American Journal of Roentgenology, Vol 171, 371-374, Copyright © 1998 by American Roentgen Ray Society
Significance of radiographic cardiomegaly in orthotopic heart transplant recipients
JD Murphy, PJ Mergo, HM Taylor, R Fields and RM Mills Jr
Department of Medicine and Diagnostic Radiology, University of Florida, Gainesville 32610-0374, USA.
OBJECTIVE: The purpose of this study is to evaluate the clinical
significance of radiographic cardiomegaly in orthotopic heart transplant
recipients and to identify causative anatomic and physiologic parameters.
MATERIALS AND METHODS: We retrospectively compared the cardiothoracic ratio
(CTR) measured using standard posteroanterior chest radiography with left
ventricular end-diastolic diameter and left ventricular ejection fraction
measured on two- dimensional echocardiography; right ventricular systolic
pressure; and systolic, diastolic, and mean blood pressure measured at
biopsy in 46 heart transplant recipients. RESULTS: Twenty-eight (61%) of
the 46 patients had radiographic cardiomegaly. When we compared heart
transplant recipients who had a CTR greater than 0.5 with recipients who
had a CTR less than or equal to 0.5, we found no significant difference
between their respective left ventricular end-diastolic diameters, left
ventricular ejection fractions, right ventricular systolic pressures,
systolic blood pressures, or mean blood pressures. A statistically
significant difference existed between the mean values of diastolic blood
pressure for transplant recipients with and without radiographic
cardiomegaly. We found no significant correlation between CTR and left
ventricular end-diastolic diameter, left ventricular ejection fraction,
systolic blood pressure, diastolic blood pressure, or mean blood pressure.
CONCLUSION: The statistically significant difference between the mean
values of diastolic blood pressure of transplant recipients with and
without radiographic cardiomegaly is clinically insignificant and unlikely
to account for the finding of radiographic cardiomegaly. We conclude that
radiographic cardiomegaly, which occurs frequently in heart transplant
recipients, does not correlate with anatomic or physiologic parameters
obtained under the same conditions. Radiographic cardiomegaly in heart
transplant recipients does not connote allograft dysfunction or heart
failure.