TMT- EXERCISE ECG

1. EXERCISE
ELECTROCARDIO
GRAM
DR SUHAIL
KIMS,TRIVANDRUM
ROBERT A. BRUCE, CONSIDERED
THE “FATHER OF EXERCISE
PHYSIOLOGY”.

2. INTRODUCTION
•
Non- invasive tool to evaluate the cardio
vascular system's response to exercise under
carefully controlled conditions.
•
Exercise is the body’s most common
physiologic stress- most practical test of
cardiac perfusion and function.
•
During exercise body increases its metabolic
rate to greater than 20 times that of rest;
cardiac out put as much as six fold.
(depends on age,sex,type of exercise,size etc)

4. MASON-LIKAR LEAD PLACEMENT
9 TAKEN FROM WELINDER (2004).

5. EXERCISE
PHYSIOLOGY
PHYSIOLOGIC PRINCIPLE & PATHOPHYSIOLOGIC PRINCILE
•
Total body oxygen up take and myocardial o2 uptake are distinct.
•
Total body o2 uptake: amount of o2 that is extracted from
inspired air as the body performs work.
•
Determinants are cardiac out put and peripheral arterio venous o2
difference.
•
Myocardial o2 uptake: amount of o2 consumed by the heart
muscle.
•
Determinants include LV pressure& EDV, contractility and HR.
•
EXERCISE INDUCED ISCHEMIA CAN CAUSE CARDIAC
DYSFUNCTION ,WHICH RESULTS IN EXERCISE IMPAIRMENT
AND AN ABNORMAL SYSTOLIC BP RESPONSE

6. METS- METABOLC EQUIVALENT OF THE TASK
• Used to express the o2 requirement of the work
rate during an exercise test on a treadmill or
cycle ergometer.
• One MET is equated with the resting metabolic
rate- 3.5 ml of O2 / kg / min.
• MET value achieved from an exercise test is a
multiple of the resting metabolic rate.

7. 1 MET
Resting
2 METs
Level walking at 2 mph
4 METs
Level walking at 4 mph
< 5 METs
Poor prognosis; peak cost of basic activities of daily living
10 METs
Prognosis with medical therapy as good as
CABG;unlikely to exhibit significant nuclear perfusion
defect.
13 METs
Excellent prognosis regardless of other exercise
response.
18 METs
Elite endurance athletes
20 METs
World-class athletes.

8. • Most important factor that influences HR
response to heart is AGE - decline in maximal
HR occurs with age.
• Age related maximal HR estimates are poor
index of maximal effort- high variability.
• So exercise should be symptom limited and not
targeted on achieving a certain HR.
• Of all HR measurements, most studies show that
HR increase at peak exercise is the most
powerful predictor of cardiovascular prognosis.
• Maximal HR is very little changed after a
program of training; resting HR is frequently
changed.(vagal).
• Initial response to exercise (100-120) is
attributable to withdrawal of vagal tone; later by
augmented sympathetic.

9. CENTRAL DETERMINANTAS
OF O2 UPTAKE
Cardiac out put
Stroke volume
End
diastolic
volume
End
diastolic
volume
PERIPHERAL DETERMINANTS
OF O2 UPTAKE

10. EXERCISE:
. Withdrawal
RECOVERY:
of vagal
tone-initial
.sympathetic
stimulation- later
in moderate to severe
exercise.
:HR at peak exercise is
powerful prognostic
marker.
.Reactivation
of
parasympathetic
initially- decline in HR.
(first 2 minutes).
.sympathetic withdrawallater.
.Delay in HR recovery is
a powerful prognostic
marker.
.plasma NE
concentration
increase/remain
constant in 1st minute of
recovery (decline late).

11. SAFETY PRECAUTIONS &PRE
TEST PREPARATIONS
• tread mill should have front and side rails.
• Should be caliberated monthly
• No automated BP measurements- but manually.
• Pt should not eat,drink, smoke at least 2 hour prior.
• Proper foot wear.
• To establish pt’s usual level of exercise activity prior***.
• Proper medical history / examination- to r/o CI.
• Pre test standard 12-lead ECG in supine & standing
position.
• Good skin preparation- esp. in elderly as they have higher
skin resistance.

12. MODIFIED LIMB LEAD
PLACEMENTS
• Arm electrodes on the shoulders.
• Rt leg electrode on the back out of cardiac field.
• Lt leg electtrode below the umbilicus.
• Record baseline ecg in supine with this- keep as reference
• Hyper ventilation should be avoided before testing- hyper
ventilation to identify false positive responders is no
longer considered.
• (ST changes can occur in nl / diseased)

13. DURING THE TEST….
• ECG, BP, history, examination; assess the appearance.
• Pt can rest hands on the rail; but should not grasp/hang
on- decreases he work performed/ over estimates the
capacity.
• Target HR based on age should not be used ; wide scatter
exists- unrealistic goal.
• Borg scale excellent means to quantify.

14. DANGEROUS
SITUATIONS!
• Pt exhibits ST elevation without baseline Q- associated
with dangerous arrythmias and tnfarction. More in V2 /aVF.
• Pt with ischemic cardiomyopathy exhibits severe anginado cool down walk.
• Pt develops exertional hypotension accompanied by
angina / ST depression or occurs in pt with
CHF, cardiomyopathy or recent MI.
• Pt with h/o sudden collapse during exercise develops
frequent pVCs – cool down walk is advisable.

15. RECOVERY….

16. CONTRAINDICATIONS
ABSOLUTE
RELATIVE
High risk unstable angina
Lt main coronary stenosis
Symptomatic severe Aortic stenosis Moderate stenotic valvular d/s
Uncontrolled symptomatic heart
failure
Tachy / brady arrythmias
Uncontrlled arrythmias causing
symptoms/ hemodyn.compromise
HOCM/ out flow tract obstructions
Acute pulmonary embolism/infarctn
Electrolyte abnormalities
Acute myocarditis/pericarditis
Severe arterial hypertension
(>200/110 mm hg)
Acute aortic dissection
High degree AV block
Mental/physical impairement

17. INDICATIONS FOR TERMINATING TEST
ABSOLUTE
RELATIVE
Moderate to severe angina
Drop in BP>10 mm hg from base line
despite an increase in work load
Sustained VT
Excessive ST depression (>2mm of
horizontal/down sloping) or marked axis
shift.
ST elevation(>1mm) in leads without
diagnostic Q waves (other than v1,aVR)
Arrythmias other than sustained VT
(SVT, Multifocal PVCs,triplets,hrt
block,bradyarrythmias)
Signs of poor perfusion (cyanosis/pallor) Development of BBB/intra ventricular
conduction delay (that cannot be
distinguished from VT)
Increase in nervous system symptoms
(ataxia,dizziness,near syncope)
Fatigue,shortness of breath, wheezing,
leg cramps, or claudication
Subject’s desire to stop
Increase in chest pain
Technical difficulties in measuring ECG / Hypertensive response (>250/115 )
BP

18. BENEFITS OF EXERCISE
TESTING POST MI
Pre –discharge submaximal
test:
Maximal test for return to
normal activity:
Optimizing discharge
Determining limitations
Altering medical therapy
prognostication
Triaging for intensity of follow
up
Reassuring employers
Reassuring spouse
Determining level of disability
First step in rehabilitationassurance,encouragement
Triaging for invasive studies
Recognizing exercise induced
ischemia and dysrhythmias
Deciding on medication
Exercise prescription
Continued rehabilitation

19. RULES
• Report exercise capacity in METs, not minutes of exercise
• Hyperventilation prior to testing is not indicated.
• ST –segment measurements should be made at Jjunction,and ST-depression should be considered
abnormal only if horizontal or downsloping.
• Raw ECG waveforms should be considered first and then
supplemented by computer-enhanced (filtered&averaged)
waveforms when the raw data are accepatable.
• In testing for diagnostic purposes,pt should be placed
supine as soon as possible after exercise ,with a cooldown walk avoided.

20. • The 3 min recovery period is critical to include in analysis
of the ST segment response.
• Measurement of systolic BP during exrecise is extremely
important and exertional hypotension is omnious; manual
BP preferred.
• Age predicted HR targets are largely useless because of
the wide scatter for any age;exercise tests should be
symptom limited.
• Protocol should be adjusted to the pt; one protocol is not
appropriate for all pts.
• Tread mill score should be calculated for every pt.

21. PROGNOSTIC SCORES
• DUKE SCORE= METs- 5 * (mm E-I ST depression) –
4*(TM AP index).
• VA SCORE=
5 * (CHF/dig) + mm E-I ST depression+
change in SBP score-METs.
•
TM AP SCORE:
0 : if no angina
1: angina during test.
2: if angina was the reason for stopping.
•
Change in SBP score: from 0 for rise greater than 40 mm hg to 5 for
drop below rest.