Massimo Giuliano Bonetti

Crossed cerebello-cerebral diaschisis: a SPECT study.

A scintigraphic single photon emission computed tomographic (SPECT) evaluation of frontal perfusion alteration was performed in five patients with known cerebellar lesions but with normal supratentorial computed tomographic (CT) or magnetic resonance (MR) scans. A clearly evident asymmetry was found in prefrontal areas in the four subjects with acquired cerebellar damage. The fifth subject, who had congenital left cerebellar hypoplasia, did not show any frontal flow asymmetry. The data support the growing clinical evidence that the cerebellum contributes to the cognitive processes of the frontal lobes and suggest a possible role for SPECT examination in the assessment of functional cognitive impairment in patients with acquired cerebellar lesions.

Considerations of brain death on a SPECT cerebral perfusion study.

Brain death imaging is often a diagnostic challenge. Cerebral angioscintigraphy is extensively used for this analysis, but this test does not allow the perfusion evaluation of the posterior fossa. The authors report a case in which a SPECT study showed persistence of blood frow in infratentorial structures with total absence of cerebral (supratentorial) perfusion. This finding excluded the diagnosis of brain death.

Pulmonary Involvement in Progressive Systemic Sclerosis: A Multidisciplinary Approach

In an attempt to define the early features and the natural evolution of lung involvement in progressive systemic sclerosis (PSS), we planned a multidisciplinary study of these patients using radiological, scintigraphic and functional methods. As yet we have studied 21 subjects, all affected by PSS according to the American Rheumatism Association criteria. A well-defined restrictive functional pattern was present only in 10 patients out of 21; an increased elastic recoil may be present before a significant decrease of the transfer test for carbon monoxide; an increased alveolar-capillary permeability assessed by the 99mTc-diethylene-triamine-pentacetic acid (99mTc-DTPA) clearance rate has been detected in almost all the patients (13 out of 14) in at least one lung field; no significant correlation has been found between the radiological lung involvement and the 99mTc-DTPA clearance rate. We think that these preliminary results are consistent with an alveolar and interstitial inflammation rather than with a vasculitic process.

Right Ventricular Aneurysm: A New Prognostic Indicator after a First Acute Myocardial Infarction

The prognostic implication of a right ventricular aneurysm after a first acute myocardial infarction (AMI) was assessed on a series of 137 AMI patients 12 of whom had a right ventricular aneurysm detected at radionuclide angiocardiography. The follow-up lasted 36 months. Mortality was 50 and 18.4% in patients with and without right ventricular aneurysm, respectively (p less than 0.02). Groups did not differ in age, male-to-female ratio, AMI site, left ventricular ejection fraction (LVEF), peak filling rate (PFR), left ventricular size. A multivariate logistic analysis showed that only three out of ten clinical and functional variables qualified to be independent predictors of death: right ventricular aneurysm (odd ratio = 2.48, confidence limits = 1.21-4.98), LVEF less than 52% (odd ratio = 1.91, confidence limits = 1.03-3.48), abnormal terminal P wave forces (odd ratio = 1.72, confidence limits = 1.07-2.75). The analysis of single case histories did not provide a clue to clarify the reasons accounting for the negative prognostic implication of a right ventricular aneurysm. In conclusion, a significant positive relationship between right ventricular aneurysm and mortality after AMI has been demonstrated; further study is needed to clarify the relevant mechanisms.

The effects of chronic hypoxia on left ventricular peak filling rate evaluated by equilibrium radionuclide angiocardiography.

Left ventricular peak filling rate (PFR) was measured by equilibrium radionuclide angiocardiography (ERNA) in 15 patients with Stage II stabilized chronic respiratory failure (CRF) without evidence of coexisting heart diseases and in 18 patients with coronary artery disease (CAD) without myocardial infarction. The study was designed to assess the effects of severe hypoxia and of ischaemia on the calcium-dependent early diastolic filling. PFR was found to be impaired in both groups of patients (mean = 1.72 EDVs-1 and S.E.M. = 0.07 in CAD; mean = 2.35 EDVs-1 and S.E.M. = 0.14 in CRF) but significantly less (p less than 0.001) in CRF patients while the left ventricular ejection fraction (LVEF) values were not significantly different between the two groups (mean = 60.0% and S.E.M. = 1.4 in CAD; mean = 62.0% and S.E.M. = 1.6 in CRF). As PFR is known to be a sensitive index of left ventricular performance the results obtained in this human model are consistent with findings obtained in animal models suggesting that hypoxia is less efficient than ischaemia in depressing left ventricular function.

A Simple Method of Predicting Left Ventricular Function in Stabilized Chronic Respiratory Failure

A simple method of assessing left ventricular function in stabilized chronic respiratory failure (CRF) is proposed. 21 patients with CRF were ranked according to the prediction of left ventricular function derived from eight elementary clinical criteria including standard chest X-ray and conventional basal electrocardiography. Equilibrium radionuclide angiocardiography was performed at rest (rERNA) for the evaluation of left ventricular systolic function (ejection fraction, LVEF; peak ejection rate) and diastolic function (peak filling rate). Right ventricular ejection fraction (RVEF) was also measured. The clinical evaluation of the left ventricular function showed a high correlation with rERNA data (p less than 0.01 by Spearmans rank test). No correlation was found between rERNA parameters and PaO2 and between RVEF and LVEF. The clinical criteria proposed can thus predict left ventricular function in stabilized CRF with a high degree of confidence.

Correlation of functional parameters derived by equilibrium radionuclide angiocardiography and left ventricular size in patients with old myocardial infarction

A total of 131 patients with old (over 6 months) myocardial infarction (MI) and 18 normal subjects underwent equilibrium radionuclide angiocardiography at rest (rERNA). The following rERNA parameters were assessed: left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and a left ventricular size index. The patients with old MI were divided into four groups (I to IV) according to increasing left ventricular (LV) size, and the behaviour of the numerical parameters (LVEF, PER, PFR) was evaluated in each group. LVEF proved to be the most sensitive numerical parameter of overall LV performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that for extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a too large fall in LV compliance. The effects of the site of the previous MI on LV performance were also evaluated. Both LV size and performance were least affected by postero-inferior MI. The LVEF was, however, a better predictor of LV size than the site of the MI.