There has been a marked increase in the availability and use of ECG machines in general practice. In 2008, Day and colleagues reported that 85% of GPs who responded to their survey had an ECG machine and that 91% of them used it at least once a week.  We report a case in which artefact was misinterpreted as torsades de pointes, often referred to simply as torsades. Our patient did not suffer any harm and did not have any unnecessary investigations, yet inappropriate treatment was administered making the potential for harm a real possibility. We describe the ECG features which differentiate artefact from torsades and review common sources of ECG artefact, in both hospital and general practice.