Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Echo 2 > Module 14 : Stress and Contrast Echo > Flashcards

Module 14 : Stress and Contrast Echo Flashcards

1
Q

describe echo imaging of the coronaries

A
  • two proximal stems of the coronaries can be seen
  • cannot diagnose reliably
  • not always visible (echo not modality of choice)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is an angiography

A
  • catheter inserted into artery
  • dye injected into the artery to display the luminal contour of the artery
  • measurement of the patent vs stenosed portion and percentage calculated
  • performed before angioplasty
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is an angioplasty

A
  • balloon is inserted into the coronary artery and the vessel is dilated while the plaque is displaced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the principle of a stress ECG test

A
  • physical stress induces ischemia of the myocardium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how is a stress ECG test done

A
  • patient with primary or secondary heart disease put on treadmill and exercised until target HR is reached
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the target HR in a stress ECG

A
  • 85-90% of max HR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how to calculate the Max HR

A
  • max HR = 220 - age
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how to calculate the target HR

A

target HR = 220 - age x 85%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the ischemic cascade

A
  • myocardial O2 supply/demand imbalance
  • perfusion abnormalities
  • diastolic dysfunction
  • systolic function
  • increase LV filling pressures
  • ECG changes
  • angina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what ST segment depression measurement will indicate positive for ischemia

A

> 1mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the metabolic equivalent of task METS

A
  • assessment of workload is measured by metabolic equivalents
  • workload is a reflection of oxygen consumption and hence energy use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how many METS is required to carry out activites of daily living an exercise

A
  • 5
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why is the specificity of ST segment depression as a main indicator for MI limited

A
  • ST segment depression occurs in up to 20% of normal individuals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the normal electrocardiographic changesdurign exercise

A
  • P wave increase in height
  • R wave decreases in height
  • J point becomes depressed
  • ST segment becomes sharply up stroking
  • QT interval shortens
  • T wave decreases in height
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the 6 ECG criteria to stop an ETT

A
  • severe ST segment depression > 3mm
  • onset of VT
  • new afib or supra ventricular tachycardia
  • development of new BBB
  • new second or third degree AV block
  • cardiac arrest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are 4 signs and symptoms to stop an ETT

A
  • patient requests stopping because of severe fatigue
  • severe chest pain dyspnea or dizziness
  • fall in systolic blood pressure > 200mmHg
  • rise in blood pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

6 positive signs of ischemia for ETT

A
  • horizontal ST segment depression of = 2mm
  • downsloping ST segment depression
  • early positive response within 6 minutes
  • perisitance of ST segment depression for more than 6 minutes
  • persistence of ST depression for more than 6 minutes into recovery
  • ST segment depression in five or more leads
  • exertion hypotension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the primary use of stress echo

A
  • assessment of cardiac perfusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the principle of stress echo

A
  • increased cardiac workload is used to unmask perfusion defects which may be silent at rest (increased O2 demand cannot be matched by insufficient coronary supply)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how is ischemia seen in a stress echo

A
  • wall motion abnormality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what 2 tings can increase cardiac load

A
  • exercise

- pharmaceutical

22
Q

what are 3 other uses for stress echo

A
  • viability of the myocardial muscle tissue after MI
  • valvular studies
  • assessment for cardiac transplants
23
Q

what are the 2 exercise protocols for stress echo

A 
- treadmill
   \+ bruce protocol = higher workload but acquire images at rest and after exercise 
- bicycle ergometer
   \+ usually recumbent/supine  
   \+ acquire during exercise and rest
24
Q

what are the 2. pharmaceutical protocols for stress echo

A
  • dobutamine
    + increases contractility and O2 consumption and BP
    + atropine increases HR
  • dipyridamole
    + has similar effects as a vasodilator
    + must stop beta blockers before procedure
25
Q

what are the 6 steps of stress echo prep

A
  • NPO > 3 hours pre test
  • obtain informed consent from patient
  • explain procedure ( patient move directly to bed after exercise)
  • set up 12 lead ECG and acquire resting trace
  • measure resting BP
  • set up test parameters
    + maximum workload
    + symptoms to be documented
26
Q

what is the diagnostic sequence for a stress echo

A
  • baseline echo images = resting wall motion abnormalities
  • exercise test = exercise duration BP, HR, symptoms, ECG changes
  • immediate post or maximal exercise image = compare baseline and stress images on quad screen cine loop
27
Q

what are the 4 baseline set of images

A
  • PLAX
  • PSAX (pap)
  • apical 4 chamber
  • apical 2 chamber
28
Q

what are 3 technical point for a stress echo

A
  • need optimal endocardial definition
  • acquire images quickly after exercise as workload declines rapidly
  • use 3D/4D
29
Q

steps to the post treadmill test

A
  • begin recording images as soon as exercise ends
  • have 60 seconds to obtain all 4 cine clips
    + PLAX/ A3C
    + PSAX (mid)
    + A4C
    + A2C
  • scan for at least 2 more minutes
  • look for WMA and calculate WMSI
30
Q

charcteristics of a dobutamine

A
  • is a synthetic catecholamine
  • infused gradually using automatic IV calibrated syringe
  • used for patients who cannot exercise or for viability tissue studies
31
Q

what are the effects of dobutatmine

A
  • causes positive chronotropic and inotropic
  • raises HR and contractility in viable myocardium
  • non viable myocardium will not respond to the drug
  • can cause high or low BP due to reflex peripheral effects
  • increases O2 demand which can trigger ischemia
32
Q

what is the the infusion protocol for a dobutamine stress test

A
  • starts = 5
  • 3 min = 10
  • 6 min = 20
  • 9 min = 30
  • 12 min = 40
33
Q

what is the data recording protocol for a dobutamine stress echo

A 
- for baseline each stage/ dose and recovery document 
  \+ HR 
  \+ BP 
  \+ symptoms : CP, SOB, syncope 
  \+ ECG 
- echo images 
  \+ PSAX at med and base
  \+ A4
  \+ A2
  \+ PLAX 
- doppler LVIT LVOT CO
34
Q

what are the 6 complications of dobutamine stress echo

A
  • PVC PAC = 10%
  • non sustained VT or SVT = 4 %
  • angina = if positive test but usually stopped
  • hypotension = 10% due to peripheral drug effect
  • MI or VF = 1/2000
35
Q

what are the dobutamine stress test conditions

A
  • supervising physician present
  • trained personnel
  • nurse
  • crash cart
36
Q

does dobutamine affect crontacitility more than HR and what can be given to augment the HR

A
  • yes
  • atropine used if
    + peripheral vasodilation occurs
    + patient on beta blockers
37
Q

does dobutamine increase venous return

A
  • no only exercise
38
Q

what are the 7 endpoints for stopping a dobutamine stress test

A
  • reaching maximum dose
  • patient discomfort
  • definite wall motion abnormality
  • ST segment elevation on ECG
  • reaching 85% of max heart rate for age
  • systolic BP > 200 of diastolic BP > 120
  • ventricular arrhythmias
39
Q

when is a stress test echo done for valvular heart disease

A
  • symptoms do not match echo assessed values
    + underestimate due to low flow state
  • dobutamine also used for valve stress echo
40
Q

what 4 things does contrast asses with improved endocardial border delineation

A
  • wall motion
  • thrombus
  • aneurysms
  • TDS patients
41
Q

what else can be studied with contrast echo

A
  • study anomalous cardiac structures for blood flow
    + shunts
    + congenital abnormalities
    + larger vessel anomalies
42
Q

what are 2 considerations that must be made before a contrast echo is done

A
  • lower mechanical index to not burst any bubbles
  • contrast injected into arm vein
    + agitated saline (right)
    + difinity (left heart)
43
Q

what is agitated saline used to look for

A
  • ASDs
  • PFOs
  • rt to lt shunts
44
Q

how is the saline agitated

A
  • pushed back and forth between syringes then injected into right arm vein
45
Q

what would indicate a positive shunt with agitated saline contrast

A
  • bubbles seen crossing septum
46
Q

characteristics of tissue viability studies

A
  • detects stunned or hibernating myocardium post MI to see if it will come back
47
Q

what is an MIBI

A
  • methoxy isobutyl isonitrile
  • radioactive tracers display where they end in the heart
  • binds to healthy heart muscle
  • ## injected at peak exercise and then at rest
48
Q

what is CT angio

A
  • computed tomography angiography
  • uses contrast to visualize coronaries
  • patients with iodine allergies must use other contrasts
49
Q

what is MRI

A
  • magnetic resonance imaging
  • uses echoes of radio frequency returning from structures with different properties within a strong magnetic filed that aligns magnetic poles of all atoms of tissues at that resonance
50
Q

what 5 things can cardiac MRI reliably image

A
  • coronary arteries
  • wall structure
  • cardiac chambers
  • pharmaceutical stress
  • contrast

Echo 2 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions