Chest pain, breathlessness, palpitations or unusually rapid exhaustion can indicate a disease of the heart muscle. However, the symptoms often resemble those of coronary artery disease and do not initially allow a clear conclusion to be drawn about their cause. Even once coronary artery disease has been ruled out, diagnosing inflammation or another disease of the heart muscle often remains difficult.
A study by the German Heart Centre of the Charité (DHZC) now shows that magnetocardiography could usefully complement this diagnostic process in future. The fully non-invasive procedure measures the extremely weak magnetic field of the heart. In the MagMa study, the method detected heart muscle diseases with high accuracy. The results have now been published in the journal JACC: Heart Failure.
Making the heart's magnetic field visible
Every heartbeat is triggered by electrical processes in the heart muscle cells. Alongside the electrical voltage, which can be measured with an ECG, this also generates a very weak magnetic field.
In magnetocardiography, or MCG for short, this magnetic field is captured using especially sensitive sensors. Patients only need to lie under a measuring device for a few minutes. No physical contact is required. The examination requires no radiation and no contrast agent, and can therefore be repeated as often as needed.
The measured signals reveal whether the electrical processes in the heart muscle are altered. Such changes can be an indication of a disease of the heart muscle.
"Magnetocardiography looks at the heart from a different perspective to established imaging," explains Prof. Dr Bettina Heidecker, senior consultant at the DHZC and head of the magnetocardiography division. "A cardiac MRI mainly shows us changes in the structure and tissue of the heart muscle. Magnetocardiography, by contrast, captures changes in the electrical processes within the heart muscle cells. Our study shows that this additional information can be highly valuable for diagnosing heart muscle diseases."
Comparison with established diagnostics
The MagMa study involved 110 adult patients. They had been examined because of chest pain, breathlessness, palpitations, reduced exercise capacity or other symptoms that could point to a disease of the heart muscle. Relevant coronary artery disease had previously been ruled out by cardiac catheterisation or computed tomography.
In addition to the usual diagnostic work-up, all patients underwent magnetocardiography. The results were then compared with the findings from established diagnostic procedures. Depending on medical necessity, these included a cardiac MRI, a PET-CT scan, or a tissue sample taken from the heart muscle, known as an endomyocardial biopsy.
The researchers also examined 220 healthy individuals who were comparable to the patient group in terms of age and sex. In total, data from 330 people were included in the study.
The results show a high level of diagnostic accuracy: of 100 people who actually had a heart muscle disease, magnetocardiography correctly identified around 95. Of 100 people without such a disease, around 99 were correctly classified as unaffected.
In technical terms, this corresponds to a sensitivity of around 95 per cent and a specificity of around 99 per cent. Sensitivity describes how reliably an examination detects an existing disease. Specificity indicates how reliably it produces a normal result in people who are not affected.
Abnormal findings despite an unremarkable cardiac MRI
The findings in three patients were particularly notable. In these cases, the cardiac MRI had not provided clear evidence of a heart muscle disease. Magnetocardiography, however, showed an abnormal result in each case. A subsequent examination of tissue samples from the heart muscle confirmed an inflammatory disease in all three cases.
"Magnetocardiography is not intended to replace either cardiac MRI or heart muscle biopsy," Bettina Heidecker emphasises. "But it could help us quickly and easily identify those patients for whom further diagnostic work-up is particularly important. Conversely, a normal result could help spare patients an extensive further diagnostic process."
An earlier retrospective study by the research group had already provided indications that magnetocardiography can detect inflammatory and other diseases of the heart muscle (see publication). In the MagMa study, the method was for the first time tested prospectively from the outset in a defined patient group and systematically compared with established diagnostics.
A possible rapid preliminary examination
According to the researchers, magnetocardiography could in future be used above all as a rapid preliminary examination. It could help identify patients with a high probability of having a heart muscle disease at an early stage and refer them specifically for specialised investigations.
"We are looking for methods that can detect early changes in the cardiovascular system. The scientific investigations using magnetocardiography are very exciting in this respect," says Prof. Dr Ulf Landmesser, director of the DHZC Department of Cardiology, Angiology and Intensive Care Medicine at Campus Benjamin Franklin and co-author of the study.
Since the examination requires no radiation or contrast agent, it could also be of interest for regular follow-up monitoring in future. For example, it might be conceivable to detect changes during treatment or a recurrence of heart muscle inflammation at an early stage. However, these potential applications were not part of the current study.
A method with a long history
Magnetocardiography is not a new invention. Scientists have been researching how the heart's magnetic field can be used for medical examinations for several decades. However, wider clinical application has long been hindered by technical difficulties and a lack of larger studies.
Among the scientists who have helped shape the development of magnetocardiography over many years is cardiologist PD Dr Jai-Wun Park. From the turn of the millennium onwards, he investigated, among other things, whether the method could provide additional information in patients with acute chest pain, and played a key role in developing magnetocardiography parameters for diagnostic purposes.
"Quantum sensor-based cardiological diagnostics has occupied medical research for decades," says Park. "The technical capabilities for analysing these extremely fine magnetic field patterns have since advanced considerably. In this context, the MagMa study is an important step in scientifically examining the potential benefit of the method for patients. We can take confidence in Germany as a centre of scientific excellence from the fact that the two most highly ranked original papers on adult magnetocardiography published worldwide since 1963 (Baule & McFee) have now both come from the Charité — within just nine weeks of each other. My warmest congratulations once again to everyone involved!"
Further studies needed
Despite the promising results, magnetocardiography is not yet suitable for widespread use in routine medical practice. The MagMa study was conducted at a single centre specialising in heart muscle diseases. The patients examined already had symptoms suggestive of such a disease. Whether the method delivers similarly reliable results in other patient groups therefore still needs to be investigated further.
The technology also currently has particular requirements. The extremely sensitive measurements must be carried out in a room shielded from interfering magnetic fields from the surrounding environment. In people with certain metallic implants in the chest, the examination may also be affected.
The researchers are therefore planning further studies at several clinics. These are intended to show whether the results can be confirmed in larger and more diverse patient groups, and what role magnetocardiography may play in medical care in future.
Source: Press release DHZC
Original publication: Suwalski P, Wilke F, Latinova E, et al. The MagMa Study – Quantum Magnetocardiography in Cardiomyopathy. JACC Heart Fail. 2026. doi:10.1016/j.jchf.2026.103182
