Download 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

• • • • • • • • • •

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

Suresh • • • • • • •

24 years BMI 20 No CP No DM Lipids N Smoking 0 ECG N Low 2%

Lakshmi • • • • • • •

54 years BMI 25 Atypical CP T2 DM 5 yrs LDL 150 Smoking 0 ECG T  L3 Intermediate 39 %

Devadoss • • • • • • •

43 years BMI 28 Atypical CP IGT + LDL, TG Ex Smoker ECG N Intermediate 46%

Masthan • • • • • • •

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    

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 – – – –

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

30-39 30-39

Males

Intermediate

Intermediate

low (75%

Atypical/Probable Non-Anginal Angina Pectoris Chest Pain

Intermediate = 15-75%

Low = 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

6 7

Very, very light

8

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

3

5

Stage 2

2.4 mph + 12% Gradient

6

7

Stage 3

3.1 mph + 14% Gradient

9

10

Stage 4

3.8 mph + 16% Gradient

12

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 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

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

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) METs65 + 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

• • • •

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