Unit 1 Lesson 3: Stress Echocardiography in Non-Ischemic Heart Disease

List the 7 non-ischemic conditions or uses that stress echocardiography can evaluate.

• Systolic/diastolic heart failure

• Non-ischemic cardiomyopathy

• Valvular heart disease

• Pulmonary hypertension

• Athlete’s heart

• Congenital heart disease

• Heart transplantation

List the 3 types of stress testing that may be used for non-ischemic heart disease.

• Exercise — treadmill or bicycle

• Dobutamine

• Vasodilators

List the 5 clinical factors shown that may lead to evaluation with a diastolic stress echo.

• Elderly age

• Diabetes

• Hypertension

• Obesity

• Sedentary lifestyle

List the 3 symptoms that may lead to a diastolic stress echo

Symptoms:

1. Dyspnea

2. Breathlessness

3. Exertional fatigue

List the 4 alternative causes of symptoms during exercise.

Alternative causes:

1. New RWMA

2. LVOTO

3. Dynamic MR

4. Chronotropic incompetence

List the 4 abnormal findings that may occur during a diastolic stress echo.

• Decreased suction reserve, or e′

• Decreased stroke-volume/cardiac-output reserve

• Increased E/e′, indicating increased LV filling pressure

• Increased SPAP/pulmonary hypertension

List the 3 measurements shown that support HFpEF during a diastolic stress echo.

• Exercise average E/e′ >14 or septal E/e′ >15

• Exercise peak TR velocity >2.8 m/s

• Rest septal e′ <7 cm/s or lateral e′ <10 cm/s

What is the preferred method for diastolic stress echo, what is the alternative, and what can happen after exercise?

• Preferred: Supine bicycle

• Alternative: Treadmill

• Diastolic dysfunction may persist after exercise.

• The protocol may be performed alone or with a RWMA assessment

What happens to E/e′ during exercise in the examples shown?

E/e′ increases during exercise and may remain elevated during recovery.

One example increases from 12 at baseline to 24 during exercise. Another increases from 12 at baseline to 15 during exercise and 19 during recovery.

When is stress echocardiography recommended in a symptomatic patient with HCM?

When resting evaluation or maneuvers fail to induce an LVOT obstruction ≥50 mmHg.

What fraction of HCM patients have SAM, what fraction may have a masked LVOT obstruction

• About 1/3 have SAM.

• Another 1/3 may have a masked LVOT obstruction.

List the 4 conditions that can reveal a masked obstruction.

It may become apparent with:

1. Standing

2. Valsalva

3. Nitrates

4. Exercise

When is stress echo not indicated for LVOTO, and is dobutamine stress echo recommended?

Stress echo is not indicated when an LVOT gradient >50 mmHg is already present at rest or with Valsalva.

DSE is not recommended.

List the 5 criteria assessed during stress echo in HCM.

• BP, HR, and ECG changes

• Symptoms

• LVOTO

• SPAP

• Diastolic parameters

List the 4 findings associated with poor exercise tolerance in HCM.

• Dynamic increase in MR

• Blunted change in e′, meaning no diastolic reserve

• Increase in E/e′

• Pulmonary hypertension with increased RVSP

List the 5 stress-echo findings associated with a poor prognosis in HCM.

• Limited exercise capacity

• Abnormal BP response — hypotensive or blunted

• Significant ST depression

• RWMAs or decreased EF

• LVOTO ≥50 mmHg

List the 6 things stress echo may evaluate in dilated cardiomyopathy.

• Contractile reserve

• Inducible ischemia

• Diastolic reserve

• SPAP changes

• Dynamic MR

• Pulmonary congestion

List the 6 imaging assessments used during exercise stress echo for dilated cardiomyopathy.

• LV views

• PW Doppler E and A

• PW tissue Doppler e′

• TR CW Doppler for SPAP

• Color-flow Doppler for MR

• Lung imaging

At what 3 levels are images obtained during exercise stress echo for dilated cardiomyopathy?

• Baseline

• Low workload

• Peak exercise

List the 6 possible exercise stress-echo findings in dilated cardiomyopathy.

• Increased contractility

• No increase in contractility

• Increased E/e′ with or without increased SPAP

• RWMAs

• Lung comets

• Increase or decrease in MR

What 2 things can dobutamine stress echo evaluate in dilated cardiomyopathy,

DSE can evaluate:

1. Inotropic reserve

2. Inducible ischemia

list the 3 possible findings dobutamine stress echo evaluate in dilated cardiomyopathy,

Possible findings:

1. Increased contractility

2. No increase in contractility

3. RWMA

List the 3 main goals of stress echo in valvular heart disease.

• Determine the need for intervention

• Elicit symptoms

• Determine disease severity

List the 3 valvular-disease situations in which stress testing may be useful.

• Severe valve disease without symptoms

• Non-severe valve disease with symptoms

• Valve disease with low flow

List the 4 measurements obtained at baseline and peak exercise in asymptomatic severe aortic stenosis.

• Aortic-valve CW Doppler

• LVOT VTI with PW Doppler

• LV function

• TR CW Doppler

List the 3 abnormal stress responses associated with severe aortic stenosis.

• Increase in mean gradient >18–20 mmHg

• Deterioration of LVEF or lack of contractile reserve

• Development of pulmonary hypertension with SPAP >60 mmHg

List the 2 types of low-flow, low-gradient aortic stenosis.

• Low-flow, low-gradient AS with reduced EF

• Low-flow, low-gradient AS with preserved EF

List the 3 criteria that define classic low-flow, low-gradient AS with reduced EF.

• AVA <1.0 cm²

• Mean gradient <40 mmHg

• LVEF <50%

List the 3 measurements obtained during low-dose dobutamine stress echo for low-flow, low-gradient AS.

• Aortic-valve CW Doppler

• LVOT PW Doppler

• LV function

What change in stroke volume indicates LV flow reserve during low-dose dobutamine stress echo?

• ΔSV ≥20% = LV flow reserve

• ΔSV <20% = no LV flow reserve

How are true-severe AS and pseudo-severe AS differentiated when LV flow reserve is present?

• Mean pressure gradient ≥40 mmHg with AVA ≤1.0 cm² → True-severe AS

• Mean pressure gradient <40 mmHg with AVA >1.0 cm² → Pseudo-severe AS

What is done when there is no LV flow reserve and the mean gradient remains <40 mmHg with an AVA ≤1.0 cm²?

A projected AVA may be calculated if the flow-rate change is adequate.

• Projected AVA ≤1.0 cm² → true-severe AS

• If projected AVA cannot be measured, CT aortic-valve calcium may be used and AS may remain indeterminate.

List the 4 criteria for low-flow, low-gradient AS with preserved EF.

• LVEF ≥50%

• Stroke-volume index <35 mL

• AVA <1.0 cm²

• Mean gradient <40 mmHg

What 2 types of stress echo may be used for low-flow, low-gradient AS with preserved EF?

1. Exercise stress echo

2. Dobutamine stress echo

The same criteria used previously can be applied.

What type of stress is preferred for MR, and when are images obtained with treadmill versus supine bicycle exercise?

Exercise is preferred.

• Treadmill: baseline and immediately after exercise

• Supine bicycle: baseline, low workload, and peak exercise

Why is dobutamine generally not used to assess MR, and list the 2 exceptions

Dobutamine is considered non-physiologic for MR assessment.

Exceptions:

1. When ischemia is suspected

2. Exercise-tolerance assessment

List the 3 measurements obtained before exercise

Pre-imaging:

1. MR assessment

2. TR and RVSP

3. LV function

List 3 measurements obtained after exercise when assessing MR.

Post-imaging:

1. LV function

2. MR

3. TR

List the 2 reasons stress echo may be useful in primary MR.

• Provoke symptoms

• Assess the SPAP response

List the 4 stress-echo findings associated with a poor prognosis in primary MR.

• Increase in MR severity

• SPAP ≥60 mmHg

• Absence of contractile reserve

• Limited RV contraction measured by TAPSE

If MR is already severe at rest, list the 2 things assessed during stress.

1. SPAP

2. LV function

There is no need to reassess MR severity during stress.

If MR is not severe at rest, list the 3 things assessed during stress.

• LV function

• Full MR assessment, including continuity and PISA

• TR assessment

List the 5 symptoms or situations in which stress echo may provide useful information for secondary MR.

• Shortness of breath with exertion not explained by LV dysfunction or resting MR severity

• Unexplained acute pulmonary edema

• Intermediate MR severity in a patient scheduled for CABG

• Risk stratification

• Persistent pulmonary hypertension after mitral repair

List the 2 predictors of poor prognosis

Poor prognosis:

1. Increase in MR severity

2. Dynamic pulmonary hypertension

List 1 finding associated with good prognosis in secondary MR.

Good prognosis:

1. Decrease in MR severity

List the 4 key points about stress testing in severe aortic insufficiency.

• Onset of symptoms is important for prognosis.

• Mortality may be as high as 10–20% per year.

• Exercise and DSE cannot be used to regrade AI severity.

• Increased HR shortens diastole and limits quantification of AI

List the 3 uses or findings of exercise testing in severe AI without symptoms.

• Exercise testing is recommended to reveal symptoms.

• Lack of contractile reserve, defined as <5% change in EF, predicts later or postoperative LV dysfunction.

• Rest and exercise longitudinal function by TDI may reveal early LV systolic dysfunction

List the 3 key points about stress testing in non-severe AI with symptoms.

• Exercise testing can confirm symptoms when their cause is unclear.

• Supine bicycle is best for EF assessment.

• Pharmacologic assessment is not recommended.

List the 3 measurements included in the image sequence for non-severe AI with symptoms.

1. LV views

2. TR for RVSP

3. MR

The sequence depends on which measurement is most important.

List the 3 things stress echo is used to assess in aortic insufficiency

Used to assess:

1. Symptoms

2. Exercise tolerance

3. LV response to stress

List 1 thing it is not used to assess aortic insufficiency in stress echo

Not used to assess:

1. Valve severity

Lack of contractile reserve is associated with postoperative dysfunction.

What valve area defines severe mitral stenosis in the PowerPoint, and what treatment is listed?

• Severe MS: valve area <1.5 cm²

• Treatment listed: Mitral-valve balloon valvuloplasty

When is stress echo indicated in severe MS without symptoms,

Stress echo is indicated to reveal symptoms and assess hemodynamic consequences when valve area is <1.5 cm² but >1.0 cm².

list the 2 additional situations in which it is indicated. for stress echo in severe MS

Also indicated when:

1. Planning pregnancy

2. Planning major surgery

List the 3 measurements obtained during the stress-echo image sequence for mitral stenosis.

• LV views

• Mitral-valve CW Doppler

• TR CW Doppler for RVSP

What is stress testing used to assess in non-severe MS with symptoms,

It assesses the hemodynamic significance of MS.

what 2 mean-gradient values indicate severe MS?

Severe MS is indicated by:

1. Mean gradient >15 mmHg with exertion

2. Mean gradient >18 mmHg during dobutamine infusi

What SPAP finding suggests hemodynamically significant MS

An early increase in SPAP during low-level exercise is abnormal, and an SPAP >60 mmHg with exertion is another marker of hemodynamically significant MS.

why is DSE not recommended for assessing SPAP?

DSE is not recommended because:

• SPAP may rise because of the medication rather than true functional limitation.

• It is less physiologic.

List the 2 things exercise stress echo can help confirm in patients with prosthetic valves.

1. Significant prosthetic-valve stenosis or patient-prosthesis mismatch (PPM)

2. Symptomatic status

List the 2 uses of low-dose dobutamine stress echo in patients with prosthetic valves.

• Used in patients with aortic or mitral prosthetic valves and a low-flow state with a small resting EOA or DVI

• Differentiates true prosthetic dysfunction/PPM from pseudo-dysfunction

What 2 exercise findings in pulmonary hypertension are associated with a poor prognosis?

1. Elevation in pulmonary artery pressure

2. Development of RV dysfunction with exercise

Why is treadmill ESE less reliable for pulmonary hypertension,

ESE is less reliable because SPAP returns to baseline quickly.

what exercise method is preferred for treadmill ESE

Semi-supine bicycle is preferred

when should Doppler recordings be obtained for treadmill ESE

Doppler recordings should be completed within 1 minute after test completion.

List the 6 measurements needed when assessing pulmonary hypertension with stress echo.

• TR velocity

• PR velocity

• RV size and function

• TAPSE and S′

• RAP using the IVC

• LV size and function

List the 3 main purposes or uses of a bubble study during exercise.

• Detect a PFO or ASD

• Elevated right-sided pressure during exercise can unmask a PFO/ASD

• Differentiate an intracardiac shunt from an intrapulmonary shunt

How does bubble timing distinguish an intracardiac shunt from an intrapulmonary shunt?

• Bubbles appearing in the LA within 1–3 cardiac cycles suggest an intracardiac shunt.

• Bubbles appearing after 3–6 cardiac cycles suggest an intrapulmonary shunt.

When can stress echo be used in athletes with a suspected dynamic obstruction, and what gradient may explain symptoms?

Stress echo can be used when a dynamic obstruction is suspected.

An obstruction >50 mmHg may explain symptoms.

List the 2 symptoms specifically mentioned when assessing an athlete with stress echo.

• Dizziness

• Syncope

How may resting LVEF appear in an endurance athlete,

Endurance athletes may have a low resting LVEF but can produce a large volume during exercise.

in an endurance athlete, what response during exercise suggests normal LV function?

An increase in LVEF with exercise suggests normal LV function.

List the 5 congenital heart conditions given in the PowerPoint that may be evaluated with stress echocardiography.

• ASD

• Tetralogy of Fallot

• Univentricular hearts

• Systemic RV

• Treated coarctation of the aorta