In a new study, researchers found a single high dose of radiation aimed at the heart could strongly reduce a potentially deadly rapid heart rhythm.
The research was conducted by a team at Washington University School of Medicine in St. Louis.
Patients in the study were severely ill and had exhausted other standard treatment options.
The radiation used to treat the irregular heart rhythm — called ventricular tachycardia — is the same type of therapy used to treat cancer.
In ventricular tachycardia (VT), the lower chambers of the heartbeat exceedingly fast and fall out of sync with the upper chambers, interfering with blood flow and raising the risk of sudden cardiac death.
Patients with VT typically are implanted with defibrillators that shock the heart back into a normal rhythm.
In an effort to stop the episodes, patients often are treated with catheter ablation procedures, in which a catheter is inserted into the heart and used to create scars in the part of the damaged heart muscle that is causing the electrical signals to misfire.
But catheter ablation is invasive, requires many hours under general anesthesia and often isn’t a permanent solution. The rapid heart rhythm returns in about half of such patients.
In the study, the team tested 19 patients with ventricular tachycardia who had not responded to other therapies.
The new method is a noninvasive outpatient procedure that involves the use of electrocardiograms and computed tomography scans of a patient’s heart to locating the origin of the arrhythmia.
The 3D visual and electrical maps of the heart then guide the noninvasive radiation therapy.
Doctors can target the problem area of the heart with a single high-dose beam of radiation that often takes less than 10 minutes to administer and requires no anesthesia or hospitalization. The patient can go home right after treatment.
According to the team, radiation therapy is a last line of defense for these patients, who are often too unwell to undergo additional traditional therapies to control heart arrhythmias.
It provides hope for patients with dangerous rhythms who have run out of options.
One author of the study is Clifford G. Robinson, MD, an associate professor of radiation oncology and of cardiology at Washington University.
The study was presented at the American Society for Radiation Oncology (ASTRO) Annual Meeting in Chicago.
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