T1 Blueprint - Cardiac Rhythm (Josh) Flashcards
What is the HR of Sinus Bradycardia?
less than 60 bpm
What are some causes of Sinus Bradycardia?
Increased Parasympathetic Tone (athletes)
SA Nodal disease (Sick Sinus Syndrome)
Meds
VAGAL STIMULATION
What is the hemodynamic effect of Sinus Bradycardia?
Decreased CO
Hypotension (orthostatic, syncope)
When do you treat Sinus Bradycardia and how do you treat?
ONLY if symptomatic
Use:
- Atropine (DOC)
- Pacemaker
What are the dysrhythmias we talked about?
Sinus Brady Sinus Tachy Afib (most common) Atrial Flutter PACs Junctionals (Accelerated Junctional, Junctional Tachy, PJCs) SVTs Ventricular Tachy Vfib PVCs Heart Blocks
What HR is Sinus Tachy?
101 - 150 bpm
What are some causes of Sinus Tachy?
Increased O2 demand (fever, exercise)
Compensatory response to low CO (CHF, Dehydration, Hypovolemia)
What are the hemodynamic effects of Sinus Tachy?
increases the heart rate and improves CO
What do you do to treat Sinus Tachy?
correct the underlying cause
***ie: if fever, treat the fever
What is the most common dysrhytmia?
Afib
What is the rate associated with Afib?
greater than 350 bpm
What are some causes of Afib?
Heart Disease
Ischemia
Rheumatic Fever
Mitral or Tricuspid Valve disorders
Overstretched Atrium (HF)
What is the hemodynamic effects of Afib?
Lose Atrial Kick
Decreased SV
Decreased Diastolic filling time
CO can decrease by 20-30%
What are the three treatment goals of Afib?
Get them out of the Rhythm
Control the Rate (if you can’t get them out of the rhythm)
Prevent complications from Stasis of Blood
What is the number one fear associated with Afib?
stasis of blood in the Atrium
Afib:
What meds can be used to get them out of the rhythm?
Amiodarone
Ibutilide
Disopyramide
Flecainide
Dofetilide
Sotalol
Afib:
If meds don’t work, what else can we do to get them out of the rhythm?
Cardioversion
Surgical ablation (MAZE procedure)
Afib:
If you can’t get them out of the rhythm, what meds can we give to control the rate?
Ca Channel Blockers
Beta Blockers
Digoxin
What is the rate associated with Atrial Flutter?
250-350 bpm
***sawtooth appearance
With Atrial Flutter, will the client always know they have it?
No, because they may have a normal ventricular rate
***still lose their Atrial Kick
What are the Junctional Rhythms we talked about?
Junctional
Accelerated Junctional
Junctional Tachy
Premature Junctional Contraction (PJC)
What is a Junctional Rhythm?
AV Node takes over as pacemaker when a higher node fails to initiate or conduct to AV node
***rate is that of AV node (40-60 bpm)
What is the rate of a Junctional Rhythm?
40-60 bpm
***the normal rate of AV node
What do you use to treat a Junctional Rhythm?
Atropine
***If symptomatic
What is an Accelerated Junctional Rhythm?
Rate increases form normal junctional rhythm (40-60) to faster rate (61-100)
How concerned should we be about an Accelerated Junctional Rhythm?
not very concerned
no treatment necessary
What is Junctional Tachy?
rate faster than accelerated junctional
rate of 101-180 bpm
What is the Hemodynamic effect of Junctional Tachy?
Decrease CO due to abnormal atrial kick and rapid rate)
What is the medication mgmt for Junctional Tachy?
Ca Channel Blocker
Beta Blocker
Amiodarone
If meds don’t work, what can we do for Junctional Tachy?
AV Node ablation with pacemaker for severe, symptomatic patients
What happens with PJC?
Premature Junctional Contraction
- single beat originating with AV junction that causes the atria to depolarize by retrograde conduction
What do we do about PJC?
just observe it
**It has no hemodynamic effect
What are some causes of PJC?
Irritable focuse within AV junction
Dig toxicity
When we think of Dig toxicity, what rate should we think of?
PJC
What is an SVT?
Supraventricular Tachy
- any rapid rate originating above ventricle
- Sinus tachy
- Atrial tachy
- Atrial flutter
- Afib
- Junctional tachy
What is the rate associated with SVT?
100-280 (with a mean of 170 in adults)
When do you treat SVT?
if it is paroxysmal (sudden onset)
What meds can be used for SVT?
Adenosine (Rapid Infusion)
Amiodarone
Cardizem
If meds don’t work, what else can be used for SVT?
Vagal Stimulation
Cardioversion
Ablation
What rate is Ventricular Tachy?
140-180 bpm
What do you do FIRST when you have Ventricular Tachy?
check pulse
- **pulseless - defibrillator
- **pulse - cardioversion
Treatment for PULSELESS Ventricular Tachy?
Defibrillator
CPR
Epi
Vasopressin
Treatment for Ventricular Tachy with a PULSE?
Amiodarone
Sotalol
Lidocaine
Cardioversion
What is the concern with Vfib and Vtach?
can lead to Torsades
What is the hemodynamic effect of Vtach?
No contraction
No forward blood flow
No CO
What are the shockable rhytms?
Pulseless Vtach
Vfib
How many jules for biphasic fibrillation?
Monophasic?
150-200j (requires less)
360j
Management of Pulseless Vtach and Vfib?
Check for Pulse
(if no pulse) SHOCK
CPR for 5 cycles (about 2 mins)
Check for Pulse
What does QRS look like with PVC?
wide and bizarre
can occur in bigeminey or trigeminy
What is treatment for PVC?
Look for cause and treat it
- Drugs
- Hypoxia
- Cardiac Disease
- Irritation of ventricle by catheter
Antidisrhythmia meds
Which Heart Block is hemodynamically stable?
1st Degree
What do you do to treat 1st Degree Heart Block?
nothing, other than treating any possible cause
ex: if hyperkalemia, then get rid of some K+
What are the different types of 2nd Degree Blocks?
Type I: Wenchenbach or Mobitz I
Type II: Mobitz II
Which 2nd Degree Block is more severe?
Type II: Mobitz II
What is hemodynamic effects of 2nd Degree Blocks?
stable but can progress to unsable
If treating the underlying cause doesn’t correct 2nd Degree block, what else could be used?
possible transcutaneous pacing or transvenous pacing
What is happening with the nodes during a Third Degree Block ?
each is firing at its own intrinsic rate (out of cycle)
Which Heart Block is hemodynamically UNSTABLE?
3rd Degree
Which Heart Block always requires pacemaker?
3rd Degree
Which electrolyte determines conduction velocity and helps to confine pacing activity to the SA Node?
Potassium (3.5-5.0)
What does Hyperkalemia do to electical system of heart?
Decreases rate of ventricular depolarization
Shortens Repolarization
Depresses AV conduction
Potassium:
Acidosis is a sign of —
Alkalosis is a sign of —
Hyperkalemia
Hypokalemia
What is treatment for Hyperkalemia?
D50W and IV Insulin (temporary)
Ca Chloride (temporary)
Cation exchange resin products into GI Tract such as Kayexalate (Permanent)
Hemodialysis or Peritoneal Dialysis (permanent)
What doe Hypokalemia do to the electrical system of the heart?
impairs myocardial conduction
prolongs ventricular repolarization
***Hypokalemia reduces the excitability of cells so they are less responsive to stimuli
What are some causes of Hyperkalemia?
Excess K+ administration
K+ sparing diuretics
ACE Inihibitors
ARBs
Renal Failure
Acidosis
Extensive Muscle Destruction (Rhabo)
What are some causes of Hypokalemia?
GI Losses
Renal dysfunction
Alkalosis
Diuretic Therapy with insufficienty replacement
Chronic Steroid Therapy
Treatment for Hyperkalemia?
K+ replacement (10 mEq per hr)
Replace magnesium if Hypomagnesium exists BEFORE replacing K+
When replacing K+, how do we give?
Slowly (10 mEq per hr)
- **High alert med
- **Never IV Push
- **Monitor for Phlebitis
What is normal Magnesium level in ECF?
1.8-2.4 mg/dL
Which is rare, Hypermagnesemia or Hypomagnesemia
Hypermagnesemia
What are causes of Hypermagnesemia?
Renal dysfunction
Tumor Lysis Syndrome
Overtreatment w/ Mag
Magnesium:
ECG for Hypermagnesemia looks similar to —
ECG for Hypomagnesemia looks similar to —
Hyperkalemia
Hypokalemia
Hypomagnesemia and Hypokalemia both do what to the electrical function of heart?
Impair myocardial conduction
Prolong ventricular repolarization
What are some causes of Hypomagnesemia?
Insufficient Mag intake
ETOH abuse
Diuresis / Diarrhea
Rapid administration of citrated blood products
Magnesium
—- can lead to:
- Sudden cardiac death
- Coronary Artery spasm
- HTN
- Torsades
Hypomagnesemia
Treatment for Hypomagnesemia?
Mag IV replacement
- **evaluate renal status first
- **Check for pulse
Pulseless = 1-2g in 10 mL D5W over 5-20 mins
Pulse = 1-2 g over 5-60 mins
Which electrolyte is an important mediator for cardiac functions like vascular tone, myocardial contractility, and cardiac excitability?
Calcium
Total serum = 8.5-10.5 mg/dL
Ionized = 4-5 mg/dL
What is difference between serum calcium and ionized calcium?
ionized is what you can actually use and represents that amount unbound to albumin
Why would the following changes be associated with Hypercalcemia:
- Shortened QTc Interval
- Bradycardia
- Heart Block
- BBB
too much calcium:
- Strengthens contractility
- Shortens ventricular depolarization
What are some causes of Hypercalcemia?
Bone Tumors
Hypomagnesemia
Endocrine Disorders
Excessive intake of Vit. D
Treatment for Hypercalcemia?
Loop diuretics (Lasix)
Calcitonin (SQ or IM)
Bisphosphonates
Hemodialysis
Why would the following be associated with Hypocalcemia:
- Variable ECG
- Bradycardia
- Vtach
- Asystole
- Prolonged QT
too little calcium causes:
- Decreased myocardial contractility
- Reduced CO
- Hypotension
- Decreased responsiveness to Digoxin
What are some causes of Hypocalcemia?
Post surgical blood loss (blood transfusions)
Alkalosis
Shock
Mag imbalances
Treatment for Hypocalcemia?
Seizure precautions
Oral and IV replacement
- Ca chloride
- Ca gluconate
12 Lead ECG:
What is Normal Axis?
Lead 1 = +
Lead aVf = +
12 Lead ECG:
What is Right Axis?
Lead 1 = -
Lead aVf = +
12 Lead ECG:
What is Left Axis?
Lead 1 = +
Lead aVf = -
12 Lead ECG:
What is NW Axis?
Lead 1 = -
Lead aVf = -
12 Lead ECG:
What causes Left Axis (+, -) Deviation?
Q waves of inferior MI
Emphysema
Hyperkalemia
Injection of contrast into Left Coronary Artery
Left Ventricular Hypertrophy
12 Lead ECG:
What causes Right Axis (-, +) Deviation?
Normal finding in children and tall thin adults
Right Ventricular Hypertrophy
Chronic lung disease eve without pulmonary HTN
Anterolateral MI
PE
12 Lead ECG:
What causes NW (-, -) Deviation?
Emphysema
Hyperkalema
Lead Transposition
Artificial Cardiac Pacing
Vtach
12 Lead ECG:
What are the Limb Leads?
What are the Precordial Leads?
Limb = I, II, II, aVr, Avl, aVf
Precordial = V1, V2, V3, V4, V5, V6
Which viewpoint of the heart do the Limb Leads provide?
frontal plane of heart
Which viewpoint of the heard do the Precordial leads provide?
horizontal plane of the heart
Where should V1 be placed?
4th ICS right sternal border
What should we see in the R waves on the Precordial leads?
R Wave progression from V1 to V6
When do you use Defibrillation?
NO PULSE
- *Pulseless Vtach
- *Vfib
When do you use Cardioversion?
PULSE
- *Afib
- *SVT
- *Vtach with a pulse
Order with Defibrillation?
1) Check for Pulse
2) (if pulseless) Shock with 150-200 (if biphasic) or 360j (if monophasic)
3) Then 5 cycles of CPR (about 2 mins)
4) Check for pulse
Cardioversion vs. Defibrillation:
Which is syncronized?
Cardioversion is synchronized because it needs to coincide with the PULSE
***Defibrillation is not synchronized because there is NO PULSE
Pacemakers:
In the 3 code system, what do the following position means:
Position I
Position II
Position III
Position I = Chambers paced
Position II = Chambers sensed
Position III = Response to sensing
Pacemakers:
What are the possible settings for Position I and Position II?
0 = None A = Atrial V= Ventricle D = Dual
Pacemakres:
What are the possible settings for Position III?
0 = None T = Triggered I = Inhibited D = Dual (T and I)
Pacemakers:
When we are pacing, what are we pacing?
A = Right Atria before P wave
V = Right Ventricle before QRS
D = both
What are some indications for a Temporary Pacemaker?
Asystole
Pulseless idioventricular rhythm
Symptomatic brady that won’t respond to Atropine or Isuprel
Drug toxicity
Implanted pacer fail
What are some containidcations for Temporary Pacemakers?
Prolonged cardiac arrest
Cardiac trauma
Extensive MI
What are some complications from Pacemakers?
Catheter dislodgement
Lead failure
Pacemaker system failure
Erosion of pulse generator
Pacer induced tachy
Infection
Cardiac perforation with tamponade
Thrombosis or SVC
Dysrhythmias
