A comparison of bolus injection of landiolol versus oral administration of propranolol before cardiac computed tomography.

Heart rate (HR) reduction is essential to achieve good image quality for cardiac computed tomography (CCT). We evaluated the efficacy of a bolus injection of landiolol, an ultra-short acting ß-blocker, without the administration of oral ß-blocker to reduce HR prior to CCT. We enrolled 678 consecutive patients who underwent CCT from December 2011 to March 2012 and divided them into three groups, which were a propranolol group (n = 277), a low-dose landiolol group (n = 188), and a high-dose landiolol group (n = 213). Patients in the propranolol group received oral propranolol (10-20 mg) prior to CCT. Patients in the low-dose and high-dose landiolol groups were administered a bolus injection of landiolol (0.125 mg/kg), while the high-dose group received an additional 3.75 mg of landiolol if the baseline HR was ≥75/min. Although the average HR was significantly lower in the propranolol group (61.6 ± 8.0/min) than in the low-dose landiolol group (64.1 ± 7.4/min, P < 0.001), there was no significant difference in the image quality (P = 0.91). Among patients with baseline HR ≥75/min, the average HR tended to be lower in the high-dose landiolol group (67.2 ± 6.9/min) compared with the low-dose landiolol group (69.0 ± 6.9/min, P = 0.10), and there was a corresponding difference in image quality between these two groups (P = 0.02). In conclusion, Although the decrease of HR was significantly larger in the propranolol group than in the landiolol groups, the image quality was similar. Among the patients who received landiolol, a higher dose was associated with a lower HR and better image quality. Further investigation to assess higher-dose bolus injection of landiolol or bolus injection following oral administration of a ß-blocker would be needed.

[Tackling hemodynamic analysis of the carotid artery using open-source software and computational fluid dynamics].

PURPOSE: The aim of this study was to evaluate the impact of wall share stress (WSS) in the carotid artery using a computed fluid dynamics analysis system and adopting open-source software. METHODS: The dependence of element number (computation time and analytical accuracy) were considered with simple vessel models. We evaluated WSS and flow velocity using a carotid artery model that was based on the outcome of simple vessel models. RESULTS: When the number of elements was 10(5) or more, the flow velocity error of the outlet decreased to 0.5% or below when using simple vessel models. The carotid bifurcation model showed a whirlpool and a decrease in flow velocity in the carotid bulb part. CONCLUSION: An analysis system was built using open source software. The results from the carotid bifurcation model suggested that hemodynamics contributes to the development of carotid stenosis.

[Validation of optimal coronary angiography angle for the branch form of the left main trunk by use of multi detector computed tomography].

PURPOSE: The aim of this study was to derive optimal coronary angiography (CAG) angle for the form information on the left main trunk (LMT) by use of multi detector computed tomography (MDCT). METHODS: To verify the accuracy of angle measurement with MDCT, the angle of phantom with known angle was compared with MDCT (CT method) and angiography (AG method). The take-off angle of LMT was derived using CT method from 200 cases who underwent cardiac CT in this institution. RESULTS: In the phantom, both CT and AG methods were indicated to have high accuracy and the errors were very small (0.3%, 0.3%). The take-off mean angle of LMT was 130.7±19.0 degrees in male, and 139.1±19.3 degrees in female. The optimal CAG angle was indicated at left anterior oblique (LAO) 41 degrees (male) and LAO 49 degrees (female). CONCLUSION: The optimal CAG angle of LMT was derived from the CT method.