Transcript TMT by Dr Sarma

Dr R.V.S.N. Sarma., M.D., M.Sc.,
Consultant Physician and
Chest Specialist
To my beloved mother
Asymptomatic
NSTEMI
Chronic Stable
Angina (CSA)
Unstable
Angina (USA)
STEMI / Re MI
SCD / CVM
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Slowly progressive CAD
CSA to USA to NSTEMI to STEMI
and CVM
Warning ++ long duration
Collateral CBF good
ECG / TMT evidence +
CAG will confirm CAD
Prognosis is good; Older
Non vulnerable plaques
Flow limiting narrowing
Form only 30 % of MI cases
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Group with sudden MACE
Give no time to act
SCD or Massive MI
No previous CSA or USA
No warning; Short duration
No time for collateral CBF
TMT/ CAG -ve before MACE
Prognosis is poor; Younger
Vulnerable ruptured plaques
Focus on factors causing rupture
Contribute to 70% of MI cases
Suresh
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24 years
BMI 20
No CP
No DM
Lipids N
Smoking 0
ECG N
Low
2%
Lakshmi
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54 years
BMI 25
Atypical CP
T2 DM 5 yrs
LDL 150
Smoking 0
ECG T  L3
Intermediate
39 %
Devadoss
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43 years
BMI 28
Atypical CP
IGT +
LDL, TG
Ex Smoker
ECG N
Intermediate
46%
Masthan
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64 years
BMI 30
Angina +
DM for 25 y
LDL HDL
Smoker 25 y
ST-T Abnor
High
98%
1. Routine Treadmill (ECG only) – ETT or
TMT
2. Stress Echocardiography
 Dobutamine Echocardiography (CSE)
 Exercise Stress Echocardiography (ESE)
3. Nuclear Imaging – Chemical Stress - MPI
 Dobutamine Nuclear Stress
 Adenosine Nuclear Stress
 Persantine Nuclear Stress
• Exercise testing is a well-established
procedure
• It is in widespread clinical use for many
decades
• The “how-to” is beyond the scope of this talk
• Although ETT is generally a safe procedure,
both MI and death have been reported
• Occur at a rate of up to 1 per 2500 tests
(0.04%)
Atypical and typical Chest pain CV risk profile
Unstable Angina – Decision on need for CAG
Risk stratification after MI and assess CABG
To prescribe exercise in CAD / Athletes/ PVD
Asymptomatic pt without CV Risk factors ??
 Perfect Lead contact – shaving the chest area in men
 Should be supervised by a well trained physician,
who should be available immediately for
emergencies
 Careful monitoring & recording in each stage of
exercise
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The electrocardiogram (ECG)
Heart rate
Blood pressure
And during ST-segment abnormalities and chest pain.
 The patient should be monitored continuously
Bicycle Ergo meter
Treadmill Test
• Cycle Ergo meters are generally
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Less expensive and smaller
Less noisy than treadmills
ECG disturbances are minimum
But, produce less motion of the upper part of
body
– The fatigue of the quadriceps muscles is a
major limitation
• Treadmills are much more commonly used
• Supine stress testing is not routinely used
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Age
Gender
Angina
H/o previous MI
Q waves in ECG
Resting ST-T
changes
• Diabetes
• Dyslipidemia
• Smoking
• Diagnostic Test utility
• Most in intermediate
probability
• Least in high or low
probability
• Typical Angina
• Sub-sternal location
• Provoked by exertion
or emotion
• Relieved by
rest/GTN
Age
Gender
Typical/Definite
Angina Pectoris
30-39
30-39
Males
Intermediate
Intermediate
low (<10%)
Very low (<5%)
Females
Intermediate
Very Low (<5%)
Very low
Very low
40-49
Males
High (>90%)
Intermediate
Intermediate
low
40-49
Females
Intermediate
Low
Very low
Very low
50-59
Males
High (>90%)
Intermediate
Intermediate
Low
50-59
Females
Intermediate
Intermediate
Low
Very low
60-69
Males
High
Intermediate
Intermediate
Low
60-69
Females
High
Intermediate
Intermediate
Low
High = >75%
Atypical/Probable Non-Anginal
Angina Pectoris Chest Pain
Intermediate = 15-75%
Low = <15%
Asymptomatic
Very Low = < 5%
Clinical
Presentation
CV Risk
Factors
Derive Pretest
Probability
Use a computer model or
Use the probability table
Low (<15%)
No Testing
Intermediate
15% to 75%
Stress
Testing
High ( >75%)
Angiography
Intermediate Probability
15% - 75%
Assess ECG and
Exercise Tolerance
Normal ECG
Can exercise
Treadmill test
Duke score
Negative
No more testing
Positive
Abnormal ECG or
Can’t exercise
MPI or ESE or CSE
Angiography
Absolute
• Acute myocardial infarction (within 2 days)
• High-risk unstable angina
• Uncontrolled cardiac arrhythmias
• Symptomatic severe aortic stenosis
• Uncontrolled symptomatic heart failure
• Acute pulmonary embolus or pulmonary
infarction
• Acute myocarditis or pericarditis
• Acute aortic dissection
Relative
 Left main coronary stenosis
 Moderate stenotic valvular heart
disease
 Electrolyte abnormalities
 Severe arterial hypertension
 Tachy or Brady arrhythmias
 HOCM and other outflow obstructions
 Mental or physical impairment
 High-degree atrio-ventricular block
Absolute indications
• Drop in SBP of >10 mm Hg from baseline BP with
accompanying evidence of ischemia
• Moderate to severe angina
• Increasing nervous system symptoms ataxia,
dizziness
• Signs of poor perfusion (cyanosis or pallor)
• Technical difficulties in monitoring ECG or SBP
• Subject’s desire to stop; Sustained ventricular
tachycardia
Relative indications
• Drop in SBP of ≥10 mm Hg BP without ischemia
• ST or QRS changes - ST depression (>2 mm of
horizontal
or down sloping ST-segment ↓) or axis
shift
• Arrhythmias VT, multifocal PVCs, triplets of PVCs,
SVT,
• Heart block or brady arrhythmias, BBB or IVCD
• Fatigue, shortness of breath, wheezing, leg cramps, IC
• Increasing chest pain; Hypertensive response >
250/115
• Only Manual SBP measurement for safety
• Adjust to clinical history (couch potatoes)
• Age predicted Heart Rate Targets ? ?
• The BORG Scale of Perceived Exertion
• METs - not ‘Minutes’ have to be used
• Use standard ECG analysis + 3 minute
recovery
• Use scores, ST/HR Index, Heart rate
recovery
Electrocardiographic
Hemodynamic
Symptomatic
Max ST  and ST
Max ETT Heart Rate
Exercise Angina
ST sloping down, up or 
Max ETT - SBP
Exercise limiting Sympt.
No. of leads showing ST change
Max ETT Double product
Time to onset of angina
ST duration into recovery
Exercise hypotension
Exercise up to stage IV
ST/HR Index, Time to onset
Exercise in METs, minutes
ETT induced ventricular arrhythmia Chronotropic failure
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7
Very, very light
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9
Very light
10
11
Fairly light
12
13
Somewhat hard
14
15
Hard
16
17
Very hard
18
19
20
Very, very hard
o Metabolic Equivalent Term
o 1 MET = "Basal" aerobic oxygen consumption
to stay alive = 3.5 ml O2 /Kg/min -70 kg, 40 yr
man
o Actually differs with thyroid status, post
exercise,
obesity, disease states
o By convention just divide ml O2/Kg/min by 3.5
METs = Speed x [0.1 + (Grade x 1.8)] + 3.5
3.5
• Total of 1+6 (Seven 3 minute stages) – (3+18
min)
• Each minute exercise is approximately 1 MET
• Pretest plain walking + 6 Stages of graded
exercise
• In each stage there is increase in speed and
gradient
• Initial 1.7 mph with 10% gradient (upward inclination)
• Maximum 5.5 mph with 20% gradient
Bruce stage
Speed and Gradient
Minutes
METs
Stage 1
1.7 mph + 10% Gradient
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5
Stage 2
2.4 mph + 12% Gradient
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7
Stage 3
3.1 mph + 14% Gradient
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10
Stage 4
3.8 mph + 16% Gradient
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13
Stage 5
4.6 mph + 18% Gradient
15
17
Stage 6
5.5 mph + 20% Gradient
18
20
o 1 MET =
"Basal" = 3.5 ml O2
/Kg/min
o 2 METs =
o 4 METs =
o < 5METs =
o10 METs =
2 mph on level
4 mph on level
Poor prognosis if < 65 years
Medical Rx as good as
CABG
o 13 METs = Excellent prognosis
o 16 METs = Aerobic master athlete
o 20 METs = Super athlete
• Lead V5 alone consistently outperforms other leads
• False + ves are high with the inferior leads
• Without prior MI and with normal resting ECGs, the
precordial leads alone are a reliable marker for
CAD.
• Exercise-induced ST-segment  only in inferior
leads is not significant for CAD.
• Down sloping or horizontal ST-segment  is a
stronger predictor of CAD but not up sloping ST 
J point depression of 2 to 3
mm in leads V4 to V6 with
rapid up sloping ST segments
depressed approximately 1
mm 80 m sec after the J point.
This response should not be
considered abnormal.
In lead V4 , the exercise ECG
result is abnormal early in the
test, reaching 0.3 mV (3 mm) of
horizontal ST segment
depression at the end of
exercise.
Consistent with a severe
ischemic response.
This “slow up sloping” ST
segment at peak exercise indicates
an ischemic pattern with a high
coronary disease prevalence
pretest.
A typical ischemic pattern is seen
at 3 minutes of the recovery phase
when the ST segment is horizontal
and 5 minutes after exertion when
the ST segment is down sloping.
This is typical ischemic response
• Early repolarization is a common resting
pattern of ST  in normal persons.
• Exercise-induced ST-segment  is always
considered from the baseline ST level.
• ST  is seen after a Q-wave infarction, but ST
 in leads without Q waves occurs in only 1 of
1000 (0.1%) patients of ETT.
• ST  is very arrhythmogenic and localizes the
IHD
• MACE : Sudden Cardiac Death (SCD), AMI and
USA
• Ruptures of high-risk or vulnerable plaques
• Inner plaque material is exposed to blood and initiates
formation of a platelet-fibrin thrombus on the rupture.
• The rupture may seal without detectable sequelae or
• The patient may experience ACS or SCD.
• Majority of the vulnerable plaques appear
insignificant on the CAG ,before rupture (less than
75% stenosis)
• Majority of the stenosis > 75% have no vulnerable
LV Functional Damage
Severity of CAD
Modifiable factors
H/o Prior MI, ECG Path Qs
Anatomic - SVD, DVD, TVD
DM, HT, Dyslipidemia
CHF, Cardiomegaly in CXR
Degree of stenosis and extent Excess weight, Smoking
 EF (<40%) and  ESV
Transient IHD on Holter
Other co-morbidities
LV -RWMA on Echocardio
ETT induced ST deviations
Other Metabolic factors
Conduction disturbances
Progressive symptoms of IHD Ventricular arrhythmias
MR,  Exercise tolerance
Increasing age
Systolic Blood Pressure x HR = Double
Product
Example: SBP 170 x HR 160 = 27, 200
Double product must be at least: 20, 000
 SBP should rise > 40 mmHg
 Diastolic BP may decline by 10 mm
 Drop of > 10 mm in SBP is ominous
(Exertional Hypotension)
• Age Predicted Maximum HR (PrMHR) = (220 – Age in
years)
• Example: For a 55 years pt Pr MHR = (220-55) = 165
• THR = 90% of Pr MHR of 165 = 148
• Chronotropic Incompetence = < 85% of Pr MHR
• In this case 85% of 165 (Pr MHR) = < 140 BPM
• Chronotropic Index (CI)= of less than 0.8 is very
significant
• (HRpeak – HR rest)÷ (PrMHR –HRrest)
• If this pt achieved HRpeak of 130 from HRrest of 90
• CI = (130 – 90) ÷ (165 – 90) = 40 ÷ 75 = 0.53 is very low
Abnormal
• If the HR is not reduced by at least 22
BPM
from peak exercise heart rate to heart rate
measured after 2 minutes.
• It is strongly predictive of all-cause
mortality.
• Duke score = Exercise time – 5 × (ST-segment
deviation in mm) – 4 × Exercise Angina Index
(EAI)
• Exercise time is based on a standard Bruce
protocol
• ST deviation is < 1 mm, is taken as 0.
• ST deviation = Max exercise ST – Base line ST
• E A I value: 0 if no exercise angina
1 if exercise angina occurred
2 if angina severe enough to stop
• High-risk group: The Duke score of  –11
13% of patients fall in this group.
Average annual CV mortality 
5%.
• Intermediate risk : The Duke score of + 4 to – 10
53% of all patients fall in this
group
Annual CV mortality 0.5% to 4%
• Low-risk group: The Duke score of  + 5
34% of patients fall in this group.
Average annual CV mortality <
This nomogram applies to patients with known or suspected coronary
artery disease, without prior revascularization or recent myocardial
infarction, who undergo exercise testing before coronary angiography.
Variable
Maximal Heart Rate
Circle response
Points
Less than 100 bpm = 30
100 to 129 bpm = 24
130 to 159 bpm =18
160 to 189 bpm =12
190 to 220 bpm =06
Exercise ST Depression
1-2mm =15
> 2mm =25
Age
Angina History
>55 yrs =20
40 to 55 yrs = 12
<40: Low probability
Definite/Typical = 5
40-60: Intermediate
probability
>60: High probability
Probable/atypical =3
Non-cardiac pain =1
Hypercholesterolemia?
Yes=5
Diabetes?
Yes=5
Exercise test
induced Angina
Choose only
one per group
Occurred =3
Reason for stopping =5
Total Score
Variable
Maximal Heart Rate
Points
Circle response
Less than 100 bpm = 20
100 to 129 bpm = 16
130 to 159 bpm =12
160 to 189 bpm =08
190 to 220 bpm =04
Exercise ST Depression
1-2mm =06
> 2mm =10
Age
>65 yrs =25
Choose only
one per group
50 to 65 yrs = 15
Angina History
Definite/Typical = 10
Probable/atypical =6
Non-cardiac pain =2
Estrogen status
Positive = -5; Negative = +5
Diabetes?
Yes =10
Smoking?
Yes =10
Exercise Induced Angina
Occurred =9
Reason for stopping =15
Total Score
<37: Low probability
37-57: Intermediate
probability
>57: High probability
 954 patients - clinical/TMT reports
 Sent to 44 expert cardiologists,
40 cardiologists and 30 MD
physicians
 Scores did always better than all
three
 The experts were the nearest to
scores
SCORE = (1=yes, 0=no)
METs<5 + Age>65 + History of
CHF + History of MI or Q wave
a=0, b=1, c=2, d=more than 2
Digoxin
Abnormal ST depression (45%)
LVH
Decreases the specificity of ETT
Resting ST depression
Marker of MACE
LBBB
ST depression has limited value
RBBB
No effect; V3-V6 to be monitored
Beta blockers
Decrease the Heart Rate response
Calcium Channel Block Decreased Chronotropic response
ETT Result
Low risk
Intermediate
High risk
Co morbidity +
CAD Prob Average Mortality
 40%
 1% per year
40 to 60% 2 – 3 % per year
 60%
 4% per year
Any prob. Any level risk
Recommend
Medical Rx.
Imaging/CAG
CAG soon
Medical Rx.
GOLD STANDARD
CAD
by CAG
No CAD
by CAG
SnNOUT (Minimum FN)
Sensitivity is
True positives
TMT + VE
TEST
True Positives False Positives
a
b
Total CAD
a
a+c
Specificity is
TMT – VE
False Negative True Negatives
c
d
True Negatives
Total No CAD
Total CAD
a+c
Total No CAD
b+d
d
b+d
SpPIN (Minimum FP)
GOLD STANDARD
CAD
by CAG
TMT + VE
No CAD
by CAG
TEST
True Positives False Positives
60
60
SnNOUT (Rules out 60%)
Sensitivity is
True positives
60
Total CAD
100
Specificity is
TMT – VE
False Negative True Negatives
40
240
Total CAD
100
Total No CAD
300
True Negatives
240
Total No CAD
300
SpPIN (Confirms 80%)
SnNout
• Gianrossi R, Detrano R,
Mulvihill D, et al.
Exercise-induced ST
depression in the
diagnosis of coronary
artery disease. Circulation
1989; 80:87-98.
• Meta-analysis of 147
consecutive studies
involving 24,074 patients
SpPin
78
76
74
72
70
68
66
64
62
SENSITIVITY
SPECIFICITY
100
90
80
70
60
Stress ECG
Stress ECHO
Nuclear
50
40
30
20
10
0
1 vessel
2 vessel
3 vessel
All CAD
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Sensitivity of ETT is as low as 30 % v/s 62% in men
Stress imaging is not the first alternative in women
Just as in men Exercise ECG testing is the first test
Multiple CV risk factors, Severe long standing DM,
PVD, CKD are indications for ETT
• Routinely in asymptomatic men/women without any
CV Risk factors – ETT is not indicated
• The false positive ETT results - unwanted tests and
treatments preclude the use of ETT as a routine test.
• Risk stratification and assessment of prognosis
• Functional capacity for activity level after
discharge
• Assessment of adequacy of medical therapy
• To decide on diagnostic or treatment options.
• ETT after MI is safe but after 2 to 3 weeks
• Fatal Re MI and cardiac rupture – 0.03%
• Non fatal Re MI with recovery – 0.09%
• Complex arrhythmias, including VT, is – 1.4%
• The two types of patients – Implications for testing
• Sensitivity (SnNout) : 62%; Specificity (SpPin) :
78%
• Pretest probability : If intermediate ETT is very
useful
• METs < 5; 5-10; >10, > 13 ; Bruce protocol minutes
• Max SBP at least 40 mm more; THR – 90% of
MHR
• Drop in SBP ominous, Chronotropic Incompetence
• Double product : Max SBP x Max attained HR
www.cardiology.org for all the calculators
http://www.emedicine.com/med/topic2961.htm
http://www.aafp.org/afp/990115ap/401.html
http://www.acc.org/clinical/guidelines/exercise
http://www.annals.org/cgi/content/full/118/2/81
http://www.webmd.com/heart-disease/exerciseelectrocardiogram
http://circ.ahajournals.org/cgi/content/full/96/1/345#T1
http://www.mssm.edu/medicine/generalmedicine/ebm/CPR/CAD.html