The association between coronary flow rate and impaired heart rate recovery in patients with metabolic syndrome: A preliminary report

Background: The aim of this study is to evaluate heart rate recovery (HRR) and association between coronary flow rate and HRR in patients with metabolic syndrome (MS) who had morphologically normal coronary angiogram.Methods: Study population included 43 patients with MS and 37 control subjects without MS. All patients were selected from individuals who had recently undergone coronary angiography in our hospital and were diagnosed as having angiographically normal coronary arteries. Exercise stress test results obtained prior to coronary angiography were evaluated for calculating HRR and other parameters. In addition, coronary flow was objectively evaluated for each major coronary artery in each subject using TIMI frame count method.Results: All HRR values calculated were detected significantly lower in MS group compared to controls (HRR first: 32 ± 9 vs. 37 ± 10; p = 0.01, second: 46 ± 11 vs. 52 ± 11; p = 0.03, third: 51 ± 12 vs. 59 ± 12; p = 0.00, fourth: 54 ± 13 vs. 61 ± 2; p = 0.02). TIMI frame counts for each major epicardial coronary artery and mean TIMI frame count were also found to be significantly higher in MS group compared to controls (left anterior descending artery:51 ± 24 vs. 39 ± 15; p = 0.009, left circumflex artery: 32 ± 11 vs. 24 ± 7; p = 0.001, right coronary artery: 33 ± 14 vs. 24 ± 10; p = 0.003, mean TIMI frame count: 38 ± 15 vs. 29 ± 9;p = 0.002). Additionally, significant negative correlations were also detected between HRR first minute and coronary TIMI frame count values in patients with MS. None of MS parameters did not affect HRR values, however mean TIMI frame count independently associated with HRR first minute (p = 0.04) in patients with MS.Conclusions: Impaired coronary blood flow occurring in MS might be a clue of autonomic dysfunction in addition to previously known endothelial dysfunction.

DETERMINATION OF ABSORBED RADIATION DOSE LEVELS OF LENSES THYROID AND ORAL MUCOSA IN COMPUTED TOMOGRAPHY IMAGINING: PHANTOM STUDY

Amaç: Baş ve boyun bilgisayarlı tomografi (BT) görüntülemesi, en sık kullanılan radyolojik incelemelerinden biridir. Birçok hastalığın tanısındaönemli rol oynar. Lens ve tiroid bezi radyasyona karşı en duyarlı organlardandır. Bu çalışmanın amacı, BT görüntülemesi yapıl an hastaların, lens,oral mukoza ve tiroid dokusunun maruz kaldığı radyasyon dozunun belirlenmesidir.Yöntem: Çalışmada, insan eşdeğeri olan Alderson Rando fantomunun tiroid, oral mukoza, lens bölgelerine termolüminesans dozimetreleri (TLD)yerleştirilmiş ve fantomun baş-boyun bölgesinin BT görüntülemesi yapılmıştır. Toplam 18 adet TLD kullanılmıştır. Öncelikle dozimetrelerinkalibrasyon işlemleri yapılmıştır. Bu dozimetrelerden 6 tanesi fantomun tiroid bölgesine, 4 tanesi oral mukozaya, 4 tanesi de lens bölgesineyerleştirilmiştir. 4 tane dozimetre ise arkaplan (background) ölçümleri için kullanılmıştır.Bulgular: Lens merkezine yerleştirilen TLD’lerdeki radyasyon dozu 15,03 ile 23,71 mSv arasında (ortalama 19,83±3,93 mSv), oral mukozada 10,36ile 19,47 mSv arasında (ortalama 15,15±2,96 mSv), tiroid bezinde ise 11,21 ile 16,73 mSv arasında (ortalama 13,97±3,90 mSv) bulunmuştur.Sonuç: Uluslararası Radyolojik Koruma Komisyonu (ICRP)raporlarında tüm vücut ve lensler için müsaade edilen radyasyon dozu, radyasyongörevlilerinde 20 mSv/yıl’dır. Hastalar için kesin bir limit olmamakla beraber, doz düzeyinin minimum tutulması amaçlanır. Bu nedenle referansdozunun bilinmesi çekim planlaması için önemlidirObjective: Head-neck computed tomography (CT) imaging is one of the most common tomography examinations in medical imaging. Lenses and thyroid are among the most sensitive organs to radiation. The aim of this study was to determine the radiation dose levels to which the patient's lens, oral mucosa, and thyroid were during head and neck CT imaging. Methods: Thyroid, oral mucosa and lens areas of human equivalent Alderson rando phantom were placed in thermoluminescence dosimeter (TLD) dosimeters and computerized tomography imaging of head-neck of phantom was performed in this study. A total of 18 TLD dosimetry was used in this study. Firstly, dosimeters were calibrated. 6 of these dosimeters were placed on the thyroid of the phantom and 4 of them were placed in the mouth and 4 of them were in the lens. 4 dosimeters were used for background measurements Results: The radiation dose in TLDs placed at the center of the lens was between 15.03 and 23.71 mSv (mean 19.83±3.93 mSv), the oral mucosa was 10.36 to 19.47 mSv (mean 15.15±2.96 mSv), and the thyroid gland was between 11.21 and 16.73 mSv (mean 13.97±3.90 mSv). Conclusion: The permissible radiation dose for whole body and eye lenses in ICRP reports is 20 mSv/year for radiation officers. Likewise, there is no definite limit for patients, it is aimed to keep the dose level to a minimum. Therefore, knowing the reference dose is important for imaging planning