Clinical Exercise Testing-07 [Compatibility Mode]

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Unformatted text preview: Clinical Exercise Testing Special Populations What are four reasons to exercise test Exercise Exercise Prescription Diagnosis Diagnosis Prognosis Prognosis Treatment Treatment Evaluation Methods of CVD Diagnostic Testing NonNon-invasive methods – – – – Exercise Stress Testing (Graded Exercise Testing – i.e. ECG) Pharmacologic Stress Testing Echocardiography Nuclear Imaging Newer NonNewer Non-invasive tests – Positron Emission Tomography – Ultrafast Computed Tomography – Magnetic Resonance Imaging 1 Methods of CVD Diagnostic Testing Gold Gold Standards – – Angiography – most common and least expensive test used as a gold standard for diagnosing CAD – Ventricularography – nuclear imaging Ventricularography nuclear imaging – Intracoronary Ultrasound – expensive and cutting edge Gold Standard in Dx of CAD Coronary Coronary Angiography – Before Tx (STENT Placement) http://www.cvmg.com/education/mpg.html Angiography (con’t) • Coronary Angiography – After STENT Placement 2 Why so many types of diagnostic tests? Probability diseaseProbability of disease- used to aid in predicting accuracy of any Dx test, without having to do invasive Dx testing (i.e. angiography) In other words what is the actual predictive In other words, what is the actual predictive value value of a given Dx test? Or how effective it is relative to – Sensitivity = TP/(TP +FN) – Specificity = TN/(TN + FP) Diagnostic Terms Predictor Predictor Criterion Criterion True True False False Positive Positive Negative Negative Sensitivity = % of patients with CAD of who will have an abnormal test 3 Specificity = the % of patients without the CAD who will have a negative test Diagnosis of CAD: GXT GXT All All methods of Dx are compared to angiography – Electrocardiogram is used as the Dx tool for the GXT GXT – Exercise stress testing 65 65 – 80 percent sensitive (68% pooled results) 65 65 – 75 percent specific (77% pooled results) See See also box’s 6-2 and 6-3 for false positive 66and false negative rates Exercise testing in those with ischemic heart disease Graded exercise testing (GXT) is used in – Healthy populations Fitness Fitness Athletes Athletes – Clinical settings Diagnosis Diagnosis of CVD (IHD) and other forms of chronic metabolic and pulmonary disease Exercise Exercise tolerance (IHD) Exercise Exercise prescription (CVD, metabolic, and pulmonary) 4 Graded Exercise Testing (GXT) – Healthy Population Terminology Terminology specifically refers to an exercise test usually conducted on a cycle ergometer or treadmill lasting approximately 8 to 12 minutes in length in which an individual must exercise to maximal point. Physiological Physiological and subjective variables (end-points): (end– – – – Plateau in oxygen consumption Heart rate (age predicted maximum) Lactate production (>8 mmol) Rating of Perceived Exertion (RPE) – RER > 1.15 NOTE: There may be different end-points for different populations end- Graded Exercise Testing (GXT) – Clinical Population Cycle Cycle ergometer or treadmill lasting approximately 8 to 12 minutes that is most likely sign or symptom limited Physiological Physiological and subject variables: – highest oxygen consumption reached – Heart rate (age predicted maximum – 85%) – Rating of Perceived Exertion (RPE = 17) – Signs and symptoms – (what was the limiting factor at the end-point?) end- GXT responses: Clinical Clinical settings Look Look for VO2pk rather than VO2max (Why?) – Below 5 METs? Heart Heart rate Blood Blood Pressure Electrocardiography Electrocardiography (ECG) SxS SxS 5 GXT Protocols Various Various testing protocols (treadmill, bike) have been developed for purposes of improving outcomes, validity, and reliability of the GXT. Some of the more popular are (see pg 98 in text) Some of the more popular are (see pg 98 in text) – Bruce Protocol (~ (~ 3 MET increase per “stage”) One One of the oldest and most commonly used, but not necessarily the best – Naughton (~ 1 MET increase per “stage”) Better Better suited for diseased population for a more gradual increase in intensity GXT responses: HR HR and BP HR HR – Within 10 beats of age predicted max? – Chronotropic response – What are the possible causes if abnormal? causes if abnormal? BP BP (be familiar with Table 6-1) 6– Peak and submaximal responses Systolic Systolic Diastolic Diastolic GXT: ECG responses ECG Know Know what should normally happen to wave forms during a GXT (I.e. P, QRS, T) Ischemia Ischemia and infarction (Fig 6-2) 6– ST-segment 1 mm is significant and considered abnormal mm Upsloping STUpsloping ST-depression means less Dx and Px than horizontal or downsloping – T wave Normalization Normalization or inversion may mean ischemia 6 GXT: ECG responses ECG Arrhythmias Arrhythmias (origin, lethal) – Supraventricular – Ventricular Angina and Dyspnea Scales 1 2 3 4 Light, barely noticeable Moderate Moderately severe Severe, Most intense pain ever experienced 1 2 3 4 Light Mild Moderate Severe Know the following Indications Indications for terminating exercise testing – Absolute (Box 5-3) 5– Relative (Box 5-3) 5- Cli Clinical significance of cardiorespiratory and hemodynamic hemodynamic responses during an exercise test (Box 6-4) 6- 7 Prognostic Use of the GXT Predicted Predicted norms (ACSM Guidelines, Table 4-8; Fig 6-2) 6Duke Duke nomogram (Fig 6.2 – CEP Text) – Based on ST-segment displacement, SxS, peak STcapacity Example Example Duke Nomogram for Prognosis Example Example 1 – Joe Shmoe (red) Completed Completed max test and reached 13 METs Had 2 mm of ST-segment depression during the test Had mm of ST depression during the test Example Example 2 – Jane Shmoe (blue) Completed Completed a max test and reached 5 METs Had Had 2 mm of ST-segment depression during the test ST- 8 9 ...
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