LEFT-VENTRICULAR LONG AXIS DISTURBANCES AS PREDICTORS FOR THALLIUM PERFUSION DEFECTS IN PATIENTS WITH KNOWN PERIPHERAL VASCULAR-DISEASE

Objective-To compare resting long axis echocardiography with adenosine thallium-201 emission tomography in detecting myocardial ischaemic ab normalities in patients before peripheral vascular surgery. Design-A p rospective and blinded preoperative examination of resting left ventri cular minor and long axes and myocardial perfusion during adenosine va sodilatation using thallium-201 emission tomography. Setting-A tertiar y referral centre for cardiac and vascular disease equipped with invas ive, non-invasive, and surgical facilities. Subjects-65 patients (40 m en) with significant peripheral vascular disease, mean (SD) age 63 (10 ) years, and 21 control subjects of similar age. Methods-Segments were classified as normal, with fixed or reversible defects according to t hallium-201 myocardial perfusion tomography. Systolic long axis abnorm alities were either reduced excursion and/or abnormal shortening after A2, and diastolic abnormalities either delayed onset of lengthening > 80 ms and/or reduced peak lengthening rate < 4.5 cm/s. Segmental perf usion defects were compared with the equivalent long axes; anterosepta l for septal, inferoseptal for posterior, and lateral for left side gi ving a total of 195 segments. Results-Systolic long axis abnormalities predicted fixed thallium defects (sensitivity 86%, specificity 87%, p ositive predictive value 0.78, negative predictive value 0.93, p < 0.0 01), and diastolic abnormalities correlated with reversible perfusion defects (sensitivity 90%, specificity 85%, positive predictive value 0 .72, negative predictive value 0.95, p < 0.001). Echocardiography char acteristics of the true and false positive segments were not different in the site or the extent of abnormalities. Conclusion-Systolic long axis abnormalities predict fixed and diastolic reversible thallium per fusion defects in patients with peripheral vascular disease. Ventricul ar long axis may thus have a value as a screening test before peripher al vascular surgery as well as providing a means of monitoring myocard ial perfusion. The high negative predictive values indicate that a neg ative long axis study makes significant perfusion abnormalities very u nlikely in patients with high pretest probability of coronary artery d isease.