Impedance cardiography during exercise – new technology, new possibilities
Małgorzata Kurpaska, Paweł Krzesiński, Grzegorz Gielerak
Exercise impedance cardiography is a non-invasive method for the assessment of haemodynamic parameters of the cardiovascular system during exercise. Owing to the technology based on morphological analysis of the impedance signal and advanced artifact filtering, the method enables to perform a test at the onset of symptoms. High repeatability and accuracy of exercise impedance cardiography have been confirmed in a number of studies. Previous clinical experience indicates the utility of exercise impedance cardiography in the objectification of reported complaints, identification of haemodynamic background of the observed symptoms and subclinical cardiovascular dysfunction. Qualitative assessment of impedance cardiography waveform may be useful in the detection of left ventricular diastolic dysfunction, ventricular dyssynchrony and hypervolaemia. Evaluation of haemodynamic parameters during exercise may support the diagnosis of ischaemic heart disease, heart failure, arterial and pulmonary hypertension. Stroke volume profile or cardiac output alterations may precede clinical symptoms and abnormalities previously detected by standard methods. Therefore, exercise impedance cardiography is undoubtedly an added value to classical diagnostic methods such as the echocardiography or exercise tests. This is highlighted in the current 2016 guidelines for the implementation of ergospirometry. Exercise impedance cardiography, as a relatively simple, inexpensive and reliable test, is likely to play an increasingly important role in evaluating patients’ physical capacity, particularly as an alternative to invasive haemodynamic methods. The clinical value of exercise impedance cardiography should be evaluated in future studies.