG Placements
- White on the Right
- Clouds over Grass
- Smoke over Fire
- I Heart Chocolate
White on Right side
Green RL
Black on Left side
Red LL
Brown in Middle
ECG Paper
Horizontal axis = time
Small square: 0.04 sec
Large square: 0.20 sec
5 Large sqaures: 1 sec
x30 Large squares: 6 sec
x1500 small square: 1 min
x 300 large squares: 1 min
Vertical axis = Voltage
Height of one small square = 0.1 millivolt in mm
Calculating Heart Rate
6 sec intervals
x7 R-R interval in 6 sec
* 7 x 10= 70 bpm
or
1500/ # small boxes in one R-R
300/ # big boxes in one R-R
QRS Complex
Time for delpolarization of both ventricles (systole)
Duration: < .10
Firing of AV node
* **Atrial repolarization also occurs, just can’t see it **
What I should ask myself: 3 R’s
Regularity: Are the QRS complexes occuring the same regularity (R-R wave)
Rate: Artial and Ventricular rate should be 60-100/min, count in the 6 sec strip (multiple 10) to get rate
Resemblance: Do they resemble a QRS complexes, is there one present after each P wave? Only 1 P wave/ QRS, Are they round and pointing up, less than 0.12 ( 3 small cubes)
P Wave
Electrical impulse starting in SA node + spreading through the atria
* Represents: atrial depolarization
* Duration: 0.06-0.12 ( Longer -> delays conduction -> could affect CO)
* Good contraction does not equal good CO (relies on good refill)
What I should ask myself: 3 R’s
Regularity: Are the P waves occuring the same regularity and the consecutive P waves on the EKG? ( Marching)
Rate: Artial should be 60-100/min, count in the 6 sec strip (multiple 10) to get rate
Resemblance: Do they resemble a P wave? Only 1 P wave/ QRS, Are they round and pointing up, less than 0.12 ( 3 small cubes)
PR Interval
Represents time taken for impulse to spread through atria, before ventricular contraction
* measured from beginning of P wave to the beginnning of QRS complex
* Full atrial depolarization -> starts of ventricular depolarization
* Duration: 0.12-0.20 (longer -> delays form SA node -> AV node ( AV node prob)
ST segment
Time between ventricular deloparization and reploarization
Measures S wave and T wave
Duration: 0.12
**Needs to be isoelectric (flat) **
End of vent. ctxs -> beginning of vent. refill
T wave
time for vent. repolarization
Duration: 0.16
What I should ask myself:
It should come after each QRS complex and be round and upright
Isoelectric Line
The heart at rest
No depolarization, no repolarization
“baseline”
No 02 req
QT Interval
Time form entire electrical depolarization + repolarization of vent.
Duration: 0.32-0.40
Normal Sinus Rhythm
Rate: 60-100 bpm
Rhythm: atrial + venticular reg
P waves: uniform, upright, one preceding each QRS
PR interval: 0.12-0.2 sec
QRS: 0.10 sec or less
1:1 atrial: vent ctxs => sinus rhythm
Sinus Tachycardia
Ventricular + Atrial rate > 100 bpm
Rhythm: reg
P wave: uniform, upright, one preceding each QRS
PR interval: 0.12 - 0.2 sec
QRS: 0.10 sec or less
Causes:
Exercise, pain, shock
Fever, increase TH (?), anxiety, Hypoxia
Treatment:
Treat underlying cause (decrease caffeine intake, fever pain etc) Perfusion ( cap. refill 1-2 sec, distal pedal , warm, pink)
Vagal maneuvers, blow through straw
Beta Blockers, Ca channel blocker works at the AV node, decrease BP
Catheter ablation: SA node reviving
check the electrod to make sure they are in the right position
Shorter filling time ( decrease CO)
Shorter isoelectric
Sinus Bradycardia
Rate: less than 60 bpm
Rhythm: atrial and vent reg
P waves: uniform, upright, one preceding each QRS
PR interval: 0.12-0.20 sec
QRS: 0.10 sec or less
Causes:
Trained athletes, medicine, OD, decrease TH, extreme cold, use of med (BB, CCB, amiodarone), vagal stim, Hypothryoid, MI (Ischemia), Hypoxia
Treatment:
Eliminate cause
increase HR if symptomatic (1st s/s: neuro changes-lethargy)
1st choice Atropine 0.5-1 mg Q3-5 mins (total 3 mg, IV push)
* if not effective (2nd choice) **Transcutaneous pacing **
3rd choice Catecholamines: epi or dopamine drip
Emergency transcutaneous pacing
Hemodynamic- Hypotension, mental status, SOB angina, PVCs
atropine is a anticholingeric that blocks vagal effects on the SA and AV nodes
Atrial Tachycardias
- Varied group of dysrhythmias that originate from an ectopic focus in the atria somewhere other than the SA node. HR>150
- Ectopic atrial focus generates impulses faster than AV node can handle. Ventricles may not respond to each one.
- Does not require the AV junction, accessory pathway, or vent tissue for it initiation
Supraventicular Tachycardia (SVT)
Atrial tachycardia
Narrow complex
Dysrhythmia orginating in atria that overrides SA node (singular ectopic beat)
T wave overrides P wave ( 0:1 ratio = atrial dysrhthmia)
Equal R-R = reg
Causes/Risk Factors:
Unrelieved sinus tach can -> SVT
Female < 40, caffeine, nictoine, Hypoxia, Stress, CAD, Cardiomyopathy
Hemodynamic Effect ( if sustained):
Palpitation, weakness, fatique, SOB, anxiety, hypotension, syncope!, angine, decrease LOC
Treatment:
**Assess the pt’s **: ABC’s, O2, IV access
Can resolve on its own, eliminate cause
Vagal maneuvers! (first try for adults, children (ice water, face in, shock, Baby (ICE pack two to cheek)
1 st choice AdenSoine - (6mg, 12 mg), fast IV push, stops the heart, short half life, follow w/ saline, arm up
* Pts must be attached to code cart
* 2nd choice, if 12 mg doesn’t work Amiodarone ( antidysrthmic) ,
* Beta Blocker, Ca channel blockers to slow rate (AV node)
* 3RD CHOICE sync cardioversion if the rhythm is resistant to drugs, wait for the QRS, it has to learn the rhythmm
* Defib- doesnt wait for the QRS
* Catheter ablation later, not emegerncy phase. (burn hyperexcitable cells)
Hemodynamic: Yes or No
Yes, do the treatments in order
No, skip straight to synchronized cardiodiversion
Adenosine
Stop the heart and allow it to rebutt, fast, follwed by flush, Half life of 10 sec.
within 1-2 sec, give close to heart as possible
Paroxysmal Supraventricular Tachycardia (PSVT)
the in SVT then autocorrect
Not a sustained SVT
Sudden onset and termination
Rate: >150
Regularity: reg
P wave: present or abnormally shaped
PR interval: may be normal or prolonged
QRS shape and duration: 0.06 - 0.10
Atrial Fibrillation
If unsure how long pt has been in Afib, pt must have work up for a clot ! put pt on anticoag before coverting to NST
Multiple ectopic foci-> ineffective atrial ctx
* + irregular ventricular response ( compromised vent. filling + decrease SV)
Poor forward movement of blood
* stagnation -> clots -> stroke, MI, DVT, PE
* Blood thinner !
Rate: Atrial > 350-600 bpm, ventricular (controlled < 100, uncontrolled > 100)
* irreg vent. rhythm ( irreg. R-R)
* unidentifiable P wave ( hunreds) 400:1 ratio
Cause:
80 + y.o, HF, Valvular disease, CHD,CAD, MI, HTN, cardiomypathy, increase TH, pulmon disease, OSA, moderate -> heavy alcohol, post open heart surgery
Hemodynamic Effects
Losse of atrial kick (25% -30% of CO) -> decrease vent. filling -> decrease SV
Thrombus formation ! (risk of CVA , peripheral emboli)
Dementia, increased risk of stroke, premature death
Treatment:
1. rhythm conversion ( cardioversion IF < 48 hr, sychronized cardioversion, heparin)
2. If > 48hrs pt must have anticoagulant b/4 converting to NSR due to risk of emboli
3. Rate control (for uncontrolled) ( ca channel blockers , beta blockers, digoxin, amiodarone
Med: Ibutilide, amiodarone
Chads 2 Score
Screening criteria to predict stroke in A-Fib
A higher score is assoicated w/ higher risk of embolic stroke
Score: 0-6
0= no treatment or aspirin
1= aspirin or warfarin
2-6= warfarin
Anticoagulation A-FIB
Heparin (to start) -> then Warfarin (need Qweekly, INR monitored)
Dabigatran (thrombin inhibitor)
Apixaban (factor Xa inhibitor)
Rivaroxaban (“ “)
revisible agent:
Coumadin- Vit. K
Dabigatarn- Idarucizumab
Apixaxaban & rivaroxaban ( adaxxa)
Atrial Flutter
Atrial tachydysrhythmia w/ reg saw toothed waves
Originates from single ectopic focus in atrium
Associated w/: CAD, HTN, PE, mitral valves disorder, lung disease, drugs - dig, epi
Reg R-R
P waves eat up T wave
Treatment:
Treat underlying causes, electrocardioversion, atrial override pacing
Pharm cardioversion: ibutilide
antidysrhythmics, catheter ablation
Ventricular Dysrhythmias
Premature Venticular Contractions
Ectopic beat fires before AV node
HR varies, irreg rhythm
QRS: wide, disorted, > 0.12 secs
P wave rarely visible, PR interval = unmeasurable
PVC’s w/ same slope = unifocal
Treatment:
O2, correct cause- electrolyte imbalances, AMI (cardiac outputs)
IV therapy: Beta blockers, ( if not a run of PVC’s) or Amiodarone (potassium blockers) , Lidocaine
Causes:
Caffiene, nicotine, alcohol, ischemia/ infarction, exercise, tachy, hypervolemia, heart failure, digitalis toxicity, hypoxia, acid/base imbalance, electrolyte imbalance - decrease K - marathon runners
Ventricular Dysrhthmias
Ventricular Tachycardia
1: check carotid pulse
unable to detemine atrial rate
vent. rate: 100-250 bpm
vent. rhythm = reg
no PR interval
QRS > 0.12 secs
Causes:
ACS, tricyclic OD, dig toxicity, cocaine abuse, mitral valve prolapse, acid-base imbalances, trauma
#2: call code (no pulse)
#3: CPR/defibrillate
Pulse present, unstable SBP < 100, HR > 150
* O2, IV access , amiodarone, cardioversion (sedate pt if conscious), pre-prodcedure sedation ( if awake and time permits)
Pulse present, stable, SBP > 100, HR >150
* Amiodarone, lidocaine
3-5 mins epi amodarone
Pulseless VT: START CPR/Defib
Ventricular Dysrhythmias
Torsade DE Pointes
Polymorphic V TACH
Unable to determine atrial rate
vent. rate 100-250
irreg venticular rhythm
P wave, PR = nonexistant
QRS: spindle node pattern
Magnesium Sulfate for prolonged QT interval, 1-2 grams diluted in 10 ml
Ventricular Dysrhythmias
Ventricular Fibrillation
irregular waveforms of varying shapes and amplitudes
multiple ectopic foci firing
no CO! quivering (lethal)
Treatment:
1. assess pt
2. CPR + defibrillation (ACL’s meds)
3. Intubation (airway and correct imbalance)
Causes:
1. V TACH -> V Fib
2. increase sym nervous system stim, vagal stim, electrolyte imbalances, electrocution, ACS, HF, meds
Ventricular Dysrhythmias
Asystole
Pulseless, no depolarization
Can’t shock
Interventions:
assess pt, ABCs
Check a second lead
immediate CPR
O2, IV access, pacing , meds
Pulseless Electrical Activity (PEA)
EKGs shows a little electrical activity, but pt w/ no pulse
poor prognosis
Can’t shock ( no enough electrical activity)
CPR, O2
causes: severe hypovolemia, hypoxia, MI, tension pnemo, cardiac tamponade, massive PE
might see a slow hr 40-50
6 H’s and T’s
Hyperkalemia Tamponade (cardiac)
Hypoxia Tension pneumothorax
Hypothemia Thrombosis (pulm embolus)
Hydrogen ion access (acidosis) Thrombosis (MI)
Hypovolemia Toxins and Trauma
Hypoglycemia
Heart Blocks
Causes of AV Blocks
Temporary: MI, Dig Toxicity, Myocarditis, Ca Channel Blocker, Beta Blockers, Cardiac surgery
Permanent: Aging, congential abnorm, MI, Cardiac surgery, Cardiomyopathy
Heart Block
First Degree AV Block
PR interval is prolonged
conduction does occur, it just take longer ( least dangerous)
PR interval > 0.20 sec
Treatment:
treat underlying casues ( reduces med dose or hold)
observe for progression of block
Heart block
Second Degree Type 1 AV Block
AKA: Mobitz Type 1
- Each successive impulse from the SA node is delayed slightly longer than the previous impulse
(pattern continues impulse to vent. fails, then cycle repeats) - Atrial rhythm= norm ( SA node unaffected)
- PR interval get longer until P wave fails to conduct to ventricles ( vent rhythm = irreg)
- usually asymptomatic (otherwise, low CO s/s: hypoTN, light-headed
- Asymptomatic: no treatment
- Symptomatic: atropine, temporary pacemaker
Heart Block
Second Degree Type 2 AV Block
AKA: Mobitz type 2
Occasional impulses from SA node fail to conduct to the ventricles
* PR interval remains the same
* consistent AV node conduction
* Occasional dropped beat
Problematic b/c slower/ abn ventricular rate -> decrease CO
Symptoms: hypotensive, light-headed, chest pain, palpitations
Treatment: Atropine, dopamine, epi, premanent pacemaker
Heart Block
Third Degree AV Block
AKA: Complete Heart Block
Impulse from atria are completely blocked at the AV node -> cannot be conducted to the ventricles
* Atrial/ SA node rate = 60-100
* Ventricular/ AV node rate = 40-60
* Purkinje Fibers rate = 20-40
Strip appearance: lots of P waves laid independtly over a strip of QRS:
* P wave does not conduct following QRS
* Some P waves are burried in QRS or T’s
* P-P = Reg
* R-R = Reg
Very Symptomatic: Severe fatigue, dyspnea, chest pain, change in mental status, hypotension, pallor, bradycardia
Treatment: Atropine, dopamine, epi, pacemaker
Artifact
No rhythm that is basline, usually w/ pt that have hairy chest.
Conduction System
SA Node -> AV Node -> Bundle of HIS -> Bundle Branches -> Purkinje Fibers
Dysrhythmias
Abnormal conductions of the heart + cardiac rhythm
Dysrhythmias does not equal abnorm heart rate
