Treadmill Test

Khairul Nizam Abdul Rahman4262143008

What is Treadmill Test?

• Treadmill test is also called a stress test, exercise electrocardiogram, graded exercise test, or stress ECG. It is used to provide information about how the heart responds to exertion. It usually involves walking on a treadmill at increasing levels of difficulty, while electrocardiogram, heart rate, and blood pressure are monitored.

Why Need Treadmill Test?Treadmill test is use to• Determine if there is adequate blood flow to heart during increasing levels

of activity.• Evaluate the effectiveness of heart medications to control angina and

ischemia.• Determine the likelihood of having coronary heart disease and the need

for further evaluation.• Check the effectiveness of procedures done to improve blood flow within

the heart vessels in people with coronary heart disease.• Identify abnormal heart rhythms.• Help to develop a safe exercise program.

Contraindication• Acute myocardial infarction (within 2 days)• High-risk unstable angina• Symptomatic severe aortic stenosis• Symptomatic heart failure• Acute pulmonary embolus or pulmonary infarction• Acute myocarditis or pericarditis• Acute aortic dissection• Electrolyte abnormalities• Tachy or Brady arrhythmias • Mental or physical impairment• Hypertension (>200/100 at rest)• Neuromuscular and musculoskeletal disorder exacerbated by exercise block

Technique

1. Patients should be instructed not to drink, eat caffeinated beverages or smoke 3hour before testing & to wear comfortable shoes and clothes.

2. Unusual physical exertion should be avoided3. Brief history & physical examination should be performed4. Should be instructed about risks and benefits5. Informed consent is taken6. 12 lead ECG is recorded with electrodes at the distal extremities7. Torso ECG is obtained in standing and sitting position8. If false +ve test is suspected, hyperventilation should be

performed

Technique 9. Area of electrode application should be rubbed with alcohol

saturated pad to remove oil and rubbed with sand paper to reduce skin resistance to 5000ohms or less

10. Cables should be light flexible and shielded11. Room temperature should be 18-24 C and humidity less than

60%12. Walking should be demonstrated to patient13. HR, BP & ECG should be recorded at the end of each stage.14. Minimum of 3 leads should be displayed continuously on the

monitor15. A resuscitator cart, defibrillator and appropriate cardioactive

drugs should be available in the TMT room.

When To Stop!?TMT might be prematurely stopped for any of the following: • Moderate to severe angina• Increasing chest pain• Increasing nervous system symptoms (ataxia, dizziness)• Signs of poor perfusion (cyanosis or pallor)• Sustained ventricular tachycardia• ST elevation (≥1.0 mm) • ST depression (>2 mm)• Drop in SBP of (≥10 mmHg) BP without ischemia• Heart block or brady arrhythmias• Technical difficulties in monitoring ECG or SBP• Fatigue, shortness of breath, wheezing, leg cramps

Bruce Protocol

• Total of 1+6 (Seven 3 minute stages) – (3+18 min)• Each minute exercise is approximately 1 MET• Pretest plain walking + 6 Stages of graded exercise• In each stage there is increase in speed and

gradient• Initial 1.7 mph with 10% gradient (upward

inclination)• Maximum 5.5 mph with 20% gradient

Bruce ProtocolStage Minutes % grade km/h MPH METS

1 3 10 2.7 1.7 5

2 6 12 4.0 2.5 7

3 9 14 5.4 3.4 10

4 12 16 6.7 4.2 13

5 15 18 8.0 5.0 15

6 18 20 8.8 5.5 18

7 21 22 9.6 6.0 20

What is MET?

• Metabolic Equivalent Term • 1 MET = 3.5 ml O2 per kilogram of body weight

per minute• Actually differs with thyroid status, post

exercise, obesity, disease states• By convention just divide ml O2/Kg/min by 3.5 METs = Speed x [0.1 + (Grade x 1.8)] + 3.5 3.5 • Calculated automatically by Device

Karvonen Method

• The Karvonen method factors in resting heart rate (HRrest) to calculate target heart rate (THR), using a range of 50–85%:

• THR = ((HRmax − HRrest) × %Intensity) + HRrest• Example for someone with a HRmax of 180 and a

HRrest of 70:• 50% intensity: ((180 − 70) × 0.50) + 70 = 125 bpm• 85% intensity: ((180 − 70) × 0.85) + 70 = 163 bpm