eet (exercise tolerance test )
TRANSCRIPT
WHAT IS ETT?
• AN EXERCISE TOLERANCE TEST OR STRESS TEST RECORDS THE HEART'S ELECTRICAL ACTIVITY (RATE AND
RHYTHM) DURING EXERCISE.
• IS ONE OF THE COMMONEST FORMS OF STRESS TESTS USED TO INDUCE PROVOKABLE MYOCARDIAL
ISCHEMIA FOR DIAGNOSTIC EVALUATION OF CORONARY ARTERY DISEASE.
EQUIPMENT REQUIRED
• TREADMILL MACHINE OR EXERCISE BIKE
• 12-LEADS ELECTROCARDIOGRAPH (ECG) MACHINE
• STOP WATCH
• LEADS
• CLIPS
• STICKING TAPE
PROCEDURE
• A PROGRESSIVE AND MAXIMUM EXERCISE TEST (STARTING FROM A WALKING PACE AND GRADUALLY
INCREASING PACE) IS PERFORMED WHILE THE ELECTRICAL IMPULSES FROM THE HEART TISSUE ARE
RECORDED BY SURFACE ELECTRODES PLACES ON THE CHEST WALL.
ETT POINTS
WHAT DOES ETT DO?
IN ETT, (ALSO KNOW AS STRESS TEST), IT MEASURES:
• HEART RATE
• BLOOD PRESSURE
• ECG
ETT
• PATIENT IS REQUESTED TO DO EXERCISE ON A TREADMILL MACHINE.
• DURATION 6 TO 10 MINUTES
Useful in diagnosis of…
• Cardiac Arrhythmias
• Myocardial ischemia and infarction
• Pericarditis
• Chamber hypertrophy
• Electrolyte disturbances
• Drug effects and toxicity
CALCULATING HEART RATE
Normal H.R. 60-90 bpm
What is an ECG?
An ECG is the recording (gram)
of the electrical activity(electro) generated by the cells of the heart(cardio) that reaches the body surface.
ECG Leads
Leads are electrodes which measure the difference in electrical potential between either:
1. Two different points on the body (bipolar
leads)
2. One point on the body and a virtual reference
point with zero electrical potential, located in
the center of the heart (unipolar leads)
ECG Leads
The standard ECG has 12 leads:
The axis of a particular lead represents the viewpoint from
which it looks at the heart.
3 Standard Limb Leads
3 Augmented Limb Leads
6 Precordial Leads
Basics
ECG graphs:
–1 mm squares
–5 mm squares
Paper Speed:
–25 mm/sec standard
Voltage Calibration:
–10 mm/mV standard
ECG Paper: Dimensions5 mm
1 mm
0.1 mV
0.04 sec
0.2 sec
Speed = rate
Voltage
~Mass
+-
RA
RA
LL+
+
--LA
LL
LA
LEAD II
LEAD I
LEAD III
Remember, the RL
is always the ground
• By changing the
arrangement of which
arms or legs are
positive or negative,
three unipolar leads (I,
II & III ) can be derived
giving three "pictures"
of the heart's electrical
activity from 3 angles.
Leads I, II, and III
I
II III