dr r.v.s.n. sarma., m.d., m.sc., consultant physician and chest specialist

Dr R.V.S.N. Sarma., M.D., M.Sc.,

Consultant Physician andChest Specialist

To my beloved mother

• 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

• 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

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%)• It is essential to screen and choose the pt for

ETT

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 The electrocardiogram (ECG) Heart rate Blood pressure And during ST-segment abnormalities and chest pain.

The patient should be monitored continuously For transient rhythm disturbances, ST-segment changes

and ECG manifestations of myocardial ischemia.

Bicycle Ergo meter Treadmill Test

• Cycle Ergo meters are generally – 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

• 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

Atypical/Probable Angina Pectoris

Non-Anginal Chest Pain

Asymptomatic

30-39

Males

Intermediate

Intermediate

low (<10%)

Very low (<5%)

30-39

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% Intermediate = 15-75% Low = <15% Very Low = < 5%

Use a computer model or

Use the probability table

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• ST elevation (≥1.0 mm) in leads without diagnostic Q

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

• ST segment changes alone will not suffice

o Metabolic Equivalent Term o 1 MET = "Basal" aerobic oxygen consumption to stay alive = 3.5 ml O2 /Kg/min -70 kg, 40 yr mano Actually differs with thyroid status, post exercise,

obesity, disease stateso By convention just divide ml O2/Kg/min by 3.5

METs = Speed x [0.1 + (Grade x 1.8)] + 3.5 3.5

Calculated automatically by Device!

• 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

• Modified Bruce – 2 warm up stages (1.7 mph 0%, 5%)• For elderly and patients with reduced exercise capacity

o 1 MET = "Basal" = 3.5 ml O2 /Kg/min

o 2 METs = 2 mph on level

o 4 METs = 4 mph on level

o < 5METs = Poor prognosis if < 65 years

o10 METs = 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

plaques

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, 200Double product must be at least: 20, 000

SBP should rise > 40 mmHgDiastolic 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 BPMfrom peak exercise heart rate to heart ratemeasured 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

ETTInterpretation contd…

• 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 < 0.5% • For Duke treadmill score Nomogram. See next slide

…

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 Circle response Points

Maximal Heart Rate

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 >55 yrs =20

40 to 55 yrs = 12

Angina History Definite/Typical = 5

Probable/atypical =3

Non-cardiac pain =1

Hypercholesterolemia?

Yes=5

Diabetes? Yes=5

Exercise test Occurred =3

induced Angina Reason for stopping =5

Total Score

Choose only one per group

<40: Low probability

40-60: Intermediate probability>60: High probability

Variable Circle response Points

Maximal Heart Rate

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

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

Choose only one per group<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

ETT Result CAD Prob Average Mortality Recommend

Low risk 40% 1% per year Medical Rx.

Intermediate 40 to 60% 2 – 3 % per year Imaging/CAG

High risk 60% 4% per year CAG soon

Co morbidity + Any prob. Any level risk Medical Rx.

Sensitivity is

True positives

a

Total CAD

a + c

CAD by CAG

No CADby CAG

TMT + VETrue Positives

aFalse Positives

b

TMT – VEFalse Negative

cTrue Negatives

d

Total CADa + c

Total No CADb + d

TE

ST

GOLD STANDARD

Specificity is

True Negatives

d

Total No CAD

b + d

SnNOUT (Minimum FN)

SpPIN (Minimum FP)

Sensitivity is

True positives

60

Total CAD

100

CAD by CAG

No CADby CAG

TMT + VETrue Positives

60False Positives

60

TMT – VEFalse Negative

40True Negatives

240

Total CAD100

Total No CAD300

TE

ST

GOLD STANDARD

Specificity is

True Negatives

240

Total No CAD

300

SnNOUT (Rules out 60%)

SpPIN (Confirms 80%)

• 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

62

64

66

68

70

72

74

76

78

SENSITIVITY SPECIFICITY

SnNout SpPin

0

10

20

30

40

50

60

70

80

90

100

1 vessel 2 vessel 3 vessel All CAD

Stress ECG

Stress ECHO

Nuclear

• 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

• ST segment depression > 1 mm V1 – V6• Exercise induced angina – 0, 1 and 2• Duke score, Nomogram, VA score :

Prediction of CAD

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/exercise-

electrocardiogram

http://circ.ahajournals.org/cgi/content/full/

96/1/345#T1

http://www.mssm.edu/medicine/general-medicine/

ebm/CPR/CAD.html