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 Resting ECG Holter Monitor Exercise ECG aka Stress Test aka Treadmill test Pros Non-invasive/Easy/Portable 5-10 min Evaluates arrhythmia Painless/Non-invasive Easy/Available Duration of exercise Inducible Changes Nuclear Stress Test aka Perfusion study aka SPECT akaThallium/Cardiolite/ Myoview Stress Echo Often follows an abnormal resting ECG; Good sensitivity/specificity Evaluates blood flow at rest and at exercise Often follows an abnormal stress test; Anatomy/function before and after stress Cons Low sensitivity/Low specificity Wear for a few days Can’t take off/bathe False positives False Positives – chest wall attenuation Invasive/radiation Costly Technical difficulties Intra and Inter Observer Variation
Cardiac Testing: pros and cons
Cardiac Test M-mode Echo Pros Non invasive/Portable Anatomy/Structure/Function Cons More expensive Technical difficulties 2D/3D Echo Transesophageal Echo aka TEE CT Angiography or heart scan EBCT Electron beam computer tomography, calcium scan Catheterization Non invasive, Anatomy/Structure/Function in fuller view, safe Clear, high quality, precise image, visualize LAE, clot, mitral value and LV Detailed view of arteries Quick (pictures in 5-10 sec) Non invasive Substitute for catheterization unless surgery contemplated Non Invasive/painless/quick Early atherosclerosis The “gold standard”, CABG/Stent Technical difficulties More invasive/mild anesthesia High dose radiation (equivalent to 600 CXRs) Expensive ($1000) Poor images when increased Ca deposit, obese patients or CKD Radiation, over sensitive $200-500 out of pocket 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 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
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Mitral Valve Prolapse
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Musculoskeletal, respiratory, gastro-intestinal Symptoms of coronary artery disease may not be classic:
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Mid back pain
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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:
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Sharp, fleeting (less than a minute) chest pain, onset 2 months ago
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No shortness of breath, no palpitations.
Non-positional, stops spontaneously Past Medical History:
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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
Major ST-T changes may give the appearance of ischemia even if NO real ischemia is present.
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.
Major T wave inversions – ischemia or LVH Minor T wave changes potential causes: CAD * Obesity * Electrolyte Imbalance-Hypokalemia * Hyperventilation * Hypothyroid * Medication 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 1 2 3 4 5 6 7 Minutes 3 6 9 12 15 18 21 % grade 10 12 14 16 18 20 22 km/h 2.7
4.0
5.4
6.7
8.0
8.8
9.6
MPH 1.7
2.5
3.4
4.2
5.0
5.5
6.0
METS 4.7
7.0
10.1
12.9
15.0
16.9
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
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
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
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:
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:
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:
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
!