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 Stress Test

Myocardial Perfusion Study-Nuclear Imaging

Stress Echocardiogram

CT Angiography (Calcium Scoring)

Cardiac Magnetic Resonance (CMR)

Event monitor

Holter monitor

Tilt-Table Test

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 MarkersPoor exercise capacity

Exercise induced “angina”

Low peak systolic pressures <130 mm Hg) or

drop systolic pressure

Low peak heart rate or dropping heart rate

EKG MarkersST Depession:

>/= 1.0 mm downsloping; >/= 2.0 mm @ low workload; multiple lead ST-Segment depression

ST Segment elevation (leads with out Q-waves) and (not AVR)

Ventricular Couplets or Ventricular Tachycardia

Exercise-induced LBBB

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 ≥+5Moderate risk – score from -10 to +4High risk – score ≤-11

>/= + 5 = 97 % 5 year survival****</= -11 = 72 % 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

stress

stress

rest

rest

rest

Lateral ischemia on nuclear perfusion scan

stress

stress

stress

rest

rest

rest

Predictors of poor performance

Exercise MarkersPoor exercise capacity

Exercise induced “angina”

Low peak systolic pressures <130 mm Hg) or

drop systolic pressure

Low peak heart rate or dropping heart rate

EKG MarkersST Depession:

>/= 1.0 mm downsloping; >/= 2.0 mm @ low workload; multiple lead ST-Segment depression

ST Segment elevation (leads with out Q-waves) and (not AVR)

Ventricular Couplets or Ventricular Tachycardia

Exercise-induced LBBB

Prolonged heart rate elevation

Stress Modalities

Exercise with:Myocardial Perfusion Imaging Stress Echocardiogram

Pharmacologic StressVasodilatorsInotropes 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

increased HR, BP, and CO.

▪ Mimics physiologic response to

exercise

▪ Protocol for infusion rate

▪ Reversal agent: Esmolol

CONTRAINDICATED in:

▪ LM disease

▪ LBBB

▪ HOCM

▪ Afib/flutter

▪ 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 Stress Test

Myocardial Perfusion Study-Nuclear Imaging

Stress Echocardiogram

CT Angiography (Calcium Scoring)

Cardiac Magnetic Resonance (CMR)

Event monitor

Holter monitor

Tilt-Table Test

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

www.acadoodle.com