Review of intracoronary Doppler catheters.

During the last 20 years several types of Doppler catheters have been developed and applied to the measurement of coronary blood flow velocity in man. Validation studies in the laboratory and in animals have shown that these catheters can accurately measure velocity from a small sample volume beside or ahead of the catheter tip. The Doppler transducers have been miniaturized enough (less than 1 mm dia) to be mounted on subselective coronary catheters or balloon angioplasty catheters without compromising any of the normal catheter functions. Good quality, high fidelity velocity signals have been recorded from many sites within the coronary circulation of patients during coronary arteriography and balloon angioplasty. Coronary flow reserve measured with Doppler catheters is a physiologic index of the severity of a stenosis which, when carefully measured, can be used for assessing lesions, planning treatment, and evaluating the success of interventions.