Clinical utility of left ventricular ejection fraction reserve by stress thallium-201 myocardial gated single photon computed tomography among patients with and suspected coronary artery disease

BACKGROUND: Coronary microcirculation impairment with sequential decrease in cardiac function is reflected by abnormal left ventricular ejection fraction reserve (LVEFR),which precedes diagnostic evidence of myocardial insult. However, prognostic utility of LVEFR is less, if not least explored. The aim of this study was to evaluate the clinical utility of LVEFR in predicting major cardiac events (MACE) among patients with and suspected coronary artery disease (CAD).MATERIALS AND METHODS: A retrospective cohort study of 245 patients who underwent stress thallium-201 myocardial perfusion scan (MPS) was conducted. The patients were categorized as having normal or abnormal perfusion scan. Each group was subdivided into normal and abnormal LVEFR groups. All subjects were followed up for any major adverse cardiac events 36 months after MPS through review of hospital records.RESULTS: There was an overall increase in the likelihood of cardiac events with abnormal LVEFR (i.e., odds ratio of 2.99,p=CONCLUSION: Abnormal LVEFR can be used as an independent predictor of cardiac events which can be observed in subjects with normal and abnormal perfusion scans alike.

Myocardial perfusion scintigraphy in transposition of the great arteries after an arterial switch operation in infants

An abnormal myocardial perfusion is not uncommon in congenital heart defects (CHD). Many case reports and prospective studies were done describing myocardial peOision scintigraphy (MPS)findings after an arterial switch operation (ASO) among transposition of the great arteries (TCA), but to the best of the authors' knowledge, none have cited MPS findings in the immediate post-operative petiod. This paper aims to show two ckfferent clinicalthuatiomts in which (MPS) was used in the assessment of myocarchalfiinction in TCA immediatelyfollowing an arterial switch operation. Two male infants; aged 2 months and 4 months; both diagnosed with transposition of the great arteries presenting with past-operative morbidities after an arterial switch operation were referred to the Department of Nuclear Medicine/or evaluation. The younger infant was ditty discharged improved with an earlier magical intervention in contrast to the other who expired Bothpatients revealed a scintigraphic picture of myocarcbal ischemia and left ventricular a54ifiniction with concomitant right ventricular hypertrophy MPS .findings and reflective clinical pictures of patients with corrected congenital disease are yet to be/illy elticidated,.from the expected natural course after the stag/Cal intervention and long term complications ofsuch cases. The two cases present an invaluable avenue of non-invasive diagnostic modality using-MPS to assess probable pathologic mechanisms that occur after an arterial switch operation, and perhaps suggest incremental value not only in the post-operative period but in the preoperative scenario in the prognostication of these patients.