As part of the clinical angioplasty procedure the patient will have a coronary guidewire passed down the artery usually from the groin to the heart which is used to position balloons and stents. OCT passes over the wire in the same way. From the patients perspective the procedure may take a small amount of additional time - maximum 10-15 minutes. We would like to be able to pass a second wire down the same coronary artery called a 'buddy wire' which is sometimes required in coronary procedures. This would be used to inflate a balloon at low pressure near the area of interest in the heart in order either to exclude blood or to oppose the OCT catheter to the vessel wall if required.