Author + information
- Maria L. Narducci, MD∗ (, )
- Gemma Pelargonio, MD,
- Andrea Natale, MD and
- Antonio Dello Russo, MD
- ↵∗Cardiovascular Sciences Department, Catholic University of Sacred Heart, Largo A Gemelli no. 8, Rome 00135, Italy
We thank Drs. Ren, Supple, and Marchlinski for their interest in our study (1) and for their thoughtful comments. The equipment used for intracardiac echocardiography (ICE) consisted of an Acuson Cypress system (Acuson-Siemens Inc., Mountain View, California) and an AcuNav 10F (Siemens Medical Solutions distributed by Biosense Webster, Diamond Bar, California) or Soundstar (Biosense Webster) probe with 64 elements phased array multifrequency transducer. We also performed very few cases with a Sequoia ultrasound system, although the majority of cases were performed with the Acuson Cypress System. The reason why we used two different types of probes with similar technical features is that, when data collection was started (i.e., 2006), only the AcuNav 10F probe was available; the Soundstar probe was released only in 2007.
As highlighted by Drs. Ren, Supple, and Marchlinski different specifications of ICE depend also on the echocardiographic console. Particularly, the Acunav and Soundstar probes could be connected to a Sequoia, a Cypress, or other echocardiography system, and the technical specifications of the console limit the range of frequency values available for the probe.
In particular, ICE probes connected to the Sequoia system could work at 5.5, 7.5, 8.5, and 10 MHz, whereas the same probes connected to the Cypress could work only at 6 MHz and 7 MHz. A frequency value of 9 MHz is not available with the Sequoia system, nor with the Cypress system. We have used mainly a Cypress system (6 MHz and 7 MHz frequencies). We apologize for the typographical error in the discussion: “9 MHz.” In our population, the 2 frequency values used (i.e., 6 MHz and 7 MHz) allowed us to obtain a good visualization of right chambers and device leads, with a substantial incremental value as compared to the current imaging gold standard for device-related endocarditis, that is, transthoracic echocardiography (TEE).
We also found no challenge in obtaining distance measurements with the Cypress system, although we agree that a Sequoia system might have improved the image resolution to obtain measurements. The latter, rather than a limitation of our study, is a major strength, as we reported an increased diagnostic yield with ICE as compared to TEE. It is conceivable that the systematic adoption of a Sequoia system would have skewed the results even more in favor of ICE, without changing any of the study results and conclusions. In addition, each case was analyzed by 2 different expert cardiac sonographers, who were blinded to the clinical characteristics and TEE results, and with excellent interobserver agreement. As quantitative measurements, we reported the maximum length (mm) of vegetations, as the filamentous-like shape of intracardiac masses was the most prevalent, which is in line with recent evidence (2).
We appreciate the interest by Drs. Ren, Supple, and Marchlinski and their important comments on differences between Cypress and Sequoia systems. As mentioned, we do feel that better ICE images, as obtainable with a Sequoia system, would have strengthened the message of our paper.
- American College of Cardiology Foundation
- Narducci M.L.,
- Pelargonio G.,
- Russo E.,
- et al.
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