EKG REVIEW

]]Pathways for conduction]]

SA node, AV node, Bundle of His, bundle branches, Purkinje fibers

• ]]SA node]]

  Located in the upper right portion of the right atrium \n Initiates the heartbeat \n The pacemaker of the heart (60-100 beats per minute) \n Normal conduction begins in the SA node

• ]]AV node]]

  Located on the floor of the right atrium \n Causes delay in the electrical impulse, allowing for blood to travel to ventricles \n It can act as a pacemaker if SA node is not working (40-60 bpm)

• ]]Bundle of His]]

  Located next to the AV node

  Transfers electrical impulses from the atria to the ventricles via bundle branches
  

• ]]Bundle branches]]

  Split the electrical impulse down the right and left side \n From the interventricular septum, the impulse activates myocardial tissue, causing contraction \n Contractions occur in left-to-right pattern

• ]]Purkinje Fibers]]

  Electrical pathway for each cardiac cell \n Impulse activates left and right ventricles simultaneously

   Produce an electrical wave
  

]]Unique qualities of the heart]]

• Automaticity- heart’s ability to generate an electrical impulse
• Conductivity-ability of myocardial cells to receive and conduct electrical impulses
• Contractivity- ability of the heart muscle to shorten in response to an electrical impulse
• Excitability-ability of the heart to respond to an impulse or stimulus

]]Autonomic Nervous system]]

• Speeds up or slows down the heart rate-
• Sympathetic branch can increase the heart rate (norepinephrine)
• Parasympathetic branch can decrease the heart rate (vagus nerve)

]]Depolarization]]

• State of stimulation, preceding contraction
• Electrical activation of heart cells
• Causes the heart to contract
• Most important electrical event

]]Repolarization]]

• State of cellular recovery, the following contraction
• Cell returns to a resting state
• Heart relaxes, allowing for the refilling of the chambers

{{Interpreting EKG waveforms{{

• Standardized graph paper used

• Each square is 1mm x 1mm

• Each vertical square represents amplitude (gain) or amount of voltage 0.1 mv (millivolt)

• Each horizontal square represents time of 0.04 seconds

• The paper runs at a standard speed of 25mm/second

• Normal amplitude is 10 mm or 1 mv

{{EKG waveform{{

-Recorded activity of depolarization and repolarization

-Isoelectric line or baseline

P Wave

-First positive deflection

-Occurs when the atria depolarize

-Small compared to other ECG waves

Q Wave

Represents the conduction of impulse down the interventricular septum

First negative deflection before the R wave

R Wave

-First positive wave of the QRS complex

-easiest to find

-Represents conduction of electrical impulse to the left ventricle

S Wave

Represents conduction of electrical impulse through both ventricles

QRS Complex

-Represents complete ventricular depolarization

-Reflects the time required for impulses to activate the ventricular myocardium to contract

ST segment

-Indicates end of ventricular depolarization and beginning of ventricular repolarization

-Elevated ST segment indicates myocardial damage

T Wave

-Represents ventricular repolarization

U wave

-Represents repolarization of the Bundle of His and Purkinje fibers

-Not on all EKG

PR Interval

-the time that the electrical impulse is initiated until the ventricles are stimulated by the impulse to start the contraction.

-should be consistent

QT interval

-Time required for ventricular depolarization and repolarization to occur

R to R interval

- Used to calculate heart rate

-readily seen on EKGs

{{Performing An EKG{{

Electrocardiogram

• Electrocardiograph – machine that records and electrocardiogram
• Monitors 12 views (12-lead) of the heart at once – 10 wires are attached to the body
• Electrodes and gel are needed to record an EKG
• Telemetry – constant monitoring of the patient in a hospital setting

Preparing the PT

• Patient removes clothing from the waist up
• Provide with drape, sheet, or hospital gown with opening in the front
• Patient removes jewelry that may interfere
• All electronic devices should be turned off and removed
• Position patient comfortably on back and provide pillow for head and knees, if preferred
• Work from patient’s left side if possible
• Ensure privacy
• Ensure that arms and legs are supported Place patient in semi-Fowler’s position if SOB
• Make sure bed/exam table is not touching wall or electrical equipment
• Ensure that patient is not touching metal

Verification

Verify physician order (requisition) for ECG \n - Patient name/date of birth \n -Location/date/time of recording \n -Patient age/sex/race/cardiac medications \n -Height and weight \n -Reason for exam

Communication

- Identify the patient \n - Check the patient name, identification number, and date of birth (two forms of identification) \n - Introduce yourself and explain what you are going to do

-If the patient refuses the ECG, determine the cause. Let them know that there is no “electricity”. It is like a photo. \n - Notify your provider if you cannot resolve the problem

Anatomical Landmarks

Midclavicular line \n -Usually starts in the center of clavicle and passes through nipple line \n -Troubleshooting – in obese patients or female patients with large breasts, midclavicular line may not run through nipple

- Anterior axillary line \n - Mid-axillary line \n - Intercostal spaces (ICS) \n - Suprasternal notch \n - Angle of Louis

Limb Lead Placement \n -Place on fleshy areas in same general vicinity (amputations, etc.) \n - Right arm – White \n -Left arm – Black \n -Left leg – Red \n - Right leg – Green \n “Right is White” \n Salt – Pepper – Ketchup – Lettuce

Bipolar Leads

• Leads I, II, and III are bipolar – records impulses that travel from a negative to positive pole
• Rhythm strip – best seen in Lead II

Unpolar Leads

• AVL, AVR, and AVF – unipolar
• Due to poor recording amplitude, the leads must be augmented to enhance the tracing

Precordial Leads \n - Precordial leads – located on the chest in front of the heart \n - Listed as V1, V2, V3, V4, V5, V6

V1-V6 Placement

v1- The 4th intercostal space, right of the sternum

v2- 4th intercostal space, left of the sterurm

v3- Between V2 and V4

v4- 5th intercostal space at midclavicular line

v5- level with v5 at left midaxillary line

Applying electrodes

-Prep the skin with either an alcohol swab or electrolyte pad \n - Shave hair if necessary

• For females, lift left breast and place electrodes in closest position possible. Do NOT place electrodes on top of breast tissue
• Non-standard location of electrodes must be documented on recording
• Troubleshooting \n -For comparing ECGs, electrodes must be located as close to original sites as possible

If Electrodes will not stick

-Cleanse skin with alcohol pads and pat dry \n - Clip or shave hair from the site only if necessary

Safety and Infection Control

- Follow universal precautions \n - Wash your hands \n - Wear gloves when exposure to blood or bodily fluids is likely

-Make sure the procedure is performed on the correct patient

-Raise bed rail if available \n - Pull out extension for legs and feet if using an exam table \n - Check grounding plug for security

-Ensure that bed or table is not touching wall or electrical equipment \n - Ensure that patient is not touching bed rail, exam table frame or safety rail \n - Check insulation wires for cracks

Checking the ECG Tracing

- Somatic tremor – Large spikes caused by muscle movement \n -Causes: shivering, muscle tension, pain, fear, talking, chewing gum, disorders such as Parkinson’s disease.

Wandering baseline

Usually caused by improper electrode application. Can also be caused by poor skin prep, pulling on \n electrodes, old electrodes or clips, oil, lotion, dried out electrodes

Alternating current (AC) interference \n -Small, uniform spikes caused by electricity radiated from other machines \n -Common sources include improper grounding, lead wires crossed, corroded or dirty electrodes

Interrupted baselines or flat lines on tracings are caused by: \n -Loose or unplugged lead \n -Switched wires \n -Broken wires

Calculating Heart Rate: 6-Second Method

\n Identify a 6-second tracing – 2 segments marked along the top \n -Count the number of complete complexes seen in a 6-second strip \n - Multiply the number of complexes by 10 \n -Do not count incomplete complexes

Equipment Placement

-For disposable electrodes, clean alligator clips and check for paste/gel \n - Disinfect cables and reusable electrodes

-Wash straps; replace cracked/broken straps \n - Wash reusable electrodes to prevent gel/paste buildup \n - Scour reusable electrodes once a week

-Wipe patient cables and lead wires with damp cloth \n - Replace cracked or broken wires \n -Store neatly

Stress testing

- Must have emergency equipment available during testing \n -Patient is attached to the EKG while exercising (bike or treadmill) to see how the heart handles the stress \n -Thallium can be used for patients that cannot exercise \n -CMA role – attach leads, monitor v/s

• Pt education:

  -Wear comfortable walking shoes \n - Wear a separate shirt and pants – to access chest for leads \n -Take regular medications the day of stress test \n -Do not eat a large meal prior to the test

Holter Monitor

-Patient will wear monitor for 24 hours or more (as ordered by provider) \n - Holter records all EKG activity for that time period \n -Patient will press a button when symptomatic (syncope, pain, palpitations) and keep a diary of all activity \n - CMA role – attach leads, patient education

• Pt education:

  -Do not remove or replace electrodes \n - Do not shower or get device wet \n - Avoid exposure to electrical forces such as metal detectors \n -Conduct normal activities while wearing \n - Return at designated time for removal

{{EKG Rhythms{{

■ Normal sinus rhythm (NSR) indicates the following: \n – All measurements are within normal limits \n – The rate is between 60 – 100 bpm \n – There is a P wave indicating that the rhythm started in the SA node (sinus)

■ Arrhythmia

– A change from normal sinus rhythm \n – Can be rate, appearance, or conduction problems

• Sinus Bradycardia

  ■ Sinus rhythm – normal P wave present, other measurements WNL \n ■ Rate <60 bpm

Sinus Tachycardia

■ Sinus rhythm – normal P wave and other measurements WNL \n ■ Rate > 100 bpm

Sinus Dysrhythmia \n ■ Sinus rhythm – P wave present, other measurements WNL \n ■ Slight irregularity in rhythm – usually associated with breathing patterns

Sinus Arrest \n ■ Normal Sinus Rhythm when complexes are present – consistent pattern \n ■ A break in the pattern is sinus arrest \n – The SA node fails to fire \n – Not significant unless lasts longer than 6 seconds

Atrial Flutter \n ■ Atria are contracting at a rapid rate –much faster than the ventricles are \n contracting \n – Sawtooth appearance of “F” waves (may look like P waves) \n – Consistent ratio (ex. 4 F waves to 1 QRS) \n – Regular rhythm - pulse

Atrial Fibrillation (A-fib) \n ■ No organized contraction of the atria \n – Quivering state \n – Blood clots can develop due to stagnation of blood \n – Irregular rhythm and pulse

Ventricular Fibrillation \n ■ OMG rhythm! \n ■ Immediate intervention needed – no pulse being generated – begin CPR \n ■ Patient will NOT be conscious \n ■ Ventricles are quivering – no wave forms on EKG \n ■ Needs defibrillation (AED)

Asystole \n ■ OMG rhythm! \n ■ No heart electrical activity or pulse \n ■ Heart has stopped – Begin CPR \n ■ Patient will NOT be conscious. If talking, check your cables.

Abnormal Waveforms – Junctional Dysrhythmia \n ■ The P wave is normally deflected upwards. \n ■ Negative P-waves indicate a Junctional Rhythm \n – The impulse is generated in the AV node instead of the SA node. \n – Junctional rhythms may not have a P-wave at all \n – Rate is often between 40-60 bpm

Abnormal Waveforms – Premature Ventricular Contractions (PVC) \n ■ If the QRS is “wide and bizarre”, suspect a ventricular arrhythmia. \n ■ Occasional PVC’s are common and can be insignificant. Usually asymptomatic. \n ■ Can occur in pairs, be unifocal, multifocal, or occur in runs \n ■ Notify provider if PVC noted on EKG

{{Blood flow of the heart{{

-Superior and inferior venal cava

-Right atrium

-Tricuspid valve

-Right ventricle

-Pulmonary valve

-Pulmonary arteries

-Lungs gas exchange

-Pulmonary veins

-Left atrium

-Bicuspid valve

-Left ventrical

-Aortic valve

-Aorta

{{Respiratory{{

Productive cough (wet cough)

Nonproductive cough (dry hacking)

Treatments for coughs (Antitussives, expectorants)

COPD- chronic obstructive pulmonary disease

chronic bronchitis

Emphysema

SRS- smokers respiratory syndrome

Epistaxis- Nosebleed

Laryngitis

Lung cancer

Pleurisy- Inflammation of the pleura

pneumonia

Rhinits

sinusitis

{{Circulatory disease{{

Anemia- an inadequate number of red blood cells

aplastic anemia- destruction of bone marrow

sickle cell anemia

Aneurysm- ballooning out of saclike on the wall of the artery

Arteriosclerosis- hardening of the walls of an artery

Atherosclerosis

Atherectomy

CABG

Congestive heart failure

Embolis- a foreign substance in the blood stream

Hemophilia

High blood pressure

Angina- narrowing of the coronary arteries which causes ischemia

Nitroglycerin- treats angina

Myocardial infraction- heart attack

Phlebitis- inflammation of the vein, usually the leg

Varicose veins- dilated swollen veins that have lost elasticity