We studied 33 patients (28 males, 5 females) with first inferior acute myocardial infarction (AMI) and 12 normal volunteers. They underwent first-pass (FP) and equilibrium-gated radionuclide angiography (EGRA) within 4 days of the onset of symptoms. The parameters [ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR)] of the time-activity curve (TAC) of both ventricles [left ventricle (LV), right ventricle (RV)] were computed. The regional wall motion (RWM) was evaluated by parametric images (amplitude and phase). In 43% of the patients with AMI, we found a depressed RVEF, while the LVEF was decreased in only 33%. The sensitivity of diastolic parameters was shown to be clearly superior to that of the systolic parameters (RVPFR, 78%; LVPFR, 79%). The abnormalities of the overall performance of both ventricles were significantly correlated with those of the RWM. The abnormal RVEF allowed us to assess the necrotic involvement of the RV, while a depressed RVPFR suggested an impaired RV compliance mostly on an ischemic basis. Congestive heart failure (CHF) and shock syndrome were significantly correlated with depressed RV parameters, while the LVEF, despite RWM abnormalities, was in the normal range. EGRA with computation of the TAC parameters of both ventricles appeared to be useful for in-hospital prognostic evaluation, therapeutic planning and clinical follow-up of patients with inferior myocardial infarction.

The purpose of this study was to assess the clinical usefulness of phase and amplitude images and of the left ventricle time-activity curve (LVTAC) obtained by equilibrium gated radionuclide ventriculography (EGRV) in patients with acute myocardial infarction (AMI). Fifty-six patients were studied within 4 days of the onset of AMI by EGRV; of these 49 also underwent first-pass (FP) angiocardiography, for comparison with EGRV, and 21 underwent repeated EGRV 3 months after AMI. Phase and amplitude images were obtained by Fourier analysis. LVTAC analysis was performed by a third degree polynomial fitting to determine peak ejection rate (PER) and peak filling rate (PFR). A substantial equivalence of EGRV and FP methods was demonstrated, as regards left ventricle ejection fraction (LVEF), while a sharp superiority of EGRV with Fourier analysis was shown with regard to the sensitivity of RWM abnormality detection. With only one exception all the cases showed RWM abnormalities, while LVEF was normal in 21 of 27 patients with less than three affected segments. The most sensitive global function index was the LVPFR. In the acute phase regional dyskinesis was observed in 14 of 56 patients. About 40% of our cases showed an improvement of the kinetic abnormalities 3 months after AMI. The highest rate of improvement was observed in the group with ECG patterns of limited infarction and with normal LVEF.

Two methods for the analysis of left ventricle time-activity curve (TAC) of equilibrium gated ventriculography were compared in three groups of subjects [8 controls, 13 patients with coronary artery disease (CAD), 11 patients with myocardial infarction (MI). The first method was based on third-degree polynomial fitting, the second on Fourier analysis. The following parameters were calculated: peak ejection rate (PER), peak filling rate (PFR), time to PER and PFR, and filling fraction at the first third of diastole. A preliminary study of changing values of PER and PFR and of the mean error with increasing number of harmonics summed in order to obtain the best fitting of TAC demonstrated that beyond the sum of the first four harmonics there was no further significant improvement. The advantages of Fourier analysis are as follows: it is independent of the operator and fits only one function to the whole cardiac cycle; it requires less computer time; it provides better differentiation between controls and CAD patients. All of the 13 CAD patients had abnormal PFR on Fourier analysis, only 9 on polynomial analysis. At rest, 9 of the CAD patients had wall motion abnormalities, while only two had an abnormal ejection fraction.

Others reported a significant reduction in the thinning rates of the left ventricular posterior wall and interventricular septum in 13 patients with Friedreich's ataxia.4The only scintigraphic studies of left ventricular function in patients with Friedreich's ataxia are those of Pentland and Fox5 and Therriault et al6 in which the ejection fraction was normal in most cases. We do not know of any radionuclide studies of the diastolic function of the left ventricle and the overall function ofthe right ventricle in this disease. We have assessed the function of both ventricles by radionuclide angiography in a group of patients with Friedreich's ataxia.Requests for reprints to Professor M Morpurgo, Via Boccaccio 24,

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