Treadmill Stress Testing for the Primary Care Physician,Anthony Beutler, MD Primary Care Sports Medicine,The Electrocardiogram,What is VO2max?,The Electrocardiographic Response,Objectives,Review essential Exercise Test Terminology Describe the Performance of the Exercise Stress Test Review Exercise Test Responses Discuss Interpretation of the Exercise Stress Test Discuss Special Considerations in Athletes,Exercise Test Terminology,The Electrocardiogram VO2max METs Myocardial Oxygen Consumption,Maximal Oxygen Uptake (VO2max),Greatest amount of oxygen an individual utilizes with maximal exercise (ml O2 per kilogram per minute) “Gold Standard” for cardiorespiratory fitness Fick Equation VO2max = (HRmax x SVmax) x (CaO2max - CvO2max),VO2max = (HRmax X SVmax) X (CaO2max - CvO2max),FICK EQUATION,METS,The MET,Metabolic Equivalents (METs),1 MET = 3.5 ml O2 per kilogram of body weight per minute,Key MET Values (part 1),1 MET = “Basal“ = 3.5 ml O2 /Kg/min 2 METs = 2 mph on level 4 METs = 4 mph on level 5METs = Poor prognosis if 65; limit immediate post MI; cost of basic activities of daily living,Key MET Values (part 2),10 METs = As good a prognosis with medical therapy as CABS 13 METs = Excellent prognosis, regardless of other exercise responses 16 METs = Aerobic master athlete 20 METs = Ooh lah lah Aerobic athlete,Myocardial (MO2),Accurate measurement requires cardiac catheterization Coronary Flow x Coronary a - VO2 difference Wall Tension (Pressure x Volume, Contractility, Stroke Work, HR) Systolic Blood Pressure x HR Angina and ST Depression usually occurs at same Double Product in an individual * Direct relationship to VO2 is altered by beta-blockers, training,.,Myocardial Oxygen Consumption,Indirectly measured as the “Double Product” “Double Product” = HR x systolic blood pressure A normal value is greater than 20,000 25,000,Performance of the Exercise Stress Test,Indications/Contraindications Running the Exercise Test Physician Responsibilities,ACSMs Guidelines for Exercise Testing and Prescription,ACSM. Lippincott, Williams & Wilkins 6th Edition 2000,Indications for Exercise Testing,Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective. Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. II a: weight of evidence is in favor of usefulness/efficacy. II b: usefulness is less well established by the evidence. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful.,Class I Indications for Performing an Exercise Test,To assist in the diagnosis of CAD in adult patients with an intermediate pretest probability of disease. To assess functional capacity and to aid in assessing the prognosis of patients with known CAD. To evaluate the prognosis and functional capacity of patients with CAD soon after an uncomplicated myocardial infarction. To evaluate patients with symptoms consistent with recurrent, exercise-induced cardiac arrhythmias.,Class II Indications for Performing an Exercise Test,To evaluate asymptomatic men 40 and women 50 who: are involved in special, high risk occupations; plan to start a vigorous exercise program; have multiple cardiac risk factors. To assist in the diagnosis of CAD in adult patients with a high or low pretest probability of disease. To evaluate patients with a Class I indication who have baseline electrocardiographic changes.,Class III Indications for Performing an Exercise Test,Routine screening of asymptomatic men or women. To evaluate men or women with a history of chest discomfort not thought to be of cardiac origin. To evaluate patients with simple PVCs on a resting ECG with no other evidence of CAD. To assist in the diagnosis of CAD in patients with evidence of LBBB or WPW on a resting ECG.,Pre Test Probability of Coronary Disease by Symptoms, Gender and Age,Contraindications to GXT Testing: Absolute,Recent acute MI Unstable angina Ventricular tachycardia Dissecting aortic aneurysm Acute CHF,Severe aortic stenosis Active myocarditis Thrombophlebitis or intracardiac thrombi Recent pulmonary embolus Acute infection,Contraindications to GXT Testing: Relative,Uncontrolled severe hypertension Moderate aortic stenosis Severe subaortic stenosis Supraventricular dysrhythmias Ventricular aneurysm,Complex ventricular ectopy Cardiomyopathy Uncontrolled metabolic disease Recurrent infectious disease Complicated pregnancy,So What Do You Do.,39 yo female with risk factors and a squirrelly story.,Comparison of Tests for Diagnosis of CAD,Which Protocol?,Vast Majority (82+%) use BRUCE So, why not you?,How to read an Exercise ECG,Good skin prep PR isoelectric line Not one beat Three consistent complexes Averages can help Garbage in, garbage out Why watch during recovery?,Symptom-Sign Limited Testing Endpoints Whe