Advanced ECG in 2016: more than just an examination?
Tobias Reichlin et al.: significant progress in biomedical computing, signal processing and computing power has given rise to new electrocardiogram markers and technologies. These open up new possibilities for addressing current needs in clinical cardiology. Even so, these ECG technologies have not yet been introduced into clinical practice.
The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is essential in managing patients with cardiovascular disease, including patients with:
- acute myocardial infarction,
- suspected chronic cardiac ischaemia,
- cardiac arrhythmia,
- heart failure,
- implantable cardiac devices.
Unlike many other methods in cardiology, the ECG is simple, compact, mobile, widely available and inexpensive, which makes it particularly attractive. Standard interpretation of the electrocardiogram is based mainly on direct visual assessment.
Advantages of the new method
Progress in biomedical computing and signal processing, together with the available computing power, offers exciting new possibilities for ECG analysis relevant to all areas of cardiology. Several digital electrocardiogram markers and advanced technologies in this field have shown good promise in preliminary studies.
This article reviews promising new surface ECG technologies in three different areas. Several topics were discussed.
- Detection of myocardial ischaemia and infarction: analysis of QRS morphology features, analysis of high-frequency QRS components (HF-QRS), methods using vectorcardiography, and ECG imaging.
- Methods of advanced P-wave analysis for identifying and treating patients with cardiac arrhythmias. The concept of ECG imaging for non-invasive localisation of heart rhythm disorders is presented.
- Several new markers for risk stratification of sudden cardiac death and for selecting patients for device therapy, including automated QRS scoring for scar quantification, the QRS-T angle, and the T-wave peak-to-end interval.
ECG imaging, for example, is a non-invasive method that combines an electrocardiogram vest with > 250 electrodes, recording electrical potentials from the body surface at high resolution, with detailed heart and torso geometry obtained from computed tomography of the chest. Local electrical signals across the entire epicardial surface of the heart can then be calculated using an inverse solution method.
Despite the existing preliminary data, none of the advanced electrocardiogram markers and technologies has yet been introduced into clinical practice. Further refinement of these technologies and broader validation in larger patient populations is the critical next step in facilitating the transition of advanced electrocardiogram technologies into clinical cardiology.
