Section 03: Pre Exercise Evaluations and Risk Factor Assessment

Transcription

1 Section 03: Pre Exercise Evaluations and Risk Factor Assessment ACSM Guidelines: Chapter 3 Pre Exercise Evaluations ACSM Manual: Chapter 3 Risk Factor Assessments HPHE 4450 Dr. Cheatham Purpose The extent of medical evaluations necessary before exercise testing depends of the assessment of risk. For many persons, especially those with CAD or other cardiovascular disorders, the exercise test and accompanying physical examination are critical to the development of safe and effective exercise programs. Not all persons warrant extensive testing 1

2 Purpose In the clinical setting, pre exercise test evaluations usually include: Medical history (ACSM Guidelines, Box 3.1, P. 42) Physical examination (ACSM Guidelines, Box 3.2, P. 43) Laboratory tests (ACSM Guidelines, Box 3.3, P. 44) (Next slide) We will focus on the blood lipid profile laboratory test Laboratory Tests 2

3 Laboratory Tests Blood Tests Fasted (at least 12 hours) blood test results are relevant to determining risk of: Hypercholesterolemia (cholesterol) Prediabetes (glucose) Two options 1) Refer to local laboratory for testing 2) Purchase instrumentation to perform tests Phlebotomy the practice of withdrawing blood from a blood vessel into a blood collection tube Insertion of needle into vein (larger volume sample) Requires professional training Finger puncture (smaller volume sample) Sufficient for mini analyzers 3

4 Risk Factor Lipids and Lipoproteins Blood Lipid Profile: Total Cholesterol (TC) Low Density Lipoprotein (LDL) cholesterol Bad cholesterol Transports cholesterol and triglycerides from the liver to peripheral tissues High Density Lipoprotein (HDL) cholesterol Good cholesterol Can remove cholesterol from within arteries and transport it back to the liver for excretion or re utilization Ratios TC/HDL: Desirable < 4.5 males, < 4.0 females LDL/HDL: Average Risk 3.6 males, 3.2 females Triglycerides Risk Factor Lipids and Lipoproteins LDL cholesterol is the primary target for cholesterol lowering therapy LDL cholesterol is a powerful risk factor for CAD and a decrease in LDL markedly decreases the incidence of CAD HDL cholesterol level is strongly and inversely associated with the risk for CAD There is growing evidence for a strong association between elevated triglyceride levels and CAD risk 4

5 Risk Factor Lipids and Lipoproteins Risk Factor Blood Glucose Standards set by the American Diabetes Association Prediabetes risk factor = mg/dl Normal values <100 mg/dl Diagnostic of diabetes = 126 mg/dl or greater 5

6 Risk Factor Blood Pressure Definition: Force of blood against walls of the vasculature created by contraction of the heart Often assessed by indirect auscultation Expressed in millimeters of mercury Systolic blood pressure (SBP): Maximum pressure during contraction (systole) Diastolic blood pressure (DBP): Minimum pressure during relaxation (diastole) Risk Factor Blood Pressure The relationship between BP and risk for cardiovascular events is continuous, consistent, and independent of other risk factors. For individuals 40 to 70 yrs of age: Each increment of 20 mmhg in SBP or 10 mmhg in DBP doubles the risk of cardiovascular disease Lifestyle modification, including physical activity, weight reduction, a DASH eating plan, and moderate alcohol consumption are the cornerstones of antihypertensive therapy. Most patients who require drug therapy, require two or more antihypertensive meds to achieve the goal BP. 6

7 Risk Factor Blood Pressure Theory of Blood Pressure Measurement by Indirect Auscultation The inflated BP cuff occludes blood flow, yielding no sound heard in the stethoscope placed beyond the occlusion Slow release of cuff pressure allows the driving pressure of the blood to force the blood beyond the cuff and yields the first sounds (turbulence) heard in the stethoscope (SBP) Sounds cease with full opening of the artery as pressure continues to decline and turbulence no longer present (DBP) Risk Factor Blood Pressure Korotkoff Sounds Phase 1: SBP Initial onset of sound (clear, repetitive tapping) Phase 2: Soft tapping, murmuring, or swishing Typically 10 to 15 mm Hg below phase 1 Phase 3: Crisp, loud tapping High pitch and intensity Phase 4: True DBP Muffling of sound Soft or blowing sound Considered true DBP, especially during exercise Phase 5: Clinical DBP Complete disappearance of sound Typically within 8 to 10 mm Hg of phase 4 Should be recorded if it is significantly different from phase 5 7

8 Risk Factor Blood Pressure Resting Measurement Procedures: The patient should be seated with the legs uncrossed The BP measurement should be done in a relaxed, comfortable setting White coat syndrome An appropriate BP cuff should be used Center the bladder over the brachial artery and secure the appropriate BP cuff snugly at the level of the heart Locate the brachial artery pulse in the antecubital fossa and place the stethoscope bell over the artery Risk Factor Blood Pressure Resting Measurement Procedures (cont d): Quickly inflate the BP cuff to: 20 mm Hg above SBP (if known) 150 to 180 mmhg Up to 30 mmhg above the disappearance of the radial pulse Release pressure 2 to 3 mmhg per heartbeat or 2 to 5 mmhg per second to the fifth Korotkoff sound Deflate the cuff rapidly to zero after DBP is obtained Record the SBP and DBP (fourth and fifth Korotkoff sounds if they are significantly different) Wait at least 1 full minute and repeat Values should be within 5 mm Hg of each other; if not, repeat 8

9 Risk Factor Blood Pressure Blood Pressure Exercise Not in your books. 9

10 Blood Pressure Exercise Not in your books. Blood Pressure Calculations Mean arterial pressure (MAP) Represents the average BP in the arterial system MAP = DBP + 1/3(SBP DBP) Pulse pressure (PP) Related to stroke volume PP = SBP DBP 10

11 Heart Rate Heart rate can be measured by: Palpation Auscultation Telemetry (HR monitors/watches) Electrocardiography (ECG, EKG) Heart Rate Palpation Palpation: 30 or 60 sec counts are more accurate for resting HR 15 or 30 sec counts are more common during exercise Begin counting the first beat felt as zero (e.g., 0, 1, 2, 3, 4...) Avoid baroreceptor reflex at the carotid artery 11

12 Heart Rate Exercise Predicted Maximal HR: 220 age Risk Factor Obesity (BMI) An excessive amount of body fat Recently considered a major, primary CAD risk factor For risk stratification purposes a height/weight comparison (BMI) and waist circumference are considered 12

13 Risk Factor Obesity (BMI) Assessment standardizations (height) Performed with a stadiometer Remove shoes and hat (if worn) Stand erect, feet flat, heels touching Heels, mid and upper body parts are against the wall Take and hold a normal breath, look straight Horizontal headboard is lowered to the top of the head Risk Factor Obesity (BMI) 13

14 Risk Factor Obesity (BMI) Weight protocol Scale calibration Wear minimal clothing Void bladder within 1 hour prior to measurement Ideal measurement is in the morning before meal consumption Variance in the above standards is acceptable with understanding of deviance between measured weight and standardized body weight Risk Factor Obesity (BMI) 14

15 Risk Factor Obesity (BMI) Body mass index = Weight in kg (Height in meters) 2 Example: BMI calculation for a 150 lb, 68 in. client: 150 pounds / = 68.0 kg (convert lbs to kg) 68 inches 2.54 = cm (convert in. to cm) cm / 100 = m (convert cm to m) m m = 2.98 m 2 (convert m to m 2 ) BMI = 68.0 kg / 2.98 m 2 = 22.8 kg. m 2 (divide kg by m 2 ) Risk Factor Obesity (Waist Circ.) Abdominal obesity is associated with greater risk Measurement protocol: Technician stands to the right of the client Measurement made on bare skin Measurement made at the end of a normal exhalation Measuring tape is held parallel to the floor and flat against skin Take multiple measurements to determine smallest site Mean of two measurements taken at this site is used 15

16 Risk Factor Obesity (Waist Circ.) Correct Incorrect Risk Factor Obesity 16

17 Risk Factor Physical Activity Most variable component of total daily energy expenditure Public heath guidelines advocate: 30 minutes of moderate intensity activity, 5 days/week, or 20 minutes of vigorous intensity exercise 3 days/week Assessment goal is to identify those not meeting threshold: Regular continuous for at least 3 months Activity below this level constitutes a risk factor inactivity Risk Factor Physical Activity 17

18 Risk Factor Physical Activity Contraindications to Exercise Testing 18

19 Contraindications to Exercise Testing Contraindications to Exercise Testing Patients with absolute contraindications should not perform exercise tests until such conditions are stabilized or adequately treated. Patients with relative contraindications may be tested only after careful evaluation of the risk/benefit ratio. Contraindications might not apply in certain specific clinical situations, such as soon after an acute myocardial infarction, a revascularization procedure, or bypass surgery or to determine the need for, or benefit of, drug therapy. 19