March 19, 2019 by John Fernandez
New Technique Spares Cardiac Patients of Radiation Exposure
(Image: Dr. Mario Pascual views a three-dimensional map of the heart from a patient with atrial flutter.)
Radiation exposure is a major concern for patients and surgical teams performing certain procedures, including catheter insertions to treat cardiac arrhythmias (rapid or irregular heartbeat).
But a new procedure spares patients of radiation during catheter ablations to treat one of the most common heart rhythm conditions, “atrial flutter.” Until now, fluoroscopy – an imaging technique that uses X-rays to obtain real-time moving images – has been used to track the path of a catheter inserted in the patient.
A team at Miami Cardiac & Vascular Institute recently became one of the first in South Florida to perform a “catheter ablation” without any radiation to restore a patient’s normal heart rhythm. Arrhythmias are treated to prevent more serious complications that can include tachycardia (an extremely fast heart rate), stroke and cardiac arrest.
This means the patient was spared radiation exposure that could equal the effect of several hundred standard X-rays. And the medical team performing the catheter ablation did not have to wear bulky lead aprons to protect themselves from any radiation.
Mapping System Helps Create 3-D Image of Heart
The Institute’s team, led by Mario Pascual, M.D., used an advanced imaging technology, the CARTO 3 mapping system that utilizes magnets placed around the patient to generate a real-time, 3-D map of the heart as the medical team monitors the movement of the catheter on computer monitors.
During ablations, doctors insert a catheter through a small puncture in the groin. It is then weaved to the heart through a blood vessel. The procedure can last about 40 minutes.
“The goal is to decrease a patient’s overall radiation exposure, and now we have certain catheter ablations that can be done without any radiation,” says Dr. Pascual, an electrophysiologist with Miami Cardiac & Vascular Institute, who performed the first atrial flutter ablation without radiation.
Traditional catheter ablation involves a series of X-ray images to track the path of the inserted catheter, which is used to create lesions or destroy heart tissue to remedy the arrhythmia. The Institute has now performed five such catheter ablations without radiation to correct “atrial flutter,” or AFL, conditions. AFL occurs when the upper chambers of the heart beat too fast. When the chambers at the top of your heart (atria) beat faster than the bottom (ventricles), the condition complicates your heart rhythm.
Although catheter ablations of most arrhythmias have a high success rate, the procedures carry a low risk of bleeding and pain at the catheter insertion site. But with this new technology the patient has one less worry: radiation. Too much exposure to radiation has been linked to increased cancers, skin injuries, genetic defects and cataracts.
New System Offers ‘Extreme Accuracy’
The new technology used by Pascual’s team, the CARTO 3 System, creates a very reliable image of the heart through electromagnetic technology, Dr. Pascual says.
“You can visualize the catheter very accurately,” he says. “The mapping has improved so much that we can precisely identify the location of the catheter with extreme confidence that it is where it should be.”
The magnet sensors on the patient create a colorized, three-dimensional image of the heart within minutes. That image takes up one monitor, while another replicates the electrical activity of the heart. The technology is poised for wider use in cardiac care, he says.
“The catheter creates small lines of scaring to prevent the arrhythmia from continuing,” Dr. Pascual says. “This mapping technology makes it possible to perform ablations with no radiation exposure. The new system will be expanded eventually for use in more complex ablations to treat more severe cases of arrhythmias.”