Critical Care: EKG Interpretation and Arrhythmias

• The notes relate to a Critical Care Unit 2 Review

Analyzing an EKG

• Several components are analyzed including determining the rate and rhythm, as well as analyzing the P wave, PR interval and QRS.

Cardiac Rhythm Origin

• Under ordinary circumstances, the SA node is the structure from which a cardiac rhythm begins.
• The normal electrical pathway of the heart is SA node -> AV node -> Bundle Branches -> Ventricles
• The SA node is recognized as the natural pacemaker of the heart
• The AV node acts as the gatekeeper for the heart's electrical activity

PVC

• PVCs (Premature Ventricular Contractions) are irregular ventricular contractions that increase the risk of V-Tach or V-Fib from occuring

PVC Treatment

• Treat V-Tach or V-Fib with a shock and/or CPR
• Treat SVT through vagal methods or Adenosine (IV), a crash cart needs to be nearby as a precaution
• Treat Torsade de Pointes with Magnesium

Bundle Branch Blocks (BBB)

• Bundle Branch Blocks can cause the left or right ventricle to beat out of sync, affecting the ventricles
• Causes include hypertension, aortic valve disease, CAD and blood clots
• The treatment is to place a biventricular pacemaker for the bundle branches, in this case a third wire is connected to the left side of the heart to keep both sides in proper rhythm.

Cardiac Hypertrophy

• Prolonged periods of pressure through narrowed valves may lead to hypertrophy, especially left ventricle hypertrophy.
• Pulmonary issues can cause right atrial hypertrophy. COPD and pulmonary hypertension.
• Increased pressure of blood pumping through a stenotic mitral valve can cause left atrial hypertrophy, with left atrial abnormality referred to as P mitral
• COPD, pulmonary hypertension and pulmonary stenosis can cause right ventricle hypertrophy, the treatment is aimed at treating the pulmonary disease
• Chronic systemic hypertension or cardiac problems may cause left ventricle hypertrophy, termed "silent killer"

Systemic Hypertension

• Systemic HTN involves high blood pressure in the systemic arteries, these vessels carry blood from the heart to the body's tissues
• Major arteries include the superior vena cava (SVC) and inferior vena cava (IVC)

ECG Changes, Potassium and Calcium

• Potassium is the primary intracellular cation that helps cardiac cells repolarize, allowing for stable polarized state
• If there is too much potassium (K >6.0), the T wave becomes highly arched, the QRS can also widen, and death can occur if not corrected

Hyperkalemia Treatment

• Calcium gluconate stabilizes all of the excitement that potassium causes
• Insulin shifts the potassium back into the cells
• Dextrose has a pulling force and works with insulin to move potassium back into the cell.
• Diuretics can also be used

Calcium Imbalances

• Hypercalcemia causes shortened a QT interval and depressed ST segments
• Hypocalcemia causes a prolonged QT wave, potentially inverting the T wave and is noticed in patients with chronic kidney disease and decreased potassium levels.
• A calcium imbalance will change the QT interval

Arterial Lines

• An arterial line is used to measure ARTERIAL blood pressure, it can be used for ABGs
• Normal systolic BP is 90-140
• Normal diastolic BP is 60-90
• Normal MAP is 65-105
• MAP or mean arterial pressure helps to evaluate perfusion to vital organs

Monitoring and Maintenance

• Make sure to zero the line at the beginning of shift
• CVP monitoring takes place in the superior vena cava near the right atrium
• CVP catheter can be placed in the jugular and subclavian vein for monitoring the RA lumen of the PA catheter

CVP Monitoring

• Assessing fluid status is the most important implication of CVP monitoring
• Normal CVP reading: 2-12
• Low CVP may indicate hypovolemia (low blood volume)
• High CVP may indicate hypervolemia (high blood volume), right ventricular failure, or decreased cardiac output
• Factors affecting CVP include: cardiac output, venous compliance, position of the patient and respiratory status

Pulmonary Artery Occlusion Pressure (PAOP)

• Important to establish if a PA catheter is properly positioned
• PAOP (or PA wedge pressure) is obtained when inflating the balloon at the catheter tip: this is the gold standard to proper placement
• Normal PAOP is 8-12
• If a reading is within normal limits like 9, then compare to previous readings
• High readings indicate fluid overload or left ventricle failure
• Low readings always indicate hypovolemia
• Readings that are off are always reported to Healthcare Professionals, who should have previous readings ready to share

Arterial Catheter

• A pulmonary artery (PA) catheter, also known as a Swan-Ganz catheter, has multiple lumens, or tubes, that serve different functions.

PA Catheter Lumens

• Blue lumen is for Right atrial ( CVP)
• White lumen is for Right atrial infusion (med port)
• Yellow lumen is foe Pulmonary artery (PAP/SvO2)
• Red lumen is for Pulmonary artery balloon port (balloon/PAWP)
• The Thermistor is for Pulmonary artery thermodilution lumen
• The Right atrial lumen is used for cold injectate during cardiac output measurements.
• The Right atrial infusion lumen is used to put fluid or medication into the heart
• The pulmonary artery is used for measuring pulmonary artery pressure and obtaining blood samples
• The Pulmonary artery balloon port is used to inflate and deflate the balloon at the tip of the catheter.
• The catheter also has an inflatable balloon at the tip that helps wedge it into a small pulmonary blood vessel.

Catheter Maintenance

• To ensure patency and to remove air catheters can be flushed with saline

Pressure Bag Maintenance

• Pressure bags can be applied to both CVP and art lines to maintain continuous, positive pressure within the catheter system
• This prevents blood clotting at the tip and ensures accurate pressure readings by delivering a steady flow of flush solution to the transducer, the lines should be kept open and correctly functioning

Complications

• Serious complications can arise from CVP, ART, or PICC lines and include:
• Air embolism: in which case COLT should be used to clamp the lines off with the pump on the left side Trendelenburg.
• Infection
• Thrombosis: A large clot can be an emergency because of proximity to parts of the heart.
• Pneumothorax (with PA caths)

Cardiac Output

• Cardiac Output (CO) = volume of blood ejected from the heart per minute
• Normal CO: 4-8 L/min
• Cardiac output is the overall determining factor of if the body is getting enough oxygen
• The determinants of oxygen are hemoglobin and oxygen saturation with hemoglobin containing most of arterial oxygen, which is measured by SaO2
• CO is assessed by evaluation of SaO2, normal levels are 1,000 mls, usually dependent on BSA
• CO is threatened by increased demands in CHF or deficiencies in hemoglobin, threats to can include cancers, anemia and chronic kidney disease

Oxygen Delivery

• Assess oxygen delivery and consumption through SvO2 or ScvO2 monitoring
• SvO2 mixed venous saturation reflects oxyhemoglobin in desaturated blood returning to the right ventricle and pulmonary artery, venous oxygen saturation can also be measured in superior vena cava ScvO2
• Monitoring is done at the bedside with CVC, PICC or PAC catheters
• SvO2/ScvO2 is used for the global balance of oxygen supply
• These measurements are lower than arterial saturation
• SvO2: 60-80%
• ScvO2: 65-85%
• These measurements really help with insight with oxygen delivery at the cellularlevel especially with cases of shock and sepsis

Fibrinolytics

• Fibrinolytics (CLOT BUSTERS) are indicated in STEMI or myocardial infarction or new onset of LBBB
• Contraindicated in patients without ST elevation or nonspecific electrocardiogram changes and should not be administered. Patients suffering from PE, DVD, CVC occlusions, and strokes.
• Common names include: Reteplase, Alteplase, Cecteplase
• Drug action: Directly or indirectly convert plasminogen to plasmin which lyses the thrombus also shown to dissolve clot, reestablish coronary blood flow, minimize infarction size and preserve left ventricle function

Fibrinolytic Nursing Care

• Cardiovascular assessment, ECG are key, administer within 30 minutes in ER or 4 hours from presenting symptoms
• Adverse Reactions:Bleeding, Intracranial hemorrhage, Stroke, Reperfusion of dysrhythmias

Anticoagulants

• Anticoagulants cannot destroy existing clots like fibrinolytics but prevent new clots from forming or existing ones from getting bigger

Heparin

• Heparin prevents clot formation by linking antithrombin III and inhibiting thrombin, the drug has a limited half-life and therapeutic range
• It does not break down the existing thrombus either and is used for unstable angina, DVT, PE and STEMI
• For nursing, monitor for signs of bleeding, assess appropriate Labs - APTT or Xa
• Additionally another IV will be needed, and protamine sulfate is the reversal agent

Lovenox

• Lovenox, or LMWH inhibits clot formation by blocking Factor Xa and thrombin
• Lovenox has a long half-life to limit frequent monitoring, and given subcutaneously rotate injection sites, and tell patients not to rub injection sites
• Platelets should be checked at a normal range of 150,000-450,000.
• It's use is limited in patients with severe renal dysfunction or patients on hemodialysis
• Possible adverse effects of Lovenox would be bleeding, thrombocytopenia, ecchymosis and hematoma

Coumadin

• Coumadin (Warfarin) used for acute MI, A-fib, cardiomyopathy, heart failure and DVT by preventing synthesis fo Vitamin K dependent clotting factors.
• Nursing assessment:
  • Patient education is key as this drug interferes with many medications and foods such as vitamin
  • The nurse must make sure that INR levels are therapeutic, these ranges are between 2-3 but for mechanical valves 2.5-3.5
  • Assess medications if pt is taking ASA, Ibuprofen these can increase bleeding.
• Bleeding (most common) may result, and its effects can be reversed with Vitamin K

Platelet Inhibitors

• Platelet inhibitors prevent platelets from sticking together to form a clot, which inhibits the processes of platelet activation
• Commonly used for blood clots, strokes and heart attacks are Aspirin, Clopidogrel (Plavix), Ticagrelor
• Adverse effects include bleeding and GI upset, neutropenia and thrombocytopenic purpura.
• During nursing, patients should be educated to observe for black tarry stool, blood when brushing their teeth or when they cough

Antiarrhythmics

• In this guide class II, III, ICDs, cardioversion and ablation are used to treat arrhythmias

Class 1 Antiarrhythmics

• Class I - Sodium Channel Blockers stabilize the cell membrane by blocking the influx of sodium into the cell -> helps slow down depolarization in the beginning of the cardiac cycle -> assist with dysrhythmias
• Lidocaine -> prolong QT intervalAdverse side effects: vertigo, headache, nausea, vomiting, diarrhea, flushing, constipation, shortness of breath, edema in the legs

Class 2 Antiarrhythmics

• Class II - Beta Blockers decrease heart rate and interfere with sympathetic nervous system stimulation, prolonged AV node conduction and decreased myocardial contractility
• Examples include Metoprolol and Esmolol, STAY AWAY FROM METOPROLOL TARTRATE AFTER A MI AND THE HEART IS WEAK
• Nursing Assessment: Assess BP (mainly pulse) -> if pulse is <60 then hold medication and contact HCP Adverse Effects: Vertigo, Bradycardia, Cold hands and feet, Rash Nausea, Vomiting Contraindicated in patients with Severe asthma, COPD, Cardiogenic shock, Severe LV failure, Second and third-degree AV heart blocks

Class 3 Antiarrhythmics

• Class III - Potassium Channel Blockers bind to potassium channels -> prevents potassium from moving through the cell and slows down electrical impulses in the cardiac cells -> prolongs repolarization (when the cell membrane returns to its resting state) Used for cardiac arrhythmias, HTN and Multiple Sclerosis Adverse effects: UTI, insomnia, headache and nausea

Amiodarone

• Amiodarone: Also a class 3 antiarrhythmics, used to treat refractory VT and Vfib
• Can also be used for RVR Afib and flutter cases
• Is a first option for treating Wide Complex Tachycardia has positive inotrope
• Nursing:Requires a filter on the IV line Always check apical pulse and full set of vitals first Can't be mixed with other medications Must check BP every 15 minutes Also be mixed with D5 First dose: 1 mg -> 6 hours later: 0.5 mg Runs continuously without having to titrate much but you are monitoring vitals and report to doc if needed and he gives you the go with titration
• DO NOT GIVE WITH DIGOXIN Must have a cardiac monitor and patient!
• Be wary of fainting, vertigo, SOB and fatigue

Class 4 Antiarrhythmics

• Class IV includes Calcium Channel Blockers which block calcium from entering cardiac cells -> relaxes the vessel and widens it (vasodilation?) -> decreases BP which can treat both HTN and arrhythmias
• Nicardipine & Clevidipine are a way faster method that are used for hypertensive crisis, these can both be given via IV and checked every 15mins
• Adverse effects: hypotension, AV block, bradycardia, headache, vertigo, constipation, flushing, peripheral edema and nausea
• Contraindications: Cardizem & Verapamil are contraindicated in VT, severe sinus bradycardia, sick sinus syndrome and WPW syndrome (Wolf-Parkinson-White) with AF

Cardizem

• Class IV - Cardizem is a calcium channel blocker.
• Mainly used with Afib Decreases automaticity of the SA and AV nodes -> slows conduction
• Negative inotrope -> slows the heart force down Used for angina, HTN, SVT Afib with RVR; contraindicated w with VT, digoxin toxicity, severe aortic stenosis and severe sinus bradycardia Check BP every 15 mins, on a cardiac monitor Also titrate by 5's unless ordered otherwise; watch for hypotension, bradycardia or peripheral edema; or N/V

Class 5 Antiarrhythmics

• Adenosine:
• Works by blocking potassium, sodium and calcium and converts SVT into NSR
• Is a negative inotropic as well to reduce the heart force
• You must have a full set of vitals before administration
• You must have a cardiac monitor and the patient be in critical care
• Standard dosing: 6 mg rapid IV push -> normal or 12mg if doesn't work at first -HCP is usually present when med admin DO NOT give while alone.

Inotropes

• Inotropic drugs increase the force of myocardial contraction and cardiac output
• Positive inotropes increase the force of the heart beat while negative inotropes decrease the force of the heart force
• Commonly given to patients with impaired myocardial contractility or cardiogenic shock Adverse effects: hypotension, breathing issues, ischemia, headache, chest pain
• Examples include: Dopamine, Dobutamine, Epinephrine and Isoproterenol

Dopamine

• Used given to Administered to pts with conditions that cause hypotension (sepsis), decreased CO and oliguria
  • Can only be given only through a central line
  • Prevents necrosis of issues (if on another line will necrosis and die)
  • Used in doses from 3-10 mcg (doses over will vasoconstrict-> will cause issues); titrated for the patient using 2mc intervals.
  • Check BP every 15 mins and goal is >= 60. Can induce tachycardia; headache/nausea, etc

Dobutamine

• Dobutamine is a class of inotropes.
• increases myocardial contractility and causes vasodilation for patients struggling with low blood pressure for cardiogenic shock,
• The dosing can be given from range between 2mcg to 20mcg per mins
• The nursing administration looks like monitoring tachycardia/ arythmia, along with the routine v/s checks.

Epinephrine

• Vasopressor but also has positive inotropic powers; given for cardiac arrest, symptomatic bradycardia, severe hypotension, anaphylaxis and anaphylactic shock
• If not in arrest, given in a central line
• Typically for arrest, a bolus can be used.
• Mainly given in ICU as a continuous IV drip to help increase BP and systemic vascular resistance May also cause cardiac disrythmia or headache.

Digitalis

• Digitalis is a cardiac medication that shows :
• Positive inotrope with antidysrhythmic and bradycardic actions, as well as inhibiting the sodium potassium pump causing a rise in sodium to promote calcium influx, which is used for HF

Vasoconstrictors

• Vasodilators can be a medication used to increase perhiperial vascular resistance, and systemic vascular resistance to help increase BP

Norepinephrine (Levophed)

Causes peripheral vasoconstriction -increasing BP- and helps to treat Septic Shock Admin via central line (to prevent necrosis) from 2 to 12 mcg. Titrate to MAP mostly and watch vitals closely Watch HTN Adverse effects can include, but are not limited to tachycardia and dysrhythmias.

Vasopressors

• Include Levo (norepi), Dopamine, & Vasopressin.
• Should monitor labs by focusing on MAP with a constant baseline and to look for the normal MAP.
• As for vasodilators, it is important to note that there may be hypotensive episodes that the patient can struggle with.

Sodium Nitroprusside

• Reduces afterload and preload and monitor for lupis (joint pain),

Magnesium Sulfate

• Drug of choice for Torsades de Pointes. Also used for refractory VT and VF and lethal disrythmias from digitalis toxicity Calcium channel blocking properties and inhibits sodium and potassium channels-
• Monitor ECG during administration and be prepared to provide 1-2g via IV with concentration. For torsades give this med in 10-20 mins and regular rate for electrolyte purposes 2-4 H and monitor patellar and knee jerk reflexes. It has several adverse effects, including hypotension, nauseam and decreased reflexes and flashing

Percutaeous Methods

• Main objective for coronary diseases is revasculatization to maintain the bloodflow in the heart
• All methods should involve a objective evidence and include non-invasive methods (stress testing, echo, etc) with a 70% range
• If goals aren't met, they should revaluated angina.

Coronary Method (CABG)

• Method should be done with sterile procedures with a access point
• The method will involve a guidewire that connects from the puncture to the site of disfunction.
• Tests that should be done prior is bloodcoag + potassium levels to ensure stability.
• After testing, review consent with patient to ensure that htey confirm their understanding.
• PT must be anticogaulatent

Post-operative Considerations

• Lay patient at 30 degrees. Pt is taught about precautions to prevent bleeding Femoral artery: leg straight: HOB > 30 Radial catheter: teach limited flexion and a radial artery compression device is placed

Coronary Artery Bypass

Used for CAD Pt undergoes intubation Must always monitor incision sites CABG has more complication than PCI

Arterial Access

Arterial access: bedrest pt for 6 hours Venous access: 4 hours. In the procedure, it will have an incision and cath insertion for treatment or monitor of the heart. Anesthesia will have an effect post procedure. And they will monitor heart status with pain.

Pacemakers

Pacemakers are used to provide electric rhythm to help perfuse through to the heart. This only take around 30 mins, and there are limited considerations to assess (the list is given in this document)

ICDS (Inflatable cardioversion)

Used to monitor and treat, if there is arrythmia. Also focuses on CPR quality and minimizes the risk of death

Pulminary System

Used when pt fails at maximum medical/pharmacological strategies if pt that have reversible cardiac and respiratory conditions, functions of the body such as heart and lungs will fall back to their original purpose and can be helpful Also known to be this high form of life support

Aortic Ballon Pumps

Helps for patients with MI, severe heart rate as well as patient waiting for transplant Helps chest pain and is usually the first to assist before other procedures

Aortic Aneurysm

Aortic Aneurysm is the dilation of the aorta to a degree where it surpasses 50%, and the location is based on severity The patient will need to be under 100 MAP. Symptoms involve abdominal pain the chest

Hypertensive Crisis

Can be caused by increased BP Can be classified between stages with different numbers. Treat with slow movements to not cause the pat

Left vs Right

Will lead up heart attacks Has the similar conditions that need to monitor and improve the state Usually diagnosed with EKG

Medications

This study guide identifies multiple medications and their use Preload is reduced with medication and should check on BP and electrolytes. And Atherosclerosis can be a major sign in heart disease

Angina

Has multiple steps that needs to be addressed. Always check EKG and if it is the priority Ischemia can be a great sign as well

Stemi and MI

Should identify the difference to evaluate with tests that may support their condition. Lab work can be helpful and it is is important to get EKG and vitals ASAP Also note that not all the cases look the same.

Cardiac Rehab

May give education to support and reduce the stress that can support their physical and mental health. This stage also recognizes that patients may develop complications

Valve Replacement

May need a sternotomy, or the use of mechanical components. It is also important to shock because of organ failure in areas if low blood. There areas will need to be maintained.

Shock

• Begins with endothelium damage
• Is classified into 3 categories (hypovolemic, Cardiogenic, Obstructive)- early looks include:
• Low BP, Tachy HR Guppy (agonal) breathing.
• Inadequate Venus retunr
• There is a high risk for cardiac death. This is identified with lab work.

PICS (Persistent Inflammation Immunosuppression and Catabolism Syndrome)

• Involves ongoing inflammation and has an increased suseptability
• Manifestations:
• Sarconeia and with the help of low nurturance
• Always check for signs to show if the patient has infections
• Important to check for bleeding when doing assesmts