Post on 20-Dec-2015
Introduction to Advanced Introduction to Advanced Cardiopulmonry Cardiopulmonry
RehabilitationRehabilitation
PED 596
Spring 2002
Review Physiological Review Physiological Responses to ExerciseResponses to Exercise
Exercise is Homeostatic Emergency
Acute = AccommodateAcute = AccommodateImmediate response to an “Exercise Emergency”GOAL: Maintain homeostasis
Chronic = AdaptChronic = AdaptRepeated exposures to “Exercise Emergencies” stimulate adaptive changes
Training Effects
Define “Exercise”Define “Exercise”You should get more “exercise!”
Muscular activity (work)Induces increased oxygen uptakeIncreased cardiac outputIncreased cellular energy metabolism
WORK CAPACITY and THE PHYSIOLOGICAL RESPONSE TO WORK
Bottom Line - Emergency #1Bottom Line - Emergency #1: : Exercise Demands: ATP supply Exercise Demands: ATP supply and substrate delivery systemsand substrate delivery systems
ATP Supply: Fuel Supply: Glucose, Fatty Acids
Oxygen Supply
Metabolic Machinery: Rate Regulating Enzymes
Delivery System: Cardiopulmonary Systems
Bottom Line - Emergency #2Bottom Line - Emergency #2: : Exercise Demands: Better Exercise Demands: Better machinerymachinery
Work Output is an “external” product of exerciseWork Capacity is in part determined by Muscle strengthMuscle Strength: Function of cross-section and neurological efficiency
AdaptationAdaptation: Improves the ability : Improves the ability to respond to each “Homeostatic to respond to each “Homeostatic
Emergency” Emergency”
Specificity of Training: Specificity of Training:
Peripheral Adaptations: Muscle Fiber: Protein synthesis, metabolic enzymes, mitochondrial density, glycogen, triglyceride and myoglobin storesAngiogenesis
Central Adaptations:Cardiovascular: Cardiac output, peripheral resistance, blood volume, RBC, ventilatory threshold, insulin sensitivity
Exercise Testing: Clinical Exercise Testing: Clinical
Clinical Indications for Clinical Indications for Exercise Testing:Exercise Testing:
Diagnosis: Reproduce symptomsCP, SOB, Poor work toleranceECG changes?
Functional Testing:Work Capacity, BP response to exercise, Exercise duration
Prognosis:AHA, AACVPR, ACP: Risk Stratification, Duke’s 5-Year Mortality prognosis
Diagnosis:Diagnosis:
Indications:Confirm or rule out suspected myocardial ischemia
Mechanisms for syncope (LOC)
Suspected arrhythmias (palpitations with symptoms) during exercise
Functional Capacity:Functional Capacity:Indications:
Assessing work capacity for return to work/leisure activites
Used in determining risk/prognostic stratification
Used in determining therapy choices
Exercise Prescription: Phase II Entrance requirements
Prognostic BenchmarksPrognostic Benchmarks
<5 METs: poor prognosis especially under 65 years old
10 METs: considered normal fitness: survival good – regardless of intervention
13 METs: good prognosis even with CAD present
BikeBike vs. vs. TreadmillTreadmill
Less expensive
Less space
Quieter
Less ECG artifact
Easier BP’s
Non-Weight dependent
More flexibility in protocolsMore reproducible (not-patient dependent)More accurate work determinations
Specificity of Testing:Specificity of Testing:
Patient Preference / Experience
Diagnostic Protocols:
To Elicit Symptoms
Often quit at ~80% predicted HR Max
Critical Measurements:Critical Measurements:
Work Loads: MET calculations
ECG: Clean ST-Segment changes
BP: Accurate work SBP/DBP
RPP: MVO2 eliciting CP
Elicited Symptoms: CP, SOB, Syncope
Myocardial O2 demand (MVO2) depends on..
Myocardial tension (pressure x volume)
Inotropic State (Measure?)
Chronotropic state (Measure?)
Myocardial mass
Indirect measure of MVO2Indirect measure of MVO2
Rate pressure product (a.k.a. double product, tension-time index)
Considers 2 of the MVO2 indices:
HR X SBP
Good estimate of oxygen use by the heart.
Used to determine angina threshold
12-Lead ECG: Electrode 12-Lead ECG: Electrode PlacementPlacement
RA/LA: On Shoulders at distal ends of clavicles: (Not over large muscle masses)
RL/LL:Base of Torso: Just medial to the iliac crests
Chest Leads: V1-V6Traditional precordial positioning
V1-V2: 4th intercostal space –R/L of sternumV4: 5th intercostal space – midclavicle lineV3: Between V2 and V4V5: At horizontal level of V4, anterior to axillaV6: Midaxillary at horizontal level of V4
Treadmill Protocols:Treadmill Protocols:Treadmill Speed: IndividualizeIncrement Size: Age, condition
Larger incremental increases for younger, more fit patientsSmaller incremental increases for elderly, de-conditioned
Test Length: Between 8-12 minutes
Estimating Work Capacity: Estimating Work Capacity: Selecting ProtocolsSelecting Protocols
Healthy Men >40 years old75% have 12.5 MET capacity
50% ~ 10 METs
Healthy Women >40 years old75% have 10 MET capacity
50% ~8-9 METs
Choose a protocol that achieves the estimated MET capacity between 8-12 minutes
Commonly Used Clinical Commonly Used Clinical Protocols: Protocols:
Naughton: 2.0 mph X 3.5% increases every 2 minutes
Max METs = 9 /16 minutes
Balke: 3.3 mph X 3% increases every 3 minutes
Max METs = 12 /18 minutes
McHenry: Similar to Balke but Stage I is 2.0 mph/3% grade
Measurements: HR, BP, Measurements: HR, BP, ECGECGPre-Test: Supine and Exercise Position
Exercise: HR/BP in final minute of each stage – ECG every minute and whenever irregularities appear
Post-Test: Immediately post exercise and every 1-2 minutes until full recovery
Measurements: RPE, Measurements: RPE, SymptomsSymptoms
RPE: In the last minute of each stage
Symptoms: Note symptoms that occur:
Ask frequently, “How are you feeling?”
Rating Anginal Symptoms: Rating Anginal Symptoms:
1+: Light, barely noticeable
2+: Moderate, bothersome
3+: Severe, very uncomfortable
4+: Most severe pain ever experienced
Post Exercise Period: Post Exercise Period: For Maximal Diagnostic Sensitivity:
No Cool Down10-sec ECG immediately 6-8 minutes of supine monitoring* - record ECG every minute or after any irregularity
*Unless patient is severely dyspneic – then sitting preferred
Testing Competencies: Testing Competencies:
Know Absolute and Relative indications for test termination:
3+ to 4+ angina
Suspected MI
Drop in SBP with increased work
Serious arrhythmias
Signs of poor perfusion
Patient request
Exercise Test Endpoints:Exercise Test Endpoints:
Pre-determined HR achieved
Pre-determined Workload achieved
Patient c/o CP, SOB, leg pains, fatigue
ECG changes:Significant ST changes
New Bundle branch or AV block
Increasing PVC frequency, VT or Fib
A Little Diagnostic A Little Diagnostic InteractionInteraction
HHMI Cardiology Lab
Cardiovascular Cardiovascular PharmacologyPharmacology
Exercise Implications
Understanding the Role of Understanding the Role of Medications in Exercise:Medications in Exercise:
What is the physiological response to exercise?
What is the mechanism of action of the drug?
Is there individual variability?
How are generalities best applied to exercise testing and prescription?
Cardiovascular Response to Cardiovascular Response to Exercise: Acute / Chronic Exercise: Acute / Chronic
Changes in Autonomic Nervous System
SNS: Acute responses
PSNS: Resting status in trained persons
Cardiovascular Changes:HR, BP, myocardial contractility, venous return, vascular resistance,
Therefore: Therefore:
Any drug that acts on the autonomic nervous system, heart, blood vessels or kidneys may impact exercise
Drug Classifications: Drug Classifications: Mechanism: Mechanism: Use: Use:
Diuretics:
ACE Inhibitors
Beta-blockers
Ca++ Channel blockers
Nitrates
Anti-hypertensiveAnti-hypertensive, CHF, Anti-hypertensive, tachycardiasAnti-hypertensive, tachycardiasAnti-anginal
Diuretics: Diuretics:
Alter renal reabsorption or secretion of H2O and/or Na+
Increase diuresis
Used for Hypertension and CHF
May cause electrolyte imbalances: especially K+
Commonly Used Diuretics:Commonly Used Diuretics:
Thiazide Diuretics: Diuril, (Lozol)
Loop Diuretics: Lasix, Bumex, Edecrin
K+ Sparing: Aldactone, Dyazide
Effects of Diuretics on Effects of Diuretics on Exercise: (See ACSM)Exercise: (See ACSM)
Very little effect except for decreased blood pressure
CAUTION: May cause PVC’s or false + ischemia signs with electrolyte imbalances
ACE Inhibitors: ACE Inhibitors: Inhibits Renin-Angiotensin Aldosterone (RAA) System:
Renin is released from kidneys in response to hypotension/ Na+
Renin increases levels of Angiotensin I (liver)Angiotensin Converting Enzyme (ACE) converts Ang I to Angiotensin II (active)
What Does Angiotensin II Do?What Does Angiotensin II Do?
Vasoconstriction Blood Pressure
Increase H2O and N+
Retention
Stimulate release of ADH and Aldosterone
Net Effect: Increase Blood Pressure
Therapeutic Uses of ACE Therapeutic Uses of ACE Inhibitors: Inhibitors:
Hypertension: Improved diuresis, vascular relaxationCHF: The combined effect of diuresis, vascular relaxation reduces Pre/After-Loads on heart
* Affects diuresis without direct action on kidneys – can be used in patients with impaired kidney function
Commonly Used ACE Commonly Used ACE Inhibitors:Inhibitors:
Captopril (Capoten): Used in mild to moderate hypertension
Vasotec, Lotensisn: Used in all hypertensions and CHF
Zestril, Prinivil: Once a day dosing
Effects of ACE Inhibitors on Effects of ACE Inhibitors on Exercise: Exercise:
Little effect except to decrease blood pressure
May actually improve exercise capacity in patients with CHF
Beta-Blockers: Beta-Blockers: Beta-adrenoceptor antagonist:
Reduces SNS stimulation of Beta-receptorsProlongs AV conduction ( HR)Inhibit Phase 4 DepolarizationDecrease Contractility
Decreases MVO2
Contraindicated: CHF*, asthma, diabetes
Therapeutic Uses Of Beta-Therapeutic Uses Of Beta-Blockers:Blockers:
Used for treating mild to moderate hypertension
Treating Angina
Reducing tachyarrhythmias
Commonly Used Beta-Commonly Used Beta-Blockers:Blockers:
InderalLopressorCorgardBlocadrenTenormimLopressor
Effect of Beta-Blockers on Effect of Beta-Blockers on Exercise:Exercise:
Reduced resting and exercise HR/BP
Reduced ischemia
Exercise capacity equivocal: may decrease in patients without angina
Calcium Channel Blockers:Calcium Channel Blockers:
Block slow calcium channels in myocardial and vascular smooth muscle cells:
Reduce vasoconstriction
Decrease cardiac contractility
Decrease MVO2
Can lead to AV-Block
Therapeutic Uses of Calcium Therapeutic Uses of Calcium Channel Blockers:Channel Blockers:
Treatment of Hypertension
Tachyarrhythmias
Cautious use in CHF
Commonly Used Calcium Commonly Used Calcium Channel Blockers: Channel Blockers:
Verapamil: Calan, Verelan
Diltiazem: Cardizem
Nifedipine: Procardia
Nicardipine: Cardene
Effects of Calcium Channel Effects of Calcium Channel Blockers on Exercise:Blockers on Exercise:
Check ACSM Manual
Variable Effects on Heart Rate
Blood Pressure
Exercise Capacity
Nitrates:Nitrates:
Dilates all blood vessels
Relieves symptoms of angina:Vasodilation decreases cardiac pre-load and MVO2
Fast acting
Short lived effects
Nitroglycerine:Nitroglycerine:
Generally used for immediate relief of anginaSublingual: also Isordil, SorbitrateAdverse Effects:
Orthostatic hypotensionHeadache, reflex tachycardiaExcesses can produce methemoglobin - hemolysis
Exercise and Nitrates:Exercise and Nitrates:
Increase HR
Decrease BP
Increase exercsie capacity for those with angina