These slides illustrates the basics of transthoracic and transoesophageal echocardiography in the cardiac operating room.
Competent surgical results in shunt lesions, valve repairs, surgery for heart failure, establishment of peripheral bypass are derivatives of good knowledge in assessing gross and finer details of the heart intro-operatively. Assessment of myocardial viability, contractility and patency of repair are few aspects that are covered under this subject. They illustrate some of the basic must-knows for cardiothoracic surgeons from the perspective of a cardiac anaesthetist.
This is courtesy of Dr. Parimala Prasanna Simha, Professor of Cardiac Anaesthesiology and Critical Care at Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru.
This presetation is part of a video which belongs to the lecture series of IACTS SCORE 2020 held at the Sri Sathya Sai Institute of Higher Medical Sciences Whitefield, Bengaluru between 7th and 8th March, 2020.
4. Optimization of 2D images
1. Transducer
a. High frequency
b. Low frequency
2. Depth
a. Deeper image: slow frame rate
b. Nearer
3. Focus: max resolution and U/S beam narrowest
4. Gain
6. Epicardial echo
• Sterilize x-ducer. Glutaraldehyde for10min, wipe
with saline. Sterile gel 20ml
• Stand offs: near field clutter with epiaortic scan
• Views
1. SAX: orientation mark to left side of the patient
2. LAX view: orientation mark to the patient’s head
3. AV SAX : transducer on proximal ascending aorta
•
8. TEE views: LV function assessment
1, ME 4C, 2C, LAX
2. TG SAX: basal, mid
3. TG 2C
9. LV Function assessment
• Preload: LVEDV
• Contractility: EF & SV do
no change in parallel.
a. EF normal, SV reduced
hypovolemia
b. Both EF & SV reduced
acute LV failure
c. EF reduced & SV
normal chronic LV
dysfunction
10. IHD assessment
• Anatomical assessment in asymptomatic
patient to exclude disease and,
• Functional assessment helpful in symptomatic
patients.
11. Coronary CT Angiogram
• Coronary CT Angiogram:
anatomic test to rule
out CAD
• Stress ECHO:
functional tests have a
greater ability to predict
benefit from
revascularization
12. Stress TEST
• Stress-induced segmental wall motion and
perfusion abnormalities detected by stress
tests such as stress ECG, ECHO, SPECT, MRI.
• Pharmacological stress test only when unable
to exercise
13. Multimodality Detection and Risk Assessment of
IHD Appropriate Use Criteria: Symptomatic
PatientsIndication Text
Exercise
ECG
Stress RNI Stress Echo Stress CMR Calcium
Scoring
CCTA Invasive Coronary
Angiography
1
Low pretest probability of CAD,
ECG interpretable, and able to
exercise
A R M R R R R
2
Low pretest probability of CAD,
ECG uninterpretable, or unable to
exercise
– A A M R M R
3
Intermediate pretest
probability of CAD, ECG
uninterpretable, and able
to exercise
A A A M R M R
4
Intermediate pretest probability of
CAD, ECG uninterpretable, or unable
to exercise
– A A A R A M
5
High pretest probability of CAD,
ECG interpretable, and able to
exercise
M A A A R M A
6
High pretest probability of CAD,
ECG uninterpretable, or unable to
exercise
– A A A R M A
14. Multimodality Detection and Risk Assessment of Ischemic Heart
Disease Appropriate Use Criteria: Asymptomatic Patients
Indication Text Exercise ECG Stress RNI Stress Echo Stress CMR Calcium Scoring CCTA Invasive Coronary
Angiography
7
Lowglobal CHD risk
regardless of ECG
interpretability and
ability to exercise
R R R R R R R
8
Intermediate global
CHD risk, ECG
interpretable and able
to exercise
M R R R M R R
9 Intermediate global
CHD risk, ECG
uninterpretable or un
able to exercise
– M M R M R R
10
High global CHD risk,
ECG
interpretable and able
to exercise
A M M M M M R
11
High global CHD risk,
ECG
uninterpretable or un
able to exercise
– M M M M M R
15. Stress echocardiography
Regional wall motion is
assessed from parasternal
and apical images
• Each segment is
described as either
normal,
• hypokinetic,
• akinetic, or
• dyskinetic,
17. Pharmacologic Stress
Echocardiography
• Intravenous (IV) dobutamine, dipyridamole, or
adenosine.
• Dobutamine: continuous infusion at
incremental rates starting from 5 up to 50
μg/kg/min. It is often complemented by
handgrip exercise and/or IV atropine (0.5 to
2.0 mg) to increase the heart rate.
18. STRESS RESPONSE
1. Inducible Ischemia: new RWMA that gets
progressively worse
2. Ischemia: existing RWMA that worsens
3. MI: existing RWMA that is unchanged
4. Stunning: existing RWMA that improves
5. Hibernation: existing RWMA that shows
biphasic response
6. Other signs if MI: DD, MR, aneurysm
19. Abnormal stress responses
associated with an increased risk of
adverse events• Extensive resting regional wall motion
abnormalities,
• Stress-induced ischemia,
• Worsening LV ejection fraction (LVEF) with
stress
• Absence of viability
23. Perioperative Causes of RWMA
• Myocardial ischemia: hypokinesia, LVEDA normal
• Stunning: due to inadequate myocardial protection,
normal CBF, RWMA +
• Hibernation: Reduced ventricular reserve & CBF,
biphasic response to dobutamine
• Intracoronary air
• Direct coronary occlusion: during AVR, MV repair
• Severe MS ( basal segments)
• Normal post CPB finding( inferoseptal wall)
• Hypovolemia: RWMA of the septum
• Paradoxical motion: CP, tamponade, RV dysfn. Myocardial
thickening preserved
24. A new RWMA that appears after CPB
Is the MR worsening?
New RWMA at the time of chest closure? Mechanical occlusion of the graft
Does RWMA fit with marginal graft fn?
Is the RWMA severe? Is the patient hemodynamically unstable?
Is the heart adequately filled, is the gas trapped in the heart?
New RWMA different from pre-CPB? Does it improve with dobutamine?
25. TEE and CPB
1. During cannulation: CS, IVC, SVC, AR
2. Weaning from CPB:
a. deairing
b. TG SAX; volume status, contractility
3. After weaning: assess valve repairs, IABP/
LVAD position
26.
27. TEE views for aortic valve
1. ME AV SAX: AS, AR
2. ME AV LAX: root
measurements
3. DTG LAX : AV, LVOT VTI
29. Four categories of
aortic stenosis (AVA<1sqcm)
1. High-gradient aortic stenosis
2. Low-flow, low-gradient aortic stenosis with reduced
ejection fraction [valve area <1 cm2, mean gradient
<40 mmHg, ejection fraction <50%, stroke volume index
(SVi) ≤35 mL/m2].
3. Low-flow, low-gradient aortic stenosis with preserved
ejection fraction (valve area <1 cm2, mean gradient
<40 mmHg, ejection fraction ≥50%, SVi ≤35 mL/m2).
4. Normal-flow, low-gradient aortic stenosis with preserved
ejection fraction (valve area <1 cm2, mean gradient
<40 mmHg, ejection fraction ≥50%, SVi >35 mL/m2). These
patients have only moderate aortic stenosis
30.
31. TEE during AVR
Pre- CPB
• To modify the planned
procedure
• Helping retrograde cannula
position
Post CPB
• Prosthesis dysfunction
• Ventricular dysfn
• Air embolism
• Dynamic LVOTO
39. 3D TEE for surgical repair of MV
• Accuracy of 3D TEE to detect AML prolapse
100%, bileaflet prolapse 98%. ( 2D TEE 50%)
• Information of prolapsed segment length can
guide the surgeon to decide extent of MV
resection
• Paravalvular leaks accurately detected
• Accurate estimation of coaptation zone
• Three D echo and 3D TEE for MV disease. Ashok Kumar Omar et al; JIAE; vol 3 sept-Dec
2019
40. MVP, P2P3 segment with chordae rupture real-time 3D TEE:
zoom enface view
49. Asymptomatic MR
and abnormal exercise stress
echocardiography responses.
• - RWMA consistent with ischemic territory.
• - Development of acute pulmonary edema
without obvious cause.
• - Effective regurgitant orifice area increase
>13.
50. Indication for MV surgery
(for moderate IMR), during CABG
• If myocardial viability is present
• Low comorbidity
• AF, VT or PH
• Exercise induced,
• dyspnea,
• large increase in MR severity and
• PAH
53. 3D main advantage
1. for identifying abnormalities in the subvalvar
apparatus
2. for early valve repair failure to decide on re-
repair.
3. 3DE identifies regurgitation in the
commissural region that surgical saline
testing misses.
57. Ring annuloplasty
• Classic ring – for RHD,
Titanium core, rigid, open.
• Physio ring -degenerative
valvular diseases, semirigid
structure.
• Ischemic ring - ischemic,
type IIIb dysfunction, rigid,
titanium structure to ensure
non-deformability
Too high: bright, increased noise, thickened valves
Too low: LV thrombus, SEC will disappear
Optimize: grey scale, avoid bright ambient light
Time Gain Compensation: Time is distance
LGC: endocardial border detection
Preload reserve: patients with reduced LV function are unable to increase stroke volume in response to increased afterload.
a shift away from purely anatomic assessment of CAD to an objective functional assessmentis most helpful in or low-likelihood patients, whereas
have greater sensitivity for the detection of CAD,
limited accuracy for the detection of anatomic coronary artery disease but Provides important prognostic informationhelps to define which populations of patients will benefit most from revascularization and their incremental levels of risk.
using a 17-segment model of the left ventricle (LV).
and the results of the individual segments are averaged to calculate a global wall motion score.
all of which have incrementally contributed to improved image quality, reproducibility, and accuracy. The test has gained increasing acceptance following the introduction of digital acquisition, harmonic imaging, and contrast agents, a resting regional wall motion abnormality implies a prior myocardial infarction (MI), whereas a stress-induced regional wall motion abnormality implies ischemia caused by obstructive CAD.
No contrast yet
may be used as pharmacologic stressors with echocardiography. is the most commonly used stressor.
Dobutamine increases myocardial oxygen demand by increasing contractility and the heart rate. The reported sensitivity and specificity of dobutamine echocardiography for the detection of obstructive CAD are equivalent to those reported for exercise echocardiography. The sensitivity is reduced in patients with concentric hypertrophy who experience cavity obliteration early during the test, as well as in those who do not achieve the target heart rate. Echocardiographic variables obtained during pharmacologic stress have also been shown to have significant prognostic value. 5
the presence of stress-induced RWMA, particularly when detected at low heart rates, is a strong predictor of cardiac events.
A normal dobutamine stress echocardiogram is associated with a low cardiac event rate Low dose dobutamine stress echocardiography may be performed for risk assessment in patients after MI also.
***find literature that explains prognostic significance of MVO
(valve area <1 cm2, mean gradient >40 mmHg). This is typically encountered in the elderly and is associated with small ventricular size, marked LV hypertrophy and frequently a history of hypertension.79,80 The diagnosis of severe aortic stenosis in this setting remains challenging and requires careful exclusion of measurement errors and other reasons for such echocardiographic findings (Table 6). The degree of valve calcification by MSCT is related to aortic stenosis severity and outcome.13,14,81 Its assessment has therefore gained increasing importance in this setting.
Severe aortic stenosis can be assumed irrespective of whether LVEF and flow are normal or reduced.
Severity assessmentGradient/ peak velocity
AVA
SVi> 35ml/m2
EF
Aortic dimensions in LAX view
Severity
EF
LVEDD
LVESD
MR due to IHD with asymmetric remodelling affecting infero-lateral wall
72yr patient c/o dyspnea gr III, pedal edema.
Exercise responses in asymptomatic, secondary MR:
that impacts on surgical approach and the decisions to go to surgery.
For (MV): is detection of commissural abnormalities while the right sided valve(TV) was both commissural abnormalities and leaflet prolapse. It is now becoming an integral part of our imaging