Nitrate-enhanced gated technetium 99m sestamibi SPECT for evaluating regional wall motion at baseline and during low-dose dobutamine infusion in patients with chronic coronary artery disease and left ventricular dysfunction: comparison with two-dimensional echocardiography.

BACKGROUND: The value of gated single photon emission computed tomography (SPECT) in the assessment of wall motion (WM) in patients with severe perfusion defects and in the evaluation of low-dose dobutamine (LDD)-induced changes is not yet established. In patients with chronic coronary artery disease who have left ventricular (LV) dysfunction, the results of nitrate-enhanced technetium 99m sestamibi (sestamibi) gated SPECT for the evaluation of resting and LDD WM were compared with those of baseline and LDD echocardiography (LDDE). METHODS AND RESULTS: Thirty-seven patients underwent echocardiography and nitrate-enhanced sestamibi gated SPECT within 1 week at rest and during LDD infusion. WM was scored from 1 (normal) to 4 (dyskinetic) by using a 16-segment model. Segments with sestamibi uptake less than 30% were considered unsuitable for WM analysis (36 of 592 segments). Echocardiography was technically unreliable in 10 of 592 segments. The precise agreement between echocardiography and gated SPECT for baseline regional WM was 68.4% (kappa = 0.54), without significant differences for the involved coronary artery territory. The agreement for +/- 1 WM scoring was 96.5% (kappa = 0.94). Contractile reserve during LDD was detected by means of echocardiography in 36% and by means of sestamibi gated SPECT in 33% of baseline asynergic segments. Agreement for detection of WM improvement in response to LDD was 74% (kappa = 0.41). The overall and +/-1 WM score agreement for LDD WM was 67.5% (kappa = 0.50) and 94.7% (kappa = 0.91), respectively. A significant correlation between echocardiography and gated SPECT was observed for both baseline (p = 0.78) and LDD (p = 0.74) WM score index. CONCLUSIONS: In patients with coronary artery disease who have LV dysfunction, nitrate-enhanced sestamibi gated SPECT allows a reliable WM evaluation, both at rest and during LDD infusion, in almost all segments and provides results in agreement with LDDE.

Comparison of baseline and low-dose dobutamine technetium-99m sestamibi scintigraphy with low-dose dobutamine echocardiography for predicting functional recovery after revascularization.

Injection of sestamibi during low-dose dobutamine (LDD) infusion might improve tracer ability to detect viable myocardium. This study investigated the potential value of LDD technetium-99m sestamibi (sestamibi) single-photon emission computed tomography (SPECT) in predicting functional recovery after revascularization by comparing its results with those of sestamibi SPECT at rest and of LDD echocardiography. Before revascularization, 23 patients with chronic coronary artery disease and regional left ventricular dysfunction underwent sestamibi SPECT at rest and, on a separate day, LDD echocardiography and sestamibi SPECT with tracer injection during LDD infusion. Echocardiography at rest was repeated after revascularization. Semiquantitative sestamibi uptake results (grading from 0 = normal to 4 = absent) and wall motion (grading from 1 = normal to 4 = dyskinesia) were evaluated with a 16-segment model. The ventricular wall was divided into 3 vascular territories. At follow-up, 20 of 32 asynergic vascular territories showed functional recovery, whereas 12 showed no changes. For prediction of functional recovery, LDD SPECT achieved better accuracy than SPECT at rest (87% vs 65%, p <0.05); positive and negative predictive values of LDD SPECT were 90% and 83%, respectively, which was not significantly different from the related LDD echocardiographic values (84% and 69%). Thus, LDD sestamibi SPECT appears to be a promising method for detecting myocardial viability, which provides better accuracy than sestamibi SPECT at rest, and achieves predictive values comparable to those of LDD echocardiography.

[Changes in myocardial Tc-99m-sestamibi uptake in asynergic territories during low-dose echo-dobutamine test]. / Modificazioni della captazione miocardica di Tc-99m-sestamibi in territori asinergici durante test eco-dobutamina a bassa dose.

BACKGROUND: Recent data suggest that contractile reserve in dysfunctional but viable myocardium during low-dose dobutamine infusion might be elicited not only by a direct inotropic stimulation but also by an increase in coronary blood flow. Aim of the study was to evaluate the effects of low-dose dobutamine on myocardial perfusion and function in asynergic but viable myocardium. METHODS: Nineteen patients with coronary artery disease and severe regional dysfunction were studied. Both regional ventricular function and myocardial perfusion were assessed at rest (PRE), during low-dose dobutamine (DOB) and, in twelve patients, after revascularization (POST). Regional ventricular function was evaluated with two-dimensional echocardiography using a score index ranging from 1 to 4. Myocardial perfusion was studied using Tc-99m-sestamibi Single Photon Emission Tomography (SPET); uptake defects were graded from 0 (normal) to 4 (absent uptake). For both evaluations the left ventricle was divided in 16 segments and two vascular territories were considered. RESULTS: Low-dose dobutamine elicited contractile reserve in 12 of 24 asynergic vascular territories (DOB+). Compared with PRE scintigraphy, DOB SPET showed perfusion improvement in 10/12 DOB+ and in 3/12 DOB- asynergic territories (p = 0.006). Mean uptake score decrease significantly in DOB+ (from PRE SPET 21.0 +/- 7.2 to DOB SPET 17.6 +/- 7.1; p = 0.0005) but not in DOB- (from SPET PRE 19.0 +/- 5.3 to SPET DOB 19.5 +/- 6.8, p = NS) abnormal territories. Fourteen asynergic territories underwent revascularization. Among them, 9 showed functional recovery after intervention (viable myocardium) and 5 showed no changes (fibrotic myocardium). A functional improvement under dobutamine was observed in 7 viable and in 1 fibrotic territories. Conversely, perfusion improved under dobutamine in 8 viable and in one fibrotic territory. After revascularization the perfusion defect score decreased significantly in viable territories (from PRE SPET 22.1 +/- 7.9 to POST SPET 13.3 +/- 6.6; p = 0.00001) but not in fibrotic regions (from PRE SPET 17.8 +/- 6.0 to POST SPET 15.6 +/- 4.9). CONCLUSIONS: In asynergic myocardium contractile reserve elicited by low-dose dobutamine is associated in most cases with an improvement in Tc-99m-sestamibi uptake. This suggests a possible link between increased blood flow and functional improvement during dobutamine in viable myocardium.

Limitation of myocardial infarct size by nicorandil after sustained ischemia in pigs.

Nicorandil is a compound with hybrid properties of nitrates and adenosine triphosphate (ATP)-sensitive potassium channel (KATP) opening. The effects of nicorandil and isosorbide dinitrate (ISDN) were investigated in a model of 60-min coronary occlusion/180-min reperfusion in open chest pigs. Three groups of 10 pigs were randomly assessed to receive saline or equihypotensive doses of nicorandil or ISDN. Drug infusion was started at 30 min of ischemia and continued throughout reperfusion. Area at risk (AAR) and infarcted area (IA) were assessed by monastral blue dye-triphenyltetrazolium dual staining technique and calculated by planimetry. Myeloperoxidase concentration (MPO) in the non-ischemic area and in the IA was assessed as an index of presence of neutrophils. Measurements of reduced glutathione (GSH), oxidized glutathione (GSSG), lipofuscine, and malondialdehyde were performed on coronary vein blood as indexes of oxidative stress. IA, as a percentage of AAR, was 78 +/- 10% after saline, 61 +/- 12% after N (p < 0.05 vs. saline), and 69 +/- 14% after ISDN (not significant vs. saline). Cardiac output and left ventricular dP/dt were depressed during coronary occlusion in all groups and their recovery during reperfusion was earlier in the nicorandil group. In the saline group, MPO was increased in the IA compared to the nonischemic area (78 +/- 63 vs. 21 +/- 21 micrograms/mg prot, p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac disease after chest irradiation for Hodgkin's disease: incidence in 108 patients with long follow-up.

Occult or overt but delayed cardiac disease after thoracic radiotherapy for Hodgkin's disease may be common. Detailed cardiac evaluation was performed in 108 patients, mean age 46 +/- 6.2 years, with Hodgkin's disease at 175 +/- 43 months after irradiation. The study protocol included clinical examination, graded treadmill exercise test and echocardiography. Some patients with angina pectoris, previous myocardial infarction and an abnormal ECG were studied by thallium-201 scintigraphy, cardiac catheterization and coronary angiography. Cardiac disease was found in 12 patients (11%). Three patients had angina pectoris, one patient had myocardial infarction, two complained of dyspnea on effort and two had congestive heart failure. At catheterization, constrictive pericarditis was diagnosed in four patients; in two additional patients an occult constrictive pericarditis was found. One patient had both mitral and tricuspidal regurgitation and one had mitral regurgitation alone. Eight patients (7.4%) had severe coronary artery disease; four of these had associated constrictive pericarditis. Four patients had a pericardiectomy and another four had undergone coronary artery by-pass graft. Two patients died after operation from persistent pericardial constriction. It is concluded that the incidence of delayed cardiac disease after radiotherapy is relatively high; chronic pericardial disorders and coronary artery disease are the most frequent manifestations of this disease. Standard surgical treatment may be beneficial because of the relative youth of these patients.

Pharmacodynamic characteristics of low-molecular-weight dermatan sulphate after subcutaneous administration in acute myocardial infarction.

Sixteen patients (5 female and 11 male, mean age 59.1 years) who had had an acute myocardial infarction within the previous 7 days, were enrolled in an open pharmacodynamic study. Patients were randomly allocated to two treatment groups and given a single subcutaneous dose of 100 or 200 mg of a new low-molecular-weight dermatan sulphate. The drug pharmacodynamic profile was determined 1, 2, 4, 6, 8, 12 and 24 h after administration. The following coagulation and fibrinolysis tests were performed: activated partial thromboplastin time, thrombin time, activated factor X inhibition, Heptest (global clotting time), heparin cofactor II affinity, functional and antigenic plasminogen activator inhibitor and fibrin plate assay. Both Heptest and heparin cofactor II affinity were significantly increased (P < 0.001) in a dose-dependent manner. The XaI was enhanced, though to a lesser extent. None of the other coagulation or fibrinolysis tests showed significant changes at either dose. Systemic and local tolerance were always very good.

[Restrictive cardiomyopathies]. / Le cardiomiopatie restrittive.

The restrictive cardiomyopathies are the least common of the 3 major categories of cardiomyopathic disorders seen in Western countries. According to the report of the WHO/ISFC Task Force the term restrictive cardiomyopathy applies to only 2 conditions: endomyocardial fibrosis and Loeffler endocarditis while many specific myocardial diseases can develop a restrictive pathophysiologic profile along their natural history. During the last decade this topic has received 2 main contributions: the identification of a common pathophysiologic ground linking Loeffler endocarditis and endomyocardial fibrosis and the identification of the so-called idiopathic restrictive cardiomyopathy. This condition, defined as a myocardial disease with restrictive physiology, unknown etiology and without histological evidence of infiltrative or storage diseases, appears to be the single most frequent type of restrictive cardiomyopathy in Western countries. A revision of the current classification of cardiomyopathies and particularly of restrictive myocardial disease is necessary.

[The prevalence, risk factors and clinical significance of atherosclerosis of the thoracic aorta: a transesophageal echocardiographic study]. / Prevalenza, fattori di rischio e significato clinico dell'aterosclerosi dell'aorta toracica: studio mediante ecografia transesofagea.

Available information on atherosclerosis of thoracic aorta in man is scanty and mostly derived from pathological or surgical series. Transesophageal echocardiography makes a clear definition of the entire thoracic aorta possible and enables large, population based studies. In order to define prevalence, risk factors and clinical implications of aortic atherosclerosis, the echocardiographic recordings of 220 patients suitable for both evaluation of thoracic aorta and risk factors analysis were reviewed. Transesophageal echocardiography has been performed because of valvular diseases (78), suspected aortic aneurysm or trauma (43), evaluation of valve prosthesis (39), previous cerebral or peripheral embolic events (22), infective endocarditis (14), cardiac mass lesions (12) or other indications (12). Age ranged from 5 to 81 years (55 +/- 15), male to female ratio was 0.99. Simple and complex atherosclerotic plaques were identified in 33% and 10% respectively. Complex atheromas were more frequent among patients with previous embolic episodes (6/22, 27% versus 17/198, 8.5%; p = 0.019). The prevalence of any type of atherosclerosis progressively increased from the fourth (8%) to the eighth (88%) decade of age. By univariate analysis age (p < 0.001), history of hypertension (p < 0.001), systolic (p < 0.001) and diastolic (p < 0.05) pressure, type II diabetes mellitus (p < 0.01), HDL cholesterol (p < 0.01), HDL/total cholesterol (p < 0.01) and uricaemia (p < 0.05) were associated with aortic atherosclerosis. Discriminant analysis identified 5 independent variables associated with the presence and the extent of atherosclerosis (Wilk's Lambda = 0.43): number of cigarettes per day, age, history of hypertension, systolic pressure and type II diabetes mellitus. This model provided a 63% correct classification rate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Aortic dissection without intimal laceration: a case report and review of the problem]. / Dissezione aortica senza lacerazione intimale: descrizione di un caso e revisione del problema.

A 43-year-old hypertensive woman with symptoms of aortic dissection was referred to our hospital 3 days after the initial episode. Transesophageal echocardiography and magnetic resonance showed a large intramural hematoma of the ascending and descending aorta without intimal flap and tears. Aortography confirmed the absence of intimal disruption. Medical therapy with beta and alpha blocking agents was established. After 5 months the patient was asymptomatic. On transesophageal echocardiogram and magnetic resonance, complete reabsorption of the hematoma of descending aorta was evident while a clearly identifiable false lumen and intimal flap (without tear) were present at the aortic arch level. The diagnostic criteria and therapeutic options are discussed and the literature on this topic is reviewed.

[Heart failure in patients with valve prostheses]. / Lo scompenso cardiaco nel paziente con protesi valvolare.

Congestive heart failure in patients with prosthetic valves is a complex syndrome which poses difficult clinical and therapeutical problems. In order to identify etiologic factors, pathophysiologic substrates, clinical pictures and natural history we retrospectively evaluated 124 consecutive patients (mean age 61 +/- 11 years) with prosthetic valves, hospitalized during the 1984-1990 period because of congestive heart failure. The following main etiologies were identified: acute prosthetic valve failure (19%), chronic prosthetic failure (15%), preexisting left ventricular dysfunction (9%), newly acquired left ventricular dysfunction (8%), associated valve diseases (15%), chronic constrictive pericarditis (2%), multiple causes (31%). At a mean follow-up of 8.9 +/- 4.5 years, mortality was 8.8%/patients/year in the whole group, 3% in the subgroup with chronic prosthetic failure and 19% among the cases with preexisting left ventricular dysfunction. Among the patients who underwent reoperation because of prosthetic failure, the following were incremental risk factors: mechanical (vs biological) failing prosthetic valve, mitral prosthesis, emergency operations, mitral and or aortic insufficiency as the initial diagnosis. The preliminary knowledge of the possible etiologies and of the pathophysiologic substrates can help the physician while treating the single patient with heart failure after valve replacement. Many implications derived from this kind of patients are also useful in order to select surgical candidates among patients with valve disease.