MEGA MONSTER CSCT STUDY MATERIAL

What is the normal PR interval range?

0.12 - 0.20 seconds

What is the normal QRS range?

0.08 - 0.12 seconds

What is the name of the formula for the corrected QT interval?

Bazett’s formula

What is Bazett’s Formula?

(QT/ square root of the RR interval) x 450 ms of the upper limit of normal

List the ECG criteria for LVH

R or S in limb leads is greater or equal to 20 mm

S in V1 or V2 is greater or equal to 30 mm

R in V5 or V6 is greater or equal to 30 mm

left atrial enlargement in V1

left axis deviation (-30 degrees to -90 degrees)

What is considered within the range of the normal axis?

-30 to +90

What is the range of the normal ejection fraction?

55% - 75%

During ETT, how far past the J point is the ST segment measured?

80 msec

During ETT, a drop of blood pressure greater than ______ is considered an absolute indication to terminate the test?

10 mm/Hg

What are the 3 basic functions of the electrocardiograph?

input

signal processing

output

Where is zero potential located?

center of the heart

Name the 12 leads that make up the standard ECG

I

II

III

avR

avL

avF

V1 - V6

What are the 2 main functions of the recorded ECG?

amount of voltage generated by the heart

time required for voltage to travel through the heart

What is the MOST common ECG finding in pulmonary embolism?

S1Q3T3 pattern

What antithrombolic agent is used in the 1st line of treatment for patients with chronic atrial fibrillation and significant kidney disease?

warfarin (coumadin)

What conditions are associated with a ventricular escape rhythm?

sinus arrest

hyperkalemia

3rd degree av block

Which condition is most commonly associated with abnormal Q waves?

anterior MI

What information can be detected by the ECG?

Acute MIs, injury and ischemia
Evaluation of arrhythmias
Pathological overload of the heart (hypertrophy)
Inflammation of heart's lining (endo/myo/peri - carditis)
Assessing degrees of secondary cardiac injury in ischemic hd
Assessing deterioration of heart's conduction system
Effects of antiarrhythmic drugs & other meds
Assessing metabolic & electrolyte disturbances
Coronary HD related to transient ischemia or coronary artery spasm
Assessing artificial pacemaker function

What are the limitations of the ECG as a diagnostic tool?

HINT: May Every Slut Come

mechanical function of the heart

etiology and pathology of disease

structural and functional impairment

CAD related to silent or transient ischemia

When should you not change the standarisation on an ECG machine?

angina or chest pain

What does 1 small box on graph paper equal to?

0.04 sec or 40 msec horizontally

0.1 mV vertically

What is the formula to convert BPM to ms?

60000/ BPM = milliseconds

60000/ ms - BPM

Criteria for normal sinus rhythm

Upright P wave of sinus origin in I, II and avF
Constant P configuration in any lead followed by QRS
HR between 60 -100 bpm

Define Exercise Tolerance Testing (ETT)

the observation and recording of a patient’s cardiovascular response to exercise

What are the 3 types of exercise?

isometric

isotonic

resistive

Define Isometric exercise?

muscle generate force/tension without changing length or moving a joint (no movement)

Define Isotonic exercise

muscular contraction resulting in movement

Define Resistive Exercise?

a combination of isometric and isotonic exercises which results in muscular contraction with movement (free weight lifing)

What are the 3 types of exercise tolerance tests?

treadmill

nuclear drugs

hand ergometer

Why might a patient perform an ETT using a hand ergometer?

A person who is paraplegic or is an amputee may use the hand ergometer instead of the treadmill test

Why might a patient be given nuclear drugs to perform the ETT?

elderly patients or persons who are physically or mentally incapacitated can do the ETT using nuclear drugs as a regular ETT may lead to non-diagnostic results

How does the cardiovascular system normally respond to exercise to deliver more oxygen to the muscles?

increases the heart rate

increases the blood pressure

increases stroke volume

increases O2 extraction in capillary beds

What is the formula for cardiac output

CO = HR x SV

What does VO2 max represent?

the amount of oxygen that is transported and used in cellular metabolism

What is maximum oxygen uptake (known as VO2 max)?

the greatest amount of oxygen that a person can use while performing dynamic exercise involving total muscle mass

What does MET stand for?

metabolic equivalent of task

Define MET

a unit of resting oxygen uptake: 3.5 ml of O2 per kg of body weight per minute

What is the clinical significance of the MET level?

it represents the level of O2 used by the body during activity

In terms of exercise, what does one MET represent?

one MET represents a resting stage

In terms of exercise, what does two METS represent?

walking at 2 mph on a level surface

What 3 factors determine the ability of the cardiovascular system to increase O2 consumption?

the ability to increase respiration

the ability to increase tidal volume

the ability to increase oxygen diffusion

What are the main duties of the technologist when working in the ETT lab?

1. calibration and maintenance of equipment

2. taking patient history

3. obtaining patient consent for testing

4. explanation of the test to patient

5. physical preparation of patient

6. demonstration of how to walk on treadmill

7. monitoring and recording of ECG and blood pressure

8. observing patient’s physical condition and reporting any changes to physician

9. documenting all findings

10. recording any medications given and the patient’s reaction to medications

11. patient safety

What questions should the technologist ask when taking patient history?

1. Prior chest pain or shortness of breath

2. Prior MIs

3. Prior cardiac surgeries

4. History of valve disease

5. Prior angiograms or cardiac testing

6. Does patient take cardiac medications?

7. Does patient smoke or has the patient ever smoked?

8. Family history of heart disease

9. Diabetes or family history of Diabetes

10. Conduction problems

11. Lipedemia

12. High blood pressure and family history of high blood pressure

13. Does patient have asthma or use a puffer?

14. Is patient active (e.g. can patient walk a mile and do they walk a mile? How often?)

15. List any cardiac medications that the patient is taking

How should the patient be prepared for application of electrodes (for an ETT)?

The patient's skin should be cleansed with alcohol to remove oils and dirt and then dried firmly with a clean gauze pad until it is quite pink. Finally, the skin should be lightly sanded to remove the superficial layer. Men may need to have sections of chest hair removed with a razor.

What are some of the responsibilities of the physicain during the ETT?

1. evaluation of patient prior to testing

2. selecting the appropriate protocol

3. monitoring patient during test

4. deciding termination of test

5. attending the patient in an emergency

6. interpretation of the test

What are the 3 most commonly used ETT protcols?

bruce

modified bruce

naughton

By what other name is the modified bruce protocol more commonly known?

half-bruce

How many stages make up a typical Bruce protocol?

6

How are the stages of a typical Bruce protocol numbered?

from one to six

List the speed and corresponding inclination of the Bruce protocol, starting at stage one through to stage six

(Stage 1) 1.7 mph - 10%
(Stage 2) 2.5 mph - 12%
(Stage 3) 3.4 mph - 14%
(Stage 4) 4.2 mph - 16%
(Stage 5) 5.0 mph - 18%
(Stage 6) 5.5 mph - 20%

How many stages are there in a modified Bruce protocol (aka Half-Bruce)?

6

How are the stages of Modified Bruce Protocol numbered?

0

0.5

1

2

3

4

List the speed and corresponding inclination of each stage of the Modified Bruce protocol

(Stage 0) 1.7 mph - 0%
(Stage 0.5) 1.7 mph - 5%
(Stage 1) 1.7 mph - 10%
(Stage 2) 2.5 mph - 12%
(Stage 3) 3.4 mph - 14%
(Stage 4) 4.2 mph - 16%

How long does each stage of the Bruce protocol last?

3 minutes

How long does each stage of the Modified Bruce protocol last?

3 minutes

As a general rule, what should the technologist do if the doctor is absent and the patient reports chest pain that gradually increases to 6/10 accompanied by a 2 mm ST segment depression?

the technologist should stop the test

What should the technologist do if the doctor is absent and a ST segment depression of 4 mm develops during testing?

the technologist should stop the test

What should the technologist suspect if they see LVH with strain pattern on the ECG and there is a ST segment depression of 6 mm on the ETT?

suspect ischemia

Prior to releasing a MI patient from the hospital, what length of time should the patient be able to last on the Bruce protocol before the physician will consider allowing the person to return home?

6 - 9 minutes

When is the Naughton protocol usually used?

1. patients who recently had a MI - prior to release

2. patients who have problems walking (knee/ hip problems)

3. elderly patients

List the placement of the electrodes for ETT.

Right arm - 1st ICS, mid-clavical, right of sternum
Right leg - last rib on right side, ~ mid-clavical
Left arm - 1st ICS, mid-clavical, left of sternum
Left leg - last rib on left side, ~ mid-clavical
V1 - 4th ICS, to right of sternum
V2 - 4th ICS, to left of sternum
V3 - diagonally between V2 and V4
V4 - stn ICS, mid-clavical on left side
V5 - post axillary on left, in straight line with V4
V6 - mid axillary on left, in straight line with V4, V5

What is the most common indication for a patient to be sent for an ETT?

diagnosis and evaluation of suspected or known cardiovascular disease

List some indications for ETT

1. diagnosis and evaluation of suspected or known cardiovascular disease

2. risk assessment for persons who have recently had a MI

3. determine exercise capacity for persons entering rehabilitation programs

4. assessment of patients who have had valve surgery

5. evaluation of pharmacological therapy

6. evaluate medical management of recent MI, CABG, or PTCA patients

List some ABSOLUTE contradications for ETT

1. recent (3-5 days) MI

2. unstable angina

3. uncontrolled cardiac arrhythmias with symptoms (or hemodynamic compromise

4. congestive heart failure

5. severe aortic stenosis

6. acute pulmonary embolus/ pulmonary infarction

7. acute myocarditis

8. acute pericarditis

9. third degree heart block

10. dissecting aneurysm

11. any physical disability that would impede safety of the patient

12. thrombosis of lower extremities (claudication)

What does PTCA stand for?

percutaneous transluminal coronary angioplasty

What should the technologist do if they have a patient with third degree heart block or Mobitz I or Mobitz II?

consult the physician before proceeding even with Mobitz I or II

What should the technologist do if their patient states that they have an aneurysm (of any kind)?

consult the physician before proceeding

If the doctor approves exercise tolerance testing for a patient who has a condition considered to be an absolute contraindication for ETT, what should the technologist do?

do not start testing until the doctor is present

What should the technologist do if they have any doubts about a patient's competency or ability to perform an ETT?

consult the physician

What are some relative contraindications for ETT?

1. moderate stenotic valvular disease

2. cardiomyopathy

3. complex ventricular activity

4. electrolyte abnormalities

5. ventricular aneurysm

6. acute systemic disesae

7. controlled metabolic disorders

8. disorders that make exercise difficult

9. significant atrial or pulmonary hypertension

10. mental impairment/ inability to cooperate

11. severe hypertension

12. tachyarrhythmias or bradyarrhythmias

List some ABSOLUTE indications for stopping an ETT

1. drop in systolic BP of 10 mm/Hg during exercise

2. drop in systolic BP persistently below baseline during exercise

3. increase in diastolic BP to 110 mm/Hg or more

4. increasing anginal pain (6/10)

5. ataxia, dizziness, near-fainting

6. signs of poor perfusion (pallor, cyanosis)

7. serious arrhythmias (especially ventricular)

8. technical difficulties

9. patient requests to stop (despite encouragement)

What are some relative indications for stopping an ETT?

1. ST or QRS changes

2. fatigue, SOB, wheezing, leg cramps, claudication

3. less serious arrhythmias (SVTs)

4. development of a bundle branch block that cannot be distinguished from ventricular tachycardia

What should the technologist do if they see a VT or BBB on the monitor?

1. do a rhythm strip and a 12 lead ECG and call doctor over

2. VT - stop the test

What are normal indications for stopping an ETT?

patient has achieved maximum heart rate

muscle fatigue

SOB

patient requests to stop the test

A patient experiences mild chest pain during the ETT, can the test continue?

Yes, if the patient’s ECG and blood pressure are stable and if the patient is willing

Why is systolic blood pressure at maximum exertion considered to be clinically useful?

it can be used to approximate the inotropic capacity of the heart

What might a drop in systolic blood pressure at peak exercise indicate?

it is indicative of severe CAD and ischemic dysfunction

What can exercise-induced hypotension indicate?

it indicates that a patient is at risk for ventricular (fibrillation) arrhythmia

At what blood pressure readings do most practitioners discontinue ETT?

diastolic pressure of more than or equal to 110 mg/Hg

How can you determine maximum heart rate?

maximum heart rate = (220 - age)

If a patient is on beta blockers, how is the maximum heart rate determined?

maximum heart rate = (220 - age) x 0.80 (80% of maximum heart rate)

Under what circumstances are patients considered to have "Chronotropic Incompetence"?

Patients who are not taking drugs to lower the heart rate and who cannot achieve at least 85% of their target heart rate are considered to be chronotropically incompetent

What type of person may not be able to achieve 85% of their target heart rate but still not be considered to be chronotropically incompetent?

an athlete

Unless testing for the effectiveness of the drug, when should patient taking beta-blockers cease their medication prior to ETT?

24 hours prior

What are some conditions that cause abnormalities of exercise capacity, systolic blood pressure and heart rate response to exercise?
HINT: Like I Can’t Add

left ventricular dysfunction

ischemia

cardioactive drugs

autonomic dysfunction

When in an ETT considered “maximal”?

when the patient appears to have given a true maximum effort (e.g., the point of bodily exhaustion) or clinical endpoints are met

Why is the patient not allowed a “cool down” walk after the ETT?

it may delay or eliminate any ST segment changes

How long should patient monitoring (including heart rate, ECG and blood pressure) continue after termination of the ETT?

Until heart rate slows to below 100 bpm or pretest rate and ECG changes and blood pressure return to baseline

patient reported pain during the ETT, what should the technologist do before releasing the person?

Monitor patient until the pain has subsided to 1/10 or less, do a final ECG and (if it is clear) write "pain-free" on the ECG

What normal change occurs to the QT interval during the ETT?

The QT interval shortens as the heart rate increases

What normal change occurs to the T and P waves as the heart rate increases during ETT?

Superimposition of the P and T waves (eg. they become closer)

What normal change(s) does the P wave undergo during ETT?

It becomes more vertical. In the inferior leads the magnitude increases significantly

What normal change(s) does the PR segment undergo during ETT?

It shortens and slopes downward in the inferior leads

What normal change(s) does the R wave undergo during ETT?

The R wave amplitude decreases, most notably in the V5 - V6 lateral leads

What normal change(s) does the S wave undergo during ETT?

In the vertical and lateral leads, the S wave becomes deeper

What normal change(s) does the J-point junction undergo during ETT?

A slow increase in J-point depression can be seen in all leads, reaching maximum depression during the first minute of recovery. The greatest J point depression is seen in the lateral lead

What normal change(s) does the T wave undergo during ETT?

It may decrease in amplitude

If the T wave changes deflection during the ETT, what might this indicate?

Ischemia

From which point should an upsloping ST segment depression be measured?

60 - 80 milliseconds from the J-point

From which point should a convex ST segment depression be measured?

60 - 80 milliseconds from the J-point