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Background: The role of Technetium-99 m (Tc-99m) labeled tracers has been discussed for the detection of viable myocardium. One of the methods that is considered to be used in the diagnosis of viability is gated Myocardial Perfusion Imaging (gMPI) conducted under the influence of Beta Blocker Drugs (BBD). Objective: The aim of this study is twofold: First, to evaluate the role of the Beta Blocker Drugs (BBD) on fixed perfusion defects on gated Myocardial Perfusion Imaging (gMPI) (myocardial viability) and second, to assess the role of BBD on the functional parameters of the left ventricle. Methods: 31 patients (28 men, 3 women) who were on BBD treatment and had fixed perfusion defects on their gMPI and submitted to fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) were prospectively enrolled to the study. One week after the completion of the stress-rest gMPI, rest gMPI was repeated for each patient while they were on BBD treatment. All systolic and diastolic functional measurements, perfusion defect extent and size were obtained during both rest gMPI studies with and without BBD. The parameters derived from FDG PET/CT were compared to those that were derived from gMPI without BBD. Results: A statistically significant difference between the scores of both groups was not observed, except the Time to Peak Filling Rate (TTPFR). End-systolic/diastolic volumes derived from gated FDG PET/CT were significantly lower than the ones derived from the gMPI presumably due to higher spatial resolution of the FDG PET/CT while the study did not reveal a statistically significant difference between the ejection fraction values. Conclusion: According to our results, metoprolol does not seem to change functional parameters of the left ventricle that were detected by gMPI except TTPFR. Besides, it seems that metoprolol does not affect the size of the perfusion defect, and therefore, it does not have a role to demonstrate the presence of viability that was confirmed via FDG PET/CT.

Dual left anterior descending (LAD) coronary artery anomaly is traditionally classified as four types anomaly by classical coronary angiogram. Nowadays, coronary computed tomographic angiography (CCTA) allows clinicians to understand other variants of dual LAD anomaly. Up to date, 9 types of dual LAD variants detected from not only classical coronary angiogram but also CCTA imaging have been reported.

Cardiac syndrome X is characterized by angina-like chest pain, a positive stress test, and normal coronary arteries. A patient's mean platelet volume, which potentially reflects platelet function and activity, is associated with coronary atherosclerosis and endothelial dysfunction. The aim of the present study was to evaluate the mean platelet volumes of patients with cardiac syndrome X, those with coronary artery disease and normal subjects.

Considering the role of autonomic imbalance in the pathogenesis of hypersensitivity reactions, we evaluated the autonomic system through time-domain analysis of heart rate variability (HRV) in patients with allergic rhinitis. Twenty-four patients with allergic rhinitis and 22 healthy subjects (mean age, 41 +/- 8 years and 37 +/- 9 years, respectively) were enrolled in the study. The diagnosis of allergic rhinitis was based on the history, symptoms, and skin prick tests results. Twenty-four-hour ambulatory electrocardiographic recordings were obtained, and the time-domain indices were analyzed. Analysis of HRV revealed that the SD of normal RR intervals, SD of successive differences in normal cycles, and HRV triangular index were not significantly different between the groups, but the root mean square successive difference, number of RR intervals exceeding 50 milliseconds, and percentage difference between adjacent normal RR intervals exceeding >50 milliseconds were significantly greater in the study group, compared with the control group. Our findings showed that HRV indices, which predict parasympathetic predominance, were increased in patients with allergic rhinitis. This finding shows that vagal activation is present not only in the nose but also in other systems, including the cardiovascular system.

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Copyright © 2012 S. Karger AG, Basel