This film is unmitigated drivel with a few funny bits, though there is a tiny grain of truth to the story. Jason Statham plays a hitman called Chev Chelios, whose heart is stolen by gangsters and replaced with an artificial model. In order to stay alive, he has to keep recharging its battery with electricity.

Chelios's artificial heart is called an "Aviocor". There is a real artificial heart called the Abiocor that works on much the same principle. You walk around with a battery, and power is transferred to the machine through your skin. However, I sincerely doubt you would be able to power it by electrocuting yourself with tasers, car batteries and power lines, as Chelios does. You would be more likely to fry the electrics.

The heart surgery at the beginning is implausible in the extreme (although no more so than the rest of the film). For one thing, Chelios is conscious, and this isn't the kind of operation you can perform under local anaesthetic. There are some hygiene issues, too: the gangsters appear to be operating in someone's house, with ungowned, unmasked people wandering in and flicking cigarette ash into the wound.

Chev's heart is carried away in a cooler box after the operation, and eventually transplanted into mob boss David Carradine. They don't bother to tissue-type him - obviously this heart is some kind of super-organ.

Frankly, I wouldn't rate Chev's chances in the real world very highly. Artificial hearts are pretty poor, primitive devices. They supply enough cardiac output to keep you slowly plodding around, but they certainly don't allow for martial arts and sprinting. Overcharging them won't give you super-speed, either.

• Dr Simon Grant is a consultant cardiologist at Calderdale Royal Hospital. Interview by Paul Arendt. Crank: High Voltage is on general release.