Author + information
- Jian-Fang Ren, MD∗ (, )
- Gregory E. Supple, MD and
- Francis E. Marchlinski, MD
- ↵∗Cardiac Electrophysiology Section/Cardiovascular Division, University of Pennsylvania Health System, 111 North 9th Street, Philadelphia, Pennsylvania 19107-2452
We have read with interest the study by Narducci et al. (1) comparing transesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) for the diagnostic assessment of cardiac device-related vegetation. Narducci et al. (1) concluded that ICE provided improved imaging of right-sided leads and increased the diagnostic yield of identifying attached vegetations compared with TEE. However, there are several critical questions related to their instrument, and their methodology needs to be clarified.
What type of ICE equipment was used? The AcuNav ICE catheter (Siemens Medical Solutions distributed by Biosense Webster, Diamond Bar, California) using the Sequoia ultrasound system (Acuson Corporation, Mountain View, California) with sector phased array transducer and multifrequency (5.5, 7.5, 8.5, and 10 MHz) has higher imaging resolution and electronic calipers for distance measurement. The other ICE catheter using the Cypress ultrasound system (Siemens Medical Solutions)(a simple, portable type) has a transducer with fewer ultrasonic frequencies and a lower imaging resolution, as well as limited caliper measuring capabilities as compared to the Sequoia system. The description Narducci et al. (1) provided of their ICE instrument is confusing. In their methods, they describe using a linear (rather than sector?) “phased array multifrequency (5.5 to 10 MHz) transducer…connected to a Sequoia system.” In their discussion section, however, they discuss using a 9 MHz probe: “These results could be explained by the major resolution power of the intracardiac probe (9 vs. 5 MHz).” However, the 9 MHz is not an available option on the AcuNav and Sequoia platform but may be available with the Cypress ultrasound system. In our experience, ultrasonic frequency of 9 MHz or 10 MHz is too high to image small vegetation or thrombus on a device lead in the deep of the right atrium or right ventricle (>5 cm to 10 cm). In addition, their 2 ICE images (Fig. 1B and Fig. 2C in their article) all show that Narducci et al. (1) used a Cypress, not Sequoia ultrasound system. In our experience, the ICE with the Cypress ultrasound system is not as accurate as the Sequoia, with lower imaging resolution and limited 2-dimensional and Doppler diagnostic measurement capabilities as compared to the Sequoia. Therefore, it is important to point out that using the Cypress ultrasound system to detect and quantify a small mass or vegetation on cardiac implantable electronic device leads might not be as sensitive as compared to the Sequoia system.
Finally, Narducci et al. (1) did not report their measurements of the width of vegetation. Vegetations from infective endocarditis are generally more thickened, coarse, and loose compared with lead thrombi, which may be seen in as many as 30% of patients with intracardiac leads (2). The width of the vegetation is, therefore, also an important measurement to discriminate vegetation from thrombus.
The investigators should be congratulated for reporting a large number of cases with transvenous lead extraction. However, their results for comparison with TEE of diagnostic capability for vegetation/mass have to be questioned because of the confounding of ICE instruments and methodology insufficiency.
- American College of Cardiology Foundation
- Narducci M.L.,
- Pelargonio G.,
- Russo E.,
- et al.
- Supple G.E.,
- Ren J.F.,
- Zado E.S.,
- Marchlinski F.E.