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Biomedical subjects

C Vecchio

Publications and source records attributed to C Vecchio.

At least 73 records · Page 4Linked to original sources
PubMed1993

Quantitative ultrasonic analysis of myocardium in patients with thalassemia major and iron overload.

BACKGROUND: Patients with beta-thalassemia major present with severe anemia and need continuous transfusion therapy. The consequent iron overload leads to hemochromatosis. Initial cardiac dysfunction has been documented even in thalassemics without clinical manifestations of heart failure as well as by conventional echocardiographic-Doppler techniques. The purpose of this study was to assess the acoustic quantitative properties of myocardium in patients with iron overload. METHODS AND RESULTS: Thirty-eight patients with beta-thalassemia major, without clinical signs of cardiac failure, and 20 age- and sex-matched young controls were studied by echocardiography. An on-line analysis of the ultrasonic radiofrequency signal was performed to obtain quantitative operator-independent measurements of the integrated backscatter (IB) signal of the ventricular septum and the posterior wall. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent (IB%). Thalassemic patients had been receiving transfusion therapy for 16 +/- 5 years and had received 313 +/- 138 transfusion units; they all had received chelation treatment (desferroxiamine) for 9 +/- 2 years. Patients and controls showed comparable values of echocardiographically assessed percent fractional shortening (32 +/- 3% versus 36 +/- 4%, p = NS), whereas thalassemics showed higher values of left ventricular mass index (118 +/- 30 versus 98 +/- 15 g/m2, p < 0.05). The IB% values were higher in patients with thalassemia major than in controls for both septum (35 +/- 14% versus 21 +/- 6%, p < 0.001) and posterior wall (16 +/- 6% versus 11 +/- 3%, p < 0.001). In thalassemic patients, no significant correlation was found between the septum IB% value and hematological parameters, such as the total number of transfusions (r = 0.2, p = NS) or the mean ferritin value (r = 0.1, p = NS). No significant correlation was also found between the septum IB% value and the echocardiographically assessed left ventricular mass index (r = 0.2, p = NS). CONCLUSIONS: These data demonstrate that myocardial reflectivity is abnormally increased in patients with thalassemia major under transfusion treatment, probably due to myocardial iron deposits and/or secondary structural changes. These quantitatively assessed abnormalities in regional reflectivity can be detected when conventional echocardiographic parameters of systolic left ventricular function are undistinguishable from normal controls.

Adolescent↗
PubMed1992

Cardiac involvement in thalassaemia major: altered atrial natriuretic peptide levels in asymptomatic patients.

Congestive heart failure is the most common cause of death in young adults with thalassaemia major. In the present study we compared atrial natriuretic peptide levels (ANP) in 30 asymptomatic patients with thalassaemia major (aged 16.6 +/- 6.4 years), normal left ventricular diastolic cavity dimension and systolic function, with 30 aged and sex matched normal control subjects. ANP levels were significantly higher in patients with thalassaemia major compared to controls (93.9 +/- 26.3 pg.ml-1 vs 51.8 +/- 26.5 pg.ml-1; P < 0.001). Plasmatic renin activity, aldosterone, urinary sodium and catecholamine levels at basal conditions did not differ significantly in these two groups (ns). Blood volume stimulation (blood transfusion) in thalassaemic patients was followed by an increase of mean ANP values (93.9 +/- 26.3 to 109.1 +/- 40.5 pg.ml-1; P < 0.03). ANP basal levels above two standard deviations of the mean values obtained in normal control subjects were considered as abnormal and found to be in close correlation with the presence of diastolic dysfunction of the left ventricle identified by Doppler echocardiography. The method has a 57% sensitivity and a 91% specificity for revealing pre-clinical cardiac involvement (P < 0.02). Although a longer observation period is necessary in order to define the clinical and prognostic significance of these data, our results show that an increase in ANP basal values is present in asymptomatic patients with thalassaemia major. This suggests initial myocardial involvement, while ANP response to volume overload is maintained.

Adolescent↗
PubMed1992

Predicting cardiac mortality after uncomplicated myocardial infarction by exercise radionuclide ventriculography and exercise-induced ST segment elevation.

In 183 consecutive patients with recent, uncomplicated myocardial infarction, the following variables were associated with 4-year cardiac death: haemodynamic decompensation with exercise (P = 0.01), left ventricular ejection fraction at rest (P = 0.004) and at peak exercise (P = 0.003), persistent ST segment elevation at rest in the area of infarction = (P = 0.004), exercise-induced ST segment elevation (P = 0.02), and late aneurysmal evolution (P = 0.01). Exercise left ventricular ejection fraction was the sole variable selected by Cox regression analysis as an independent predictor of cardiac death. In 40 patients with ST segment elevation at rest, left ventricular ejection fraction was 42 +/- 17% at rest and 40 +/- 18% at peak exercise, versus 52 +/- 12% and 52 +/- 14% in the remaining patients (both P less than 0.01). Among these 40, 16 (all with anterior infarction) also had exercise-induced ST segment elevation; their ejection fraction was 32 +/- 13% at rest, 30 +/- 13% during exercise, versus 53 +/- 15% and 53 +/- 15% in 129 patients with no ST segment elevation either at rest, or during exercise (both P less than 0.01). The 4-year risk of death was 20% in the former 40 patients, 36% in the latter 16, while in the complete absence of ST segment elevation, such risk was 3%. All 14 patients with ST segment elevation only during exercise were alive after 4 years: their left ventricular ejection fraction was 47 +/- 12% at rest, 45 +/- 13% with exercise. ST segment elevation was associated with late aneurysmal evolution but not with exercise-induced ischaemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Dyspnea↗
PubMed1991

Quantitative assessment of ultrasonic myocardial reflectivity in hypertrophic cardiomyopathy.

The purpose of this study was to investigate the relation between acoustic properties of the myocardium and magnitude of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy. An on-line radio frequency analysis system was used to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and posterior free wall in 25 patients with hypertrophic cardiomyopathy and 25 normal age-matched control subjects. The integrated values of the radio frequency signal were normalized for the pericardial interface and expressed in percent. Tissue reflectivity was significantly increased in the hypertrophied ventricular septum, as well as in the nonhypertrophied posterior free wall, in patients with hypertrophic cardiomyopathy (58 +/- 15% and 37 +/- 12%, respectively) compared with values in normal subjects (33 +/- 10% and 18 +/- 5%, respectively; p less than 0.001). Furthermore, measurements of reflectivity of the septum or posterior free wall, or both, were beyond 2 SD of normal values in greater than 90% of the patients and were also abnormal in each of the five study patients who had only mild and localized left ventricular hypertrophy. No correlation was identified between myocardial tissue reflectivity and left ventricular wall thickness in the patients with hypertrophic cardiomyopathy (correlation coefficient r = 0.4; p = NS). These findings demonstrate that myocardial reflectivity is abnormal in most patients with hypertrophic cardiomyopathy and is largely independent of the magnitude of left ventricular hypertrophy. Moreover, quantitative analysis of ultrasonic reflectivity can differentiate patients with hypertrophic cardiomyopathy from normal subjects independently of clinical features and conventional echocardiographic measurements.

Adolescent↗
PubMed1991

Left ventricular thrombus in anterior acute myocardial infarction after thrombolysis. A GISSI-2 connected study.

BACKGROUND: Streptokinase reduces the incidence of left ventricular thrombosis after acute myocardial infarction. However, it is unknown whether a similar effect can be obtained with different thrombolytic agents and whether subcutaneous calcium heparin can have an additional efficacy. METHODS AND RESULTS: To compare the effects of two different thrombolytic agents combined or not with heparin on the incidence and features of left ventricular thrombi and their related embolic events, we performed a GISSI-2 ancillary echocardiographic study (the first echocardiogram obtained within 48 hours of symptoms onset and the second before hospital discharge) that enrolled 180 consecutive patients (mean age, 63 +/- 11 years, 142 men) with a first anterior acute myocardial infarction. Patients were randomized into four groups of treatment: recombinant tissue-type plasminogen activator (rt-PA) (n = 47), rt-PA plus heparin (n = 45), streptokinase (n = 39), and streptokinase plus heparin (n = 49). Left ventricular thrombosis was observed in 51 of 180 patients (28%). No significant differences were found concerning the incidence of thrombi in the four treatment groups. Mural shape of left ventricular thrombi was found more frequently than the protruding shape (71% versus 29% at the first examination, 64% versus 36% at the second), particularly in heparin-treated patients (93% versus 7% at first examination, 70% versus 30% at the second). Only one embolic event (0.5%) occurred during the hospitalization. CONCLUSIONS: We conclude that 1) the rate of left ventricular thrombi does not differ in patients with acute myocardial infarction treated either with streptokinase or rt-PA, 2) subcutaneous heparin, when begun 12 hours after intravenous thrombolysis, does not appear to further reduce the occurrence of thrombi but seems to influence the shape of left ventricular thrombi, and 3) during the predischarge period, embolic events are rare in patients treated by thrombolysis.

Adult↗
PubMed1991

[Supraventricular tachyarrhythmias during acute myocardial infarction: short- and mid-term clinical significance, therapy and prevention of relapse].

Clinical significance, short and long-term prognostic value, and treatment of supraventricular tachyarrhythmias were evaluated in 208 patients with definite acute myocardial infarction (AMI). No patient received thrombolytic therapy. In Coronary Care Unit supraventricular tachyarrhythmias were detected by continuous electrocardiographic monitoring in 30 (14%) patients: 18 had atrial fibrillation, 1 atrial flutter, 9 paroxysmal atrial tachycardia and 2 non-paroxysmal junctional tachycardia. These episodes began within the first 48 hours of AMI in 93% of patients, and generally they were preceded by frequent or repetitive atrial premature beats. Supraventricular tachyarrhythmias were significantly associated with older age, higher incidence of overt left ventricular dysfunction (both p less than 0.05) and higher Peel Index (p less than 0.02). They caused severe hemodynamic consequences in 20% of patients. In 8 patients they were selflimiting, in 20 they were suppressed by means of medical therapy and in one by DC countershock. During hospitalization supraventricular tachyarrhythmias recurred in one patient; moreover, in this period cardiac death occurred in 26% of patients with supraventricular tachyarrhythmias and in 13% of the remaining (p: ns). Multivariate analysis showed that supraventricular tachyarrhythmias are not important factors in identifying patients at risk of cardiac death. At hospital discharge, patients with supraventricular tachyarrhythmias showed significantly higher values of left ventricular end-diastolic and end-systolic dimensions (both less than 0.05), and a greater use of digitalis-diuretics and/or vasodilators (p less than 0.03). By contrast, in patients with and without supraventricular tachyarrhythmias no significant difference was present with regard to the frequency of New York Heart Association functional classes III-IV for congestive heart failure, frequency of significant tachyarrhythmic events during 24-hour continuous electrocardiographic recording, X-ray cardiac size and left ventricular ejection fraction at rest. In the 2 years following AMI, survival curves showed no significant difference in the risk of cardiac death among patients with or without supraventricular tachyarrhythmias; in particular, in the first group only 2 patients had severe hemodynamic events and no patient showed recurrences of tachyarrhythmia. Our findings suggest that although supraventricular tachyarrhythmias complicating AMI frequently occur in patients with severe cardiac disease they are not related to a higher risk of cardiac death either during in-hospital period or in the 2 years following AMI; medical therapy is effective and safe to suppress these arrhythmias; a systematic use of specific antiarrhythmic drugs to prevent their recurrences is not necessary.

Adult↗
PubMed1990

Frequency, characteristics and significance of supraventricular tachyarrhythmias detected by 24-hour electrocardiographic recording in the late hospital phase of acute myocardial infarction.

The incidence, characteristics and clinical significance of supraventricular tachyarrhythmias occurring in the late hospital phase of acute myocardial infarction (AMI) were assessed in 209 consecutive patients. Arrhythmias were quantified by 24-hour electrocardiographic recording 16 +/- 3 days after AMI, and were classified according to the degree of complexity in 5 classes. Class 0 = less than 5 premature beats/hr; class 1 = between 5 and 100/hr; class 2 = greater than 100/hr or repetitive premature beats; class 3 = atrial-junctional tachycardia; class 4 = atrial flutter-fibrillation. Supraventricular tachyarrhythmias classes 1 to 2 always occurred in the absence of symptoms in 86 patients (41%); supraventricular tachyarrhythmias classes 3 to 4 (paroxysmal, self-limiting, brief) occurred in 27 patients (13%), symptomatically in 6. The presence of supraventricular tachyarrhythmias classes 2 to 3 was related to age over 55 years and complex ventricular tachyarrhythmias (greater than 20 premature beats/hr, ventricular tachycardia) (both p less than 0.05). Increasing complexity of supraventricular tachyarrhythmias was significantly associated with presence and entity of cardiac enlargement and left ventricular dysfunction (both p less than 0.01). Patients with class 4 showed the most severe cardiac deterioration. During the 2 years after AMI, patients with classes 2, 3 and 4 had a higher incidence of acute pulmonary edema, New York Heart Association functional classes III to IV for congestive heart failure (both p less than 0.005) and a greater need of digitalis and diuretics (p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Early appearance of left ventricular thrombi after anterior myocardial infarction: a marker of higher in-hospital mortality in patients not treated with antithrombotic drugs.

Left ventricular thrombus may develop both early and late after acute anterior myocardial infarction. To assess the possible prognostic implication of the time of thrombus appearance, 125 patients (87 males; age ranging from 35 to 92 years, mean: 65 +/- 10 years) consecutively admitted to our coronary care unit within 24 h of a first acute anterior myocardial infarction, untreated with antithrombotic drugs, underwent serial two-dimensional echocardiographic studies during hospitalization, then monthly for a follow-up of 1-48 (mean: 23 +/- 16) months among survivors. Left ventricular thrombi, detected in 71 patients (57%), appeared from 1 to 362 (mean: 13 +/- 44) days after acute infarction. In 40 patients (56%), early thrombus development, within 48 h of symptom onset, was noted. During the study period, 52 patients (42%) died. Global mortality rate was similar in patients with thrombi compared with those without thrombi (32/71: 45%, vs 20/54: 37%; P = ns). However, in-hospital mortality of patients who developed left ventricular thrombi within 48 h (17/40: 42.5%) was significantly higher compared with both patients with later thrombus appearance (4/31: 13%; P less than 0.008) and those without thrombi (10/54: 20%; P less than 0.01). Embolic events were more frequent in patients with thrombi (9/71, 13% vs 1/54, 2%; P less than 0.02), but there was no relationship with the time of thrombus appearance. The values of peak CPK levels and the degree of left ventricular wall motion abnormalities observed in patients with early left ventricular thrombus were significantly higher than the values detected in patients without thrombi, but similar to those obtained in patients with later thrombus occurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗