Stress Echocardiography by Sruthi Meenaxshi

1. STRESS ECHOCARDIOGRAPHY
Dr.Sruthi Meenaxshi MBBS,MD,PDF

2. STRESS ECHOCARDIOGRAPHY
• Stress Echocardiography enables evaluation of
cardiac function at rest
• during pharmacologic stress,
• during or immediately following dynamic
exercise.

3. • Stress echocardiography can be accomplished
using either
• exercise (treadmill or bicycle) or
• pharmacologic agents
(predominantly dobutamine) as the stress
mechanism

4. • Exercise two-dimensional (2D) imaging is
used primarily
• to detect the presence and extent of coronary
artery disease
• to detect regional ischemia resulting wall
motion abnormalities.

5. • exercise Doppler permits
• evaluation of valvular function
• pulmonary artery pressure
• left ventricular outflow tract gradients
• global ventricular systolic and diastolic
function.

6. • Echocardiographic contrast agents may be
useful in enhancing endocardial border
definition when two or more segments of the
left ventricle are not well visualized.

7. INDICATIONS
●Evaluation of patients with known or suspected coronary artery disease.
●Assessment of myocardial viability
●Evaluation of dyspnea of possible cardiac origin
●Evaluation for pulmonary hypertension, as pulmonary artery systolic pressure can be
estimated atrest and with exercise.
●Evaluation of mitral valve disease, including mitral stenosis and mitral regurgitation
●Evaluation of aortic stenosis. Stress echocardiography may be reasonable and helpful
in patients with low gradient aortic stenosis or asymptomatic aortic stenosis. (
●Evaluation of left ventricular outflow tract gradients, mitral regurgitation, and
pulmonary hypertension in patients with hypertrophic cardiomyopathy.

8. CONTRAINDICATIONS
 Acute myocardial infarction (within two days)
 Ongoing unstable angina
 Uncontrolled arrhythmias with hemodynamic compromise
 Symptomatic severe valvular stenosis
 Decompensated heart failure
 Active endocarditis
 Acute myocarditis or pericarditis
 Acute aortic dissection
 Acute pulmonary embolism, pulmonary infarction, or deep
venous thrombosis
 Physical disability that precludes safe and adequate testing

9. STRESS TECHNIQUES
• Protocols — The practice guidelines from the American Society of
Echocardiography (ASE) recommend symptom-limited exercise
according to standard protocols using either a treadmill or bicycle
• These guidelines note that if evaluation of wall motion is the main
purpose of the test, then treadmill exercise is usually used, whereas
if stress Doppler information is desired, bicycle exercise should be
considered because it enables Doppler as well as wall motion
evaluation during each stage of exercise .
• As with any exercise stress test, exercise should be performed until
the patient feels that he/she cannot exercise further due to fatigue
or symptoms, although in some instances there may be appropriate
endpoints determined by the provider or the protocol.

10. The practice guidelines from the American Society of
Echocardiography (ASE) recommend symptom-limited
exercise according to standard protocols using either a
treadmill or bicycle
• These guidelines note that if evaluation of wall motion is the main
purpose of the test, then treadmill exercise is usually used,
• Stress Doppler information is desired, bicycle exercise should be
considered because it enables Doppler as well as wall motion
evaluation during each stage of exercise
• As with any exercise stress test, exercise should be performed until
the patient feels that he/she cannot exercise further due to
fatigue or symptoms, although in some instances there may be
appropriate endpoints determined by the provider or the protocol.

12. EXERCISE ECHOCARDIOGRAPHY
• Exercise echocardiography is most commonly performed using a
treadmill protocol
• Echocardiographic images are acquired prior to and immediately
after completion of exercise .
• This method requires that the patient transfer from the treadmill
into a recumbent position for imaging within a few seconds so that
a complete set of images can be obtained as rapidly as possible,
usually within 60 seconds after cessation of exercise.
• Use of digitized images permits review of multiple cardiac cycles,
as well as side-by-side comparison of these images. This approach
maximizes accuracy of interpretation. Continuous recording of
images is also recommended as backup

13. • For maximal diagnostic accuracy, images
should be obtained prior to the heart rate
decreasing toward baseline.
• Early image acquisition is necessary since
ischemia-induced wall motion abnormalities
may resolve rapidly as the heart rate slows,
causing a decrease in the sensitivity of the
test, especially for single vessel disease.

15. Bicycle ergometry
• Some laboratories perform stress
echocardiography using supine or upright
bicycle ergometry.
• A typical symptom-limited supine bicycle
protocol starts at a workload of 25 watts and
increases by 25 watt increments every three
minutes until an endpoint is achieved.

16. • A major advantage of supine bicycle ergometry is
that it allows continuous monitoring of wall
motion during exercise.
• Imaging throughout the study may permit
detection of the onset of wall motion
abnormalities and improve sensitivity of
detection of coronary artery disease.
• Moreover, acquisition of Doppler imaging during
each stage of exercise is also feasible during
supine bicycle exercise.

17. Supine Bicycle ergometer

18. Upright bicycle ergometer

19. PHARMACOLOGIC STRESS
ECHOCARDIOGRAPHY
• Pharmacologic stress is employed in patients who are
unable to perform exercise testing.
• myocardial viability assessment
• involves the administration of dobutamine with the
addition of atropine as needed to achieve the target heart
rate
• The American Society of Echocardiography guidelines
recommend dobutamine as preferable to vasodilators (eg,
dipyridamole, adenosine .

20. DOBUTAMINE

21. Dobutamine
• Dobutamine is a direct-acting agent whose
primary activity results from stimulation of
the β1-adrenoceptors of the heart,
increasing contractility and cardiac output.

23. DOBUTAMINE STRESS
ECHOCARDIOGRAPHY
• Graded dobutamine infusion in five three-minute stages starting at
5 mcg/kg/minute, followed by 10, 20, 30, and 40 mcg/kg/minute
• An initial dose of 2.5 mcg/kg/minute may be used in tests
evaluating viability.
• Low-dose stages facilitate recognition of viability in segments with
abnormal function at rest, even when viability evaluation is not the
main focus of the test.
• Atropine, in divided doses of 0.5 mg to a total of 2.0 mg, should be
administered as needed to achieve target heart rate. Atropine
increases the sensitivity of dobutamine

25. • During dobutamine echocardiography,
echocardiographic images are acquired prior to the
start of the dobutamine infusion, at the completion
of each stage, and during recovery.

26. End point of the test
 The standard endpoint for dobutamine stress echocardiography is
the achievement of target heart rate, defined as at least 85 percent
of the age-predicted maximum heart rate.
 The test may also be terminated following the development of
significant symptoms,
 new or
 worsening wall motion abnormalities of moderate degree,
 significant arrhythmias,
 hypotension
 (systolic blood pressure less than 90 mmHg), or
 severe hypertension

27. VASODILATOR STRESS
ECHOCARDIOGRAPHY
• Dipyridamole is administered at up to 0.84 mg/kg in two separate infusions: 0.56 mg/kg
over four minutes ("standard dose"), followed by four minutes of no dose and
• Additional doses may be required in patients receiving beta blockers and those with
single vessel disease .
•
• Some laboratories also use a sustained isometric hand grip or a low-level
• dynamic foot exercise (with or without atropine) in the late stages of the dobutamine
• protocol as a supplemental maneuver to achieve peak heart rate.
• 0.28 mg/kg is given over two minutes.
• If no endpoint is reached following the second infusion
• (total of 0.84 mg/kg), then atropine (doses of 0.25 mg, up to a maximum of 1 mg) may
be
• administered

28. dipyridamole
• pyridamole is a nucleoside transport
inhibitor and a PDE3
inhibitor medication that inhibits blood
clot formation
• when given chronically and causes blood
vessel dilation when given at high doses
over a short time.

30. • Adenosine is typically infused at a maximum dose of 140
mcg/kg/minute over six minutes.
• Imaging is performed prior to and after starting adenosine infusion.
• Adenosine is a shorteracting agent employed for myocardial
perfusion contrast echocardiography
• Vasodilator stress may be better suited for perfusion than wall
motion analysis
• contraindicated in patients with reactive airway obstruction or
significant conduction defects
• Not widely used

31. Temporary pacing
• Tachycardia induced by a pacemaker is an alternative to
pharmacologic stress in patients who are not able to exercise.
• In selected patients with a permanent pacemaker, increasing
the pacing rate to facilitate achievement of target heart rate
may be used; this stress method is combined with
dobutamine infusion
• Dobutamine is increased at a slower rate
• During recovery the pacing rate is progressively reduced at
one-minute intervals.

32. HAND GRIP EXERCISE
• Handgrip exercise — Handgrip may be used as an
adjunct to exercise or dobutamine stress
echocardiography
• During the last stage of exercise or dobutamine infusion
and 30 seconds before acquiring the peak exercise
images, patients are asked to exert a sustained grip on a
tennis ball.
• The hand grip response reliably raises blood pressure at
least 10 mmHg and usually also increases heart rate

33. IMAGING TECHNIQUES
• Baseline echocardiography —
screening assessment of
• ventricular function, chamber sizes,
• wall thicknesses,
• aortic root diameter,
• pericardial effusions, and
• gross valvular structure and Function
• estimate of pulmonary arterial systolic pressure using the tricuspid
regurgitation velocity
• It also allows the diagnosis of ancillary conditions in the setting of
coronary artery disease, such as intracavitary thrombus or ischemic
mitral regurgitation.

34. 2D IMAGING
• To evaluate coronary artery disease
• Side by side comparsion of global and regional left
ventricular systolic function at rest and after stress
• Pre peak and peak stress images are taken
• With stress the normal ventricle becomes
hypercontractile , cavity size becomes small and
ejection fraction increased

35. • Function in each segment is graded (normal,
hyperdynamic, hypokinetic,
• akinetic, dyskinetic, or aneurysmal) at rest and
with stress. In addition, global left ventricular
• systolic function and cavity size are evaluated

38. 17 segment model

40. • Detection of segmental left ventricular dysfunction is
useful in diagnosing and localizing obstructive coronary
artery disease
• The development of new or worsening segmental wall
motion with stress suggests presence of
hemodynamically significant coronary artery stenoses
supplying the abnormal segments.
• Decrease of global left ventricular ejection fraction,
and/or increased left ventricular end-systolic volume,
suggest presence of severe obstructive coronary
arterial disease such as flow-limiting left main stenosis
or severe multivessel coronary artery disease

41. Doppler imaging
• Doppler echocardiography enables measurement of
flow velocities and pressure gradients.
• Because Doppler recordings display instantaneous
changes in these parameters, this is an excellent
technique for the study of hemodynamic response to
exercise or pharmacologic stress.
• Doppler examination following stress should be
individualized based on the findings from the baseline
(resting) echocardiogram as well as the indications for
the study. :

42. The common potential targets for
Doppler examination following stress
testing include
 Mitral valve – Changes in mitral stenosis gradient or mitral
regurgitation quantity following stress
 Aortic valve – Evaluation of aortic valvular gradients in suspected
low-flow, low-gradient aortic stenosis
 Tricuspid valve – Assessment of tricuspid regurgitation velocity for
estimation of pulmonary artery systolic pressure in patients with
suspected pulmonary hypertension
 Left ventricular outflow tract (LVOT) – Evaluation for inducible or
worsening LVOT gradient in suspected or known hypertrophic
cardiomyopathy

43. Use of Contrast agents
• Microbubble ultrasound contrast agents
• can enhance left ventricular endocardial
border definition during stress
echocardiography.
• Administered through IV access

44. Indications of echo contrast
• Enhances endocardial border and doppler
signals
• Intravenous agitated saline is used
• Indicated in multiple coronary artery disease ,
abnormal baseline ecg, chronic lung disease,
smoking , referral for dobutamine stress
echocardiography, high body mass index

45. safety
• Safety of dobutamine administration —
• Dobutamine is generally safe and well tolerated when used
in stress testing .
• Arrythmia , chest pain left ventricular obstruction can occur
• Minor arrythmia predominantly ventricular and premature
atrial complex
• Atrial fibrillation , premature supraventricular complex
• Non sustained ventricular tacyarrthymias can occur