ASE: Nurses Can Do Stress Echocardiograms Safely

SEATTLE, June 19 -- Appropriately trained nurses can supervise stress echocardiograms with no more risk than in physician-supervised tests, a review of 15,404 nurse-monitored tests suggests.

During the 2-year period reviewed, complications occurred in 1 of every 280 cases, a rate comparable to those reported for physician-supervised testing, Mary J. Hepinstall, R.N., of the Mayo Clinic in Rochester, Minn., told attendees at the American Society of Echocardiography meeting here.

Within the past 10 years, some medical centers have allowed specially trained registered nurses to supervise and conduct stress echocardiography, but little information has been available about the safety of the nurse-coordinated imaging studies.

The 15,404 cases comprised 8,592 treadmill exercise tests, 6,755 dobutamine stress tests, and 57 instances of transesophageal pacing. The cases were reviewed for several types of complications: rhythm or hemodynamic disturbance, myocardial infarction, need for hospitalization, myocardial rupture, and death.

Atrial fibrillation was counted as a complication if its onset coincided with the stress echo procedure and if it required medical therapy or persisted until the patient left the echocardiography laboratory.

The indications for stress echocardiography consisted of chest pain or dyspnea in 44% of cases, preoperative evaluation in 26%, known coronary artery disease in 20%, and suspected CAD in 10%.

A total of 55 complications occurred, which translated into a complication rate of 0.36%. Hepinstall reported that 47 of the 55 complications occurred during dobutamine stress tests, resulting in a complication rate of 0.7% compared with 0.09% for treadmill stress testing.

The most common complications were supraventricular tachycardia or atrial fibrillation requiring medical therapy (N=37) and transfer to hospital (N=26). No cardiac ruptures occurred, and no patient died. Complications were significantly more common in patients who had regional wall motion abnormalities on with stress (P<0.001).

At Mayo most of the nurses who supervise stress echocardiograms have backgrounds in critical care medicine, and all are experienced in cardiology, said Ms. Hepinstall. Before overseeing the tests, nurses must complete an extensive orientation program that includes training in electrocardiogram (ECG) interpretation. The nurses work with a sonographer and ECG technician. Physicians review and sign off on every study.

"We run seven rooms and have two doctors reading our studies," she said. "We do three or four rounds [of tests] in the morning and four rounds in the afternoon. That's a lot of studies that can be done with two physicians reviewing."

"These procedures can safely be supervised by specially trained nurses with complication rates comparable to previously reported studies that assessed the safety of physician-supervised stress echocardiography," said Hepinstall.