A method is disclosed for generating cardiac CT representations of a beating heart of a patient with the aid of a multi-tube CT system with application of a contrast medium. In at least one embodiment, the method includes carrying out a first CT scan with the multi-tube CT system, wherein at least one tube generates an X-ray spectrum, and reconstructing at least one CT representation of the same cardiac phase with a first temporal resolution; subsequently carrying out a second CT scan with the multi-tube CT system, wherein at least two angularly offset tubes generate different X-ray spectra; reconstructing at least one CT representation of the same cardiac phase per X-ray spectrum with a second temporal resolution; and generating a combined CT representation from results of the first and of the second scan.