Transcript Slide 1

Cardiac Testing
Pete Bell, MD
in collaboration with
Julia Smith, FLMI
Cardiac Testing
Heart Anatomy
Who needs cardiac testing?
Clinically:
 New onset of chest pain, dyspnea
 Pre-operative evaluation
 Elderly
 Special occupation (pilot, police officer, bus driver)
 In presence of known risk factors for heart disease
 Known heart disease.
Who needs cardiac testing?
Underwriting--Applicants
 Age and amount
(ECG/ Treadmill for older ages/ higher face amounts)
 Abnormal resting ECG
 History of heart disease
Cardiac Testing: pros and cons
Cardiac Test
Pros
Cons
Resting ECG
Non-invasive/Easy/Portable 5-10
min
Low sensitivity/Low specificity
Holter Monitor
Evaluates arrhythmia
Painless/Non-invasive
Wear for a few days
Can’t take off/bathe
Exercise ECG aka Stress
Test aka
Treadmill test
Easy/Available
Duration of exercise
Inducible Changes
False positives
Nuclear Stress Test
aka Perfusion study aka
SPECT
akaThallium/Cardiolite/
Myoview
Often follows an abnormal resting
ECG;
Good sensitivity/specificity
Evaluates blood flow at rest and at
exercise
False Positives – chest wall attenuation
Invasive/radiation
Costly
Stress Echo
Often follows an abnormal stress
test; Anatomy/function before and
after stress
Technical difficulties
Intra and Inter Observer Variation
Cardiac Testing: pros and cons
Cardiac Test
Pros
Cons
M-mode Echo
Non invasive/Portable
Anatomy/Structure/Function
More expensive
Technical difficulties
2D/3D Echo
Non invasive,
Anatomy/Structure/Function in
fuller view, safe
Technical difficulties
Transesophageal Echo aka TEE
Clear, high quality, precise image,
visualize LAE, clot, mitral value
and LV
More invasive/mild anesthesia
CT Angiography or heart scan
Detailed view of arteries
Quick (pictures in 5-10 sec)
Non invasive
Substitute for catheterization
unless surgery contemplated
EBCT
Electron beam computer
tomography, calcium scan
Non Invasive/painless/quick
Early atherosclerosis
Radiation, over sensitive
$200-500 out of pocket
Catheterization
The “gold standard”, CABG/Stent
Invasive, complications: bleeding,
arterial damage
Labs (Troponin, cardiac enzymes,
pro-BNP, C-reactive protein)
Troponin very sensitive indicator
of myocardial damage, pro-BNP
indicative of myocardial disease
High dose radiation (equivalent to
600 CXRs)
Expensive ($1000)
Poor images when increased Ca
deposit, obese patients or CKD
Pro-BNP has poor sensitivity and
specificity, CRP non-specific marker,
Does chest pain mean heart disease?
Common causes of chest pain:
 Angina due to coronary artery
disease, spasm, syndrome X
 Heart Attack
 Mitral Valve Prolapse
 Pericarditis
 Recent chest trauma
 Peptic Ulcer
 Aortic dissection
 Atypical chest wall pain
 Anxiety or panic disorder
 Asthma, bronchitis, pneumonia,
pleuritis
 Gastrointestinal
If chest pain is new onset,
worsening, accompanied
with chest tightness, dyspnea
or risk factors associated
with heart disease, then
getting an ECG is the first
step to evaluate.
If chest pain is chronic or
recurrent, angina due to
coronary artery disease is a
possibility and treadmill
testing is the first step
Chest Pain in Males
In men:
 Men delay evaluation and treatment.
 Musculoskeletal, respiratory, GI
CAD symptoms classic:
 Exertional chest pressure
 Dyspnea, nausea and vomiting
CAD risk factors remain very powerful prognosticators:
Chest Pain in Females
In women:
 Coronary artery disease onset is typically ten years later
than men
 Chest pain often due to other causes
– Mitral Valve Prolapse
– Musculoskeletal, respiratory, gastro-intestinal
 Symptoms of coronary artery disease may not be classic:
– Mid back pain
– Nausea and vomiting
 Risk factors for coronary artery disease remain very
powerful prognosticators:
Risk Factors for Coronary Artery Disease
 Tobacco exposure-includes cigarette/cigar
smoking/chewing tobacco/secondhand cigarette smoke
 Dyslipidemia
 Hypertension
 Diabetes
 Obesity
 Physical inactivity and low fitness
 Family history of cardiovascular disease in 1-st degree
relative
 < 55 years old in men
 < 65 years old in women
Medical Case #1
55 year old female, applying for 2.5 million of life insurance
Exam :BP 135/85, 5.5/145, no pertinent physical findings, family
history negative for CAD
Labs: total cholesterol 217, HDL = 58, Ratio = 4.2 glucose 109, HOS
WNL
Minor ST-T changes on ECG
Present History:
– Sharp, fleeting (less than a minute) chest pain, onset 2 months
ago
– No shortness of breath, no palpitations.
– Non-positional, stops spontaneously
Past Medical History:
– Mild osteoarthritis
– Hypertension, treated x five years
– Meds: Dyazide, Lisinopril and Aspirin as needed
– Non-smoker
Probability of Disease
Medical case #1
Offer, postpone for additional testing?
ECG abnormalities
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Major ST-T changes may give the appearance of ischemia even if NO real
ischemia is present.
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Juvenile T Waves can be a normal variant-mostly seen in young healthy
females, persistently negative T wave leads V1-V3, usually not deeply
inverted.
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Major T wave inversions – ischemia or LVH
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Minor T wave changes potential causes: CAD * Obesity * Electrolyte
Imbalance-Hypokalemia * Hyperventilation * Hypothyroid * Medication
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Non specific ST changes are not diagnostic
Probability of Disease
1 in 10 chance of coronary heart disease
Risk Assessment
Low risk for CAD
Medical case #2
Same applicant, 55 year old female, applying for 2.5 million of life
insurance
 Same Minor T changes on insurance resting ECG.
 Producer is concerned.
Medical Case #2
How to improve the offer?
 Stress test?
Bruce Protocol
Stage
Minutes
% grade
km/h
MPH
METS
1
3
10
2.7
1.7
4.7
2
6
12
4.0
2.5
7.0
3
9
14
5.4
3.4
10.1
4
12
16
6.7
4.2
12.9
5
15
18
8.0
5.0
15.0
6
18
20
8.8
5.5
16.9
7
21
22
9.6
6.0
19.1
METS and activity level
2-3 Walking at a slow pace ,Playing musical instrument, Dancing
(slow), Golf using power cart, Bowling, Fishing
4-5 Walking at a very brisk pace , Climbing stairs, Dancing
(moderately fast), Bicycling <10 mph, leisurely, Slow swimming,
Golf, carrying clubs
6 Slow jogging (one mi/ 13 to 14 min) , Ice or roller skating, Doubles
tennis (if you run a lot)
6-8 Rowing, canoeing, kayaking vigorously, Dancing (vigorous),
Some exercise apparatuses
7-12 Singles tennis, squash, racquetball
8 Jogging (1 mile every 12 min), Skiing downhill or cross country
10 Running 6 mph (10-minute mile)
13.5 Running 8 mph (7.5-minute mile)
16 Running 10 mph (6-minute mile)
Poor prognostic findings on Stress Test
 Low workload
 Mets <6.5
 Time: < 5-6 minutes on Bruce protocol
 Low peak Heart Rate
 Pulse < 120 without Beta-Blocker therapy
 Systolic Blood Pressure decreased or flat response
 Remains under 130 mmHg
 ST segment depression >2mm
 ST segment depression in multiple leads
 Prolonged ST depression after Exercise (>6 min)
 ST Elevation without abnormal Q wave
 Increase in complex ventricular ectopy
 Exercise induced typical Angina
 Frequent ventricular ectopy
Medical case #2
Same applicant, 65 year old female, applying for 2.5 million of life
insurance
 Same Minor T changes on insurance resting ECG.
 How to reconsider the offer?
Minor ST changes on ECG=> Negative stress ECG
Producer no longer concerned
Medical case #3
Same applicant, 55 year old female, applying for 2.5 million of
life insurance
 Sharp, fleeting (less than a minute) chest pain, onset 2
months ago
 no dyspnea or palpitations
 ECG with minor ST-T changes
 Standard treadmill test performed to consider for
improved offer, but it comes back with 1- 2 mm ST
depression at 7 METS exercise.
Stress Test Tracing
Medical case #3
Minor ST changes on ECG=> Positive stress ECG
Now what?
Probability of Disease
Post-Test Probability
Post Test probability of disease is now 47%
Post-Test Decision
Flip a coin
Medical Case #2
Oh boy, what now?
Stress Echo?
Perfusion Stress Test?
Stress test, Stress Echo, Nuclear stress
If the treadmill is equivocal or positive -- a stress perfusion treadmill
or stress echocardiogram can be performed to investigate further.
If the workload on the follow up stress perfusion/echo is equal to or
higher than that achieved on the original treadmill, then follow up
stress perfusion/ echo results are considered valid.
Stress Echo
The echocardiogram is a cardiac ultrasound performed at rest and after
exercise.
It shows the structure of the heart
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valves
chambers size and wall motion function
wall thickness
wall motion during exercise - abnormal may be indicative of ischemia.
Stress Echo
Nuclear stress
AKA - Perfusion study, Cardiolite study, Nuclear Test, Thallium Study,
Myocardial Perfusion Imaging (MPI), Stress SPECT.
 involves injecting a radioactive tracer into the bloodstream
 obtains images of the heart using a gamma camera.
 pictures are taken shortly after exercise and then after resting for 2/3
hours
If the perfusion is normal during rest, but diminished following exercise, the
results are consistent with a obstruction in one or more coronary arteries.
If the test shows reduced perfusion during both rest and exercise, then the
blood flow is limited at all times and is consistent with a prior myocardial
infarction
Stress Echo
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6.0 minutes – stage II of Bruce protocol
BP 173/98 Max HR = 159
7 METS
Stopped because target heart rate achieved
No chest pain or palpitations
Echo showed no wall motion abnormalities, normal wall thickness,
chamber size and valves
Post-Test Probability
Post Test probability of disease is 10%
Risk Assessment
Low risk for CAD
Happy Producer
Medical case - #4
70 year old male, non smoker applying for $500,000, Term
 5.6, 180 lbs
 130/86, 140/80, 130/70
 Ins labs 4/12 - Chol 171, ratio 3.4, HDL = 48. LDL
104
 Meds – Vytorin, Lisinopril
 History of hypertension, hyperlipidemia, OSA
treated with CPAP
 Family history – non contributory
Medical case - #4
APS:
 1/11/11 – Asymptomatic, resting ekg read as previous inferior
myocardial infarction
 1/17/11 – treadmill to 10 METS, stopped due to MPHR, no
symptoms, normal BP response. NSSTW changes on tracings,
SPECT scan => normal wall motion and thickness, mild inferior
defect, can not exclude attenuation.
 1/18/11 - Cath => 20 – 30% LM lesion, can not exclude catheter
induced spasm, 30 – 40% mid – LAD lesion, 90% distal LAD lesion
with collateral flow. MD notes “no significant CAD, continue with
clinical treatment”
Cardiac Catheterization
Coronary Artery Catherization
 Diagnostic gold standard.
 Invasive
 Bleeding
 Arterial damage
 Infection
 Also, can be therapeutic
 Stent
 Percutaneous Transluminal Coronary Angiography
 Rate of progression
 Hard to predict
 Evidence of regression
 Satins
 ACE inhibitor
 Exercise
Favorable Factors
Coronary Artery Stenosis
CAD Significance
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over 50% plaque obstruction
coupled with typical angina symptoms
at the bifurcation of 2 major (e.g.,LAD and Circumflex) or a major and
second-level (LAD and obtuse marginal ) vessel.
20 mm or greater in length in that it usually impedes flow reserve
regardless caliber.
the report of “no flow-limiting lesions” has to be taken into context with
risk factors and symptoms.
lesions < 50%, more significance for women than men, as women are more
prone to coronary artery spasm
diffuse small lesions are fairly innocuous only in the elderly or at any age if
risk factors are meticulously controlled.
lesions as they appear on cath are smaller when actually seen, so the
presence of symptoms are important to assess the significance.
Catheterization
Medical case - #4 - Solution
70 male with stable CAD per MD notes, good control of blood
pressure and lipids.
The cath is equivocal for LM disease. Definite mid-LAD
obstruction and a significant distal lesion. Assuming the reason
there is no obstruction to blood flow is due to collateralization, as
otherwise a lesion that size would obstruct proximal flow.
MD is continuing with clinical treatment only and doesn’t note
CAD as significant.
Moderate risk of disease
Summary
Look at the likelihood of disease being present:
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Consider the history, symptoms and risk factors to develop a sense of
whether or not disease is present.
And if so, what disease it is it?
Look at the studies:
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Does one appear better quality? Full versus sparse descriptions, etc.
A better quality testing labs? Referral center versus private office?
What about the tests? One is very positive while the other may be more
ambiguous.
Draw a conclusion:
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No risk factors and the negative tests are more accurate, while the positive
tests are more likely false positive
Many risk factors and the positive tests are more accurate, while the
negative tests are more likely to be false negative
Consider the probability of disease being present. It may not be what you
think!
Questions