1

STRESS TEST AND HEMODYNAMICS Lois Rowland, MS, RRT-NPS, RPFT, FAARC

Objective: Prepare NBRC candidate for CRT and WRT Content Outline

Perform, evaluate patient response to, interpret results from:

Stress testing e.g. ECG, pulse oximetry Hemodynamic assessment

2

STRESS TESTS / EXERCISE TESTING

Exercise Test Indications • DOE, angina, fatigue

3

Exercise Test Indications • DOE, angina, fatigue • Ventilatory limitations to work • Cardiovascular limitations to work

Exercise Test Indications • DOE, angina, fatigue • Ventilatory limitations to work • Cardiovascular limitations to work • Conditioning or deconditioning

4

Exercise Test Indications • DOE, angina, fatigue • Ventilatory limitations to work • Cardiovascular limitations to work • Conditioning or deconditioning • Maximum tolerable workload • Disability assessment • Appropriate levels of supplemental O2

• Outcomes following treatment

Exercise Test Contraindications

MI within 4 weeks Unstable angina 2nd or 3rd degree heart block Rapid arrythmias Orthopedic impairment Severe aortic stenosis CHF Uncontrolled HTN Severe pulmonary HTN

Dissecting/ventricular aneurysms Limiting neurologic disease Thrombophlebitis or intracardiac thrombi Recent systemic or pulm.embolus Acute pericarditis PaO2 < 40 mmHg on RA PaCO2 > 70 mmHg FEV1 < 30% predicted

These are relative contraindications, case-by-case:

5

Exercise Test Equipment Treadmill Cycle Ergometer

Workload measured in METs MET: multiples of the resting O2 uptake, usu. 3.5 ml/kg

Primary Indication

Exercise Equipment

Measurements Test End

6 Minute Walk Test (6MWT)

pre- and post-tx evaluation

Hallway 100+ ft.

distance walked, O2 setting and how transported (optional SpO2)

walk as far as possible X 6 minutes, signs ischemia

6

Primary Indication

Exercise Equipment

Measurements Test End

6 Minute Walk Test (6MWT)

pre- and post-tx evaluation

Hallway 100+ ft.

distance walked, O2 setting and how transported (optional SpO2), dyspnea score

walk as far as possible X 6 minutes, signs ischemia

Interpretation: serial, comparative

Primary Indication

Exercise Equipment

Measurements Test End

Cardiac Stress CAD evaluation Treadmill, cycle ergometer, pharma-cologic

BP, HR, ECG End protocol, sustained Vtach, signs ischemia

7

Primary Indication

Exercise Equipment

Measurements Test End

Cardio- Pulmonary Exercise Testing (CPET)

Cardiac &/or pulm exercise in/tolerance

Treadmill, cycle ergometer

BP, HR, ECG, RR, SpO2 or ABG, expired gases (O2, CO2, volumes)

Predetermined HR or VO2max, exhaustion, signs ischemia

Image courtesy of MEDGRAPHICS®

CPET (CPX) Collection and analysis: •  tidal volume, RR, minute ventilation • VO2: O2 consumption or O2 uptake • VCO2: CO2 production • AT: anaerobic threshold, when ventilation ↑ disproportionately to VO2

60-70% pred. VO2max

8

VCO2

VO2

Anaerobic Threshold (AT)

AT: ventilation increases disproportionately to O2 uptake •  Cardiac disease: AT occurs at <40% of VO2max •  Deconditioning: AT occurs at <pred. VO2max, no s/s cardiovascular disease

40% VO2 pred

VCO2

VO2

Anaerobic Threshold (AT) not met

AT: ventilation increases disproportionately to O2 uptake • Ventilatory limitation: AT not met

9

Exercise Test Interpretation Normal Cardiac Disease Ventilatory

Disease Deconditioning

VO2max 80% pred ↓ ↓ ↓

VEmax < 70% MVV N > 90% MVV N

AT 60-70% pred achieved, low VO2 not achieved achieved, low VO2

HR 220 – age (target usu. 85%) ↑ N ↑

ECG signs of ischemia none Present &/or chest

pain N N

SaO2 or SpO2

> 90% N ↓ N

Primary Indication

Exercise Equipment

Measurements Test End

Exercise bronchial challenge

EIB Treadmill, cycle ergometer

During: BP, ECG, SpO2 (optional ABG) Pre & post spirometry

85% pred max HR X 6-8 min.

FEV1 after exercise • 1 minute • 2 minutes • Every 5 minutes

10

Primary Indication

Exercise Equipment

Measurements Test End

Exercise bronchial challenge

EIB Treadmill, cycle ergometer

During: BP, ECG, SpO2 (optional ABG) Pre & post spirometry

85% pred max HR X 6-8 min.

FEV1 after exercise • 1 minute • 2 minutes • Every 5 minutes

Interpretation: ↓ 10-15% from pre-exercise FEV1: airway hyperreactivity

Primary Indication

Measurements Interpretive value

6 Minute Walk Test (6MWT)

pre- and post-tx evaluation

distance walked, O2 setting and how transported (optional SpO2), dyspnea score

comparative

Cardiac Stress CAD evaluation BP, HR, ECG presence or severity of CAD

Cardio- Pulmonary Exercise Testing (CPET)

Cardiac &/or pulm exercise in/tolerance

BP, HR, ECG, RR, SpO2 or ABG, expired gases (O2, CO2, volumes)

Differential dx of cardiac and/or pulmonary conditions; evaluate exercise tolerance, endurance

Exercise bronchial challenge

EIB During: BP, ECG, SpO2 (optional ABG) Pre & post spirometry

Presence or severity of airway hyperreactivity, responsiveness to bronchodilator therapy

11

HEMODYNAMICS

12

13

14

15

16

17

18

19

References American Thoracic Society/American College of Chest Physicians. ATS/ACCP

Statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003; 167: 211-277.

American Thoracic Society. ATS Statement: Guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002; 166: 111-117. Pilbeam, S. P., & Cairo, J. M. (2006). Mechanical ventilation: Physiologic and clinical applications. (4th ed.). St. Louis, MO: Mosby Elsevier. Ruppel, G. (2003). Manual of pulmonary function testing. (8th ed.). St. Louis, MO: Elsevier Saunders. Wilkins, R. L., Stoller, J. K., & Kacmarek, R. M. (2009). Egan's fundamentals of respiratory care. (9th ed.). St. Louis, MO: Mosby Elsevier.