Objective: To investigate the feasibility of one-step coronary and carotid-cerebrovascular computed tomography angiography (CTA) using high-pitch Double Turbo Flash mode and to analyze the image quality and radiation dose in patients with heart rate variability using multi-slice detector dual-source CT. Methods: A total of 79 patients with heart rate variability higher than 3 beat/min (bpm) were retrospectively analyzed. They were grouped by the scanning methods. Group A (n=40) were performed double turbo flash mode for one-step coronary and carotid-cerebrovascular arteriesinjected with one injection of contrast agent.further divided into Single A (only the phase 1 image)and Double A(combined images of phases 1 and 2). Group B (n=39) were performed separately with twice injection of contrast agent. Subjective scoring was performed on the image quality of the group Single A, Double A and B using a 4-point. Then the objective parameters of image quality, CT attenuations, image noise, signal-to-noise (SNR), and contrast-to-noise (CNR), were evaluated. Then subjective scores, objective evaluation indicators, and radiation dose were compared with one-way ANOVA analysis among the three groups.Contrast agent were compared by using t test in group A and B. Results: No significant difference was found (F=2.093, P=0.128) for the subjective scores of the head and neck CTA among the three groups with (3.47±0.51), (3.53±0.51), (3.69±0.47). Significant difference was found (F=50.955, P<0.01) for the subjective scores of coronary CTA among the three groups with (2.70±0.76), (3.35±0.66), (3.58±0.50), and there was no statistically significant difference between Double A and B groups (P=0.104), met the requirements for diagnosis. The objective evaluation of the three groups compared the head and neck CTA images were statistically significant (P<0.05), of which the difference between the Single A and the Double A was not statistically significant (P>0.05), met the requirements for diagnosis; the differences in SNR and CNR of coronary CTA images are statistically significant (F=12.991, 12.236, P<0.01), and there was no statistically significant difference between Double A and B (P>0.05), met the requirements for diagnosis. Radiation dose in the group Double A was lower than group B (decreased by 46.15%,P<0.01).The amount of the contrast agent in the group Double A was lower than group B (decreased by 44.13%, t=-45.455;P<0.01). Conclusion The double turbo flash mode is feasibility for one-step coronary and carotid-cerebrovascular CTA in patients with the heart rate variability using multi-slice dual-source CT.This scan mode can maintain the diagnostic image quality with low contrast agent and radiation dose.