Stress Echocardiography;Which Method?

Seung Woo Park, MD.

CVIC, Samsung Medical CenterSungkyunkwan University School of Medicine

Sequence of Events During PTCAIschemic Cascade

Sigwart, 1984Sigwart, 1984

OcclusionOcclusion

Relaxation failureRelaxation failure

Contraction failureContraction failure

filling pressurefilling pressure

ECG changesECG changesAnginaAngina

IschemiaIschemia

SecondsSeconds1010 2020 3030

Stress ModalitiesExercise

•Treadmill•Bicycle – upright or supine

Pharmacologic•Dobutamine•Dipyridamole•Adenosine•Ergonovine

Other•Transesophageal atrial pacing•Combined modalities

Echo Parameter

Regional wall motionDoppler parameters

•Diastolic function of LV•Coronary flow reserve (CFR)•Myocardial velocity•Strain, Strain rate

Other•2-D strain, strain rate•Perfusion with contrast agent

Qantitative Assessment

• May be future• Simplification for measurement• More validation

ASE guideline 2007

Exercise vs Nonexercise

A patient’s exercise capacity carries prognostic information, independent of demonstration of ischemia

McCully: JACC, 1998 (exercise echo)Goraya: Ann Int Med, 2000 (exercise ECG)

Exercise Echocardiography

•Detection of CAD

•Quantification of CAD

•Prognostic value

Exercise Echo Protocol

Exercise Echo Protocol

• Baseline images• Baseline HR, BP, ECG• Symptom-limited exercise test. BP, HR,

ECG monitoring• Post-exercise (peak for bicycle) images• Side by side display of rest and stress

images

TMET Stress Echo

Advantages

• Physiologic

• ECG predictable

• Exercise information

• 2 sets of Images

Disadvantages

• Must be able to walk

• ? Reach target HR

• Peak images only and

may be difficult

Bicycle Stress Echo

Advantages• Continuous Imaging

• Ischemic threshold

• Hemodynamics

• ? Detect more ischemia

Disadvantages• Exercise awkward

• Lower work load

• HR lower, BP higher

Recovery time (min)Recovery time (min)

HRHR

60708090

100110120130140150160170

Peak 1 2 3 4 5 6 7 8 9 10exercise

Peak 1 2 3 4 5 6 7 8 9 10exercise

AtropineAtropineSalineSaline*P<0.05*P<0.05

**

****

** ** ** ** ** **

Attenhoffer et al: Echocardiography, 2000

Heart Rate Decline After Exercise

82

67

888075

60

8190

0

20

40

60

80

100Supine bikeSupine bike

Overall 1 vessel 2 vessel n=10n=57 n=15 n=42

Sensitivity Specificity

%

TreadmillTreadmill

Badruddin et al: JACC, 1999

Sensitivity and Specificity of SupineBike vs Treadmill Exercise Echo

Disadvantages• Not as physiologic

• Low dose - contractility

• High dose - HR

• Need IV

• Dynamic LVOT

• Arrhythmias

Dobutamine Stress Echo

Advantages• No exercise

• Target HR reached

• Continuous imaging

• Ischemic threshold

• Hemodynamics

• Viability

• Images easier

Dobutamine PharmacologyDobutamine Pharmacology

• Synthetic catecholamine, B1• Increases myocardial oxygen demand

Increases contractilityIncreases heart rate

• Half-life 2 minutes

Dobutamine Stress EchoContraindications

Dobutamine Stress EchoContraindications

• DobutamineUncontrolled hypertensionUncontrolled dysrhythmia

• AtropineUntreated narrow angle glaucomaSevere urinary retention

Dobutamine Stress EchoProtocol

Dobutaminedose(mcg/kg/min)

Dobutaminedose(mcg/kg/min)Time (min)BPEchoECG

Time (min)BPEchoECG

00 33 66 99 1212 1515

55

1010

2020

Atropine 0.5 mg,repeat 0.25 q minuteAtropine 0.5 mg,repeat 0.25 q minute

4040

3030

Dobutamine Stress Echo Endpoints

Dobutamine Stress Echo Endpoints

• Peak dose• Target heart rate .85 (220-age)• Moderate or extensive wall motion

abnormalities• Significant arrhythmia• Hypotension, severe hypertension• Intolerable symptoms

Dobutamine-side effectsDobutamine-side effects• Palpitations• Chest pain• Tremor or shivering• Headache• Urinary urgency• Nausea• Dyspnea• Lightheadedness• Hypertension, hypotension• Arrhythmias

Dobutamine Stress EchoAssessment of Myocardial Viability

Early after MI(stunned)Early after MI(stunned)

Chronic LV dysfunction(hibernating)Chronic LV dysfunction(hibernating)

TimeTime CABG orPCICABG orPCI

Improved contractility with dobutamine

Predicts recovery of LV function

Myocardial ViabilityDobutamine Stress Echocardiography

RestRest Low doseLow dose High doseHigh doseX XX XX XX X

Open

Scar

Open

Viable

Viable

Normal Response in DSE

Stunned Myocardium in DSE

Nonviable Myocardium in DSE

Hibernating Myocardium in DSE

Low Dose

Baseline

High Dose

SensitivitySpecificitySensitivitySpecificity

Echo vs Nuclear ImagingPrediction of Contractile Recovery

%%

Studies (no.) 32 22 11 20 20Patients (no.) 1,090 557 301 488 598Studies (no.) 32 22 11 20 20Patients (no.) 1,090 557 301 488 598

81 80 86

59

88

50

8166

93

58

Bax, et al Curr Prob Cardiol, Feb 2001

Vasodilator Stress Pharmacology

•DipyridamoleIncreases endogenous levels of adenosine

•AdenosineDecreases resistance

Dipyridamole Stress EchoProtocol I

Infusion of 0.14 mg/kg/minx 4 min (0.56 mg/kg)

• Additional 0.28 mg/kg x 2 min • Atropine, handgrip exercise

Imaging if no RWMA for 4

min

EAE guideline 2008

Dipyridamole Stress Echo Protocol II

EAE guideline 2008

AdenosineAdenosine

50 g/kg/min50 g/kg/min

EchoEcho1 min1 min

4 min4 min7575

100100

140140

HandgripHandgrip

Adenosine Stress EchoProtocol

Vasodilator Stress Contraindications

• DipyridamoleHypotensionUnstable carotid disease

• Adenosine or dipyridamoleSevere bronchospasmHeart block: 2nd or 3rd degree

Response for Stress Modalities

Rest Stress Interpretation

Normal Hyperdynamic Normal

Normal New wall motion Ischemiaabnormality

Wall motion Worsening Ischemiaabnormality

Wall motion Unchanged Infarctabnormality

Wall motion Biphasic Viableabnormality

Interpretation of Regional Wall Motion

Stress EchocardiographyValidation with Coronary Angiography

No. Sens SpecTreadmill 1,020 88 82

Bike 676 89 83

Dobutamine 1,240 85 83

Pellikka: Prog in CV Dis, 1997

88 82 8782 77 8274

9477

0

20

40

60

80

100

Sensitivity Specificity Accuracy

%%

ExerciseExercise DobutamineDobutamine DipyridamoleDipyridamole

n=119n=119 n=17n=17 n=136n=136

P=0.002P=0.002 P=0.001P=0.001

n=136

Beleslin et al. Circulation, 1994

Comparison of Tests in Detecting CAD

Dip-stress vs Exe-stress EchoCG for detection of coronary artery disease

Sensitivity Specificity Accuracy Feasibility

EAE guideline 2008

Dip-stress vs Dob-stress EchoCG for detection of coronary artery disease

EAE guideline 2008

Esophageal Pacing Stress Echo

Lee et al JACC,1999

Protocol

1. Small esophageal lead placed

2. Begin pacing 10 beats/min above baseline

3. Increase pacing 20 beats/min every 2 min until 85% HR reached or other endpoints

Esophageal Pacing Stress Echo

Advantages• Fast protocol

• Reach target HR

• Continuous imaging

• Avoid arrhythmias

• Avoid HTN response

Disadvantages• Esophageal intubation

• Rare sedation needed

• IV start

• BP response variable

• Atropine +/-

• Role of stress echo in predicting cardiac events has been documented in >40 studies in >10,000 patients

• Positive study identifies patients at risk of events during follow-up

• Normal study predicts a good outcome

Stress EchocardiographyPrognostic Value

50

60

70

80

90

100

0 1 2 3 4

%%

Follow-up (years)Follow-up (years)

Median follow-up 23 mo

ObservedExpected

McCully et al: JACC, 1998

Normal Exercise EchoOverall Survival in 1,325 Patients

0

20

40

60

80

100

0 1 2 3 4 5Years

%Exercise WMSI =11 exercise WMSI 1.5Exercise WMSI 1.5P<0.001

Arruda et al: JACC, 2001

Effect of Exercise WMSI on Survival Free ofAll Cardiac Events in 2,632 Patients > 65 years

0

50

100

150

200

X2X2 0.0030.0030.00010.0001

0.00010.0001

Clinical and Rest EchoClinical and Rest Echo + Exercise ECGClinical and Rest Echo + Exercise ECG + Exercise Echo

Cardiac death or myocardial infarctionArruda et al: JACC, 2001

Incremental Value of Exercise Echocardiography in 2,632 Patients 65 years

Conclusion

• Various stress echo modalities significantly improve the diagnostic and prognostic power in the evaluation of patients with CAD.

• The choice of imaging modality in a particular setting depends on several factors including availability, feasibility, experience and cost considerations.