EHR519 Week 4A Graded Exercise Testing PDF

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Warning This material has been produced and communicated to you by or on behalf of Charles Sturt University in accordance with section 113P of the copyright act (Act). The material in this communication may by subject to copyright under the act. Any further reproduction or communication of this material by you may be the subject of copyright protection under this act. Do not remove this notice  EHR519 week 4A Graded Exercise Testing Cardiovascular diseases Atherosclerosis Ischemic Heart Disease Angina Peripheral artery disease Valvular diseases Myocardial infarction  Learning Outcomes On successful completion of this subject, you should: be able to explain the purpose of graded exercise testing (GXT), the common modes and protocols, and which populations they are used for; be able to describe the relative and absolute contraindications to terminate a GXT; be able to explain the appropriate measures to be recorded before, during and after a GXT, and the normal and abnormal responses; be able to outline the risk factors, complications and comorbidities that must be accounted for when applying exercise interventions to individuals with atherosclerosis, ischemic heart disease and angina; and, be able to describe common treatments, and the effects of commonly prescribed medications on acute and chronic exercise responses that must be accounted for when applying exercise interventions to individuals with atherosclerosis, ischemic heart disease and angina. 3 Overview 1. Graded Exercise Testing 2. Testing for specific Cardiovascular Conditions NB: important for appropriate Ex Rx 4 Graded Exercise Testing Non-invasive GXT used for differential diagnosis of adults with suspected IHD < 50 GXT + 12-lead ECG is test of choice to evaluate myocardial ischemia in those with normal resting ECG, and physically able to exert themselves. + expired gas analysis = CPET Physiological responses monitored during standardised incremental work rate exercise Progressively increased metabolic demand until a sign (S-T segment depression), or symptom limited (angina or fatigue) maximum level of exertion is reached Before a GXT is performed it is important to understand (a) which patients the GXT is useful for; (b) the reason for completing the test; and (c) although the risks of an adverse event during or immediately after are rare, there are still risks involved.. 5  Indications and Assessments Indications: Diagnosis Prognosis Evaluation – Most common being the assessment of symptoms suggestive of IHD Considered in patients with intermediate probability of CHD, not yet diagnosed – age, sex, symptoms (typical or atypical), prevalence in same demographics – not in asymptomatic individuals with low pre-test probability of IHD. Assessments before, during and after GXT Electrocardiogram (ECG) Heart Rate (HR) Blood Pressure (BP) Scales (Dyspnoea, Angina, Claudication, RPE) Respiratory Gas Exchange (VO2, VCO2, VE) 6  Gas Exchange Independent, graded and inverse association between directly measured or estimated VO2 peak and mortality 13 % reduction in risk for all-cause mortality associated with each 1-MET increase in cardiorespiratory fitness (Grazzi et al. 2014) – increase accuracy with respiratory gas exchange Useful in defining prognosis (and thus help guide the timing for cardiac transplantation) in patients with heart failure Slope of change in VE to change in VCO2 production (Ve-VCO2 slope) during an exercise test = related to prognosis for patients with CHF Others measures from CPET = ventilatory-derived AT, oxygen pulse, oxygen uptake efficiency slope, partial pressure of end tidal CO2, breathing reserve, and respiratory exchange ratio Gas exchange useful to identifying if unexplained dyspnoea has a cardiac or pulmonary aetiology. 7  Diagnostic value of determining the presence of CAD is greatest in those with intermediate probability of CAD, which is based on the person’s Age and sex Presence of symptoms (stable or unstable) Prevalence of CAD in other persons of the same age and sex. Factors that influence prognosis of CVD Angina Presence of ST-segment depression evident on the ECG during exercise or in recovery Magnitude of ST depression (1 mm vs. 3 mm, where more ST depression represents greater risk) The number of ECG leads showing significant ST-segment depression Time of onset for ST depression during exercise Time during recovery to resolve ST-segment abnormalities observed during exercise, Functional capacity (FC) as measured by exercise duration or metabolic equivalents of task (METs). 8 Example Client A Client B Angina pain Symptom free Demonstrates 2.5 mm of ST-segment Completes 10 METs of work depression in four ECG leads just 3 min No ECG evidence of ST-segment into an exercise test depression. Workload or FC that approximates just 4 METs But if an abnormal ECG response In people found to be at high risk (i.e., does not occur until the person abnormal GXT response at low reaches 10 METs, the prognosis is workloads, 1mm of horizontal or downsloping ST-segment depression that occurs 0.08s past the J point = myocardial ischemia Likelihood of CAD is extremely high when Occurrence with angina Early onset, > ST depression, more leads with ST depression, longer duration for ST depression to resolve in recovery J-point depression with an upsloping ST segment > 1.5 mm depressed at 0.08 s past the J point = exercise-induced ischemia slow or gradual upsloping ST depression = increased probability of CAD. 25 Isoelectric line  S-T Segment Elevation ST-segment or J-point elevation on a resting ECG is often attributable to early repolarization and not necessarily abnormal in healthy people, Should be documented on the GXT report. New ST-segment elevation with exertion (with normal resting ECG) → rare finding May suggest transmural ischemia or a coronary artery spasm. (test termination) When Q waves are present on the resting ECG from a previous infarction, ST elevation with exertion may reflect a LV aneurysm or wall motion abnormality ST-elevation can localise ischemic area/ arteries involved 27  T-wave Changes Healthy individuals = T-wave amplitude initially decreases with the onset of exercise then T-wave amplitude increases at maximal exercise. Flattening or inversion of T waves may not be associated with ischemia Common in the presence of LVH Normalization of T-waves also present during ischemic responses associated with coronary spasms Overall, T-wave changes with exertion are not specific to exercise-induced ischemia 28 Arrhythmia Used to evaluate the effectiveness of medical therapy in controlling an arrhythmia. When arrhythmias appear during the GXT, must document The onset of the arrhythmia Any signs or symptoms associated with the arrhythmia Any ECG changes (e.g., ST depression). 3 major types of ECG rhythm or conduction abnormalities during exercise: 1. Supraventricular arrhythmias that compromise cardiac function (e.g., atrial flutter, atrial fibrillation) 2. Ventricular arrhythmias that have the potential to progress to a life- threatening arrhythmia 3. The onset of high-grade conduction abnormalities 29  Reporting Summary report including information that should be interpreted relative to diagnosis, prognosis or risk of developing a disorder 1) Angina status Present or not. If so, onset (HR or MET level). Was angina the reason for test termination; intensity or grade reached, interventions during recovery (rest, medications). 2) ECG findings ST-segment information gathered at rest, during exercise, and in recovery. If resting ECG normal, simply state, based on the presence or absence of ST depression during exercise, the test does or does not meet the criteria for exercise-induced myocardial ischemia. 3) Functional Capacity Stated as estimated METs or measured O2, as an absolute number and qualified (e.g., above average, poor, superior) relative to normative data (similar age and gender). See ACSM’s guide. 30 4) HR responses Determine if normal (exceeded 80% of age predicted) or consistent with a chronotropic incompetence (less than 80% of age predicted) response. Prognostic value of poor HR response = that of an exercise-induced myocardial perfusion deficit. Failure of HR to decrease by at least 12 beats after 1 min, or 22 beats by 2 min is independently associated with increased risk for mortality over the next 3 to 5 y Cannot discriminate those with coronary disease and should be used to supplement other predictors 5) BP responses Identify normal or abnormal BP responses (the magnitude of the increase approximates 10 mmHg per 1 MET of work). Peak SBP of >250 mm Hg = absolute contraindication. delay in decrease in SBP related to ischemic abnormalities and poor prognosis (3 mins post exercise SBP should be < 90% of peak measure) 6) Other observations and notes 31