531 Exam 2
V2
fourth intercostal space to the left of the sternum
V1
fourth intercostal space to the right of the sternum
Equipment and units used to measure DYNAMIC strength
free weights and exercise machines (1-RM) (kg or lb)
Anterior track of SA node
front side, bachmanns bundle (polarize R to L)
dynamic contraction
generates force to move an object
Factors influencing the location of the axis (mean QRS vector)
heart size, patients body size, conduction pathways
Sarcopenia
inability to perform daily tasks
Equipment and units used to measure Isokinetic strength
isokinetic dynamometers (peak torque) (Nm or ft-lb)
Pros of resistance exercise machine
isolate muscle groups, safe
Equipment and units used to measure STATIC strength
isometric dynamometers, cable tensiometers, strain gauges, load cells, handheld dynamometers (MVIC (kg or N))
Static Contraction
isometric, maintain length, no movement, ex. plank
V5
level with V4 at anterior axilliary line
V6
level with V5 at midaxilliary line
T wave
repolarize slower process larger and broader than P wave, rounded, and slightly asymmetrical upwardly deflection 5-10 mm in height
Countdown method
start with HR on bold line and go to next R wave - 300, 150, 100, 75, 60, 50 only used if rhythm is regular
Chest Leads
V1 - V6
Purpose of Musculoskeletal Fitness Assessment
-Prerequisite for good physical function. (ability to move/lift. ) -Health related effects (improved posture, less risk of injury, better bone mass, improved glucose uptake, increased metabolic rate) -Fitness and Performance (enhanced muscular strength, endurance, speed, power, agility, balance, performance, confidence, improved body comp, reduced risk of injury)
P wave
-atrial depolarization - less then 0.10 sec in length/duration -less then 2.5 mm height -atrial contracting, pushing blood into ventricles
QT interval
-beginning of QRS complex to end of T wave -duration of ventricular systole -less then 0.44 sec
ST segment
-between end of QRS and beginning of T wave -plateau phase of ventricular repolarization -isoelectric
Functional Implications
-directly related to an individuals functional status -functional capacity
PR segment
-end of P wave to start of QRS complex - measures time from end of atrial depolarization to start of ventricular depolarization, represents the electrically quite period between atrial and ventricular depolarization
Disadvantages of Max exercise test for measuring CRF
-exercise to point of exhaustion -high level of motivation -considerable amount of time to administer -medical supervision and emergency equipment -higher costs associated with equipment for open circuit spirometry
PR interval
-includes P wave and straight line connecting it to QRS complex -measures time from the start of atrial depolarization to the start of ventricular depolarization -.12-.2 sec (3-5 small boxes)
Advantages of Max exercise test for measuring CRF.
-increase sensitivity in the diagnosis of coronary artery disease in asymptomatic individuals -valuable prognostic and diagnostic info for people with and without chronic diseases -provides accurate measurement of anaerobic threshold and VO2max
Why is CRF an important component of health-related index of fitness?
-low levels of CRF associated with increased risk of premature death (cardiac disease) -increase in CRF associated with reduction of death -increase in CRF associated with increase physical activity
Main functions of ECG
-provides info about HR, heart rhythm and various abnormalities of the heart -identify a potentially life threatening arrhythmya -diagnose evolving myocardial infarction -screen for ischemic heart disease -pinpoint the chronic effects of sustained hypertension -pinpoint the acute effects of a massive pulmonary embolism.
1500 method
-regular rhythm -count number of small squares between 2 R waves and do #/1500
QRS Complex
-septal depolarization (q wave) -ventricular depolarization (rs) -0.06-0.10 sec in length -5-20 mm high
Left bundle branches
-septal- help carry impulses from AV node to interventricular septum (L to R side) - anterior- action potential is carried to anterior wall of LV -posterior- impulse will travel to posterior ventricular wall
Health Implications
-to individualize the exercise program - to track progress and serve as a motivation to the patient in an exercise program -to assist in identifying and diagnosing chronic diseases
5 assumptions to be met in order to produce the most accurate estimates of VO2max
1. linear relationship exists between HR and workrate. 2. steady state HR is obtained 3. difference between actual and predicted max HR is minimal 4. mechanical efficiency is same for everyone 5. subject is not on medications that alter HR, using high quantities of caffeine, under large amounts of stress, ill, or on a high temperature environment, all of which may alter HR
What is the common paper speed of ECG
25 mm/sec
Queens College Step Test
3 minute test with same step height but different step rates for men and women. -mens rate of 24 per min (96bpm) -female of 22 per min (88bpm)
Borg's perceived exertion scale
6 (no exertion) - 20 (max exertion) 0-10 (5-6 moderate) (7-8 vigorous)
Test environment: What is the appropriate temperature and humidity?
68-72 degrees F (20-22 degrees C) and humidity <60%
Ideal duration of maximal exercise test
8-12 minutes
Limb Leads
RA, LA, RL, LL
Cardiorespiratory Fitness (CRF)
ability to perform large muscle, dynamic, moderate to vigorous intensity exercise for prolonged periods
Max disadvantages using step test
adjustable steps, difficult to measure HR and BP, safely hazard for some subjects
6 minute walking test
assess exercise endurance capacity by measuring max distance a person can walk quickly (self paced) in 6 min. Most possible and commonly used submax test which can be used to assess aerobic capacity in various populations such as the older sedentary adults, patients with heart failure or pulmonary complications. Distance has been shown a good predictor of peak O2 uptake in patients wit advanced heart failure
Purkinje Fibers
countless tiny fibers extend just underneath endocardium. Ventricular depolarization starting in the endocardium and proceeding outward to the epicardium, rate of 20-40bpm
Cons of field testing
difficult to monitor physiological changes, environment can affect oucomes, lack of submax testing protocols
Cons of using free weights
difficulty isolating muscle groups, safety risk
V3
directly between leads V2 and V4
Advantages using step test
easily transportable, inexpensive, modality, requires little space, usually of short duration, can be used with most populations, stepping skills require little practice, advant ageous for mass testing
Advantages of using YMCA Submaximal Bench Press Test
equipment in most gyms, test is simple to perform
Disadvantages of using YMCA Submaximal Bench Press Test
experienced and good technique needed for safety reasons, Experience allows lifters to maximize their score, Numbers of reps changes involvements of muscle energy systems, spotter required
V4
fifth intercostal space at midclavicular line
isotonic contraction
fixed amount of resistance
isokinetic contraction
fixed amount of speed/velocity
1.5 mile test
fixed distance, requires client to complete the distance in the shortest time possible, by running or combo, need effective pacing and subjects motivation VO2max = 3.5 = 483/time ex. time to complete was 11.12 so time used in formula would be 11.2 because 12/60 = .2
Cooper 12 minute
fixed time test, to cover a max distance in 12 minutes either walking, running, or a combo of both, hard to administer because exact distance determination is difficult. VO2max= (distance in meters - 504.9) /44.73
AV node
floor of right atrium, only pathway for impulses to move from atria to ventricles, conduction through the AV node is slower, intrinsic HR of 40-60 bpm
What is the basic aim of submaximal test?
limit the clients effort to less then max exertion to determine HR response to 1 or more submax work rates and uses the results to predict VO2 max
Cons of resistance exercise machine
limited movement patterns, variability, resistance to two different patterns not necessarily, typically of everyday activities, difficulty tracking
What is considered to be a gold standard test?
maximal exercise test with collection of expired gas -field test-non-lab setting -submax exercise test-effort limited to submax exertion
Predicting VO2 using Queens
men: VO2max=111.33 - (.42 * HR) women: 65.81 - (.1847 * HR)
Pros of field testing
moderate to high correlation of VO2max, use of natural activity, ability to test in groups
eccentric contraction
muscle is lengthened during contraction
concentric contraction
muscle is shortened during contraction
General Indications for Stopping Exercise Test
onset of angina or like symptoms, drop in SBP of greater then 10mmHg, excessive rise in BP, SBP above 250, DPB above 115, shortness of breathe, wheezing, leg cramps, claudication, signs of poor perfusion, failure of HR increase, notifiable change in heart rhythm, request to stop, physical or verbal manifestations of severe fatigue, failure of equipment.
Define VO2 peak
plateau in human body where O2 consumption is observed during max effort.
bundle branches
play an integral role in the electrical condition system of the heart by transmitting cardiac action potentials from the bundle of His to the Purkinje fibers
SA node
posterior wall of right atrium, primary pacemaker, intrinsic rate of 60-100 bpm. Once SA node depolarizes it wants to depolarize everything and does this through conductive pathways
Functional capacity
the extent to which a person can increase exercise intensities and maintain at those increased levels.
Posterior track of SA node
thorels pathways
Pros of using free weights
uniformity, wide range of motion, similarity of daily activity
Submax disadvantages using step test
unnatural movement for many people, might not be suited for patients with balance problems or are extremely deconditioned some single stage step test require 7-9 METS; which may exceed the max capacity of person, inadequate compliance to the cadence, unmonitored due to difficulty in measuring HR and BP during the test
6 second method
used for irregular rhythm -count number of QRS or P wave in 6 second section and multiply by 10
Middle track of SA node
wenchebach bundle, depolarize from SA node to AV node