RESEARCH :Ions against cardiac fibrillation

Carbon ions from the particle accelerator could be a gentle alternative to conventional catheter treatment.

In the ring accelerator, carbon ions are brought to the desired speed to irradiate the heart tissue.

Photo: A. Zschau, GSI Helmholtz Center for Heavy Ion Research

Carbon ions are now used for cancer treatment. They can also help with cardiac arrhythmia - as a gentle alternative to heart catheters or medications. Biophysicists from the GSI Helmholtz Center for Gravitational Research in Darmstadt and physicians from the University of Heidelberg and the Mayo Clinic in the USA have developed a procedure for this, as reported in the specialist magazine Scientific Reports.
Approximately 350,000 patients suffer cardiac arrhythmia alone in Germany. They are therefore threatened by permanent damage, such as a stroke, or even sudden cardiac death. In the case of foreskin or tachycardia, the cardiac heart comes out of its regular rhythm. Instead of up to 60 beats per minute, the sinus node in the right atrium as a pulse generator drives the pulse to over 100 beats per minute. To treat the disorder, the so-called catheter ablation is often used in addition to drug administration. In this case, the physician guides a catheter to the heart through the inguinal vein, for example, and there raises the affected tissue with high-frequency current.
With high-energy carbon ions generated in the Darmstadt ring accelerator, the researchers have now been able to produce changes in the heart tissue that prevent the transmission of the electrical signal from the sinus node.
Carbon ions are fed into the ring accelerator from a linear accelerator and brought to higher energies. The electrical voltage prevailing on the so-called acceleration paths makes it always faster. Magnets hold them on their orbit.Once the particles have the desired velocity, they are directed to the workplace where they are available for medical intervention.
"The new method allows us to perform the treatment without a catheter for the first time," says H. Immo Lehmann, doctor and researcher at the Mayo Clinic."Heart tissue can be altered in such a way that the spread of interfering impulses is interrupted permanently," adds Christian Graeff, head of the working group Medical Physics at GSI.
Radiation of the tissue with carbon ions promises to be more gentle and potentially more effective than treatment with catheters. Once the method has matured technically, the procedure will only take a few minutes. A substantial advantage lies in the non-limited penetration depth of the ions. Because the left ventricular wall of the heart is extremely thick, it is often not possible to perform an effective sclerotherapy with catheters. But right now, patients with so-called ventricular tachycardia need to be treated.
"The carbon beam can be used with surgical precision to treat sensitive organs," says Paolo Giubellino, Scientific Director of the international particle accelerator "Fair" and the GSI in Darmstadt.
With the now established method many thousands of patients were treated in cancer therapy worldwide. Now, experiments are planned to be implemented at the Heidelberg Ion Beam Therapy Cent