Dr. Levine is the Head of the Division of Pediatric Cardiology, The Children's Regional Hospital at Cooper Hospital/University Medical Center, Camden, NJ.

The Children's Regional Hospital at Cooper University/Hospital, Camden, NJ recently acquired a portable echocardiographic system (Cypress, Acuson, Mountain View, CA). The system was purchased to support an outreach clinic. This article reports our initial experience with the system.

Results

We performed a total of 90 echocardiography studies with the system. The ages of the patients examined ranged from 1 day to 19 years (mean age 5.8 ± 6.1 years). Two fetal echo-cardiograms were performed, one each at 12 and 20 weeks gestational age. Of the total 90 studies performed, 44 were normal (including the fetal studies). The 46 abnormal studies included a variety of diagnoses (Table 1). The average study size was 32 ± 24 MB (range 1 to 107 MB).

Case Reports

Patient 1 is a 5-year-old boy noted to have a secundum atrial septal defect (ASD) several years ago. His initial echo (done on an Hewlett Packard Sonos 1000 system [Philips Medical Systems, NA, Bothell, WA]), showed an 8-mm defect, and observation was recommended. His repeat study done on the Cypress system again showed an 8-mm ASD (Figure 1), and the decision was made to close the defect. At cardiac catheterization, the stretched diameter of the defect was 15 mm, and the defect was closed successfully with a 16-mm Amplatzer device (AGA Medical Corp., Golden Valley, MN).

Patient 2 is a 1.7-kg newborn twin boy who was evaluated because of a heart murmur. The echocardiogram showed a small apical muscular ventricular septal defect (VSD) (Figure 2).The patient was discharged with clinical follow-up. Interestingly, his identical twin brother had a similar defect.

Patient 3 is a newborn boy who had been diagnosed prenatally with Transposition of the Great Arteries. He was severely cyanotic at birth, with oxygen saturations in the mid 50s. His initial echo study with the Cypress revealed Transposition of the Great Arteries, with a restrictive atrial septal defect, and a large patent ductus arteriosus (PDA) (Figure 3). There was bidirectional shunting noted at the PDA, which is consistent with the restrictive ASD. He was taken to the cath lab, where the diagnosis was confirmed. A balloon atrial septostomy was performed, with a resulting gradient between the atria of 1 mm Hg, and an increase in his oxygen saturations to the mid 70s. He subsequently underwent a successful arterial switch operation.

Patient 4 is a 9-month-old boy with a hypoplastic right ventricle (RV). In the newborn period he underwent a balloon atrial septostomy, and a central shunt from the ascending aorta to the right pulmonary artery (RPA). At repeat catheterization at 6 months of age, it was discovered that the right pulmonary artery and the left pulmonary artery had become discontinuous, at the insertion site of the ductus. The left pulmonary artery was hypoplastic. The patient underwent a central shunt from the left subclavian artery to the hypoplastic left pulmonary artery, which resulted in significant growth of the left pulmonary artery. A subsequent study on the Cypress system allowed visualization of both pulmonary arteries; the right pulmonary artery measured 4.3 mm and the left pulmonary artery measured 4.4 mm (Figure 4). There was also mild to moderate mitral valve insufficiency. These findings were confirmed on cardiac catheterization, and the patient underwent a hemi-Fontan operation, with reconstruction of the pulmonary artery confluence.

Patient 5 is a 19-year-old woman with sub-aortic stenosis. Her initial echocardiogram showed a peak gradient of 67 mmHg from the left ventricle (LV) to the aorta, and mild aortic insufficiency. She underwent resection of a discrete subaortic ridge, and the gradient postoperatively was 10 to 20 mmHg. She continued to have aortic insufficiency and also developed a pericardial effusion following surgery. A postoperative echocardiogram clearly showed the residual muscular ridge and the pericardial effusion (Figure 5). Pulse Doppler accurately measured the residual gradient and color flow Doppler demonstrated the aortic insufficiency.

Patient 6 was a 20-week gestational age fetus. The fetal echocardiogram showed normal 4-chamber views (Figure 6), and color Doppler demonstrated normal flow across the tricuspid and mitral valves, and through the foramen ovale. Both the aortic arch and pulmonary arch were demonstrated clearly. The inferior and superior vena cava were seen entering the right atria (RA) and several pulmonary veins were identified.

Discussion

The Cypress system has performed very well for our needs. In general, the system is easy to use. The controls are well laid out and the calculation package quite easy to learn. The two-dimensional resolution, while not quite as good as the Sequoia (Acuson), is certainly more than adequate for most purposes. The only limitation we have experienced is with patients who weigh <1000 grams, where the near-field resolution has not been adequate for complete studies. The trackball is small, but with some practice it can be controlled precisely. We initially experienced some difficulty with the color Doppler setting, but after some in-service programs, the pictures are now very good.

We had initially planned to use the system at an outreach clinic, and are now planning to open additional clinics. In addition, the system has proven very useful for doing consultations at some of our referring hospitals. Prior to obtaining the Cypress system, we would have to arrange to "borrow" an echo machine from the adult lab, which often involved upsetting someone's schedule, as well as having the machine transported to the nursery when the cardiologist arrived. Now, the on-call cardiologist leaves the Cypress in his/her car trunk, so it is always available if he/she is called for an emergency consultation.

Prior to obtaining the Cypress system, our lab only stored echo studies on videotapes. Digital storage has proven to be very efficient; studies can be recalled instantly for viewing or further measurements. As an unexpected benefit, we discovered that echo loops could be converted to AVI files and transferred via a network connection to a desktop computer. We have now begun to incorporate these into the student and resident lectures. It has taken some practice to learn to store the studies digitally. Initially we tried to use the digital storage like a tape recorder, and some of the initial study files were more than 100 MB. As we have gotten more used to viewing loops, full studies are usually no more than 40 to 50 MB. This should allow us to store at least 80 studies on the system's internal hard drive and 12 studies on a 640-MB magneto-optical (MO) disk. Although the MO disks more expensive than videotapes, the convenience is more than worth the price difference.

Conclusion

We have been very satisfied with our Cypress system. It has proven to be a versatile system with a short learning curve. The image quality has been more than adequate for almost all of our needs. Its portability has allowed us to use it for outreach clinics and consultations at referring hospitals. We have also been very pleased with the digital storage capabilities. We anticipate the system will significantly enhance our ability to deliver top quality care to our patients. *