W1 Cardiac Studies Flashcards
Ambulatory electrocardiogram monitoring
—when would it be used?
—aids in the diagnosis of what? 3
Non-invasive EKG — suspected arrhythmia during normal activities
— aids in dx of of pt w/ palpitations, lightheadedness or syncope
Types of monitors:
Holter
Event
Real time cardiac monitors
Adhesive patch monitors
Implantable loop recorders
Holter — 2-3 EKG channels, 24-48hrs
Event — 2-3 EKG channels, 30-60d. Only records event when pt presses button
Real time cardiac monitors — 14-30d, good for silent or asymptomatic arrhythmias
Adhesive patch monitors — no wires, convenient
Implantable loop recorders — invasive, up to a year
Abnormalities, palpitations, PVCs — what can be said about them?
When do you get the highest yield diagnosis with palpitations?
PVC = premature ventricular contractions
Catheter ablation is a procedure used to remove or terminate a faulty electrical pathway from sections of the heart of those who are prone to developing cardiac arrhythmias such as atrial fibrillation, atrial flutter and Wolff-Parkinson-White syndrome
Role of modern pacemakers and defibrillators in stroke:
What is the term for an unexplained stroke? What is the % of their occurrence?
Which device would be suitable to identify one?
Reduces need to ambulatory device
Afib patients
Cryptogenic stroke = a brain infarction not clearly attributable to a definite cardioembolism, large artery atherosclerosis, or small artery disease despite extensive investigation
ILR = implantable loop recorder
What are you looking for in a chest X-Ray? 5
When do you order one?
What finding would you see in pleural effusion?
Chest pain
Volume status, SOB
—Cardiac contours, size
—Pulmonary vascular markings
—Devices (defibrillator, pacemaker)
—Central lines / endotrachel tubes
—Surgical changes
Pleural effusion blunts the costophrenic angle
Study this X-ray
What can we diagnose with chest x-ray, or at least give you suggestions?
8
All patients with chest pain even if suspected MI
Aortic dissection (tear)
PE
SQ emphysema
Esophageal rupture
Pneumothorax
Hiatal hernia
Pneumonia
Pericarditis
[SKILLS OSCE] Heart size is enlarged if?
Which arteries are prominent in RV enlargement vs LV enlargement ?
The size is equal to or greater than 2x the hemithorax.
It should fit in one lung capacity
CHF»_space; it dilates»_space; elongates and gets bigger
RV enlargement
— pulmonary arteries are prominent and the aorta is diminutive
LV enlargement
—aorta is prominent and the pulmonary arteries are normal
[SKILLS OSCE] What is this?
What could it clue you in to? 2
An enlarged heart
CHF
Pericardial effusion
[SKILLS OSCE] What are the 3 findings on chest X-Ray that could clue you in to left atrial enlargement ?
What about for a RA enlargement?
-
double density sign
— the left atria bulges out behind the right atria on the right side of the heart, so you see two lines on the right side of the heart, the innermost line is the LA -
3rd Mogul
—1st mogul is the aortic knob/arch
—2nd mogul is the main pulmonary artery
—3rd mogul: a convexity between the L pulmonary artery and the left ventricle: = never normal -
splaying of the carina
—increased angle of the left and right bronchi
RA enlargement
— lower right heart border bulges outward to the right
[SKILLS OSCE] Study this —
What does a double density sign indicate?
Left atrial enlargement
[SKILLS OSCE] Study this —
What does splaying of the carina indicate?
Left atrial enlargement
[SKILLS OSCE] Study this chest x-ray showing left atrial enlargement and the third mogul
Widened mediastinum — what are you concerned for?
2
—aortic dissection/rupture»_space; mediastinal bleeding
—tumours, lymphoma, thymus tumours
What is a water bottle heart?
could indicate chamber enlargement or pericardial efffusion
[SKILLS OSCE] What is this?
Water bottle heart
Could be pericardial effusion
[SKILLS OSCE] What is this?
What could it lead you to think?
Widened mediastinum
Could be TAA or dissection but lacks sensitivity
Signs of CHF (4)
Stage I or redistribution
stage 1 or redistribution : appearance of pulmonary vasculature
—Enlarged cardiac silhouette/left atrial enlargement
—Hilar fullness — due to increased pulmonary pressure
—Vascular redistribution — vessels in upper lobe, pulmonary arteries and veins become bigger
—Increased vascular pedicle width — due to increase pulmonary circulation
[SKILLS OSCE] What is this
Bilateral hilar enlargement
CHF: stage 1 redistribution
[SKILLS OSCE] What are Kerley’s lines?
What do they signify?
Fluid in the interstitial
[SKILLS OSCE] What is this?
Vascular redistribution
Early CHF
[SKILLS OSCE] Signs of CHF — 2
Stage II, what is it?
What two things do you see on CXR?
or interstitial edema from increased hydrostatic pressures
—Kerley’s lines
—Peribronchial Cuffing (bronchial wall thickening or fluid around bronchi due to lymphatic congestion
[SKILLS OSCE] What are the purple arrows pointing to?
Kerley lines (interstitial pulmonary edema)
Found in stage II CHF along with donut holes
What would peribronchial cuffing look like on a CXR?
Signs of CHF
Stage III or alveolar edema
What occurs?
Left ventricular dysfunction leads to?
Right ventricular dysfunction leads to?
Pleural effusions (abnormal accumulation of fluid in the pleural cavity)
Pleural effusions are common in patients with congestive heart failure. This process is felt to be due to left ventricular (LV) dysfunction leading to elevated pulmonary venous and left atrial pressures
[SKILLS OSCE]
CXR: batwing or butterfly pattern could indicate?
Fluid in the alveoli produce fan shaped opacities radiating from the hilar region
[SKILLS OSCE] CXR: air bronchogram ?
Air filled bronchi/bronchioles (which are normally dark) become visible by opacification of the surrounding alveoli (white). Always pathological and indicates something other than air is in the alveoli
[SKILLS OSCE] CXR: What is this?
Pleural effusion
Alveolar edema — stage III CHF
[SKILLS OSCE] What is this?
Air Bronchogram: air filled bronchi/bronchioles (normally dark) become visible by opacification of the surrounding alveoli (white).
Always pathologic and indicates something other than air is in the alveoli (i.e fluid)
[SKILLS OSCE] What is rib notching?
As a result of?
Often seen with?
—enlargement of intercostal arteries
—often seen with coarctation of the aorta
—Coarctation of the aorta is a narrowing/constriction and is recognised by a figure 3 sign on SXR
[SKILLS OSCE]
What are these arrows pointing to?
What is the pathological process that leads to this?
What is the dx and Tx?
Rib notching
number 3 sign is the other finding associated with ⬇️
Often seen with coarctation of the aorta (present at birth, congenital, narrowing of aorta, presents as infant: claudication in LE when attempting to walk. Asymptomatic until then since demand on the heart is less pre-walking. cyanosis in LE)
—Rib notching occurs because in the adult, coarctation of the aorta leads to a severe narrowing in a portion of the aorta and to overcome this, collateral vessels are created to help deliver blood to the lower extremities.
—The collaterals swell and erode into the bone around them
—DX with CT
—TX w/surgery
What are you able to see with an echocardiogram?
Structural changes of the heart:
—wall thickness, chamber sizes
—valves
—ventricular assessment
—pressure and velocity measurements
—thrombus
—congenital abnormalities
What is the most commonly used measurement of the LV systolic function?
How is it calculated? (Equation)
LV ejection fraction
LVEF = (end diastolic volume - end systolic volume)/ end diastolic volume
What does diastolic function assessment identify?
How is LV relaxation determined?
How is LV preload measured?
LV preload — transMITRAL early diastolic filing velocity (E)
LV relaxation — tissue Doppler to measure diastolic filling velocity (Ea)
Diastolic dysfunction (LV filling velocity) = E/Ea
Take note of this echo image
[SKILLS OSCE]
What can you see with a TEE (transesophageal echocardiogram)
[SKILLS OSCE]
What is this?
Descending thoracic aortic dissection (tear)
What is the purpose of a right heart catheterisation?2
venous access
—measure intra cardiac pressures
—determine CO
What is the purpose of left heart catheterisation?
What is used?
Where do you enter?
arterial access (as opposed to right heart catheterisation which is to gain venous access)
—gold standard to identify coronary anatomy
—uses contrast and radiation
enter through radial or femoral artery
What are these vessels?z
LMT = left main trunk
OM = obtuse marginal
Stress imaging
What is:
Sensitivity
Specificity
Bates Theorum
How sensitive is the test to THAT disease specifically
How specific is the test such that a true negative DOES occur in someone WITHOUT the disease
think speciFFFically FFFalse
Bayes:
What are the indications for exercise stress
—diagnose obstructive CAD
—reevaluate pts who have CAD + a structural change
—to detect MI in patients being considered for revascularisation
—pts with exercise induced arrhythmias
—follow up
What is metabolic equivalent (MET)?
Give two examples
Which functional capacity of METS is associated with a worse/good prognosis?
<5 METS has a poor prognosis
>10 METS has a better prognosis
running is 10 METS
light walking is 2 METS
Stress EKG
What is the sensitivity? Specificity?
What HR % do you have to achieve for it to be diagnostic?
What EKG changes do you have to see to be diagnostic?
Advantages? When could it be useful?
—low sensitivity and specificity (68 and 70%)
—have to achieve 85% maximum HR to be diagnostic (not possible for everyone)
—EKG changes > 1mm ST elevation or depression in 3 consecutive beats
—useful if you have a subject with low pre-test probability, i.e the young firefighter
How is a cardiopulmonary exercise stress test performed?
What does it differentiate?
Who could it be considered for?
To differentiate cardiac vs pulmonary causes of exercise induced dyspnea
Stress Echo
Effective for what?
Sensitivity?
Specificity?
Can differentiate what from what?
—treadmill/chemical
—evaluating CAD
—differentiate between viable myocardium and scarred myocardium —> predictor of LV function
Stress imaging — nuclear
What is it known as?
Sensitivity ?
Specificity?
What does it assess?
What is a perfusion defect? What are the two types?
—assesses myocardial blood flow
—if defect at rest and stress = dead, fixed
—if just during stress = reversible
reperfusion defect is an area of reduced isotope uptake, meaning an area of dead myocardium
[SKILLS OSCE]
What does the bottom left indicate?
Anterior wall doesn’t light up so there is a blockage
What is a PET scan?
What two things is it assessing?
Myocardial perfusion
Myocardial viability (Ischemic myocytes need more glucose
What is a CT scan?
What do you need?
What is coronary calcium scoring?
What is the sensitive and specific of CT?
—contrast dye
—Coronary CT is an accurate non-invasive modality to visualise coronary arteries with a sensitivity of 85% and a specificity of 95-98%. It is excellent for ruling out coronary disease
—absence of coronary calcium = CAD unlikely & low risk of future events
—Agaston calcium score most used
—higher the score = higher the risk
[SKILLS OSCE]
Familiarise yourself with this CT scan
MRI
Which contrast is used?
Clinical uses
Disadvantages
—uses magnetic field
—no ionising radiation
—uses gadolinium contrast
—clinical uses: visualise AA, dissection etc
—disadvantages: expensive, hard to get, patient compliance
What are some of the restrictions for cardiac MRI? Think about what filters the dye
—renal disease / reduced renal function
—vascular surgery
—dialysis
—AKI
