NEW ORLEANS -- About 13% of patients who undergo lung transplantation procedures develop atrial flutter after the life-saving therapy, researchers reported here at the annual meeting of the American College of Cardiology.
However, in this study -- believed to be the first to study the incidence of atrial flutter within this special population -- most of the cases were treated conservatively, with only three patients developing persistent arrhythmia requiring ablation procedures, said Peyman Azadani, MD, a research fellow in cardiology at the University of California San Francisco.
In the study, Azadani and colleagues reviewed the medical records of 269 consecutive patients who underwent unilateral or bilateral lung transplantation from April 1998 to May 2010 at UCSF.
"We identified 35 patients -- about 13% of the total -- who developed atrial flutter," Azadani told MedPage Today at his poster presentation. "About 68% of these patients had atypical atrial flutter, while the others had typical atrial flutter," he added.
Postoperative atrial flutter was diagnosed based on a review of all 12-lead electrocardiograms performed after transplant surgery by two electrophysiologists who were blinded to each other's diagnosis.
Azadani and his team suggested that "suture lines in the left atrium likely serve as the electrophysiological substrate for atrial flutter circuits."
For most of the patients who developed atrial flutter, medical treatment was sufficient to control the condition. Heart rate control medication stopped the flutter in 89% of the patients, he reported. The other 11% required cardioversion techniques, Azadani said.
"Though atypical atrial flutter commonly occurs after lung transplantation in adults, it is most often a self-limited arrhythmia that resolves spontaneously without the need for ablation," he commented.
Of the three patients who underwent ablative treatment for persistent atrial flutter, two showed atypical flutter patterns, he said.
"The news in this study is that it is the first time someone has determined the incidence of atrial flutter among this population of lung transplant patients," said Mariell Jessup, MD, professor of medicine at the University of Pennsylvania in Philadelphia, who commented on the study as a spokesperson for the American Heart Association.
"The mechanisms for the incidence of atrial flutter among these patients are not well understood," Jessup told MedPage Today.
She agreed that suspicion regarding anastomosis techniques might be related to development of the arrhythmias.
"Atypical atrial flutter commonly occurs early after lung transplantation," Azadani remarked.
In the study group, atrial flutter appeared after a mean of 11.7 days following the transplant surgery.
By 50 days post-surgery, the arrhythmia had vanished except in the three patients where the rhythm was persistent and ablative technology was required.
There were no major differences as to how patients responded to atrial flutter -- whether it was a typical or atypical pattern.
After performing multivariate logistic regression of atrial flutter predictors, the researchers determined that patients who were more likely to experience atrial flutter included whose who were of advanced age -- who had small but statistically significant 4% increased risk.
Patients who were diagnosed with idiopathic pulmonary fibrosis had a 2.94-fold increased risk (P=0.009) of developing atrial flutter.
Those who had left atrial enlargement had a 2.86-fold risk of atrial flutter (P=0.036).
"Rate control with or without cardioversion are reasonable initial strategies for treatment of atrial flutter with ablation required for only persistent cases," Azadani said.