99m Tc-pyrophosphate imaging of the myocardium

In the present study Tc-PYP data in patients with known dilative cardiomyopathy (DCM) are correlated with the hemodynamic and sonographic findings and with the clinical cours. Twentytwo patients aged between 35 and 61 years were examined. The diagnostic program included routine laboratory tests, T4, right and left heart catheterization with coronary angiography and left ventriculography, bicycle ergometry, echocardiography as well as Tc-PYP imaging and radionuclide angiography. Tc-PYP images were obtained 70 to 90 minutes after intravenous application of Tc-PYP, 15 mCl, in the ap, LAO and left lateral projections with an Ohio Nuclear Scanner with core storage. Images were evaluated visually using the Parkey scoring system with scores from 0 to 4, 2 to 4 being abnormal. Group I comprised 7 patients with normal Tc-PYP images, while group II included 15 patients with abnormal Tc-PYP. Groups were well matched for average age and duration of history. Differences were found to be present in cardiac dimensions expressed as cardio-thoracic ratio; in left ventricular volume index; in echocardiographic dimensions; and in left ventricular wall thickness. In addition, groups differed significantly in terms of left ventricular filling pressure; cardiac index; and in terms of left ventricular ejection fraction. Accordingly, group I showed a better exercise tolerance than group II. At a follow-up period of 6 to 52 months no deaths occurred in group I. In group II 4 of 15 patients died. In our experience patients with DCM and abnormal Tc-PYP images (group II) are characterized by pronounced cardiac enlargement, reduced ventricular wall thickness, severely comprised pumping function with a low cardiac index, limited ejection fraction and increased left ventricular filling pressure. They should thus be considered as high-risk cases with a poor prognosis. (Author)