Stress ECG

Some heart conditions only become apparent during physical exertion. In particular, with coronary heart disease (CHD), the resting ECG is frequently unremarkable. In a stress ECG, however, the condition can be diagnosed through arrhythmias or ECG changes. Further indications for a stress ECG include:

• Follow-up after heart attack or bypass surgery
• Exercise-induced cardiac arrhythmia
• Monitoring the progress of a treated arrhythmia
• Hypertension
• Assessment of individual exercise capacity
• Monitoring the success of pharmacological treatment (e.g. for hypertension)

As with a resting ECG, the doctor places electrodes on the patient's skin and connects them via cables to an ECG device. This 12-lead ECG then records cardiac activity while the patient is physically active, for example on a treadmill or a stationary bicycle (cycle ergometer). The exercise device can be set to different levels of exertion corresponding to the physical demands of everyday life:

• 25 to 50 watts: normal walking
• 75 to 100 watts: climbing stairs or slow cycling
• 125 to 150 watts: jogging or fast cycling
• above 150 watts: strenuous sporting activity

The workload is increased by 25 watts every two minutes. The stress ECG lasts approximately 15 minutes. The doctor immediately terminates the stress ECG if there are dangerous ECG changes, an excessive rise in blood pressure (> 250 mmHg systolic and > 120 mmHg diastolic), or if the patient develops symptoms. Otherwise, the wattage continues to be increased until the maximum heart rate (= 220 minus age) is reached or the patient is exhausted. After the exercise phase, the patient is monitored for a further six minutes to assess the recovery of heart rate.

In addition to performance — measured in watts — the practice also assesses the patient's subjective perception of exertion. The patient provides feedback during the examination regarding their perceived level of effort. Blood pressure and heart rate are also recorded for monitoring and diagnostic purposes.

The resting heart rate is 60 to 80 beats per minute and rises naturally with physical exertion. To determine the individual target performance capacity, the doctor uses the following rule of thumb for the stress ECG: the patient's age in years is subtracted from a heart rate of 220 beats per minute, giving their exercise limit.

If the patient has a cardiac condition, typical changes in the ECG are often visible. However, particularly in patients in whom coronary heart disease is not yet known and/or who have no symptoms, the stress ECG may also yield false-normal results. This means: no abnormalities are found, even though the person has CHD. For this reason, doctors usually supplement the stress ECG with further investigations.

A stress ECG cannot be booked directly at one of our practices. It is usually performed in the context of an investigation for coronary heart disease or a suspected diagnosis thereof.