EKG
Post Cardioversion Care
- Get an EKG -Check pulse -Watch BP -Watch rhythm -Airway, vitals
What is the junctional escape beat/junctional escape rhythm
- Normal rhythm and then it's delayed - If it stays in that rhythm, it'll be an escape rhythm -Heart is sending out the impulse, then there is a delay, and then the heart recognizes that the SA node isn't firing, so it stars an impulse in the AV node
Atrial Dysrhythmias
-Abnormal electrical activity that results in stimulation outside the SA node but within the atria -P waves will be affected Ex: AFib and A flutter
External electrical therapy
-Cardioversion -Defibrillation -Pacemaker -ICD
What is premature atrial contraction?
-Conduction in atria coming from other site than SA node -The PA comes EARLY in CYCLE and looks different than normal sinus P wave -Usually not life threatening -Premature beat. Differentiate by:
How to break an arrhythmia?
-Cough -Bear down If it doesn't break amiodarone- Cardiac arrest 300 MG direct IV push V-tach but they aren't out- 150 MG amiodarone in 100 CC D5W and run it over 10 min IV piggy back Lidocaine- can cause confusion in elderly. Can use for V-tach and Ventricle arrhythmia. Numbs heart and brain
Diagnostic Testing
-Echocardiogram •TTE •TEE -Percutaneous Coronary Intervention (PCI) •PTCA •Coronary Artery Stent
Afibrillation
-Irregular rhythm -Wavy baseline with no coordinated P waves
Taking care of a pt, and K+ is low (norm 3.5) Mag is low as well 1.5 (norm1.7-2.5) What do we give first? potassium or mag?
-Magnesium first because it has a stabilizing property on the heart- stabilize potassium
What kind of pt is defibrillation NOT used for?
-Not used for pt who are conscious or who have a pulse
What are Junctional/Idionodal Rhythm ?
-Occurs when AV node (instead of SA node) becomes the pacemaker of the heart. -Origin: AV node -Rhythm: Regular -Rate: 40-60; 60-100; >100 BPM -P waves: Precede, follow or buried in QRS -PR Interval: short, <12 seconds when precede QRS -QRS is normal -Not usually dangerous when rate is normal. If too fast or slow, cardiac output and possibly hemodynamic instability. (Digitalis toxicity) -Treatment: Not usually necessary. Bradycardia-> Give atropine
Delivery of Electric Current
-Paddles -Conductor pads (most common), multifunction pads: hands free, AED -Implanted device: ICD
defibrillation or cardioversion
-Remove meds patches on them like lidocaine -Remove metals -Remove any wet clothing
What's indicative of a successful cardioversion
-Sinus rhythm -Adequate peripheral pulses -Adequate blood pressure -Airway patency must be maintained and LOC should be assess -Vitals (peripheral pulse) and oxygen are monitored and EKG until pt is stable -Skin under the pads/paddles is inspected for burns
Sure beats picking corns Meds to use Choose meds based on provider and pt
-Sodium channel blockers (lidocaine and norpaste) -Betablockers "lol" -Potassium channel blockers: amiodarone -Calcium channel blockers: Cardizem
What is the J point? Junction point
-The point where the QRS complex meets the ST segment.
Atropine
-Treat bradycardia (first line choice): Prevents activation or parasympathetic nervous sys. Increase HR. 2nd degree HB type 2 or 3rd degree HB wont be affected by this. -Side effects: dry mouth, blurred vision, headache/dizziness/tachycardia -AE: hallucionation, seizure, reflex brady, V-Fib, hypoglycemia -May reverse the effects of paralytics
Cardioversion Defibrillation
-Used to treat tachyarrythimias -Electrical current that depolarized a critical mass of myocardial cells -After repolarization occurs the SA node is able to restart as the heart's pacemaker -Difference is the timing of the delivery of the electric current -Cardioversion: synched with the heart's electrical activity...patient MUST have a pulse. Marks the R wave. Make sure to hit the 'sync' button so it sync with the R wave and NOT t wave. -Defibrillation: immediate, unsynchronized...patient has no pulse, no BP
Two safety measures when pads or paddles
1) Good contact must be maintained between the pads or paddles and the patient's skin to prevent electrical current from leaking through the air (arcing) when the defibrillator is discharged. 2)An appropriate conductive medium must be used. (Ultrasound gel is NOT ALLOWED) 3) No one is to be in contact with the patient or with anything that is touching the patient when the defibrillator is discharged, to minimize the chance that electrical current is conducted to anyone other than then patient. -Three clear check
AED
1)Turn it on 2) Advise shock- or continue CPR 3) Delivery shock
How many big boxes are in a 6 seconds EKG strip?
30 big boxes 5 big boxes is 1 second small boxes are 0.04 seconds and 5 small boxes is 0.20 seconds.
H's and T's of ACLS (Should be used whenever your pt codes) reversible
6 H's Hypoxia: Respiratory failure/airway obstruction. ABG. O2. Give 02, ventilate/intubate Hypovolemia: Decrease tissue perfusion. Poor intake/losses. Vomiting/diarrhea/burns/blood loss. Hypotension or tachycardia prior? elevated temperature? Treat: IV/IO access- volume Hydrogen ion (acidosis) Respiratory failure or Metabolic acidosis (sepsis/ingestion) Treat: ABG and assess if its respiratory or metabolic & correct Hypo / Hyper kalemia (less than 3.5 or more than 5.5) Hypothermia: Low temp. Blankets, warm fluids Hypoglycemia: Give D50 5 T's Tension pneumothorax Tamponade: Post cath lab, trauma. Assess Beck triad (Hypotension, muffle heard sounds, JVD) Toxins: Calcium channel blockers, Potassium channel blockers, cocaine, digoxin Thrombosis (pulmonary or coronary) Trauma
What is Sinus bradycardia?
A rate between 40-60 BMP Can be due to sleep, hypoxia, sleep apnea, vagal stimulation (from pain, gagging, vomiting, bearing down)
Conduction Abnormalities
AV blocks (1st, 2nd-I and II, 3rd degree)
PJCs (Premature Junctional Contractions) AKA: Junctional Premature Beats??????
An impluse that starts in the AV nodal area before the next normal sinus impulse reaches the AV node Less common than PACs Digoxn toxicity, heart failure, coronary artery disease P wave may be absent, before or after the QRS Premature beats. PQRST, PQRST, premature beat-narrow- looks like QRS but cant see P wave. 1)Short PRI 2) Can be in the QRS (common) 3) Can appear after QRS
Junctional Rhythm
Can be diagnosed by it's rate 40-60 BPM AV node becomes the pacemaker of the heart Sinus nodes becomes slow, impulse cannot be conducted, the AV takes over Ventricle rate 40-60 Regular QRS is normal If P wave present, PRI is less than 0.12 seconds S&S reduces cardiac output Treatment like bradycardia- Atropine or dopamine -P wave will be in front of QRS -P will will be after the QRS -P wave will be hidden in QRS
Epinephrine (adrenaline)
Common in: Cardiac arrest: Vasoconstrictor, increase perfusion. IV push 1 mg/1ml q 3-5 min As Per ACLS Anaphylaxis: Vasoconstrictor Increase perfusion, bronchodilator Hypotension/shock: Vasoconstrictor. increase perfusion Vasoconstrictor: increase PB Impacts Ionotropy (increase heart contraction) and chronotropy (heart rate) Side effects: Tachy, hypertension, cardiac arrythmias, Vfib,
Heart blocks
Conduction is excessively delayed or stopped at AV node or bundle of His -PR Interval is the key to identifying the type of block. -The width of the QRS complex and the ventricular rate are keys to differentiating the location of the block. The lower the location of the block in the conduction system, the wider the QRS complexes and the slower the ventricular rate.
Counting heart rate 1500 rule
Count the number of small boxes between the R waves 1500 divide 43 = 34
Synchornized Cardioversion
Delivery of electrical energy to terminate tachy-arrhythmia Not always in an emergency Treat: Atrial tachy/SVT A-Fib A flutter V-tach WITH pulse Synchronizing with R wave (ensure shock isn't deliver on T wave- risk putting patient in a lethal arrhythmia) - Hold "shock" button because there might be a wait before shock is deliver Less energy- 50 to a 100 J Pt will be awake- SEDATE pt. This is painful
Fixed vs Demand
Fixed •Pacemaker is set to pace but not to sense •Paces at a constant rate, independent of the patient's intrinsic rhythm Demand •Pacemaker is set to to sense and respond to intrinsic activity •Fires only when the patient needs it
Ventricular asystole
Flatline Absent QRS -Code -start CPR -Give epi 3-5 min -rotate CPR provider q 2 min -Make sure code board is under pt SHOULD not defibrillate IF shock- can be doing them more harm
If someone K+ is 3.3 and you give 40 Meq K-something by mouth and draw blood 4 hours later, what can you expect K+ to be?
For every 1 0 meq of K we give, it raise the blood serum by 0.1 should raise to 3.7
Pacing - transcutaneous
If atropine does not work for symptomatic bradycardia, what could be done (non medicinally?) - Use when bradycardic and symptomatic - AV block 2 and AV block 3 - Use analgesia or sedation
Ventricular fibrillation
Most common dysrhythmia with cardiac arrest Rapid rate (greater than 300 pm), disorganized Quivering defib cpr epi vasopressin if shock 3x
Failure to capture (pacemaker)
Occurs when a pacing stimulus is generated, but fails to trigger myocardial depolarization. On the ECG, failure to capture is identified by the presence of pacing spikes without associated myocardial depolarization.
Focused Assessment Medical history
Sample Signs and symptoms Allergies Meds Post medical history Last meal Events leading up to this scenario
Automaticity
The ability of the heart to generate and conduct electrical impulses on its own. Sinus Node: 60-100 AV node: 50-60 Ventricles: 20-40
Automaticity
The ability of the heart to generate and conduct electrical impulses on its own. 60-100 BPM
Capture
The term used to denote that the appropriate complex followed the pacing spike
Ventricular tachycardia
Three of more PVCs in a row Rate exceeding 100 bpm (100-200 bpm) RegularWide bizarre QRS -Can be stable or a code situation -CPR -Defibrillator If pt feels okay -have them cough -check mag and K+ -CALl provider -Give amiodarone if not a code situation
What is the difference between cardioversion and defibrillation?
Timing of delivery of electrical current -In cardioversion, the delivery of the electrical current is synchronized with the patient's electrical events. Patient MUSt have a PULSE -In Defibrillation, the delivery of the current is immediate and unsynchronized. Patient has NO PULSE, NO BLOOD PRESSURE.
Pacemaker design and types
Two components •Electrical Pulse Generator -Circuitry that detect intracardiac electricity and cause a response (sensitivity), measured in millivolts (mV) (can pacemaker see anything? everything? too much? may stimulate extra shocks or may not stimulate at all) -Batteries- determine rate in beats per min Determines output (strength) in milliamps (mA) •Pacemaker Electrodes-Leads carry the impulse created by the generator to the heart
Failsure to sense (pacemaker)
Undersensing occurs when a pacemaker fails to sense or detect native cardiac activity. Pacing spikes will be seen when none should occur.
Everyone you cardioversion or defibrilate pt...
You raise the level of trans-thoracic resistance to chest.. so you need more energy every time you shock. Do not mis-apply shock for this reason. -Can burn pt -Hair does not really cause an issue
Asystole Check it in 2 leads
cpr should be started at once followed by epinephrine and atropine SHOULD not defibrillate
Transesophogeal Echocardiogram
•High quality imaging •Topical anesthetic •Moderate sedation-outpatient setting •NPO •IV patency •Monitor BP, HR, Sp0 during procedure -Sore throat after
Cardiac Catheterization
•IV insertion-Sedatives, fluids, heparin •BP, ECG, •Resuscitation equipment •Radiopaque contract agents are used •Monitor BUN, PT/aPTT, INR, H&H, plts, electrolytes •Arterial hemostatis RISK FOR BLEEDING Ejection fraction: 50-70
Transthoracic Echocardiogram
•Painless •30-45 mins •Limited quality
Second degree heart block type 2 (incomplete heart block because the AV node at least conduct one impulse to the ventricles)
-Affects cardiac output -Some SA node impulses conduct to the ventricles, while other do not and produces a block. Problem at the bundle of HIS or bundle branches. More p waves than QRS complexes. -Regular P waves -Irregular QRS -No cycle, no patterns -Drop QRS -Symptoms: fainting/dizzy/SOB/Chest pain -Easily progress to 3rd degree Heart block. Some of the atrial impulses are conducted through the AV node into the ventricles PR interval is constant More P waves than QRS complexes PR interval is measured consistently then there is a drop QRS. Ratio: 2:1 or 3:1 There is more than one P-waves before each QRS complex (usually two or three). The PRI may be normal or prolongs but remains consistent. Narrow QRS -Atrial can be 100 BPM -Ventricle can be 40 BPM
Placement
-Anterior-posterior or Anterior-apex -Women with large breasts should have left pad/paddle placed underneath or lateral to the left breast.
What is sinus arrhythmia?
-Basically everything is within normal limits on EKG except the R-R interval is variable -Typical in peds -Benign rhythm -HR will speed up when breath in HR will decrease when pt breaths out-
If pt just had a heart attack and now they are tachy..what to give?
-Beta blockers
Pacemaker Therapy
-Electronic device that provides electrical stimuli to the heart muscle. -Used when a patient has permanent or temporary slower-than-normal impulse formation or a symptomatic AV or ventricular conduction disturbance -May also be to control some tachydysythmias that does not respond to meds -May be permanent or temporary. Used for: -symptomatic (syncope, hypoxia) bradycardia (less than 60 BMP) Heart blocks (usually 3rd degree) Heart failure Heart attack heart surgery Dextrocardia is a rare heart condition in which your heart points toward the right side of your chest instead of the left side
When to use defibrillation
-Emergency: Ventricular fibrillation, pulseless V-tach -Pulseless VT (most common cause of sudden cardiac death) -Early defibrillation=better survival rate -AEDs in public places •Depolarizes a critical mass of myocardial cells all at once •Higher voltage than cardioversion-120-360 joules-Cause more damage •If unsuccessful- Give epinephrine to make it easier to convert rhythm to normal. Give meds such as amiodarone, lidocaine or magnesium if ventricular dysrhythmia persist. Continue meds with CPR and ACLS protocols (epi every 3-5 min and rotate providers CPR) until patient is cannot be revived.
Supraventricular tachycardia
-Extremely fast-> P wave get hidden in T waves. Will only see one large wave after QRS 1)Typically Regular 2)Rate over 150 3) Unable to see P waves 4) QRS is normal 5) PRI can't measure b/c P waves are invisible.
•Persistent tachyarrthymia (with a pulse) causing:
-Hypotension -Altered mental status -Signs of shock (hypotension, tachycardia, sweating, cold/clammy skin) -Ischemic chest pain -Acute heart failure •Afib (HR over a 100) •SVT (130 BMP or more) Usually give Adenosine •VT (Amiodarone, lidocane-cautiously with elderly or pro
Defibrillation steps
1) Apply pads 2) Turn on defib 3) Charge 4) Clear 5) Shock 6) Continue CPR Hospitals are using Biphasic delivers electricity in one way and then switches it to the other way (prevent burns, injuries, less energy and higher chance of first shock success. Monaphasic: Delivered in one direction. Start at 120 J-->150-->200 stay at 200 (external pads)
How to Analyze a Rhythm Strip
1) Determine the regularity of R waves: Measure from R waves to R waves across the rhythm strip. If the rhythm doesn't vary by 0.12 seconds, the rhythm is regular. Or count the boxes between the R-R waves 2) Calculate the heart rate: Count the R waves in a 6 seconds strip and multiple by 10 seconds. If the it's a 3 sec strip, multiple by 20. Premature heart rate isn't included in the calculations of the HR (it's from a different pacemaker site in the heart) OR Count the small boxes between two QRS complexes and divide into 1500. Ex 1500 divide by 32. More accurate unless the rhythm is irregular. 3) Identify and examine P waves: Analyze the P waves. One P wave should be identical in size, shape and position. There is one P wave for every QRS. If no P waves, atria isn't contracting. 4) Measure PR Interval: Measure from the beginning of the P wave as it leaves baseline to the beginning of the QRS complex. Count the number of small squares contained in this interval and multiply by 0.04 second. Should be less than 0.20 seconds. If longer->indicative of heart block. 5) Measure the QRS complex: Measure from the beginning of the QRS complex as it leaves baseline until the end of the QRS complex when the ST segments begins. Each small box is 0.04 second. 3 box is 0.12 seconds.
Defibrillator
A device that delivers an electric shock to the heart to restore its normal rhythm It has 3 main functions/modes -Defibrillator -Cardioversion -Pacing Use in lethal arrhythmia such as V-tach without a pulse or v-fib (never has a pulse) NEVER USE FOR ASYSTOLE OR PEA
Ventricular Tachycardia
A rapid heart rhythm in which the electrical impulse begins in the ventricle (instead of the atrium), which may result in inadequate blood flow and eventually deteriorate into cardiac arrest. DEADLY -Fast rate and wide QRS -No P waves -No T waves -Can have a pulse or not. Check patient.
What is the U wave?
A small deflection sometimes seen just after the T wave Its presence is not normal nor abnormal Normal U waves are small, round and asymmetrical. Can be seen in slow HR
Third Degree Heart Block (Complete Heart Block)
AV block in which electrical impulses from the atria fail to reach the ventricles; also called complete heart block (CHB) -Two pacemaker stimulate the heart P waves and QRS are regular but beating INDEPENDENTLY. EX: can be 5 P waves and 3 QRS complex. P waves are marching through, no correlation P waves are not conducting to the ventricles -Escape rhythm is present: -----> Junctional rhythm 40-60 bpm -----> Ventricular rhythm 20-40 bpm S&S: syncope, confusion, dyspnea Medical emergency, No atrial impulses are conducted through the AV node into the ventricles Two impulses stimulate the heart (two pacemakers) Atria: P waves may be seen Ventricle: QRS complexes Seem to be together, but not connected Atria and ventricles block independently of each other.
Adenosine
Antiarrhythmic -Given a dose in 6 mL, direct IV push-Fast -Can be given twice -Before give the drug- warn pt of lightheadedness -Meds stop heart for 2-3 seconds -Follow by 10 cc of normal saline- fast
Atrial Flutter
Atria contracting at a high rate (250-400 BPM) Sawtooth baseline -Irregular rhythm -Normal rate usually -More P's than QRS -Normal QRS -PRI can't be measure because it isnt constant
P wave
Atrial depolarization = contraction -Originates in sinus node and travel through atria. -Characteristics: smooth and round 0.5 to 2.5 mm in height 0.10 second or less in duration/width -Two types: 1) Impulse originates in sinus node and travel through enlarged atria resulting in abnormal depolarization of atria. Tall and peaked P wave = right atrial hypertrophy. Sometimes refers to as P pulmonale because it signifies COPD and asthma. Wide and notched (m shaped) P wave = mitral stenosis 2)The impulse originates in an ectopic site. Originates from a site other than SA node. P waves may appear small and pointed, biphasic, wavy or sawtooth. It can also be inverted if the ectopic site is close to the AV junction. Sometimes P waves are hidden within QRS complex and not visible.
Second degree heart block Type 1/Wincheback
Cycle of lengthening of the PR Interval Impulses from SA node are progressively delayed, until an impulse fails to conduct to the ventricles PR Interval prolongs until a QRS is dropped. Cause: CAD, IWMI, Rhematic fever, Dig toxicity, beta-blockers, calcium channel blockers No treatment Repeating pattern in which all but one atrial impulses are conducted through the AV node into the ventricles Progressive/Gradual lengthening of the PR interval, until one QRS drops
Cardioversion
Delivery of brief discharges of electricity that pass across the chest to stop a cardiac arrhythmia and restore normal sinus rhythm; also called defibrillation •Synchs with EKG (electrical impulse discharge during ventricular depolarization) -The synchronous prevents the discharge from happening during the vulnerable period of repolarization (T wave), which could result in Ventricular fibrillation. -Patient needs to be connected to a cardiac monitoring on the defibrillator so it can sense the R wave -R wave will be "marked" -Discharges energy on ventricular depolarization (In the QRS) •Delay in discharge-Discharge buttons must be held down until shock is delivered because there may be a short delay until recognition of the R wave
What is Sinus Pause (Sinus Arrest and Sinus Exit Block)
Describes rhythms in which there is a sudden failure of the SA node to initiate or conduct and impulse. To differentiate between the two rhythms, mark the R-R interval of the underlying rhythm on an index card and measure R-R interval across the strip and through the pause until the underlying rhythm resumes. Sinus Block: R-R regularity not interrupted rhythm resumes on time after pause Sinus Arrest: R-R regularity interrupted rhythm does not resume on time after pause. May occur in: Increased vegal tone Ischemic, inflammatory or fibrotic disease.
Ventricular Fibrillation
Disorganized, ineffective twitching of the ventricles, resulting in no blood flow and a state of cardiac arrest. Ventricles are quivering, not pumping. PULSELESS RHYTHM DEADLY
Diagnostic Testing
Echocardiogram: TTE and TEE Percutaneous Coronary Intervention: PTCA and Coronary Artery Stent
What causes arrhythmia? HIS DEBS
Hypoxia (MI. Anything that deprives myocardium, (COPD, PE) Ischemia: MI, viral infection of myocardium, angina Sympathetic stimulation: Hyperthyroidism, exercise Drugs: arrhythmia meds. Antibiotics can cause prolongation of QT segment Electrolytes: Magnesium, potassium, calcium. Bradycardia Sympathetic stretch: enlargement of ventricles (pt who hasn't been taken care of HTN)
Before Cardioversion
If cardioversion is elective and the dysrhythmia has lasted longer than 48 hours, anticoagulation for a few weeks before cardioversion may be indicated. -Digoxin is held 48 hours before cardioversion to prevent dysrhythmia -NPO for at least 4 hours before. -Pads placed antero-posteriorly (front and back) -Sedation via IV as well as analgesic/anesthesia. -Respiration is supported with supplemental oxygen delivered by a bag-valve mask with suction equipment readily available -Intubation equipment is nearby -Voltage 50-360 joules
First degree heart block
Impulse are delayed when conducting from SA node to AV node. A hesitation. -PRI is LONG (normal sinus rhythm with this one exception) > 0.20 sec. Now .28 or 3.0 Asymptomatic Causes: Calcium channel blocker, digoxin, MI DELAY more than a block - Con't to monitor- may progress to Heart block type 2
Ventricular Dysrhythmias - check mag and K+ PVC
Impulse starts in the ventricle and is conducted through the ventricles before the nest normal sinus impulse -A normal beat and then a premature beat comes in and it's wide and bizarre- QRS will be 0.12 or greater - More than 4 PVC in a row- it's considered V-tach - 2 PVC together is called a couplet - 3 PVC together is called 3-in-a-row -4 PVC or more is called V-Tach
Dopamine
Increase HR and stroke volume. Increase cardiac output- increase perfusion Increase blood pressure -Treat bradycardia: Increase HR -Treat shock: Vasoconstrictor
Dobutamine (Dobutrex)
Increases contractility, CORONARY blood flow, and HR by acting on B1 adrenergic receptors. Used to improve Cardiac output Use" Cardiogenic shock: Increase SV and HR Perserve systemic blood flow Support late stage HF (ionotropic support)
What is sinus tachycardia?
It is defined as a sinus rhythm with a rate of greater than 100 BPM. It is a normal response of the heart to the body's demand for increased blood flow as in exercise or intake of stimulus such as caffeine and cocaine. Can also be caused by pain, anxiety, fear, fever, hypoxia. Higher heart rate decreases the amount of time the heart spends in diastole, leading to a decrease in coronary artery perfusion (coronary arteries are perfused during diastole) Persistent sinus tachycardia may be an early sign of heart failure. Give beta blocker Formula: predicted maximum heart rate 220-age Ex: 220-29 = Should never have a heart rate over 91
Torsades de pointes
May be treated with magnesium
Fine ventricular fibrillation
can defibrillate/shock
QRS complex
Represent depolarization of right and left ventricles ->triggers ventricle contraction. Measured from beginning to end of QRS Should be less than 0.12 seconds or less than 3 boxes. -A QRS complex is wide with a duration of 0.12 seconds or more. Abnormally wide QRS complex may result in: 1)An ectopic site electrical impulse 2) An electrical impulse that has arrived early (as with premature beats) Slow conduction 3) An electrical impulse that has been conducted from the atria to the ventricles through an abnormal accessory conduction pathway that bypasses the AV node. Slow conduction
What is the ST segment?
Represents early ventricular repolarization The ST segment is a flat line line between the QRS complex and the T wave. -Common causes for ST elevation: Myocardial infarction (STEMI) Coronary artery spasm Acute pericarditis Ventricular aneursm Hyperkalemia Hypothermia -Decreased ST segment may be due to: Myocardial ischemia Non-ST elevation MI (Non-STEMI) Digitalis/Digoxin effect
PR Interval
Represents the time from the onset of atrial depolarization to the onset of ventricular depolarization. Includes P wave and a short isoelectric line. PRI is 0.12 to 0.20 seconds Prolonged PR are seen in first degree AV block Represents the time it takes for the SA node to fire, get to the AV node and Av node pause to then send signal to ventricles. If it's slow it means something is wrong with SA and AV node communication. Should be less than 5 small boxes.
What is the QT Interval?
Represents total time from the beginning of ventricular depolarization to the end of ventricular repolarization. Measured from the beginning of QRS complex to the end of the T wave. Standard QT interval changes with heart rate.
What is the T wave?
Represents ventricular repolarization Always follow QRS Can be flat, tall, inverted or biphasic
What is the normal electrical conduction of the heart?
SA node (60-100) -> AV node (40-60 BPM)-> bundle of HISS (20-40) --> left and right bundle branches -->Purkinje fibers
Pacemaker Function
Universal Code: 1.Chamber being paced (A, V, D) Atria ventricle dual/both, Being paced *2.Chamber being sensed (A, V, D, O) pacemaker is sense, not doing. Sensing is temp disable *3.Type of response from pacemaker (I, T, D, O) Response to sense events: I= inhibit pulse in response to sense events T= trigger pulse in response to sense events D= Pulse can be either inhibited or triggered O= No response to sense events *4.Rate responsiveness ability (O, R) 5.Multisite capability (A, V, D, O) or Antitachycardia function * Only the first three letters are used for pacing codes
Ventricular dysrhythmias (ventricles) deadly rhythm
Ventricular dysrhythmias originate in the ventricles below the Bundle of His. Life threatening. Major characteristics of ventricular dysrhythmias are absent P-waves and wide bizarre QRS-complexes. -Ventricular tachycardia - V-Fib
Idioventricular rhythm
Ventricular escape rhythm Rate 20-40 bpm Regular Wide, bizarre QRS -VERY SLOW Give atropine 20-40 BPM = Idioventricular rhythm 40-60 BPM = Accelerated Idioventricular rhythm Over 100 BPM V-tach DONT GIVE LIDOCANE OR AMIDIODARONE
Pulseless Electrical Activity (PEA)
a condition in which the heart's electrical rhythm remains relatively normal, yet the mechanical pumping activity fails to follow the electrical activity, causing cardiac arrest Can cause PEA 5 H's Hydrogen/acidosis Hypo/hyperkalemia (high- give reg insulin IV push follow by D50- force K+ into cells) Hypothermia Hypovolemia (ringer lactate or Normal saline) Hypoxia Can cause PEA 5 T's Coronary thrombosis/heart attack Cardiac tamponade PE Tension Pneumothorax Toxins- drugs/overdose
•Cardiac Catheterization
•Cardiac Catheterization -Invasive procedure -Diagnostic for CAD -Assess coronary patency -Determine extent of atherosclerosis -Determine if revascularization procedures will benefit patient Choice of •PCI•CABG After: -Avoid lifting anything heavy -Avoid soaking wound under water -Monitor for infection esp site -Hydrate- flush out dye - Check kidney function -creatinine -Allergy to iodine- -Bleeding at catheter site -Pt will be supine after -NO SEMI FOWLER, NO CROSSING LEGS -NO BLOOD THINNER after -Call doc if can't palpate pedal pulse
Practice Code EX
•DVI -Dual •Both the atrium and ventricle have pacing electrodes -Ventricle •Only the ventricle is bring sensed -Inhibited •The pacemaker's stimulating effect is inhibited by the ventricle activity. It will not create an impulse when it senses the ventricle is active
Diagnostic Testing-Echo
•Echocardiogram -Transthoracic (traditional) Tech -Transesophogeal (TEE): invasive/consent/sedation •Non invasive ultrasound -Measure EF%-Size, shape and motion of the cardiac structures
ICD
•Electronic device that will detect and terminate life threatening episodes of tachycardia or fibrillation •Indicated for patients surviving VT/VF arrest, cardiomyopathy, R or L ventricular dysfunction •Responds to two criteria: -Rate exceeding a predetermined level: rate goes to fast and its trying to override it -Change in the isoelectric line segment Can come in the form of a shirt -Its like an internal AED
Meds during CPR
•Epinephrine IV push -Convert to NSR -Increase cerebral and coronary artery blood flow •Amiodorone oral form/long term on meds can cause: Blue man syndrome (bluish/grayish skin color) or bradycardia, interstitial lung disease, thyroid problems, discolored corneal, skin problems -IV form: amiodorone can cause hepatic problems and hypotension •Magnesium -If ventricular rhythm persists
Nursing management of the patient with an ICD/Pacemaker
•Incision site assessment and care •Chest Xray to confirm lead placement-pneumothorax •Get an EKG done •Medication evaluation for changes in regimen
Pacemaker Complications
•Local site infection: Prophylaxis has helped greatly •Pneumothorax/Hemothorax: Use of sheaths marked as "safe" reduces the risk •Bleeding, hematoma": manage by Cold compresses and discontinuation of anti-platelet and antithrombotic meds •Ectopy from irritation of electrode •Dislodgement of electrodes -Phrenic nurse, diaphragmatic (hiccuping may be a sign) -Avoid high voltage electrical lines - Avoid strong magnetic fields such as MRI -Avoid chainsaws, weidling equipment -If pacemaker is in left chest wall- don't keep cell phone close to it.
Types of Defibrillators
•Monophasic-Deliver current in one direction-Requires increased energy selection •Biphasic-Delivers energy from positive paddle/pad , then reverse back to the original paddle/pad-Allows for lower energy usage, non progressive. More efficient, more cardio-protective
Types of Pacemakers???
•Permanent -Implanted generator -Implanted leads •Temporary -Wire •Transvenous •Epicardial •Ventricular probe (via Swan Ganz catheter) -Pads •Transcutaneous
Activation of an ICD
•Rate sensor activated •Requires a set duration of time to identify the arrhythmia •Device charges
