Dr R.V.S.N. Sarma., M.D., M.Sc.,Consultant Physician andChest Specialist

To my beloved mother

Slowly progressive CADCSA to USA to NSTEMI to STEMI and CVMWarning ++ long durationCollateral CBF goodECG / TMT evidence +CAG will confirm CADPrognosis is good; OlderNon vulnerable plaquesFlow limiting narrowingForm only 30 % of MI casesGroup with sudden MACEGive no time to actSCD or Massive MINo previous CSA or USANo warning; Short durationNo time for collateral CBFTMT/ CAG -ve before MACEPrognosis is poor; YoungerVulnerable ruptured plaquesFocus on factors causing ruptureContribute to 70% of MI cases

Routine Treadmill (ECG only) ETT or TMTStress EchocardiographyDobutamine Echocardiography (CSE)Exercise Stress Echocardiography (ESE)Nuclear Imaging Chemical Stress - MPIDobutamine Nuclear StressAdenosine 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 talkAlthough 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 menShould be supervised by a well trained physician, who should be available immediately for emergenciesCareful monitoring & recording in each stage of exerciseThe 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 smallerLess noisy than treadmills ECG disturbances are minimumBut, produce less motion of the upper part of bodyThe fatigue of the quadriceps muscles is a major limitation Treadmills are much more commonly usedSupine stress testing is not routinely used

Age

Gender

Typical/Definite Angina Pectoris

Atypical/Probable Angina Pectoris

Non-Anginal

Chest Pain

Asymptomatic

30-39

Males

Intermediate

Intermediate

low (90% Intermediate = 10-90% Low =

AbsoluteAcute myocardial infarction (within 2 days)High-risk unstable anginaUncontrolled cardiac arrhythmias Symptomatic severe aortic stenosisUncontrolled symptomatic heart failureAcute pulmonary embolus or pulmonary infarctionAcute myocarditis or pericarditisAcute aortic dissection

RelativeLeft main coronary stenosisModerate stenotic valvular heart diseaseElectrolyte abnormalitiesSevere arterial hypertensionTachy or Brady arrhythmiasHOCM and other outflow obstructionsMental or physical impairmentHigh-degree atrio-ventricular block

Absolute indicationsDrop in SBP of >10 mm Hg from baseline BP with accompanying evidence of ischemia Moderate to severe anginaIncreasing nervous system symptoms ataxia, dizzinessSigns of poor perfusion (cyanosis or pallor)Technical difficulties in monitoring ECG or SBPSubjects desire to stop; Sustained ventricular tachycardiaST elevation (1.0 mm) in leads without diagnostic Q

Relative indicationsDrop in SBP of 10 mm Hg BP without ischemiaST or QRS changes - ST depression (>2 mm of horizontal or down sloping ST-segment ) or axis shiftArrhythmias VT, multifocal PVCs, triplets of PVCs, SVT,Heart block or brady arrhythmias, BBB or IVCD Fatigue, shortness of breath, wheezing, leg cramps, ICIncreasing chest pain; Hypertensive response > 250/115

Only Manual SBP measurement for safetyAdjust to clinical history (couch potatoes)Age predicted Heart Rate Targets ? ?The BORG Scale of Perceived ExertionMETs - not Minutes have to be usedUse standard ECG analysis + 3 minute recoveryUse scores, ST/HR Index, Heart rate recoveryST segment changes alone will not suffice

Metabolic Equivalent Term 1 MET = "Basal" aerobic oxygen consumption to stay alive = 3.5 ml O2 /Kg/min -70 kg, 40 yr man Actually differs with thyroid status, post exercise, obesity, disease states By convention just divide ml O2/Kg/min by 3.5METs = 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 METPretest plain walking + 6 Stages of graded exerciseIn each stage there is increase in speed and gradientInitial 1.7 mph with 10% gradient (upward inclination)Maximum 5.5 mph with 20% gradientModified Bruce 2 warm up stages (1.7 mph 0%, 5%)For elderly and patients with reduced exercise capacity

Lead V5 alone consistently outperforms other leadsFalse + 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 USARuptures of high-risk or vulnerable plaquesInner plaque material is exposed to blood and initiates formation of a platelet-fibrin thrombus on the rupture.The rupture may seal without detectable sequelae orThe 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 DamageSeverity of CADModifiable factorsH/o Prior MI, ECG Path Qs Anatomic - SVD, DVD, TVDDM, HT, DyslipidemiaCHF, Cardiomegaly in CXRDegree of stenosis and extentExcess weight, Smoking EF (

Systolic Blood Pressure x HR = Double ProductExample: SBP 170 x HR 160 = 27, 200Double product must be at least: 20, 000SBP should rise > 40 mmHgDiastolic BP may decline by 10 mmDrop 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) = 165THR = 90% of Pr MHR of 165 = 148Chronotropic Incompetence = < 85% of Pr MHRIn this case 85% of 165 (Pr MHR) = < 140 BPMChronotropic 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 90CI = (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 protocolST deviation is < 1 mm, is taken as 0.ST deviation = Max exercise ST Base line STE 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 1053% 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

Chart1

0.5521

+5 or Greater

-10 to +4

Less than -10

Sheet1

Four Year Event Rate

-10 to +45

Less than -1021

+5 or Greater0.5

Choose only one per group60: High probability

VariableCircle responsePointsMaximal Heart RateLess than 100 bpm = 30100 to 129 bpm = 24130 to 159 bpm =18160 to 189 bpm =12190 to 220 bpm =06Exercise ST Depression1-2mm =15> 2mm =25Age>55 yrs =2040 to 55 yrs = 12Angina HistoryDefinite/Typical = 5Probable/atypical =3Non-cardiac pain =1Hypercholesterolemia?Yes=5Diabetes?Yes=5Exercise testOccurred =3induced AnginaReason for stopping =5Total Score

Choose only one per group57: High probability

VariableCircle responsePointsMaximal Heart RateLess than 100 bpm = 20100 to 129 bpm = 16130 to 159 bpm =12160 to 189 bpm =08190 to 220 bpm =04Exercise ST Depression1-2mm =06> 2mm =10Age>65 yrs =2550 to 65 yrs = 15Angina HistoryDefinite/Typical = 10Probable/atypical =6Non-cardiac pain =2Estrogen statusPositive = -5; Negative = +5Diabetes?Yes =10Smoking?Yes =10Exercise Induced AnginaOccurred =9Reason for stopping =15Total Score

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 wavea=0, b=1, c=2, d=more than 2

ETT ResultCAD ProbAverage MortalityRecommendLow risk 40% 1% per yearMedical Rx.Intermediate40 to 60%2 3 % per yearImaging/CAGHigh risk 60% 4% per yearCAG soonCo morbidity +Any prob.Any level riskMedical Rx.

CAD by CAGNo CADby CAGTMT + VETrue PositivesaFalse PositivesbTMT VEFalse NegativecTrue NegativesdTotal CADa + cTotal No CADb + d

CAD by CAGNo CADby CAGTMT + VETrue Positives60False Positives60TMT VEFalse Negative40True Negatives240Total CAD100Total No CAD300

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

Sensitivity of ETT is as low as 30 % v/s 62% in menStress imaging is not the first alternative in womenJust as in men Exercise ECG testing is the first testMultiple CV risk factors, Severe long standing DM, PVD, CKD are indications for ETTRoutinely in asymptomatic men/women without any CV Risk factors ETT is not indicatedThe false positive ETT results - unwanted tests and treatments preclude the use of ETT as a routine test.

Risk stratification and assessment of prognosisFunctional capacity for activity level after dischargeAssessment of adequacy of medical therapy To decide on diagnostic or treatment options.ETT after MI is safe but after 2 to 3 weeksFatal 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 testingSensitivity (SnNout) : 62%; Specificity (SpPin) : 78%Pretest probability : If intermediate ETT is very usefulMETs < 5; 5-10; >10, > 13 ; Bruce protocol - minutesMax SBP at least 40 mm more; THR 90% of MHRDrop in SBP ominous, Chronotropic IncompetenceDouble product : Max SBP x Max attained HRST segment depression > 1 mm V1 V6Exercise induced angina 0, 1 and 2Duke 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

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