Non Invasive Investigations in Cardiology

8/3/2019 Non Invasive Investigations in Cardiology

http://slidepdf.com/reader/full/non-invasive-investigations-in-cardiology 1/67

Presenter :Parvathy Joshy

Msc nsg 1st yr



Diagnostic studies provide im portant

infor mation in

monitor ing the patient¶s condition and

Planning appropr iate interventions.

These studies are considered to be objective

data.



Non invasive

Invasive



Chest x ray Electrocardiogram(ECG)

Am bulatory ECG monitor ing Exercise treadmill test Echocardiogram MUGA

Magnetic resonance imaging CT PET PFT



It is a radiographic picture.

PURPOSETo depict

cardiac contours

Heart size

Conf iguration and

Anatomical changes in individual cham bers.



Postero-anter ior

Antero-poster ior

Lateral







Positioning-PA frontal chest radiograph



Positioning-AP chest radiograph



Inquire about frequency of recent x rays and

possi bility of pregnancy.

Provide lead shielding to areas not beingviewed.

Remove any jewelry or metal ob jects that

may obstruct view of heart and lungs.

Infor m patient that he/she has to hold breath

while tak ing x ray



ECG records electr ical potential changes in

the electr ical f ield produced by the heart.



To detect rhythm of heart

For diagnosing arrhythmias

To detect site of pacemaker

To detect position of heart

To detect size of atr ium and ventr icles

To detect the presence of any injury.

To detect electrolyte abnor malities





Atrial flutter Atrial pacing





12 lead ECG:each lead has 2 electrodes with

opposite polar ity( bi polar ) or 1 electrode and a

reference point(uni polar ) 6 lim b leads:electr ical activity in the frontal

plane(up,down &rt ,lt in the heart)

6 precordial leads:in hor izontal plane(ant,post

& rt/lt)



The ECG records

3 bipolar f rontal plane leads

Lead I,Lead II,lead III 3 unipolar f rontal plane leads

aVR,aVL&Avf

6 unipolar precordial leads

V1,V2,V3,V4,V5,& V6



ECG wavefor ms are pr inted on graph paper that is divided by light and dark vertical and hor izontal

lines at standard intervals . Time and rate are measured on the hor izontal axis

of the graph, and am plitude or voltage is measuredon the vertical axis.

When an ECG wavefor m moves toward the top of the paper, it is called a positive def lection.

When it moves toward the bottom of the paper, itis called a negative def lection



Wave forms

p wave

QRS com plexT wave

U wave

Intervals

PR interval

ST segment

QT interval



The P wave represents the electr ical im pulse starting in the

sinus node and spreading through the atr ia.

P wave atrial muscle depolarization.

It is nor mally 2.5 mm or less in height

0.11 second or less in duration.



The QRS complex ventricular muscle depolarization.

Duration:< 0.12 s

Q wave:

The f irst negative deflection after the P wave

nor mally less than 0.04s in duration and

less than 25% of the R wave am plitude;

R wave:

the f irst positive deflection after the P wave

S wave:

the f irst negative deflection after the R wave.



The T wave ventr icular muscle repolar ization .

follows the QRS com plex

usually the same direction as the QRS com plex.

TheU

wave repolar ization of the Purk injef i bers,

but it sometimes is seen in patients with

hypokalemia, hypertension, or heart disease.



The PR interval is measured from the beginning of

the P wave to the beginning of the QRS com plex and

represents the time needed for sinus nodestimulation, atr ial depolar ization, and conduction

through theAV node before ventr icular

depolar ization.

In adults, the PR interval nor mally ranges from 0.12

to 0.20 seconds in duration.



The ST segment early ventr icular repolar ization,

lasts from the end of the QRS com plex to the beginning of the T

wave.

The QT interval total time for ventr icular depolar ization and

repolar ization,

is measured from the beginning of the QRS com plex to the end

of the T wave.



A 1-minute str i p contains 300 large boxes and 1500

small boxes.

count the num ber of small boxes within an RR interval

and

divide 1500 by that num ber.

exam

ple, there are 10 sm

all boxes between two R waves,heart rate is 1500 ÷ 10= 150

if there are 25 small boxes, HR is 1500 ÷ 25= 60



when the rhythm is irregular,

count the num ber of RR intervals in 6 seconds

multi ply that num ber by 10.

The top of the ECG paper is usually marked at 3-

second intervals, which is 15 large boxes hor izontally



Hypokalemia : ST segment depression,

inverted T waves

large U waves,slightly prolonged PR interval.

Hyperkalemia : peaked T and

prolonged PR and QRS



Infor m patient that no discomfort is involved.

Instruct patient to hold still



Continuous (Holter monitoring)

Non continuous(Trans telephonic event

recorders)



Recording of ECG rhythm for 24-48 hours andthen correlating changes with sym ptoms.

Nor mal patient activity encouraged tostimulate conditions that produce sym ptoms. Five electrodes placed on chest and recorder is used to store infor mation until it is

recalled,pr inted,and analysed for any rhythm disturbance. It can be perfor med on an inpatient and

outpatient basis.







Preparation of sk in and application of

electrodes and leads.

Explain im portance of keeping accurate diaryof activities and sym ptoms.

Tell patient that no bath or shower can be

taken dur ing monitor ing.



Allows more freedom in wear ing and recordingthan regular Holter monitor.

Records rhythm disturbances that are not frequent

enough to be recorded in one 24 hr per iod. Some units have electrodes attached to chest and

have a loop of memory that captures the onsetand end of an event.

Other types placed directly on patient¶swr ist,chest ,or f ingers and have no loop of memory,but record patient¶s ECG in real time.

Recordings are transmitted over the phone to areceiving unit and then pr inted out for review.



Tracings can then be erased and unit can be

reused.



Instruction in use of equi pment for recording

and transmitting of transient events.

Careful instruction of sk in preparation for lead placement or steady sk in contact for units not

requir ing electrodes.

This will ensure reception of optimal ECG

tracings for analysis.



This test is used to evaluate the effect of

exercise tolerance on myocardial function.

Bruce Protocol: uses 3min stages at set speedsand elevation of treadmill belt.

Continuous monitor ing of vital signs and ECG

rhythms or ischemic changes im portant in the

diagnosis of ventr icular function and CAD.



H/O & P E

Refrain from ingesting food , alcohol, and caffeine or

tobacco products with in 3 hrs. of testing

Clothing

Infor med wr itten consent

Medications









a common treadmill protocol in which the speedand grade of the treadmill are increased every 3 minutes.

The goal of the test is to increase the heart rate to the³target heart rate.´

Dur ing the test, the following are monitored: two or more ECG leads for heart rate, rhythm, and ischemicchanges; BP; sk in tem perature; physical appearance; perceived exertion; and sym ptoms including chest pain, dyspnea, dizziness, leg cram ping, and fatigue.



The test is ter minated when the target heart rate

is achieved or when the patient exper iences chest

pain, extreme fatigue, a decrease inB

P or pulserate, ser ious dysrhythmias or ST segment changes

on ECG, or other com plications.

When signif icant ECG abnor malities occur

dur ing the stress test (ST segment depressions),the test result is reported as positive and further

diagnostic testing is required



Instruct patient to wear comfortable clothes and shoes

that can be used for walk ing and running.

Instruct patient about procedure and application of lead

placement.

Monitor vital signs and obtain 12-lead ECG before

,dur ing each stage of exercise, and after exercise until

all vital signs and ECG changes have returned to

nor mal.



Small transducer that emits and receives ultrasound waves

placed in four positions on chest above heart.

Transducer records sound waves that are bounced off heart.

Also records direction and flow of blood through heart and

transfor ms it to audio and graphic infor mation that measures

valvular abnor malities ,congenital cardiac defects, and cardiac

function.







Place patient in supine position on left side

facing equi pment.

Instruct family and patient about procedureand sensations ( pressure and mechanical

movement from head of transducer ).

No contraindications to procedure exist.



This test obtains infor mation about cardiac

tissue integr ity ,aneurysms , ejection fractions

,CO , and patency of proximal coronaryarter ies.



Explain procedure to patient.

Infor m patient that small diameter of the

cylinder ,along with cloud noise of the procedure, may cause panic or anxiety.

Antianxiety medications and music may be

recommended.



Multiple-gated acquisition (MUGA) scanning:

uses a conventional scintillation camera interfaced

with a com puter to record images of the heart

dur ing several hundred heartbeats.



The com puter processes the data and allows for sequential viewing of the functioning heart. Thesequential images are analyzed to evaluate left

ventr icular function, wall motion, and ejectionfraction. MUGA scanning can also be used to assess the

differences in left ventr icular function dur ing restand exercise.

The patient is reassured that there is no knownradiation danger and is instructed to remainmotionless dur ing the scan



uses x-rays to provide cross-sectional images

of the chest, including the heart and great

vessels. These techniques are used to evaluate cardiac

masses and diseases of the aorta and

per icardium.



Patient preparation

The nurse should instruct the patient that

he will be positioned on a table dur ing the scanwhile the scanner rotates around him.

The procedure is noninvasive and painless., the

patient must lie perf ectly still dur ing the scanning

process. An intravenous access line is necessary if

contrast enhancement is to be used



Provides more specif ic infor mation about myocardial

perfusion and viability

helps evaluate the patency of native and previously

grafted vessels and the collateral circulation





Instruct the patient to refrain from using tobacco and

ingesting caffeine for 4 hours before the procedure.

They should also reassure the patient that radiation

exposure is at safe and acceptable levels, similar to

those of other diagnostic x-ray studies.



a group of tests that measure how well the lungs take

in and release air and how well they move gases such

as oxygen from the atmosphere into the body's

circulation



PFT results are interpreted on the basis of the degree

of deviation from nor mal, tak ing into consideration

the patient¶s height,weight, age, and gender



Forced vital capacity Forced expiratory volume(qualif ied by

subscr i pt indicating the time intervals inseconds)

Ratio of timed forced expiratory volume toforced vital capacity

Forced expiratory flow Forced mid expiratory flow Forced end expiratory flow Maximal voluntary ventilation







What are the var ious non-invasive

investigations in cardiology?

What is the duration of p wave in a nor malECG?

How the target HR is calculated in TMT?

What do you understand by holter monitor?

What is MUGA?



Non-invasive investigations play an im portant

role in cardiology .As nursing personnel we have

to understand the purpose, indications,

contraindications, and side-effects if any of the

investigations.

Many of the patients need further infor mation

regarding these procedures , so we have to utilizeour knowledge in helping patients

physiologically as well as psychologically.



Susan L.Woods,cardiac nursing ,5th edition

Brunner and suddarth ,text book of medical

surgical nursing



Documents

Non Invasive Investigations in Cardiology