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Dobutamine Stress Testing as an Early Diagnostic for Radiation‐Induced Heart Disease
Author(s) -
Lieblong Benjamin,
Bhatti Sabha,
Mulkey Robin,
Fletcher Terry,
Rusch Nancy,
Boerma Marjan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.942.1
Subject(s) - medicine , dobutamine , cardiology , ischemia , heart disease , electrocardiography , stress testing (software) , cardiac function curve , heart failure , hemodynamics , computer science , programming language
Radiation‐induced heart disease (RIHD) is a potentially severe side effect caused by irradiation of all or part of the heart in radiotherapy for intrathoracic and chest wall tumors. Currently, there is no recommended approach for early detection of the disease. However, dobutamine stress testing (DST) is used clinically to unmask other forms of heart disease. Our study sought to determine whether DST may represent an early diagnostic strategy to detect RIHD. Male Sprague‐Dawley rats received X‐irradiation locally to the heart via 5 fractions of 0 (sham), 6, or 9 Gy, and then animals were subjected to DST after 2, 3 and 6 months. Dobutamine was infused in increasing doses (10 ‐ 60 µg/kg/min i.v.) while echocardiography and electrocardiography were performed. At 3 months, radiation caused a dose‐dependent increase in myocardial collagen deposition and alterations in left ventricular function, both of which progressively worsened by 6 months. However, as early as 2 months after irradiation, DST dose‐dependently caused ST‐segment elevation on ECG in irradiated rats, while functional alterations were not present at this time point. The ST‐segment elevations may be an indication of myocardial ischemia. Our results suggest that DST may induce ST segment abnormalities in irradiated hearts prior to detection of functional or histological abnormalities, and thereby may represent a strategy to diagnose and treat myocardial ischemia during early RIHD to prevent later cardiac events. Supported by CA1487679 to MB (NIH/NCI)