Echo techs shine in performing hand-carried ultrasound cardiac exams

November 12, 2007
Wendy Despain
Wendy Despain

Hospitalists given focused training for conducting cardiac exams with hand-carried ultrasound systems still could not match echocardiography technicians at acquiring images, though they came closer at measurement and interpretation. Hand-carried ultrasound devices are growing in popularity, but training methods for noncardiologists have not been well defined.

Hospitalists given focused training for conducting cardiac exams with hand-carried ultrasound systems still could not match echocardiography technicians at acquiring images, though they came closer at measurement and interpretation. Hand-carried ultrasound devices are growing in popularity, but training methods for noncardiologists have not been well defined.

Dr. David Martin and colleagues in the department of medicine at Johns Hopkins University School of Medicine and Johns Hopkins Bayview Medical Center published their research in the November issue of the American Journal of Medicine. They recruited 10 hospitalists to complete focused training in cardiac exams using a hand-carried ultrasound device.

The training began with an introduction from an echocardiography technician and access to online resources. The hospitalists then performed five training echocardiograms, during which they received hands-on training from the technicians on obtaining images, interpreting them, and taking measurements using both 2D and Doppler ultrasound. This step was followed by six hours of interpreting conventional echocardiograms with a cardiologist.

After training, the hospitalists conducted hand-carried cardiac ultrasound exams on a total of 354 inpatient cardiac cases, a mean of 35 cases per hospitalist. These exams were compared with images acquired by five echocardiography technicians using the same equipment and gold-standard conventional echocardiograms conducted within 24 hours.

An expert cardiologist graded all the hand-carried ultrasound exams and interpretations on how closely they agreed with the corresponding conventional echocardiogram. The performance of the hospitalists was then compared with that of the echocardiography technicians and the interpretations of six senior cardiology fellows.

The researchers found that hospitalists had a harder time learning image acquisition than image interpretation. They averaged 80.6% agreement with the conventional echocardiogram on the quality of the acquired image, while the echocardiography technicians averaged 98.9% agreement.

The technicians were also better at making key measurements on the hand-carried cardiac ultrasound exams, though by a lesser margin. Hospitalists averaged 80.2% agreement with the conventional echocardiogram, while the technicians averaged 89.9% agreement.

Overall, the hospitalists did significantly worse than technicians in the combined skills of image acquisition and interpretation, with an average of 78.9% agreement with conventional echocardiogram. The mean for the technicians was 91.3% agreement.

The hospitalists nearly matched the cardiology fellows when it came to interpreting the images. Their performance was not significantly different for diagnosis of three different conditions, but they had significantly lower scores on four others.

The researchers concluded that their training methods helped hospitalists learn certain aspects of hand-carried echocardiography, but they could not replicate the quality of conventional echocardiography methods.

"Hospitalists trained the way we trained them did learn a lot, and it is likely that their heart exam combined with a physical exam is much better than physical exam alone," said researcher Dr. David B. Hellman.

This is the subject of Hellman's next research project. The current study suggests that one way hospitals could provide round the clock bedside echocardiography would be to hire technicians and allow them to provide preliminary readings checked by cardiologists, he said.