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 (test of choice true workload/hemodynamic response)

• 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

(90% of HF cases have diastolic dysfunction)

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

Symptoms:

1. Dyspnea

2. Breathlessness

3. Exertional fatigue

List the 4 alternative explanations for symptoms during exercise.(the stress test is normal, these are other reason for symptoms)

Alternative causes:

1. New RWMA

2. LVOTO

3. Dynamic MR

4. Chronotropic incompetence

Chronotropic incompetence is a medical condition where the heart fails to increase its rate appropriately during physical activity or stress to meet the body's metabolic demand. The inability of the HR to increase while exercise

Dynamic mitral regurgitation is a condition where the backward leakage of blood through the mitral valve temporarily worsens during physical exertion, stress, or changes in body position, even if it appears mild or moderate when a person is resting

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

• Decreased suction reserve e′

• Decreased stroke-volume/cardiac-output reserve

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

• Increased SPAP/pulmonary hypertension

= HFpEF

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

• Exercise average E/e′ >14 or septal E/e′ Ratio is >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? & How is the protocol performed?

• Preferred: Supine bicycle

• Alternative: Treadmill

• Treadmill SE is alternative b/c, Diastolic dysfunction may persist after exercise.

• The protocol may be performed alone (looking at diastology) 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.

E/e’ remains the same or a little increase this is a normal response

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

SE is recommended in symptomatic patients if rest/maneuvers fail to induce LVOTO ≥ 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. (can only be seen in certain conditions)

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 7 criteria assessed during stress echo in HCM.

• BP, HR, and ECG changes

• Symptoms*

• LVOTO

• SPAP / RVSP

• Diastolic parameters

List the 4 findings associated with poor exercise intolerance in HCM. (signs cant tolerate exercise well)

• Dynamic increase in MR

• Blunted change in e′, meaning no diastolic reserve (heart cannot relaz properrly)

• Increase in E/e′ (jncreased filling pressures)

• Pulmonary hypertension with increased RVSP

List the 6 stress-echo findings associated with a poor prognosis in HCM.

• Limited exercise capacity (also called exercise intolerance) means your body has a reduced ability to perform physical activity or handle exertion

• Abnormal BP response — hypotensive or blunted response

• Significant ST depression (EKG changes)

• 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

Inducible ischemia means that your heart muscle does not get enough blood flow and oxygen when it is put under stress, even though it receives enough blood while you are resting

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 dobutamine 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 (lung ultrasound that indicate excess fluid or scar tissue in the lungs)

• 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 end goals of stress echo in valvular heart disease.

• Determine the need for intervention (repair Vs replacement)

• Elicit symptoms

• Determine disease severity

Elicit symptoms means to bring out or provoke symptoms that may not be present at rest.

So during a stress echo, the patient exercises to see if symptoms like shortness of breath, chest pain, dizziness, or fatigue appear. This helps determine whether the valve disease is actually affecting them during activity. That’s why your slide lists “elicit symptoms” as one of the end goals of hemodynamic stress testing.

Simple:
Elicit symptoms = make hidden symptoms show up during stress/exercis

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

• Severe valve disease without symptoms

• Non-severe valve disease with symptoms (moderate)

• Valve disease with low flow (LFLG)

List the 4 measurements obtained at baseline and peak exercise in asymptomatic severe aortic stenosis. what exercise do we use? list 2

• Aortic-valve CW Doppler (looking at how high does the gradient get)

• LVOT VTI with PW Doppler (SV)

• LV function (LVEF)

• TR CW Doppler + IVC

• Exercise treadmill or supine bicycle

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

• Increase in mean gradient >18–20 mmHg

• Deterioration of LVEF, the 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. & how / what is this assessed with?

• AVA <1.0 cm²

• Mean gradient <40 mmHg

• LVEF <50%

Assessed with Low dose Dobutamine stress echo* - most useful to assess AS severeity and EF

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

(taken at each stage, basline, low dose, peak dose

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

LV flow reserve means the left ventricle is able to increase the amount of blood it pumps forward when stressed.

The heart is basically being asked, “Can you pump more blood when we stimulate you?”

If yes → it has flow reserve.
If not → the LV has poor reserve and cannot significantly increase its output.

This is especially useful in low-flow, low-gradient aortic stenosis to help determine whether the AS is truly severe.

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 the Mean gradient and AVA when there is no LV flow reserve SV <20%

MPG <40 mmHg

AVA ≤1.0 cm²

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. SV ≥ 20%

• Projected AVA ≤1.0 cm² → true-severe AS

• AVA > 1.0 cm² → Pseudo - Severe

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

(stress test helps deteremine if it is true or not severity)

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? & what criteria can be applied?

1. Exercise stress echo

2. Dobutamine stress echo

The same criteria used previously can be applied. (AV CW, LVOT PW, LV Function for measurements and the chart)

What type of stress is preferred for MR, and when are images obtained with treadmill versus supine bicycle exercise? & what should not be used for MR (The type of testing)?

Exercise is preferred.

• Treadmill: baseline and immediately after exercise

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

Dobutamine- should not be used

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

non-physiologic means it does not reproduce the body’s normal response to real exercise.

With exercise, the heart is stressed naturally by things like increased heart rate, blood pressure, blood flow, and body demand. With dobutamine, a medication artificially stimulates the heart to beat harder and faster. Because of that, the way mitral regurgitation changes during dobutamine may not match how it changes during normal physical activity.

That’s why your slide says exercise is preferred for MR and dobutamine generally should not be used for routine MR assessment.

Simple:
Non-physiologic = an artificial stress, not the body’s natural exercise response.

• When ischemia is suspected: Dobutamine may be useful because it increases the heart’s workload and can help reveal ischemia/RWMAs while you also observe what happens to the MR.

• Exercise tolerance: If the patient cannot exercise adequately on a treadmill or bicycle, dobutamine may be used as an alternative stress method.

List the 3 measurements obtained before exercise / pre imaging for MR

Pre-imaging:

1. MR assessment (continuity, PISA)

2. TR and RVSP

3. LV function

List 3 measurements obtained after exercise / post imaging 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.

It means that if the MR is already severe at rest, you do not need to keep re-measuring how severe the MR becomes during stress.

Instead, during the stress test, you mainly focus on:

• SPAP — does pulmonary artery pressure rise with stress?

• LV function — how does the left ventricle respond to stress?

So those are not just “rest measurements”; they are the important things to assess with stress when MR is already known to be severe at baseline

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 (means using the stress echo to help decide whether the patient is at higher risk for worsening heart failure, pulmonary hypertension, or other poor outcomes.)

• Persistent pulmonary hypertension after mitral repair

List the 2 predictors of poor prognosis for secondary MR

Poor prognosis:

1. Increase in MR severity

2. Dynamic pulmonary hypertension

dynamic means it changes with stress or exercise instead of staying the same.

So:

• Dynamic PH = pulmonary hypertension that appears or gets worse during exercise/stress

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.

1. What is vital to know for prognosis

2. What is the Mortality reported per year

3. What is the fact about regrading AI severity

4. what Limits quantification

• In severe AI, the onset of symptoms is vital to know 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

When the heart rate goes up, diastole gets shorter.

But aortic insufficiency/regurgitation happens during diastole, when blood leaks backward from the aorta into the LV.

So if diastole is shorter, there is less time to observe and measure the regurgitation accurately.

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

1. Why is Exercise testing recommended?

2. What was found to predict LV dysfunction development at what 2 places?

3. Rest and exercise - what measurement may reveal what?

• Exercise testing is recommended to reveal symptoms.

• The lack of contractile reserve (<5% change in EF) was found to predict LV dysfunction development at f/u or post op aortic replacement or repair

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

If the EF increases by less than 5% during exercise/stress, the LV does not have good contractile reserve.

That is a bad sign because it suggests the LV is already starting to lose its ability to increase contraction when stressed. Those patients are more likely to develop LV dysfunction later at follow-up or after aortic valve repair/replacement.

Simple:

EF goes up <5% with stress = poor contractile reserve = higher risk the LV will become weak later.

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

1. What can Exercise testing confirm?

2. what tesing is best for EF assessment?

3. what assessment is not recommended?

• 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. & What does the sequence image depends on?

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

The lack of contractile reserve is associated with what?

Used to assess:

1. Symptoms

2. Exercise tolerance

3. LV response to stress

4. LACK OF CONTRACTILE RESERVE IS ASSOCIATED WITH POST OP DYSFUNCTION

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

Not used to assess:

1. Valve severity

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 without symptoms

Also indicated when:

1. Planning pregnancy

2. 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,

Used to assess 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 infusion

What SPAP finding suggests hemodynamically significant MS

An early increase in SPAP during low-level exercise

& SPAP >60 mmHg with exertion is another marker of hemodynamically significant MS.

What is not recommended for assessment of SPAP?

DSE is not recommended for assessment of SPAP

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 3 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.

1. Used in patients with what prosthetic valves? & what state?

2. What does it Differentiates?

• 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 SPAP

Semi-supine bicycle is preferred

PHTN

Doppler recordings need to be completed within how long of test completion?

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

(b/c right heart pressures drop fast)

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

• TR velocity

• PREDV 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.

1. what can it detect?

2. what can it unmask during exercise

3. differentiates what shunts?

• 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 when what is suspected?

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.

It means some endurance athletes can have a lower EF while resting, but that does not necessarily mean the heart is weak.

Their heart may be very efficient and able to pump a large stroke volume when they exercise.

So:

Low resting EF in an endurance athlete can be normal if the LV shows a strong response during exercise and increases the amount of blood pumped.

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