Chapter 232 - Basic Biology; 236 - Imaging Flashcards
Normal ef
Normal end diastolic volume
Normal end systolic volume
Normal ef 67 +/-8%
Normal end diastolic volume 75 +/- 20cc
Normal end systolic volume 25 +/- 7
O2 requirement of heart
15% of that of entire organism
Heart source of energy
Ffa - plasma (ffa metab = 70% in resting/fed state)
Glucose - plasma, glycogenolysis
Shifts between heart preference for glycolysis vs beta oxidation
Gluc - increase cardiac work, inotropes, hypoxia, ischemia
Ffa - beta adrenergic stimulation
Bernoulli equation
P=4v^2
Coronary artery calcium ct scoring
Agatson score
- minimal 0-10
- mild 10-100
- moderate 100-400
- severe >400
Radiation dose per imaging
Cac measurement in ct: 1-2mSv Typical mp spect scan: 4- 11 Mp pet scan: 2.5-4 Coronary cta: 5-15 Coronary angio: 7
**1 yr equivalent background radiation: 3msv
Pathognomonic findings of infarct and and microvascular obstruction on cmr
Infarct: Late gadolinium enhancement in areas or ccoronary artery distribution; sensitivity acute -99% chronic -94%
Microvascular obstruction: dense hypoenhanced areas within the core of a birght region of infarction
Assessment of lv systolic and diastolic fxn
Systolic = normal ef >55%; low normal ef 50-55%
Diastolic = mitral relaxation velocity - prognostic significance
Mitral deceleration time <150ms - restrictive physiology and severe diastolic dysfunction
Assessment of rv fxn
Fractional area chabge: correlate with outcomes
Contrast induced nephropathy return to baseline of renal function
7-10 days
Gadolinium nephropathy
Nephrogenic systemic fibrosis - unchelated form of gadolinium
Hallmark of myocardial ischemia on 2d echo
- Wall motion abnormalities
- reduced systolic wall thickening
Rate of major adverse cardiac event annually if PET/SPECT is normal
<1% annnually
Normal coronary flow reserve
> 2.0
Fractional flow reserve
Pressure differential between a coronary segment distal to a stenosis and the aortaPressure differential between a coronary segment distal to a stenosis and the aorta
Normal=1
Low risk ett
> 10 mets without chest pain or ecg changes
= managed medically
High risk ett
- Typical angina with >2mm st dep
- ste
- sustained arrhythmia
- drop in bp
Management: refer for coronary angio
Aortic valve estimation of area most accurate technique
- continuity principle
<1.0cm2 severe
<0.6cm2 critical
Aortic regurg estimation
Mitral regurg estimation
Aortic - vena contracta
Mitral - proximal isovelocity surface area (pisa)
Rheumatic mitral stenosis distinct appearance
- hockey stick type deformity: tethering at the leaflet tips with relative pliabikity of the leaflets themselves
Ff up imaging post myocardial infarct timing
1-6mos
Pet vs dobu echo sensi vs speci comparison
Sensitive - pet
Specific - dobu echo
Cardiac mri findings
Cardiac mri findings
- infarct or ischemia: lge of subendocardium following coronary distribution
- infiltrative: lge subepicardium and intramuscular not following coronary distribution
- t2 enhancement: edema - myocarditis
- t2 flair: iron deposition - hemochromatosis
**PET FDG: sarcoidosis
Clinical diagnosis of chemotx associated cardiotoxicity
- > 10% reduction in lvef to <55% in those without symptoms
- >5% reduction in lvef to <55% in those with symptoms
2d echo findings of pericardial effusion
- distance between parietal and visceral peritoneum >1cm
- rv free wall diastolic collapse
- respiratory flow variation: echo equivalent of pulsus paradoxus
Atrial myxomas most common chamber in heart
75% la
20% ra
5% mixed or ventricular
Initial test of choice for px with mechanical aortic or mitral valve and suspicion of IE
TRANSESOPHAGEAL echo
- vegetation size should be measured because has prognostic significance
Gorlin syndrome
- cardiac fibromas
- bifid ribs
- gingival hyperplasia
Patent foramen ovale test
Bubble test (agitated saline test) - manuevers to increase ra pressure >la: sniff maneuver, valsalva maneuver
Iron toxicity cardiomyopathy cmr finding
t2 value (rate of signal reduction/decay in the myocardium) <20ms
Elective cardiac catheterization risk
Allergic rxn <5% Access Bleeding 1.5-2% Death 0.1% Mi <0.1% Stroke 0.01% Ciaki 2-7% Ci aki in high risk 20-30% Dialysis 0.3-0.7%
Ci aki definition and prevention
Increase by >0.5mg/dl or >25% crea within 48-72hrs
Prevention
1. Nss x 1-1.5cc/kg/hr 3-12hrs pre and 6-24hrs post contrast
2. Metformin hold 24hrs pre and 48hrs post
3. Nahco3 3cc/kg 1hr pre and 6hrs post
4. Limit contrast volume <50cc
Coranary angio antiplatelets and anticoag
- ok with antiplatelets, load if with planmed pci
- hold warfarin 2-3days target inr <1.7
- hold noacs 24-48hrs
Test to assess palmar arch patency prior to catheterization
- allen test and barbeau test
Normal hemodynamic values: ra, rv-pa, la, lv-ao
Ra: 0-5 La: 4-12 Rv/pa: 17-32/1-7 Lv: 90-130/5-12 Ao: 90-130/60-85
Systemic vascular resistance
Pulmo vascular resistance
S: 900-1400
P: 40-120
Cardiac index
CI 2.8-4.2 Lmin/m2
AV O2 difference
AV O2 difference 3.5-4.8%
Hocm hemodynamic sign on cardiac catheterization
Brockenbrough-Braunwald sign: after pvc, increase in lv pressure but decrease aortic pressure
Hemodynamic measurements
Tamponade vs
constrictive pericarditis vs
Restrictive cm
Tamponade
- ra: increased
- y descent: decreased or absent
- diastole pressures: equalization in all chambers
constrictive pericarditis
- ra: increased
- y descent: prominent, square root sign
- diastole pressures (most specific sign of constriction): rv increase, lv decrease** chapter 235
**chapter 265 equalization of all pressures
Restrictive cm
- ra: increased (>60mmhg)
- y descent: prominent, square rt sign
- diastole pressures: both rv and lv increase but separation by >5mmhg
Intracardiac shunt hemodynamic assessment
Significant shunt ratio and indication for surgery
- step up: left to right shunt
- step down: right to left shunt
Shunt ratio for asd - > 1.5: significant
- > 2.0 + lv overload: indication for sx
Circulation dominance
- depends on origin of av nodal branch, posterior descending artery, posterior lateral vessels
- right 85% - rca
- left 5% - lcx
- codominant 10%
- *sa nodal artery source
- rca: 55-60%
- lcx: 40-45%
Stenosis of how much is considered significant
50%
Most common coronary artery anomaly
- separare ostia for lad and lcx
Timi flow
0 - no flow
1 - no distal perfusion
2 - delayed distal perfusion
3 - normal flow
Hemodynamically sig stenosis by fractional flow reserve
<0.80
- ratio of pressure of distal to stenosis vs proximal to stenosis
