COLUMBUS, Ohio – Surgeons at the Ohio State University Medical Center are fixing out-of-sync hearts with a minimally invasive technique that allows them to return normal rhythm to the heart and double-check the effects of their work, all in a procedure conducted through a few small incisions in the patient’s side.
The technique is a surgical repair of atrial fibrillation (AF), a condition in which the heart beats out of rhythm because of disordered electrical impulses in the upper chambers, or atria. The condition affects about 2.5 million Americans, and its incidence doubles with each advancing decade of life. Long-term atrial fibrillation can lead to stroke or heart failure.
Radiofrequency ablation via a catheter has become a common treatment method for atrial fibrillation, but this new approach allows surgeons to directly view the effectiveness of the ablation, or application of heat, by observing the heart response without opening the chest, said Dr. John Sirak, a cardiothoracic surgeon at OSU Medical Center.
During the procedure, surgeons enter the chest cavity through small pencil-sized holes in the patient’s side, inserting instruments through the ribcage. Surgeons first identify electrical miscues by mapping the heart with a tiny wire, and use a heat-based ablation device to place lesions that electrically isolate the problem tissue; in 90 percent of AF cases, the source of the chaotic impulse is tissue connecting the pulmonary veins to the left atrium.
“We are able to use this targeted heat source to eliminate the sources of abnormal signals on the surfaces of the atria themselves,” Sirak said. After applying the heat, surgeons electrically stimulate the mapped sites to test the signals and make sure they respond appropriately.
“Because this is driven by mapping, there is no need to assume a standard ablation has resulted in a cure. We can tell on the spot whether the treatment is working,” Sirak said. “Also, the heart remains beating throughout the operation, so we can tell if the patient has converted to proper rhythm during the treatment. We can see exactly how the heart is responding.”
Traditional surgical treatment for AF involves opening the chest and placing the patient on a heart-lung bypass machine. The minimally invasive approach is equally effective, and allows patients to recover more quickly, experience less pain and, in some cases, go home as early as 18 hours after the operation, Sirak said.
In a normal heart, electrical impulses from the two atria at the top of the heart send electrical impulses to the ventricles, the lower chambers, and the ventricles contract, pumping blood to the lungs or the rest of the body. Sirak said in atrial fibrillation, the impulses are “extremely disordered, giving a ‘bag of snakes’ appearance to the atrium.” AF typically leads to a 20 percent reduction in cardiac output.
Age is the most common risk factor for atrial fibrillation, but others include diabetes, high blood pressure and organic heart disease. Symptoms of AF include palpitations, the sensation that the heart is racing, fatigue and reduced energy. “Some patients know exactly when it’s happening by the way it makes them feel, but a significant number don’t know,” Sirak said.
Traditional medical treatment has included a trial of drugs to control the heart rate and thin the blood to reduce the risk for clots. Surgical repair is most commonly recommended for patients who do not respond to or cannot tolerate medications for the disorder.# # #
Medical Center Communications