Non-Invasive Cardiovascular Evaluation Thom Kidd, PA-C
West Virginia University Heart & Vascular Institute Berkeley Medical Center Campus Financial and other Disclosures
None Presentation Objectives
Better understanding of available non- invasive diagnostic CV studies.
Selection of the optimal study Goal of Cardiovascular testing
Assess the functional or physiological consequences of: Anatomic coronary artery disease (CAD) Arrhythmias Valvular / structural abnormalities Assessment of Cardiac Output Available non-invasive CV studies
Regular Treadmill Exercise Cardiac Magnetic Stress Test Resonance (CMR)
Myocardial Perfusion Study- Event monitor Nuclear Imaging Holter monitor Stress Echocardiogram Tilt-Table Test CT Angiography (Calcium Scoring) Echocardiogram +/- TEE Indicators for Cardiovascular Evaluations
Chest pain – “angina” – “angina equivalents”
History of CAD/CHF with worsening symptoms
Newly diagnosed heart failure / CMP
Arrhythmias
Pre-operative evaluation
Pre-employment or continued employment
Unexplained syncope “Angina” Chest Pain
Chest pain is the chief complaint in 1-2% of outpatient visits 1 Chest pain is one of the most common reasons for seeking care in the U.S. 2 8 million ED visits annually in the United States
Acute Coronary Syndrome is missed in approximately 2% of patients
• 1. Hsiao CJ, Cherry DK, Beatty PC, Rechtsteiner EA. National ambulatory medical care survey: 2007 summary. Natl Health Stat Report. 2010; (27):1-32. • 2. Bonow RO, Braunwald E. Braunwald's heart disease : a textbook of cardiovascular medicine. 9th ed. Philadelphia: Saunders; 2012
“Angina Equivalent Syndrome”
Several reports in 1980-1990’s documented that between 25 and 45 percent of patients with coronary heart disease have myocardial ischemia during daily life.
Greater than 75 percent of these ischemic episodes are not associated with chest pain.
Dyspnea (10-30%) - Unexplained decrease energy level - Palpitations/Syncope
Diabetes - Older adults - Women - Those with prior myocardial infarction or surgical revascularization The optimal non-invasive vascular diagnostic study is stress testing
The patient is exercised on the treadmill to maximal exercise tolerance utilizing the Bruce Protocol**
Goal is to achieve at least 85 % Maximal Predicted Heart Rate MPHR = 220 – age (years) x 85 % = MPHR 220 – 50 x 85 % = 144 How patients view a exercise treadmill test Bruce Protocol for Treadmill Testing
STAGE TIME SPEED (mph) GRADE (%) METS
REST 00.00 0.0 0.0 1.0
1 03.00 1.7 10.0 4.6
2 03.00 2.5 12.0 7.0
3 03.00 3.4 14.0 10.1
4 03.00 4.2 16.0 12.9
5 03.00 5.0 18.0 15.1
6 03.00 5.5 20.0 16.9
7 03.00 6.8 22.0 19.2 Clinical decisions on choosing stress testing modality:
Ability to perform adequate exercise
Resting ECG
Clinical indication for performing the test
Patient's body habitus
History of prior coronary revascularization Clinical decisions to choosing an imaging study:
Cost - Treadmill $300 Echo stress tests run about $1,500 Nuclear tests can go as high as $3,500
Availability
Potential side effects
Expertise
Body habitus Regular Treadmill Exercise Stress Test
If the Patient can exercise and has a normal ECG a Regular exercise stress test is the recommended initial study.
Exercise capacity is one of the most important determinants of prognosis.
In older adults it’s a strong predictor of increased morbidity and mortality.
Unable to exercise to a satisfactory workload
Baseline LBBB should have a vasodilator radionuclide myocardial perfusion imaging or stress echocardiography.
Marked obesity may need a 2 day radionuclide study with vasodilator. Stress Modalities
Exercise Treadmill Pharmacologic Vasodilators Inotropes and/or Chronotropes: Atropine
Predictors of poor performance Exercise Markers EKG Markers Poor exercise capacity ST Depession: >/= 1.0 mm downsloping; >/= 2.0 mm @ low workload; multiple lead Exercise induced “angina” ST-Segment depression
ST Segment elevation (leads with Low peak systolic pressures out Q-waves) and (not AVR) <130 mm Hg) or Ventricular Couplets or Ventricular drop systolic pressure Tachycardia
Low peak heart rate or Exercise-induced LBBB dropping heart rate Prolonged heart rate elevation Duke Activity Status Index The Duke Treadmill Score
Minutes on Treadmill With Bruce Protocol - 5 x ST Segment Depression - 2 x Chest Pain Score
Classified as low, moderate, or high risk Low risk – score ≥+5 Moderate risk – score from -10 to +4 High risk – score ≤-11
>/= + 5 = 97 % 5 year survival****
Cardiovascular Imaging Myocardial Perfusion Imaging (MPI) Test Three part Study Part 1: Rest images are obtained approximately 45 minutes after injection of the isotope
Part 2: Exercise** on TM to 85 % MPHR and a 2nd injection of the isotope is administered
Part 3: approximately 45 minutes after exercise obtain the “exercise images” Normal nuclear perfusion scan stress
rest stress
rest stress
rest Lateral ischemia on nuclear perfusion scan stress
rest stress
rest stress
rest Predictors of poor performance Exercise Markers EKG Markers Poor exercise capacity ST Depession: >/= 1.0 mm downsloping; >/= 2.0 mm @ low workload; multiple lead Exercise induced “angina” ST-Segment depression
ST Segment elevation (leads with Low peak systolic pressures out Q-waves) and (not AVR) <130 mm Hg) or Ventricular Couplets or Ventricular drop systolic pressure Tachycardia
Low peak heart rate or Exercise-induced LBBB dropping heart rate Prolonged heart rate elevation
Stress Modalities
Exercise with: Myocardial Perfusion Imaging Stress Echocardiogram
Pharmacologic Stress Vasodilators Inotropes and/or Chronotropes: Atropine Most appropriate patients**
Patients at intermediate-to-high risk for CAD who are having symptoms suggestive of CAD
Patients with known CAD who have new or recurring symptoms that may be attributable to myocardial ischemia
Patients with prior revascularization who have recurrent symptoms
Patients who have had recent myocardial infarction who did not undergo an early cardiac catheterization and reperfusion treatment strategy. Pharmacologic patient candidates
Cannot exercise Baseline ECG is not interpretable left bundle branch block ventricular pacing severe baseline ST segment abnormalities Preoperative risk stratification prior to high-risk non-cardiac surgery
Common side effects of Lexiscan / Adenosine Headache Dizziness Nausea Stomach discomfort Decreased sense of taste Mild chest discomfort Shortness of breath Flushing (warmth, redness, or tingly feeling under your skin).
Aminophylline Stress Testing Agents: Dobutamine
▪ Synthetic catecholamine acts on β1 and β2 receptors resulting in CONTRAINDICATED in: increased HR, BP, and CO. ▪ LM disease ▪ Mimics physiologic response to ▪ LBBB exercise ▪ HOCM ▪ Protocol for infusion rate ▪ Afib/flutter ▪ Reversal agent: Esmolol ▪ Significant ectopy ▪ Ventricular or supraventricular STRESS ECHOCARDIOGRAPHY Stress Echocardiography
▪ Stress echo allows for dynamic evaluation of cardiac structure and function at rest and during stress
▪ Evaluate extent of ischemia secondary to obstructive CAD
▪ Cardiovascular stress can be obtained by: ▪ Exercise ▪ Pharmacologic: Dobutamine Dobutamine Stress Protocol Indicators for Cardiovascular Evaluation
Chest pain – “angina” – “angina equivalents”
History of CAD/CHF with worsening symptoms
Newly diagnosed heart failure / CMP
Arrhythmias
Pre-operative evaluation
Pre-employment or continued employment Available non-invasive CV studies
Regular Treadmill Exercise Cardiac Magnetic Stress Test Resonance (CMR)
Myocardial Perfusion Study- Event monitor Nuclear Imaging Holter monitor Stress Echocardiogram Tilt-Table Test CT Angiography (Calcium Scoring) Echocardiogram +/- TEE Echocardiogram Transesophageal Echocardiogram Cardiac MRI
Tilt Table
Take home points 1. Screening asymptomatic patients with electrocardiography has an extremely low yield for detecting pathology it leads to multiple false positive results.
2. The exercise electrocardiogram (ECG) is a well-validated procedure for establishing the diagnosis and prognosis of coronary heart disease, as well as assessing functional capacity.
3. Inappropriate cardiac stress test with imaging studies lead to one half billion dollars a year in unnecessary medical cost
4. In a patient with low test probability the results are more likely to be a false positive 5. Coronary artery calcium scores may be of some benefit in screening of low risk patients for implementing statin therapy
6. Absolute and relative contraindications to exercise testing should be considered when ordering the test.
7. Pre-test resting EKG and basic instructions at the time the test is ordered is important.
8. There are a wide variety of non-invasive cardiac diagnostic studies available to help you in the care of your patient.
9. Remember atypical presentations in diabetics, the elderly and females. Resource
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