In Lithuania, more and more people are suffering from cardiovascular diseases. So it's important to spot disorders in time so they can be addressed in time. An excellent way to do this is bicycle ergometry (an exercise stress test). During it, an attempt is made to provoke possible heart rhythm disorders and to observe changes in existing arrhythmias under a dosed physical load, as well as changes in arterial blood pressure during exertion. The examination is carried out by pedalling a special stationary medical bicycle, while the cardiologist monitors the heart rate, breathing, electrocardiogram, blood pressure and the patient's general condition. The ECG (electrocardiogram) is monitored and recorded before, during and after the exertion. This examination is also recommended for prevention for people who have no heart complaints. It's prescribed for patients and athletes when the heart and the quality of its work need to be assessed, as well as to assess physical fitness (relevant for athletes, as the limits of training load are found out) and to assess the effect of rehabilitation. Before the procedure it's not recommended to: take long-acting nitrates (1 day); take long-acting calcium channel blockers (3 days); take β-blockers (3 days); take cardiac glycosides (5 days); take amiodarone (1 month). The patient must have eaten; wear comfortable clothing and footwear; and have drunk a sufficient amount of fluids in the 2 hours before the examination.