exercise treadmill testing
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Exercise Treadmill TestingPart I
Eugene Orientale, Jr., MDAssociate Professor, Family Medicine
University of Connecticut School of Medicine
ETT Workshop Format
Introduction Feasibility / Equipment ETT basics Other diagnostic tests... Clinical Cases / Discussion
OBJECTIVESTo improve the current office screening practice of
patients with possible coronary artery disease.
To facilitate greater understanding amongst faculty and residents of the use of diagnostic office ETT.
To augment the diagnostic capabilities of a Family Medicine office practice.
To further educate and validate the need for resident education in the use of electrocardiography and ACLS.
ETT by Family Physicians ?
A random sample of 211 practicing members of the Nebraska AFP found that 58% performed Exercise Stress Testing
Goeschel DP et al, J Fam Pract 1994; 38:132
ETT by Family Physicians ?
“ 92 % of Family Practice Residency Program Directors surveyed believed that FPs should be taught this skill...”
Jurica,JW et al. Graded Exercise Stress Testing in Family Practiceand Internal Medicine Residencies . J Fam Pract 1989; 29: 537-41
Why ETT?
“ Clinically, inclusion of Exercise Testing in a Family Physician’s array of diagnostic procedures increases physician confidence and security in evaluating and managing the overwhelming majority of patients who are seen in the office for chest pain.”
- Ken Grauer, MD
Why ETT?
“ Even if there were enough cardiologists in the country to perform exercise testing on all persons with potentially valid indications for the test, the fact remains that patients with minimal or no symptoms do not routinely present to a cardiologist’s office with these concerns in mind.”
- Ken Grauer
Why ETT by Family Physicians?
Patient Care Cost Containment Comprehensive Care Financial Considerations
Reasons cited by FPs not performing ETT:
Never had training No time in practice to perform procedure Cannot afford to purchase the unit No access to a treadmill unit Lack of hospital privileges No interest in the procedure Inadequate reimbursement
J Fam Pract 1994 ; 38 (2) : 135
Conclusion“ Whether family physicians should be doing
Exercise Stress Testing is academic. Family physicians will continue to perform the test because demographics and public awareness and expectations will require it. We need to recognize this reality and focus our efforts toward providing competent and well-trained physicians to serve the needs of the public.”
Goeschel, DP et al. Geographic Variation in Exercise Testing by Family Physicians. J Fam Pract 1994; 38 (2):132-137
Feasibility Current UConn Family Practice referral rate for ETT
is 5--6 / month. This amounts to 60-72 referrals per year. Yearly revenue lost (assuming $250 / test) is:
• 60 tests: $15,000• 72 tests: $18,000
CPT code for ETT/Interpretation is 93015 Medicare reimbursement: $126 - 200 Common office charge: $229 - 285 UConn Family Medicine ETT charge: $250
Clinical Competence in ETT:ACP / ACC / AHA Task Force, 1990
“ Some Internal Medicine residency programs provide training in exercise testing, often as an elective. A minimum of 4 weeks should be devoted to this training to achieve competence... The number of procedures necessary to insure competence has not been established by objective criteria... The majority opinion of this committee and its consultants is that the trainee should participate in at least 50 exercise procedures during training... However, it is recoqnized that not all training or practice environments are the same and a greater or smaller number of procedures may be deemed appropriate.”
Maintenance of Competence:ACP / ACC / AHA Task Force, 1990
“ Twenty five tests per year are suggested as the minimum number the physician should perform to maintain clinical competence. Successful completion of a course in ACLS and renewal on a regular basis is necessary.”
ACC / AHA Task Force, 1997
“Exercise testing should be supervised by an appropriately trained physician… exercise testing in selected patients can be safely performed by properly trained nurses, exercise physiologists, physical therapists, or medical technicians working directly under the supervision of a physician, who should be in the immediate vicinity and available for emergencies.”
Treadmill Systems Evaluated
Spacelabs / Burdick Quest Stress System
Marquette Max-1 Stress SystemCase 8000 Stress System
Quinton Q4500 Stress Test SystemQ Stress System
Treadmill Systems Quinton Q Stress System
- durable treadmill construction- powerful motor (3HP)- programming ease- stores numerous testing protocols- software upgradeable- ease-of-use- “filter” technology for cleaner tracings- design your own display format- longest treadmill available (for athletic training / testing)- Q-care service contract
ETT System Layout
Treadmill
BP Cuff
Recorder
Monitor
Controller
Crash Cart
Treadmill System Treadmill
– slope 0 - 25 degrees– speed 1 - 15 mph
Monitor– displays 3 or 12 leads– computerized (digital) technology
Recorder– prints reports – includes customized summary report
Patient Selection Criteria
Always have a purpose in mind when selecting patients for Exercise Treadmill Testing...
Chest Pain...
Atypical Chest Pain Atypical Angina Typical Angina
Risk Factors: Coronary Artery Disease
Hypertension Hypercholesterolemia Smoking Family History Male >40, Postmenopausal Female Diabetes Mellitus Abnormal ECG Obesity
Other Indications for ETT...
Evaluating Dysrhythmias Determining Functional Capacity Evaluating Antianginal or
Antihypertensive therapy
Patient Selection CriteriaIndications for Office-Based Graded Exercise Testing:Screening for ischemic heart disease in asymptomatic individuals (especially those with multiple cardiac risk factors)
Evaluation of (atypical) chest pain Determining exercise capacity; and giving an exercise prescription.
Patient Selection CriteriaRelative Contraindications to ETT:
Left Bundle Branch Block WPW (pre-excitation syndrome) Marked ST-segment changes at rest
(e.g. drug effect from digoxin) Prior Q wave infarction. Middle Aged Female...
Patient Selection Criteria Absolute Contraindications to ETT: Acute MI Unstable Angina Concurrent CHF Hx. rapid ventricular or atrial
dysrhythmia IHSS Hx. recent pulmonary embolism
Before the ETT... Perform a complete medical
examination Obtain informed consent Withhold any medication that
may affect the ST wave or any interval
e.g. Digoxin, B- Blockers, Ca Channel Blockers
In patients on diuretics, confirm a normal potassium level
Informed Consent
Complications are rareDysrhythmias 5 : 10,000Infarction 5 : 10,000Death 1 : 10,000
Complications of ETT Hypotension CHF Severe Cardiac Dysrhythmia Cardiac Arrest Acute Myocardial Infarction Acute CNS event (syncope,
stroke) Accidental trauma (falls, etc) Death
Five Year Experience: ETT in a FP Residency, Scottsdale Arizona
202 ETT tests 88 % male, mean age 48.3 No serious complications or adverse outcomes most common indications:
fitness for duty (106)... 3.8 % abnormalmultiple risk factors (50) ... 6 % abnormalChest pain (27)... 18.5% abnormal
Fam Med 1994; 26:290-292
How long? How fast? “Maximal” Test
The patient achieves 85% of MPHR(maximal predicted HR = 220 - Age)
“Submaximal” TestThe patient becomes symptomatic, i.e. chest pain, dyspnea ( MPR generally not achieved)
Until a positive result is achieved
Which ETT Protocol ? Bruce slope / rate ; very strenuous Modified Bruce slower rate ; strenuous Balke II slope only; moderate Balke I slope only; mild Naughton slope only; mild
ETT Tracing...
ST morphology Depth of change duration of depression, and recovery
Patterns indicative of ischemia...
Exercise induced ST Depression ...
Does not localize ischemia It is a global subendocardial
phenomenon
Patterns not indicative of ischemia...
Sign/Symptom Testing Endpoints
Dyspnea, fatigue, chest pain Systolic blood pressure drop ECG-ST changes, arrhythmias Physician assessment Borg Scale
Relative Indications for terminating the ETT...
Moderate chest pain, claudication or dyspnea Marked ST segment depression ( > 2 mm) Marked Hypertension Failure of the SBP to rise 22mm Hg after stage 3 Acute ECG change, e.g. BBB
Absolutely terminate the test when... At the patient’s request Decreasing SBP Serious Dysrhythmias
• Atrial Fibrillation or Flutter• Second or Third Degree Heart Block• 3 consecutive PVCs• Ventricular dysrhythmias
Evidence of acute MI Equipment malfunctions
Possible causes of False Positive ETT for CAD:
Female gender Hyperventilation Mitral Valve Prolapse Syndrome LVH Drugs (digoxin ) Anemia Electrolyte disturbances ( hypokalemia ) Lead Misplacement Pre-existing cardiac abnormalities (e.g. LBBB, WPW,
Cardiomyopathy, Valvular Heart Disease
Options for evaluating ischemia
Holter - ECG during everyday activities Exercise ECG with Treadmill (ETT) Nuclear perfusion (Thallium) to increase
sensitivity and localize perfusion deficits Add-ons: ECHO, VO2 Pharmacologic stressors:
Dobutamine/Persantine/Adenosine
Echocardiography
Wall motion abnormalities pre- and post- exercise Ejection fraction Valvular heart disease
Testing options... ETT $191 Thallium ETT $1075 Persantine Thallium Scan $1314 Cardiac Catheterization
Left heart, with coronaries $1744Right/Left heart, with coronaries$2178
These are hospital charges alone, at BMH from April 1994.
When is a Thallium ETT needed?
BBB (especially LBBB) WPW Marked ST wave changes at rest (or with
hyperventilation) Q wave infarctions (with baseline ST changes) Unable to stop medications (such as digoxin,
quinidine, or procainamide)
Sensitivity / Specificity
Sensitivity: % of those with disease that have an abnormal test
(TP/TP+FN)
Specificity: % of those free of disease with a normal test
(TN/TN+FP)
Sensitivity / Specificity
ETT ThalliumETT
CardiacCath.
0
10
20
30
40
50
60
70
80
90
100
ETT ThalliumETT
CardiacCath.
SensitivitySpecificity
( $ 250) ($ 1300 +) ($ 3000+)
Clinical Case 1 A 43 y.o. female smoker is seen for a chief
complaint of left sided chest pain, which is non-exertional, sporadic, and lasts a few minutes during each episode. She has approximately two episodes per week, and there has been no change in several months. Other risk factors are negative.
Physical examination and resting ECG are unrevealing.
Would you order an ETT?
Clinical Case 2 A 53 y.o. black male with stable hypertension (on a
thiazide diuretic) is seen for a complaint of left sided chest pain which is exertional, lasts minutes, is sometimes associated with dyspnea, and responds to oral nitrates. Pain has increased in both severity and intensity over the past month. The number of episodes has progressed from intermittent to daily.
Physical exam and ECG are negative.
Would you order an ETT?
Clinical Case 3 A 60 y.o. white male smoker is seen for his regular
annual exam. He has a history of hypercholesterolemia, which has been well controlled on lovastatin. He notes that things are going well, and he is able to tend to his job as a farmer. He is ocassionally bothered by chest pain, which is quickly relieved by sublingual nitrates. There has been no change in the character or frequency of his pain over the past three years.
His physical examination is noncontributory. His resting ECG is once again normal.
Would you order an ETT?
Clinical Case 4 A 40 y.o. black male complains of vague, intermittent
chest pains, which come and go. Episodes can last up to a few minutes, and arise both with exertion and rest. He has a family history notable for a father who died of an MI at age 59. The patient’s exam is remarkable for his weight which exceeds his I.B.W. by 30 lbs. He has moderate truncal obesity. His resting ECG is notable only for low voltage.
Would you order an ETT?
Clinical Case 5
A 52 y.o. postmenopausal white female is seen for her routine annual visit. She quit smoking 3 years ago after accumulating a 40 pack year history. She is tolerating estrogen replacement therapy well, but notes vague intermittent chest discomfort which she “can’t quite put a finger on.” Pain is intermittent, last minutes, and is centrally located within the chest. Her physical exam is unrevealing. Her ECG reveals a pattern consistent with a Left Bundle Branch Block (LBBB).
Would you order an ETT? A Thallium ETT?
Caveats on ETT...
Small decrease in SBP at high stages of ETT may not be consistent with CAD
Use the double product as one means of establishing surgical clearance, i.e. HR x SBP : > 18,000 is acceptable
Most specific finding: downsloping ST depression > 2mm Patients with unusually high pre-test likelihood of CAD,
e.g. men with “classic” angina should be considered for a more specific test, e.g. Thallium ETT, or cardiac cath.
Referral from clinical sites Discuss necessity of procedure with an
Attending Have staff obtain insurance
authorization for referral Fill out UConn referral form (include
baseline ECG) Have staff contact UConn Family
Medicine office to schedule patient You will be mailed a full report