holter monitor1

Ambulatory Monitoring(H lt M it Ch t )(Holter Monitor Chapter)

Table of ContentsL i Obj tiLearning Objectives

1. History / Introduction2. Role of Cardiology Technologist3 Indications & Diary Findings For Ambulatory Monitoring3. Indications & Diary Findings For Ambulatory Monitoring4. Components & Principles of Ambulatory Monitoring5. Conduction Disturbances6 Arrhythmias6. Arrhythmias7. Drugs & Miscellaneous8. Reporting & Standards for Ambulatory ECG9. Pediatrics10. Pacemaker Indications11. Review Questions12. Summary /References13. AECG Report Examples

Learning ObjectivesDefine Ambulatory ECG monitoring• Define Ambulatory ECG monitoring

• Identify indications used in ambulatory ECG monitoring to rule out arrhythmias• Identify the items that are important to include in a patients history• Describe step by step the procedure for application of the ambulatory ECG

recording systemg y• Identify potential areas where artifact could develop and how to prevent them• Identify the important points to remember when disconnecting a patient from an

ambulatory ECG recorder• Describe sudden cardiac death and explaining why ambulatory ECG monitoring

is preferred diagnostic procedureis preferred diagnostic procedure• Describe the cardiac events that are considered within a normal range• Identify and compare the types of ambulatory ECG recording systems• Explain the importance of standardization and how the equipment is calibrated• Identify the considerations that should be made when selecting the most y g

appropriate recording leads.• Explain how the patient diary is a valuable aid in the analysis of ambulatory

monitoring• Describe a systematic approach to performing ambulatory ECG monitoring

analysisanalysis• Identify and describe the major scanning modes• List the items that should be included on an ambulatory ECG monitor report• List conditions and factors that can cause false positive ST changes• Describe the care and maintenance of recording and scanning equipment

Chapter 1Introduction / History

What is Ambulatory or Holter Monitoring?Holter Monitor

• Holter monitoring is a continuous, twenty four or forty eight hour electrocardiography (ECG) recording of the heart's rhythm or taking bloodelectrocardiography (ECG) recording of the heart s rhythm or taking blood pressure.

• Electrodes are placed on the chest area with the leads attached to a small recorder. These electrodes will pick up the signals from the heart and transfer them to the portable recorder, where the electrical impulses will be

d d Th di ill l t b l d d i t d i t t hi hrecorded. The recording will later be analyzed and printed into a report, which the doctor will make a final interpretation.

• The patient will keep a 24-hour diary to record daily activities, exercise and any symptoms experienced.

• It will take approx. 15 minutes to have the monitor put on.It will take approx. 15 minutes to have the monitor put on. • The patient will return the next day to have the monitor removed. • This test must be ordered by a doctor.

Blood Pressure Monitor:• The portable automatic blood pressure monitor measures and stores blood• The portable automatic blood pressure monitor measures and stores blood

pressure and heart rate at predetermined intervals (every 30 minutes during the day, and every 60 minutes during the night).

• The monitor is used to assess the heart muscle's reaction to the activities of daily living.

E t M it

Chapter 1Introduction / History

• Event MonitorsEvent monitors are small devices that are used by patients over a longer period (weeks to months, typically one month). Two sticky patches (electrodes) on the chest connect two wires to the event recorder. The monitor is always on b t ill l t th ti t’ h th h th ti t i h thbut will only store the patient’s rhythm when the patient or caregiver pushes the button. Most monitors will save the rhythm for several seconds of rhythm before the button is even pushed. The rhythm is also saved for a period after the button is pushed. A few specialized monitors are used only after the patient has

t Th i t t i f t t it t b h iblsymptoms. The intent is for most event monitors to be worn as much as possible every day to increase the chances of recording the patient’s rhythm when he/she has symptoms.

• Implantable Loop Recorders (ILRs)Some patients have serious but very infrequent symptoms that can't be recorded by regular event recorders because they occur so rarely. In these cases, it may become necessary to implant a special event recorder called an ILR under the patient’s skin. An ILR is the size of an adult’s little finger. It is implanted under the skin by a one-inch incision on the chest. The battery lasts 14 months. It is always watching the patient’s rhythm. It will make a recording of the patient’s rhythm when either the patient places an activator over the ILR and pushes a button when they are having a symptom or when the patient’s rate goes above or below the limits set in the ILR. The recordings cannot be sent over the phone. Instead, a programmer machine reads the information with radio waves. The ILR will store up to 14 events between each reading.

Chapter 1History•Norman Jefferis "Jeff" Holter (February 1, 1914, Helena, Montana – 1983) was an American biophysicist who invented the Holter monitor, a portable device for , pcontinuously monitoring the electrical activity of the heart for 24 hours or more.•Holter graduated from the University of California at Los Angeles in 1937. He then earned Master's degrees in chemistry and physics, and continued his education by completing postgraduate work at the University of Heidelberg (Germany), the University of Chicago the Oak Ridge InstituteUniversity of Chicago, the Oak Ridge Institute of Nuclear Studies, and the University of Oregon Medical School. During World War II, Holter served as senior physicist in the U.S. Navy, studying the characteristics of waves. In 1946, he headed a government research team involved in the atomic-bomb testing at Bikini Atoll. After the war, he continued work with the United States Atomic Energy Commission and served as president of theCommission, and served as president of the Society of Nuclear Medicine from 1955-1956.

Chapter 1History

•In 1964, he became a full professor at the University of California in San Diego, coordinating activities at the Institute of Geophysics and Planetary Physics In 1979 the Association for thePhysics. In 1979, the Association for the Advancement of Medical Instrumentation (AAMI) awarded Holter with the AAMI Foundation Laufman-Greatbatch Prize for his contributions to medical technology.•Starting in radio telemetry and research towards EEG, he later switched to the ECG recording, working t th ith J h A G llitogether with Joseph A Gengerelli

Chapter 2Role of a Cardiology Technologist

Define principles of operation of various instruments that are used in non-invasive cardiology such as electrodes, electrocardiograph, treadmills, ambulatory monitor analyzers, and computers Identify the conduction system of the heart and correlate with y yelectrocardiography Explain lead theory and describe appropriate lead placement for all cardiology related tests Recognize the sensitivity and specificity of all cardiology related testsg y p y gy Understand the concepts of basic cardiac pacing, including sensitivity, capture, polarity, NBG code, and timing cycles Activate equipment and record cardiac waveforms (tracings) Identify ECG waveforms checking for technical accuracy, ensure artifactIdentify ECG waveforms checking for technical accuracy, ensure artifact free tracing and correct lead placement.Apply ambulatory ECG monitor/recorder. Ensure patient identification and review indications for procedure Label tape or digital card with patient demographics Label tape or digital card with patient demographics Explain purpose of the procedure and clarify requirements of the patient, including diary entries, notation of symptoms, activities, and monitor/recorder care.Prepare skin sites appropriately prior to electrode applicationPrepare skin sites appropriately prior to electrode application

Apply sensors (electrodes) and secure. Connect lead wires to monitor/recorder and secure these wires to minimize artifact


Record rhythm strip and/or 12-lead tracing (where applicable) to ensure correct calibration, lead placement (sufficient amplitude of the R wave) and good connections (electrodes, leads and battery)

Ensure proper working order such as tape movement

Secure recorder, assisting patients to dress if required, and provide patient with instructions for return of monitor/recorder

Upon patient return, disconnect monitor/recorder and clean patient skin and equipment Assess skin integrity post applicationequipment. Assess skin integrity post application.

Query patient for any significant symptoms and review diary prior to the patient’s release

Inspect equipment to ensure proper working order and take any actions asInspect equipment to ensure proper working order and take any actions as required

Prepare recording for analysis.

Analyze ambulatory ECG monitor recordings. Ensure that patient information or requisition is applicable to the digital card including patient diary and 12 lead ECG

Review indication of test, ECG and test strips (where applicable) and determine history of conditions such as known or suspected cardiac abnormalities arrhythmiashistory of conditions such as known or suspected cardiac abnormalities, arrhythmias, pacemaker function, medical disorders (i.e. sleep apnea, diabetes, etc.) and pharmacological implications


Review and enter data into computer analyzer including age, name, di i d d i f di i di i f b i dmedications, date and time of recording, indication for test, symptoms obtained

from diary, referral source Initiate recording for analysis using facility and computer protocols Identify and save appropriate strips for reports of cardiac arrhythmias,

k d i l t bl di d fib ill t ti itpacemaker and implantable cardiac defibrillator activity Using standard terminology, prepare the patient report, which is a representative document of underlying rhythms and any ECG abnormalities Take timed strips and examples of the abnormalities etc., their morphology, f d il f i t t tifrequency and compile for interpretation Take responsibility for analysis and report to ensure a comprehensive and accurate overview of the ECG data has been acquired Enter comments on quality of the recording and any additional pertinent b ti Diff ti t b t h th i d tif tobservations. Differentiate between arrhythmias and artifact

Make any necessary amendments to data; e.g. change labels of strips or beats if the analyzer has mislabeled them Identify and report any ominous arrhythmias, making a comprehensive report t h i i d/ di l i tto physician and/or cardiologist Communicate effectively and answer any questions or concerns regarding the report Troubleshoot for recorder malfunctions, broken patient lead wires, timing

tif t h t t t h t l t i l i t f d ft bl tartifact such as tape stretch, etc., electrical interference and software problems, etc. Participate in research projects and be able to follow specific analyzer protocols and procedures

Chapter 3Indications & Diary Findings For Ambulatory Monitoring

• Detection of conduction disturbances and arrhythmia’s

– Atrial ectopy - described as an early contraction from the upperAtrial ectopy described as an early contraction from the upper chamber of the heart (atrium). A premature atrial beat can happen occasionally, in a regular pattern, or multiple beats in a row. This is usually a harmless disturbance. Some people are sensitive to the disturbance but most are unaware. The ECG will show a normal beat that occurs usually immediately after the T wave instead of the normal pauseoccurs usually immediately after the T wave instead of the normal pause between beats.

– Ventricular ectopy – described as an early contraction from the lower chambers of the heart (ventricle). These are common rhythm di t b d l iti t th t b t (f lidisturbances and some people are very sensitive to the extra beat (feeling of a pounding or squeezing known as palpitations). These do not always indicate a problem unless the person has a history of arrhythmias or known heart disease. Premature ventricular beats may be followed by ventricular tachycardia and ventricular fibrillation that eventually can lead t dd di d th Th ECG ill ll h id lto sudden cardiac death. The ECG will usually show a wider complex occurring immediately after the T wave. This can occur as a single occurrence (PVC), in a regular pattern (V bigeminy or trigeminy) or all in a row (Ventricular tachycardia)


• A Fib/ Flutter – this is an abnormal rhythm which occurs in the artia• Blocks (1st, 2nd, 3rd, LBBB, RBBB, etc.)• Tachy/Brady (heart rate variability)• Pauses, arrest• Prolonged QT – indicates an abnormality in the electrical activity that

leads to irregularities in the heart muscle contraction• Cardiomyopathy – basically limited to the myocardium There are 3Cardiomyopathy basically limited to the myocardium. There are 3

different types

1) Dilated cardiomyopathy – this is characterized by ventricular enlargement with impaired systolic contractile function.p y

• ECG findings – demonstrates atrial and ventricular enlargement with a wise array of arrhythmias (A Fib & V Tach). A conduction defect, being mostly LBBB or RBBB occurs in majority of cases. Diffuse repolarization (ST & T waves) is common. Regions of dense myocardial fibrosis may produce localized Q waveslocalized Q waves

2) Hypertrophic cardiomyopathy – characterized by an abnormally thickened ventricle with abnormal diastolic relaxation.

• ECG findings – typically shows left ventricular hypertrophy. Prominent Q g yp y yp p ywaves are common in inferior and lateral leads. Atrial and ventricular arrhythmias are also very frequent


3) Restrictive cardiomyopathy – characterized an abnormally stiffened myocardium such that diastolic relaxation is impaired but the systolic contractile is usually preserved.

• Symptoms are usually similar or identical to constrictive pericarditisSymptoms are usually similar or identical to constrictive pericarditis– Sudden cardiac death (cardiac arrest) – this is an unexplained death due

to some type of heart problem mostly being arrhythmias. There is usually no way of predicting this from happening. The ECG can sometimes show rhythm disturbances or prolonged QT that might give clues to a deeper problem This is not the same as actual death Sudden cardiac death isproblem. This is not the same as actual death. Sudden cardiac death is potentially reversible with quick response.

• Evaluation of symptoms (causes)Palpitations– Palpitations

– Dizziness, lightheadedness– Nausea– Chest pain/ discomfort– Shortness of breath– Back pain, jaw pain, arm pain– Syncope, pre-syncope– FatigueFatigue– Central nervous system symptoms


• Evaluation of therapeutic interventions– Medication’s

• Evaluation of pacemaker/ICD function– Single and dual chambered– Failure to sense, output, capture

• Detection of myocardial ischemia– Anti-ischemic therapy evaluation– Ischemic heart disease– Post myocardial infarction– Valvular heart disease

• Research purposesp p– Coronary rehab and surgical evaluation– Congestive heart failure– Medication– EPP studies

• Other– Peripheral vascular disease– Sleep apnea syndrome– Chronic obstructive lung diseaseC o c obs uc e u g d sease– Risk stratification– Electrolyte abnormalities


• Diary

The patient is asked to keep a diary of all symptoms, activities, and events during the period of AECG monitoring. When carefully recorded and timed correctly the log is valuable in diagnosing the complaint of the patient Obviously patients should record symptoms such as palpitationsthe complaint of the patient. Obviously patients should record symptoms such as, palpitations, dyspnea, fatigue ,dizziness, chest pain/discomfort, arm pain, nausea, presyncope or syncope.

Patients are not usually aware of the fact that silent angina shows ischemic ST changes without typical chest pain. Patients should be recorded to record any discomfort, not only chest pain, e.g. pain in the neck, arm, jaw, as soreness, heaviness, pressure, sharp pain and indigestion.

The patient should be instructed to grade symptoms as severe, moderate or slight. It is also important that the patient should note the following carefully at the time of occurrence:meals– meals,

– taking of any stimulants, coffee, chocolate, smoking,– taking medication– Stress such as anger, frustration, sorrow, depression, anxiety,– Exercise sexual activity– Exercise, sexual activity, – Bowel movement, straining and any valsalva maneuvers, heavy lifting, and hyperventilation.

The diary is also an essential tool to exclude false positive or false negative findings. All diary entries should be shown in AECG strips even if the rhythm is normal. This way the reading p y y gphysician will be sure that there is nothing significant happening at that time.

Chapter 4Components & Principles of Ambulatory Monitoring

Lead Placement

When monitoring patients, we should monitor them with leads that give us the most information about disturbances of rhythm and conduction. Visibility of P waves is necessary to distinguish PAC’s and PVC’s, identify atrial beats, atrial fibrillation, atrial flutter and SVT. The leads that provide us with this information the best are leads II and V1. When considering leads for monitoring ST segment changes, leads V2, V5, and AVF are recommended.

Lead II provides a positive, high-voltage defection resulting in tall P, R and T waves making it a commonly used lead for AECG monitoring. It is useful for detecting sinus node and atrial arrhythmias and monitoring the inferior wall of the left ventricle.

1 f CG 1 fLead V1 is also a helpful lead in AECG monitoring. Lead V1 is useful in monitoring ventricular arrhythmias, ST segment changes and bundle branch blocks. It helps to distinguish between right and left ventricular ectopic beats that result from myocardial irritation or other cardiac stimulation outside the normal conduction system (QRS is mostly positive and is more prone to the R on T phenomenon). Most importantly V1 gives you the information needed to differentiatethe R on T phenomenon). Most importantly V1 gives you the information needed to differentiate between ventricular tachycardia and aberration.

To determine between ventricular tachycardia and SVT with aberration you need to look closely at the configuration of V1. If the wide complex QRS

Chapter 5Conduction Disturbances


Introduction

• Conduction Abnormalities can occur anywhere in the Conduction System !y y• SA Node• AV Junction• Bundle Branches• Bundle of HIS• Purkinje Fibers

• Sinus Block / Arrest• Sinus Block / Arrest• No Conduction through the SA Node


AV Blocksoc s• 1st Degree AV Block

• PR interval > 0.20s. • 1 P-wave per QRS

2nd Degree AV Blockg•Type 1 Wenckebach

• PR interval gets longer until a non-conducted P-wave occurs


• Type 2 Mobitz / ClassicalType 2 Mobitz / Classical• Some impulses are conducted some are blocked. • PR interval is constant• More then 1 P-wave per QRS

3rd Degree AV Block•Complete Conduction Failure•Complete Conduction Failure

•Atria and Ventricles are working independently.

•P-P is regular

•R-R is regular


RBBB•QRS duration >0.12s

•Terminal R wave in V1 ( rSR complex )

•Terminal S waves in leads I AVL V6•Terminal S waves in leads I, AVL,V6

LBBB

•QRS duration >0.12s

•Terminal S wave in V1

•Terminal R waves in lead I aVL V6Terminal R waves in lead I, aVL, V6


W lff P ki Whit WPW

•Initial slurring of the QRS complex (delta wave) representing early ventricular conduction through normal ventricular muscle in the accessory pathway

Wolff-Parkinson-White WPW

• QRS (>0.10s)

• Secondary ST-T changes due to the altered ventricular conduction sequence

Chapter 6Arrhythmiasy

Brief Overview: BasicsThere are many various rhythms and abnormalities that occur during holter monitoring. This can vary from each

patient to patient. Below is a brief description of the various types or rhythms or arrhythmias that may occur during holter monitoring.

The role as a cardiology technologist:The role as a cardiology technologist:Cardiology technologist is responsible for proper skin preparation and electrode application to ensure a proper

tracing will be achieved. They must be able to communicate effectively with their patients to obtain satisfactory cooperation and compliance permitting an effective recording. They must be able gain the patient’s confidence to achieve the patient’s cooperation in keeping a satisfactory diary of symptoms, medications and activities. It is important to be familiar with the mechanical and technical details of the precorder including proper techniques for attaching and disconnecting the cables as well as proper maintenance of the recorder such as cleaning and lubricating. In addition it is important that Cardiology technologist should be able to identify any immediate life threatening arrhythmias or abnormalities and follow protocols to notify a physician or cardiologist.

In Normal Sinus Rhythm the rate of the sinus nodes generally fires off impulses between the rates of 60 to 100 beats per min. This varies and depends on age, gender, and fitness. As a cardiology technologist we can use these criteria as bench mark to document any abnormalities arrhythmias of the heart.

Sinus TachycardiaSinus TachycardiaWhen the blood pressure is increased or other environmental factors such as stress or exercise is put upon the

body numerous physiological factors such as adrenaline could cause the heart rate to increase. In sinus tachycardia the sinus node fires off at a rate of greater than a 100 beats per minute.

Sinus BradycardiaSinus bradycardia is the term used when the sinus rate is less than 60 bpm. Heart rate less than 50 bpm are

termed marked sinus bradycardia and considered abnormal and in the absence of drugs such as beta-blockers, calcium channel blockers or digitalis it reflects abnormality in the sinus node.

Sinus Arrhythmia:Sinus arrhythmia is an irregular heart rhythm where the P-R interval remains constant and the R to R interval is

Chapter 6Arrhythmias

Sinus arrhythmia is an irregular heart rhythm where the P-R interval remains constant and the R to R interval is changed or varies this may occur depending on several different factors such as age or particularly during respiration and in younger people.

Multi-focal Rhythm: Wandering PacemakerThis is an arrhythmia due to the impulses fired from a different focus in the atrium. Hence this rhythm is indicated by y p y ythree or more different morphologies of P-waves. It is an irregular rhythm that can be noted in the electrocardiogram, with varying P-R and the R-R interval.

Junctional RhythmsA junctional rhythm is indicated by a short PR interval, or a retrograde P-wave. The P-wave occurs after the QRS

l h th t i d l i li htl ft th t i l If i l f th S A d d AV d ficomplex when the atrium depolarizes slightly after the ventricles. If impulses from the S.A. node and AV node fire off at the same time the P-wave can be hidden in the QRS complex, hence there is no p-wave present at all before the QRS complex. A junctional rhythm can also be indicated by the negative deflection of the P-wave in leads 2 and AVR, this occurs when the atrium depolarizes slightly faster than the ventricle. A junctional rhythm rate is between 40 to 60 beats per minute. If the rate is greater than 60 beats to a 100 beats per minute it is termed an accelerated junctional rhythm In junctional tachycardia the rate is increased to greater than aminute it is termed an accelerated junctional rhythm. In junctional tachycardia the rate is increased to greater than a 100 beats per minute. If the rate is less than 40 beats per minute it is termed junctional bradycardia.

Idioventricular RhythmAn idioventricular rhythm is indicated by a wide and bizarre QRS complex. The rate is generally between 15-40 beats per minute with no synchronization between atrial and ventricular activity when there is atrial activity is present. In accelerated idioventricular rhythm the rate is between 40-100 bpm.

Ventricular Tachycardia: Ventricular Tachycardia is a fast ventricular heart rate rhythm that originates in one of the ventricles of the heart. This rh thm is indicated b ha ing morpholog of 4 or more beats of greater than a 100 beats per min te There areThis rhythm is indicated by having morphology of 4 or more beats of greater than a 100 beats per minute. There are two types of ventricular tachycardia; a period of 3 to 5 rapid beats is called a salvo, the fast rhythm terminates itself within thirty seconds it is termed an un-sustained VT, if the fast rhythm does not terminate itself within 30 seconds it is called a sustained VT. This is a life threatening arrhythmia that may lead to ventricular fibrillation and sudden death.

Ventricular Flutter


In ventricular flutter is a rapid heart rate that originates from the ventricles, because of the electrical conduction pathways, an organized signal is provided to the ventricles, allowing them to beat. There is usually no p-wave present, and the QRS complex and T-wave are merged in regularly which occurs at a rate of 180 to 250 beats per minute. This rhythm is often associated with a heart attack in which the ventricular muscle doesn't get enough blood supply (myocardial ischemia), becomes irritated, and causes the whole ventricle to stop beating and degenerates into ventricular fibrillationdegenerates into ventricular fibrillation.

Ventricular FibrillationIf ventricular tachycardia is left untreated or occurs it may lead to ventricular fibrillation where the heart twitches randomly in attempt to pump blood into the systemic and pulmonary circulatory system, but lacks any cardiac output This is a life threatening rhythm in which there is uncoordinated contraction of the heart and is indicated byoutput. This is a life threatening rhythm in which there is uncoordinated contraction of the heart and is indicated by the dissociation of impulses which vary in magnitude, direction and morphology and may lead to death

Supra-ventricular tachycardia:Is a rhythm which originates in the atrium hence it’s name; “above the ventricles”. SVT is a fast heart rate caused by a re-entry circuit in the atria and is indicated by a narrow QRS with no p-wave present and a rate of acaused by a re entry circuit in the atria and is indicated by a narrow QRS with no p wave present and a rate of a 150 beats per a min or more.

Atrial Flutter:This abnormal heart rhythm occurs within the atria and falls into the group of supra-ventricular rhythms. This abnormality usually degenerates into atrial fibrillation and is indicated by a regular RR interval with a two to one y y g y gratio with the appearance of saw tooth waves and no P-wave present. There are two types of atrial flutter:

Type1: A) Type A is typical and counter clockwise (early), originates from the tricuspid annulus and contains a positive deflection in V1 and inverted in the inferior ECG leads (2, 3, AVF).B) T B i t i l d id d l k i t ti (l t ) it i i t f th i d ltB) Type B is atypical and considered as clockwise rotation (late), it originates from the coronary sinus and results in a negative deflection in V1 and upright flutter waves in the inferior ECG leads (2, 3, AVF). Type 2:Is faster with a rate of 350 to 450 beats per a minute and fails to respond to atrial pacing.


Atrial Fibrillation:This type of cardiac arrhythmia is due to disorganised activity in the atria and effects the irregular conduction impulses to the ventricles. The result of this is an irregular heart beat indicated by fine or coarse fibrillatory waves and an irregular r to r interval with no distinctive p-waves in the heart tracing. This type of arrhythmia is not considered life threatening but can result in palpitations, chest pain, fainting or congestive heart failure if left

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untreated.

Premature Atrial Contractions:Also known as PAC’s, APB, SVPB, and SVEA PAC is an early electrical impulse that occurs anywhere in the atrium and is the most common cause of palpitations This premature atrial contraction occurs early with the same deflection as the previous beat A PACpalpitations. This premature atrial contraction occurs early, with the same deflection as the previous beat. A PAC differs in morphology, and results in an irregular r to r interval cycle. In addition the PAC’s P-R interval will also vary, and results in an incomplete compensatory pause but will have the same deflections as the previous beats. The incomplete compensatory pause is due to interruption of the sinoatrial node. This is an atrial beat and is one of the three types of PAC’s; this electrical impulse travels right through the ventricles. In a non-conductive PAC the electrical impulse lands on a both refractory periods of the left and right bundle branches. The p-wave will appear p y p g p ppjust after the repolarisation of the ventricles (the t-wave) at which during the refractory period of this stage no matter how strong the stimulus, the myocardial cells cannot elicit a response or contraction of the muscles. In an aberrant beat the electrical impulse fires through the conduction system and passes through the left bundle branch but not the right bundle branch due to its longer refractory period. In an aberrant beat its morphology results in an RR prime in V1. This is due to the longer refractory period of the right bundle branch. If PAC i i l i i d l If h h i i dIf a PAC occurs in two consecutive cycles it is termed couplets. If there are three or more it is termed a run.

Premature Ventricular Contractions:Also known as heart palpitations the depolarization begins at the ventricles rather than the S.A. Node. PVC’s can originate anywhere within the ventricles and occur early. Its morphology is identified by its wide and bizarre shape of usually greater than a 120ms and has an opposite deflections of the other beats If there are PVC’s occurring inusually greater than a 120ms, and has an opposite deflections of the other beats. If there are PVC’s occurring in two’s they are termed a couplet, if there are three; triplets, and if there are four or more it is termed a ventricular run. If PVC’s occur every other beat this rhythm is termed: PVC’s in bigeminy, if the PVC’s occur every third beat this rhythm is called PVC’s in trigeminy and if every fourth beats it is called PVC’s in Quadrageminy.


Several factors should be kept in mind when describing and interpreting the characteristics of arrhythmias:

• Many portions of the impulse generating and conduction system as well as portions of the heart, are capable of impulse generation.• Functionally the heart consists of two double pump chambers two atria and two ventricles

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Functionally the heart consists of two, double pump chambers, two atria, and two ventricles linked by the atrio-ventricular-purkinje conduction system• The syncytial nature of the myocardial muscle enables the wave of depolarization to spread over muscle tissue to all contiguous myocardial cells• The conduction time in muscle is much slower than in specialized conducting fibers. Muscle

t ti d i i l d ti i l ti ill b di t d hilcontraction during impulse conduction in muscle tissue will be uncoordinated while contraction mediated by the SA node-AV node-Purkinje system will be synchronous and coordinated.• The wave of excitation from and abnormal (ectopic) pacemaker may follow an abnormal course through the myocardium. This will change the pattern of depolarization and g y g p pconsequently also the ECG wave configuration.

The following are general procedures for analysis:• Classify each beat as normal sinus rhythm, supra ventricular (atrial, AV nodal, AV bundle), ventricular ectopic paced other or unknownventricular ectopic, paced, other or unknown,• A template for each type of abnormal beat is created. The computer program tabulates the number of ectopic beats in each template.• A summary of describing the frequency of occurrence of each type of aberrant beat of atrial or ventricular origin are created by the program and can be presented and printed in tabular or graphic form.

Chapter 7Drugs & Miscellaneousg

Holter Monitoring can be used to evaluate the effectiveness of a patients cardiac medication. If the medication can suppress 85% or more ectopic beats and/or runs of ventricular tachycardia it is

id d t b ff ti di ticonsidered to be an effective medication. The cardiac classes of medications that are commonly evaluated are:

Class IClass II Class IIIClass IIIClass IV

It is extremely important that when you are filling out the patient’sIt is extremely important that when you are filling out the patient s information that you list off any medication that they might be taking. It is very helpful to the analyzing tech to have as much information as possible.

Chapter 7Cardiac Medications

• CLASS I – Antiarrhythmic Drugs

CLASS II – Beta Blockers

CLASS III D i Bl k d P t i (K )CLASS III – Drives Blocked Potassium (K+)

CLASS IV – Calcium Channel Blockers (Ca++)

CLASS V – Vago-tonic Antiarrhythmic Drugs


• CLASS ICLASS I

• ANTI-ARRHYTHMIC DRUGSAnti-arrhythmic drugs are classified by there effect on the T-mapy g y p

CLASS 1a: Primarily effects the fast sodium (Na+) channels (depolarization during phase 0 of the cardiac action potential)

1. Procainamide2. Quinidine3. Disopyramide

Treats: Both Ventricular and SVT Arrhythmias

ECG Changes: a) Prolonged QT d) Depressed T-waveb) Depressed ST segment e) U-wave c) Wide QRS)

- Side effects may include hypotension, syncope


CLASS I• CLASS IAnti-arrhythmic Drugs

CLASS 1b Sl h 0 d h t h 3CLASS 1b: Slows phase 0 and shortens phase 31. Lidocaine2. Mexilitene3 Tocainide3. Tocainide4. Phenytonin (treats toxic levels of digoxin (digitalis))

Treats: Ventricular Arrhythmia’s

ECG Ch M li htl h t QT i t lECG Changes: May slightly shorten QT interval

- Side Effects may include Slurred Speech Tremors NauseaSide Effects may include Slurred Speech, Tremors, Nausea


• CLASS ICLASS IAnti-arrhythmic Drugs

CLASS 1c: Marked Phase 0, Reduces Conduction1. Flecainide2. Propafenone3. Encainide

Treats: both SVT and Ventricular Arrhythmias - Can cause SVT or VT if dosage is incorrectCan cause SVT or VT if dosage is incorrect- ECG Changes:

- Prolonged PRI - Wide QRS- Prolonged QT interval

Side Effects may include Vision Disturbances Dizziness Pre syncope- Side Effects may include Vision Disturbances, Dizziness, Pre-syncope


CLASS II• CLASS IIBeta-adrenergic antagonists - Beta Blockers (olol)

Promotes parasympathetic (slows heart rate down), conserves O2

1. Propranolol 4. Sotolol 2. Metoprolol 5. Acebutolol3 Atenolol 6 Nadolol3. Atenolol 6. Nadolol

Treats: a) Ischemia d) Arrhythmiasb) Angina (except prinzmetals) e) CHF) g ( p p ) )c) Hypertension f) Cardiomyopathy

- Can also be used to prevent migraines, anxiety

ECG changes: a) Prolonged PRI c) U-wave may be evidentb) Shorten QT interval


CLASS III• CLASS IIIMixed Agents - Drives Blocked Potassium (K+)

Prolongs Repolarization and Refractory Period. Blocks Phase 3 so K+ leaves slowly.g p y y

1. Ibutilide 3. Amiodarone2. Dofetilide

Treats: a) Torsades e) PVC’sTreats: a) Torsades e) PVC sb) BBB (if patient is symptomatic) f) Lowers Blood Pressurec) Bradycardiad) Tachycardia

ECG Changes: a) Shortened PRI c) Prolonged QRS Durationb) P l d QT i t lb) Prolonged QT interval


CLASS IV• CLASS IVCalcium Channel Blockers (calcium antagonist)

Acts by vaso-dilation increases refractory period of the AV NodeActs by vaso dilation, increases refractory period of the AV Nodealso effects calcium channels

1. Verapamil 4. Felodipine 2. Diltiazen 5. Amlodipine3. Nifedipine 6. Atropine

Treats: a) Hypertension c) some arrhythmiasb) Angina d)control rapid Vent rate

ECG Changes: a) prolongs the AV nodal conductionb) slows the sinus rate


CLASS V• CLASS VVagotonic Antiarrhythmic Drugs

Decreases Conduction in the AV NodeDecreases Conduction in the AV Node

1. Digoxin2. Lanoxin

Treats: a) Control Arrhythmia (A-fib)b) Sl V t i l R t ( ll f filli ti )b) Slows Ventricular Rate. (allows for filling time)

ECG Changes: a) ST Depression / hook shape e) Prolonged PRIECG Changes: a) ST Depression / hook shape e) Prolonged PRIb) Short QT interval f) 2nd Degree AV Blockc) Flat or inverted T-Wave g) Sinus Bradycardiad) Notched P-Wave

Analyzing Systems

Holter Monitors

Systems

Pediatric Monitoring

Chapter 8Reporting & Standards for Ambulatory ECGReporting & Standards for Ambulatory ECG

The purpose of the report is to compile an overview summary of the relation between symptoms or events that the patient may have experienced and possible aberrations in the AECG recording. The AECG is a suitable method to determine if symptoms may be related to cardiac diseases. y p yEvents such as daily activities or unusual stress could have precipitated or evoked arrhythmias or ischemic episodes.

The frequency and seriousness of the AECG aberrations should be evaluated in order to supply the physician with essential information to make a diagnosis and to help decide on appropriatethe physician with essential information to make a diagnosis and to help decide on appropriate treatment.

A huge amount of raw ECG data is acquired during the period of recording and the important task of the cardiology technologist is to process it by scanning, integrating and summarizing the data in such a way that the final report shows the diagnostically important information in a reliable, clinically understandable, easy and quick-to-read format. To do this the cardiology technologist must be able to recognize the diagnostically important features of the AECG recordings and correlate it with the patient’s diary notes on symptoms and events and report it.

The symptoms that usually prompted the recording of the AECG are:• palpitations• episodes of dizziness or lightheadedness• pre-syncope• syncope• chest pain

Chapter 8Reporting & Standards for Ambulatory ECGReporting & Standards for Ambulatory ECG

A report should include quantitative as well as qualitive information.

Quantitative information should include the following:g• total values at regular intervals, usually hourly breakdowns of results about the recordings• trends in heart rate, pauses, arrhythmias, and ischemic episodes.• correlation of measured number and types of arrhythmias during waking compared to sleep.• frequency of PVC’s should be indicated• frequency of PVC s should be indicated.

Standards of practice refer to: ACC/AHA Guidelines for Ambulatory Electrocardiographyin Journal of the American College of Cardiology, Volume 34, No. 3,

pages 912-948

Chapter 9Pediatrics

Pediatric patients require a lot of time and patience.

Chapter 9Pediatrics

Fig. 1: A three-lead rhythm strip from a 15 year old boy who suffered syncope while playingtennis. The rhythm is atrial fibrillation and Wolff-Parkinson-White syndrome. He had a leftlateral accessory pathway which statistically placed him at risk for sudden death,necessitating radiofrequency catheter ablation.

Chapter 9Pediatrics

Fig. 2: An example of "tachy-brady syndrome" in a 9 year old who had undergone a lateral tunnel type of Fontan operation at 4 years of age. Demonstrated are brief self-limited runs of atrial flutter, followed by severe sinus/junctional bradycardia.

Chapter 9Pediatrics

Fig.2 - A 10-year-old girl experienced her first syncope episode during emotional stress when she was seven years old. She suffered many similar episodes thereafter, which were always triggered by physical effort or emotion. Her initial diagnosis was epilepsy, and she was treated with barbiturates. She was referred to our hospital after being resuscitated from sudden cardiac death. During the diagnostic g gevaluation, 24-hour Holter monitoring showed a sequence of isolated premature ventricular complexes, which degenerated into sustained polymorphic ventricular tachycardia (bidirectional), leading to y ( ), gsyncope and convulsive movements with spontaneous recovery (figure 1). Treadmill testing (Bruce protocol) and isoproterenol infusion at increasing doses were able to reproduce sustained polymorphic VT. p p y pDuring treadmill testing, Holter monitoring, and isoproterenol infusion the first premature ventricular complex (PVC) started when her heart rate exceeded 100-120 beats/min, which were followed by120 beats/min, which were followed by bigeminy, coupled PVC, and nonsustained VT. Syncope occurred only during Holter monitoring (figure 1).

Chapter 9Pediatrics

Chapter 10Pacemaker Indications

SSI: A pacemaker that senses and stimulates one chamber at one rate.

AAI: A pacemaker that stimulates and senses the atrium at one rate

VVI: A pacemaker that stimulates and senses the ventricle at one rateVVI: A pacemaker that stimulates and senses the ventricle at one rate

SSI.R: A pacemaker that senses and stimulates one chamber at a rate determined by a sensor

AAI.R: A pacemaker that senses and stimulates the atrium at a rate determined by a sensor

VVI.R: A pacemaker that senses and stimulates the ventricle at a rate determined by a sensor

DDD: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is determined the maximum tracking rate and a minimum rate.determined the maximum tracking rate and a minimum rate.

DDD.R: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is governed by a maximum rate, the rate determined by a sensor and the minimum rate.

DDI A k th t d ti l t b th t i d t i l Th ti l ti t iDDI: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is fixed.

DDI.R: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is governed by a maximum rate, the rate determined by a sensor and the minimum rate.g y , y

VDD: A pacemaker that senses the atrium and ventricle and paces the ventricle.


In some cardiac conditions when other treatments fail, it is necessary to implant specific devices to correct defects. It is also possible to implant a device that can record AECG’s and monitor the function of an implanted electronic pulse generator (EP). Implantable defibrillator devices or implantable cardioverter-defibrillators (ICD) are also in use.p ( )

It is important to be able to monitor these EP and ICD functions by means of the AECG. In order to evaluate patients for EP and ICD implantation the information from the AECG is of importance. The AECG is essential to correlate the symptoms of patients (palpitations, pre-syncope syncope) with their rhythm abnormalities (usually bradyarrhythmias or heart block e gsyncope, syncope) with their rhythm abnormalities (usually bradyarrhythmias or heart block, e.g. Stokes-Adams syndrome). After implantation it is also essential to monitor the functioning of a device and to aid in programming, e.g. pulse rate. Most EP devices cannot replace the conventional AECG because they do not have the storing capacity to record data for long periods of time. The AECG is also important in fine tuning the implanted devices.

When the heart’s own pacemaker (SA node) fails or, if permanent blocking of conduction occurs somewhere between the SA node and the ventricles, an implantable electronic pulse generator may be the treatment of choice. Electronic pacemakers are also available for treating tachycardia's by interrupting the aberrant reentrant impulse circuitstachycardia s by interrupting the aberrant reentrant impulse circuits

On the AECG recording, the fast electronic pulse of an implanted electronic pacemaker can be seen as a small sharp spike during capture, just before the QRS complex.


In interpreting the AECG recordings during EP monitoring the following should be kept in mind:

– Is there complete capture, i.e. Is each EP spike followed by a wide QRS?

– Are there P waves visible? During SA node failure or atrial fibrillation distinct P waves are not visible. Atrial asystole or fibrillation is present.

– If P waves are present, are they independent from EP spikes and QRS complexes? If yes, one can assume that the rate of the EP is faster than the rate of any other atrial pacemaker (SA node, atrial ectopic focus, AV node).

– EP are often used for serious atrial bradycardias with failure of any normal escape impulse foci in the heart. A very slow rate of P waves will then be recorded.

– During AV block P waves independent from EP spikes and QRS complexes may be recorded.

Chapter 11Review Questions

1. Name 10 indications for AECG recording

2. Define Palpitations

3. Define Sinus Bradycardia

4. What symptom may occur during sinus arrest and why?

5. What are the contraindications for a Holter?

6. What critical value found on a holter would required a cardiologists attention?

7. What is the location of placements, skin prep etc?

8. Why is the percentage of A Fib/A Flutter important to document?

9. Why is it important to document all diary findings regardless if there is something shown on the Holter or not?

10 Wh i i i d h d d f h h i ?10. Why is it important to record the onset and end of an arrhythmia?

Chapter 11Review Questions

11. Name six items of diagnostic importance that should be included in the Holter report.

12. List the pacemaker evaluation data that should be recorded in a Holter report

13. What symptoms correlate better with arrhythmias?

14 Wh t th t b i t th t ti t h ld d i di ?14. What are the most obvious symptoms that a patient should record in a diary?

15. How would you identify failure of ventricular capture on an AECG report?

16. What is the purpose of the AECG report?

17. What part of the AECG recording should the report cover?

18. Describe the ECG difference between 1st, 2nd, and 3rd degree AV block.

Chapter 12Summary/References

• www.emedu.org/ecg/givemall.php

• www.Answers.com

• www.wikipedia.org• www.animalshelter.org• ACC/AHA Guidelines for Ambulatory Electrocardiographyy g p y

in the “Journal of the American College of Cardiology, Volume 34, No.3, pages 912-948.

• http://www.fac.org.ar/cvirtual/cvirteng/cienteng/cpeng/cpc1205i/ikanter/ikanter.htm

• http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2001000100007

Holter Report ExamplesAsystole

Holter Report ExamplesV-Tach

Holter Report Examples A Fib

Top Four Canadian Holter Manufactures

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Puppy Holter Monitoring

The Process

Evolution

Radio transmitter in the form of an 85 pound backpack

Time trend developments of Holter technology

Evolution

holter monitor1

Health & Medicine