Breaking News
December 16, 2018 - Johns Hopkins researchers identify molecular causes of necrotizing enterocolitis in preemies
December 16, 2018 - Advanced illumination expands capabilities of light-sheet microscopy
December 16, 2018 - Alzheimer’s could possibly be spread via contaminated neurosurgery
December 16, 2018 - Unraveling the complexity of cancer biology can prompt new avenues for drug development
December 16, 2018 - Inflammatory Bowel Disease, Prostate Cancer Linked
December 16, 2018 - Cannabis youth prevention strategy should target mental wellbeing
December 15, 2018 - Recent developments and challenges in hMAT inhibitors
December 15, 2018 - Sewage bacteria found lurking in Hudson River sediments
December 15, 2018 - CDC selects UMass Amherst biostatistician model that helps predict influenza outbreaks
December 15, 2018 - Researchers reveal brain mechanism that drives itch-evoked scratching behavior
December 15, 2018 - New computer model helps predict course of the disease in prostate cancer patients
December 15, 2018 - Obesity to Blame for Almost 1 in 25 Cancers Worldwide
December 15, 2018 - How the brain tells you to scratch that itch
December 15, 2018 - New findings could help develop new immunotherapies against cancer
December 15, 2018 - World’s largest AI-powered medical research network launched by OWKIN
December 15, 2018 - Young people suffering chronic pain battle isolation and stigma as they struggle to forge their identities
December 15, 2018 - Lifespan extension at low temperatures depends on individual’s genes, study shows
December 15, 2018 - New ingestible capsule can be controlled using Bluetooth wireless technology
December 15, 2018 - Researchers uncover microRNAs involved in the control of social behavior
December 15, 2018 - Research offers hope for patients with serious bone marrow cancer
December 15, 2018 - Link between poverty and obesity is only about 30 years old, study shows
December 15, 2018 - Mass spectrometry throws light on old case of intentional heavy metal poisoning
December 15, 2018 - BeyondSpring Announces Phase 3 Study 105 of its Lead Asset Plinabulin for Chemotherapy-Induced Neutropenia Meets Primary Endpoint at Interim Analysis
December 15, 2018 - Study finds that in treating obesity, one size does not fit all
December 15, 2018 - Tenacity and flexibility help maintain psychological well-being, mobility in older people
December 15, 2018 - Study reveals role of brain mechanism in memory recall
December 15, 2018 - High levels of oxygen encourage the brain to remain in deep, restorative sleep
December 15, 2018 - Experimental HIV vaccine strategy works in non-human primates, research shows
December 15, 2018 - Genetically modified pigs could limit replication of classical swine fever virus, study shows
December 15, 2018 - FDA Approves Herzuma (trastuzumab-pkrb), a Biosimilar to Herceptin
December 15, 2018 - Cost and weight-loss potential matter most to bariatric surgery patients
December 15, 2018 - Cancer Research UK and AstraZeneca open new Functional Genomics Centre
December 15, 2018 - New research lays out potential path for treatment of Huntington’s disease
December 15, 2018 - Prestigious R&D 100 Award presented to Leica Microsystems
December 15, 2018 - Study shows septin proteins detect and kill gut pathogen, Shigella
December 15, 2018 - Study sheds new light on disease-spreading mosquitoes
December 15, 2018 - 2017 Saw Slowing in National Health Care Spending
December 15, 2018 - Monitoring movement reflects efficacy of mandibular splint
December 15, 2018 - Study supports BMI as useful tool for assessing obesity and health
December 15, 2018 - Self-guided, internet-based therapy platforms effectively reduce depression
December 15, 2018 - Organically farmed food has bigger climate impact than conventional food production
December 15, 2018 - Faster, cheaper test has potential to enhance prostate cancer evaluation
December 15, 2018 - Researchers study abnormal blood glucose levels of patients after hospital discharge
December 15, 2018 - Swedish scientists explore direct association of dementia and ischemic stroke deaths
December 15, 2018 - Study finds 117% increase in number of dementia sufferers in 26 years
December 15, 2018 - Eczema Can Drive People to Thoughts of Suicide: Study
December 15, 2018 - Link between neonatal vitamin D deficiency and schizophrenia confirmed
December 15, 2018 - Nurse denied life insurance because she carries naloxone
December 15, 2018 - Ritalin drug affects organization of pathways that build brain networks used in attention, learning
December 15, 2018 - Research pinpoints two proteins involved in creation of stem cells
December 15, 2018 - Gut bacteria may modify effectiveness of anti-diabetes drugs
December 15, 2018 - A new type of ‘painless’ adhesive for biomedical applications
December 15, 2018 - Early physical therapy associated with reduction in opioid use
December 15, 2018 - Breast cancer protection from pregnancy begins many decades later, study finds
December 15, 2018 - How often pregnant women follow food avoidance strategy to prevent allergy in offspring?
December 15, 2018 - Using machine learning to predict risk of developing life-threatening infections
December 15, 2018 - How imaginary friends could boost children’s development
December 15, 2018 - Folate deficiency creates more damaging chromosomal abnormalities than previously known
December 15, 2018 - Study provides new insights into molecular mechanisms underlying role of amyloid in Alzheimer’s disease
December 15, 2018 - For the asking, a check is in the mail to help pay for costly drugs
December 15, 2018 - UA scientists uncover biological processes leading to rare brain disorder in babies
December 15, 2018 - The largest database on industrial poisons
December 15, 2018 - ESMO Immuno-Oncology Congress showcases novel technologies set to benefit many cancer patients
December 15, 2018 - Ovid Therapeutics Announces Plans to Move into a Phase 3 Trial in Pediatric Patients Based on End-of-Phase 2 Meeting for OV101 in Angelman Syndrome
December 15, 2018 - Left ventricular noncompaction – Genetics Home Reference
December 15, 2018 - Children’s sleep not significantly affected by screen time, new study finds
December 15, 2018 - When should dementia patients stop driving? A new guidance for clinicians
December 15, 2018 - Researchers use INTEGRA’s VIAFLO 96/384 to streamline the experimental workflow
December 15, 2018 - Researchers discover protein involved in nematode stress response
December 15, 2018 - Cancer patients have greater risk of developing shingles, study shows
December 14, 2018 - UAlberta scientists identify biomarkers for detecting Alzheimer’s disease in saliva samples
December 14, 2018 - Study uncovers link between tube travel and spread of flu-like illnesses
December 14, 2018 - Caffeine plus another compound in coffee may fight Parkinson’s disease
December 14, 2018 - GW researchers review studies on treatments for prurigo nodularis
December 14, 2018 - Lack of peds preventive care ups unplanned hospital admissions
December 14, 2018 - Miscarriage: When Language Deepens Pain
December 14, 2018 - New method helps better understand pathological development of ALS
December 14, 2018 - Intellectually active lifestyle confers protection against neurodegeneration in Huntington’s patients
December 14, 2018 - Mammalian collagen nanofibrils become stronger and tougher with exercise
December 14, 2018 - Considerable Morbidity, Mortality Due to Animal Encounters
Heart researchers develop a new, promising imaging technique for cardiac arrhythmias

Heart researchers develop a new, promising imaging technique for cardiac arrhythmias

image_pdfDownload PDFimage_print
Maelstroms in the heart
From ultrasound images (left), Max Planck researchers have reconstructed how the heart muscle contracts vortex-like (centre) in cardiac arrhythmia. This also allows the researchers to locate the filaments (right) that form the centre of the vortices. It is hoped that these insights will provide the basis for developing improved treatment methods. Credit: MPI for Dynamics and Self-Organization

Every five minutes in Germany alone, a person dies of sudden cardiac arrest or fibrillation, the most common cause of death worldwide. This is partly due to the fact that doctors still do not fully understand exactly what goes on in the heart during the occurrence. Until now, it was impossible to visualize dynamic processes in the fibrillating heart muscle, or myocardium. In today’s publication in Nature, an international team of researchers headed by Jan Christoph and Stefan Luther of the Max Planck Institute for Dynamics and Self-Organization and Gerd Hasenfuß of the Heart Center at the University Medical Center Göttingen show for the first time how vortex-like, rotating contractions that underlie life-threatening ventricular fibrillation can be observed inside the heart with the help of a new imaging technique, which can be used with existing ultrasound equipment. In the future, this newly developed imaging technique may help medical doctors to image and thus identify heart rhythm disorders, helping them to better understand cardiac disease and further develop new, more effective methods for treatment.

When the heart muscle no longer contracts in a coordinated manner, but simply flutters or twitches – a condition referred to medically as “fibrillation” – it is a highly life-threatening situation. If the ventricles, the main chambers of the heart, twitch in this disorderly way, there is just one opportunity for medical intervention: the heart must be defibrillated within a few minutes with a strong electrical shock, which is very painful and can damage the heart’s tissue. Fibrillation of the atria, on the other hand, is not directly life-threatening; however, if left untreated it can have dire consequences. For over 100 years, researchers have sought to understand the mechanisms behind fibrillation so as to improve treatment options. “The key to a better understanding of fibrillation lies in a new, high-resolution imaging technique that allows processes inside the heart muscle to be observed,” says Stefan Luther, Leader of the Biomedical Physics Research Group at the Max Planck Institute for Dynamics and Self-Organization and Professor at University Medical Center Göttingen.

Diagnostic breakthrough

“The mechanical movements of the myocardium during fibrillation are highly complex, but they are also highly characteristic – almost like a fingerprint of fibrillation,” says Jan Christoph, a researcher at the Max Planck Institute for Dynamics and Self-Organization and the Heart Center at the University Medical Center Göttingen and lead author of the study. Together with Stefan Luther and an international team of researchers, the physicist has presented an imaging method that allows the fibrillating myocardium to be visually time-resolved in three dimensions, and therefore much more accurately than was previously possible – and it does so using clinically available high-resolution ultrasound equipment.

3D ultrasound measurements of mechanical filaments in the fibrillating heart. Credit: Max Planck Society

The new diagnostic method will help to make the treatment of ventricular fibrillation and possibly also atrial fibrillation more effective. The improved understanding of fibrillation, which can be achieved with the procedure, could help to advance the development of novel defibrillation techniques. In low-energy defibrillation, for example, the electrical pulses used to stop fibrillation are much weaker but much more targeted compared to the current, very painful method, which uses high-energy electric shocks. With the new form of ultrasound imaging, researchers could learn how to use low-energy pulses to restore normal heart rhythm.

The Göttingen-based researchers are now refining the method so that it will also be able to visualize the complex excitation dynamics, which occur during atrial fibrillation. In the future, cardiologists will be able to see exactly where pathological foci of excitation need to be removed by ablation. The new ultrasound method may also be helpful in the research, diagnosis and treatment of heart failure, during which the myocardial cells do not work effectively as their coordinated contractile movements are disrupted. Doctors would be able to determine the causes with the help of detailed ultrasound scans, enabling them to detect heart failure earlier and treat it more effectively.

Electrical waves cause mechanical contractions of the heart

Every heartbeat is triggered by electrical waves of excitation that propagate through the myocardium at high speed and cause the myocardial cells to contract. If these waves become turbulent, the result is cardiac arrhythmia. Doctors have long known that in cardiac arrhythmias, rotational electrical waves of excitation swirl through the heart muscle. Until now, their investigations of cardiac arrhythmias have focussed on such electrical vortices. However, they have not been able to ascertain a full picture of the dynamics, neither in the laboratory nor in the clinical setting. The MPIDS researchers took a different approach. Instead of concentrating on electrical stimulation, they looked at the twitching contractions of the fibrillating myocardium. “Until now, little importance was attached to the analysis of muscle contractions and deformations during fibrillation. In our measurements, however, we saw that electric vortices are always accompanied by corresponding vortex-shaped mechanical deformations,” physicist Jan Christoph explains.

Computer simulation of an electromechanical vortex in the heart muscle tissue. Credit: Max Planck Society

Ventricular fibrillation in 3-D

In order to visualize the trembling movements inside the heart muscle in three dimensions and to correlate them with the electrical excitation of the heart, the researchers developed new high-resolution ultrasound measuring methods. They also showed that these methods can be used in high-performance ultrasound equipment that is already in routine use in many cardiology institutions. By analyzing the image data of the muscle contractions, they were able to observe exactly how areas of contracted and relaxed muscle cells move in a vortex through the myocardium during fibrillation. They also observed filament-like structures that were previously known to physicists only in theory and from computer simulations. Such a filament-like structure resembles a thread and marks the eye of the whirlpool-like wave or cyclone moving through the myocardium. It is now possible for the first time to pinpoint these centres of the vortices inside the myocardium.

In addition to ultrasound scans, the researchers used high-speed cameras and fluorescent markers that reveal the electrophysiological processes in the myocardium. The images obtained confirmed that the mechanical vortices correspond very well with the electrical vortices.

According to the researchers in Göttingen, ultrasound technology has progressed tremendously in recent years in terms of image quality and imaging speeds, and the potential of modern ultrasound technology has yet to be fully exploited. “Together with the immensely increased computing power of modern computers and rapid advancements in computer graphics and digital image processing, new measurement and visualization possibilities are being created for investigating the heart. We can apply these developments in medicine today,” Jan Christoph says.

Electrical waves on the heart surface. Credit: Max Planck Society

From physics to medicine

The study is an example of successful interdisciplinary collaboration between physicists and doctors at the DZHK. “This revolutionary development will open up new treatment options for patients with cardiac arrhythmias. As early as 2018, we will use the new technology on our patients to better diagnose and treat cardiac arrhythmias and myocardial diseases,” says Gerd Hasenfuß, co-author of the study, Chairman of the Göttingen Heart Research Center Göttingen and the Heart Center at the University Medical Center Göttingen. Stefan Luther is certain of one thing: “Peering deeply into the inner dynamics of the heart marks a milestone in heart research and will decisively shape our understanding and treatment of heart disease in the future.”


Explore further:
Cause of killer cardiac disease identified by new method

More information:
J. Christoph et al. Electromechanical vortex filaments during cardiac fibrillation, Nature (2018). DOI: 10.1038/nature26001

Journal reference:
Nature

Provided by:
Max Planck Society

Tagged with:

About author

Related Articles