It is a cardiac stress test, measuring hearts ability to sustain stress given by exercise in controlled environment.
Mainly used to diagnose Coronary artery disease or determine prognosis after Myocardial infarction (heart attack) or coronary revascularization (angioplasty or bypass surgery).
Before doing the test, its preferable not to eat before two hours. Patient can have water if they feel like having.
Total time is approximately an hour. Test lasts for 10 to 15 minutes. Preparation takes around 15 minutes.
After taking history and checking vitals, chest leads are applied and patient is explained that machine will gradually increase speed and slope every three minutes. For better application of electrodes, shaving may be preferable in chest. Test can be immediately stopped if patient feels so or having chest pain, breathlessness or fatigue. Doctor can also order stopping of test upon finding ECG changes. Most adults achieve target heart rate in 9 minutes.
Positive test means patients ECG is showing changes of angina (lack of adequate blood supply to heart) after workload. It means patient is suffering from ischemic heart disease.
Negative result means even at moderate or high workload, patients heart is having enough blood supply and there is no signs of ischemic heart disease.
There can be exacerbation of angina, breathlessness, arrhythmia or death. Chances of these complications are 1 %. Test should be carried out in presence of doctor and in set up where iCU and defibrillator facilities are available.
Sensitivity of Tredmill test is 73 – 90 % and specificity is 50 – 74 %.
In India, average costing is between 1800 – 2500 Rs. Test is being carried out on OPD basis and needs no hospitalization.