Author + information
- Daniel M. Spevack, MD⁎ ( and )
- Ramesh Chandra, MD
- ↵⁎Montefiore Medical Center, Echo Laboratory, 111 East 210th Street, Bronx, New York 10467
We would like to congratulate Owan et al. (1) for their paper in a recent issue of the Journal. In their work, they collected echocardiographic data on 338 patients before and 2 years after undergoing gastric bypass surgery. It occurred to us that since the patients' weight decreased from 136 to 91 kg after surgery, without a change in patient height, then the body surface area (BSA) also decreased substantially. By our calculation, the BSA decreased from 2.52 to 2.06 m2 during the study period.
Current recommendations by the American Society of Echocardiography recommend indexing measured cardiac chamber sizes to the BSA (2). This study highlights the major limitation of this approach. Using the indexed chamber sizes, the patients in this cohort would appear to have had an increase in chamber size over the study period. Left atrial volume index changed from 21.9 to 26.2 ml, and left ventricular volume index increased from 39.3 to 44.7 ml. Because body weight, and consequently BSA, may change substantially over time, perhaps indexing to body height, a less mutable measure of body size, may be more advisable. Extreme fluctuations in weight, like those seen in this study, are also commonly seen in the heart failure populations due to change in patient volume status.
We agree with the authors' decision to examine for change in the actual, nonindexed values. They, therefore, concluded that there was no change in the left-sided chamber sizes.
- American College of Cardiology Foundation
- Owan T.,
- Avelar E.,
- Morley K.,
- et al.
- Lang R.M.,
- Bierig M.,
- Devereux R.B.,
- et al.