A long waitlist for heart scans is expected to put patients at serious risk

It's believed there are around 15 thousand people on the waitlist for an echocardiogram.

New Zealand Cardiac Society Chair Dr Martin Stiles says it's a diagnostic tool not a treatment.

He says if scans get delayed it can mean operations are high risk or even impossible.

Stiles says the delays are getting serious.

He says at the worst hospitals scans which should be done in 5 to 6 weeks are taking a year to complete.