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D Neglia

Publications and source records attributed to D Neglia.

At least 37 records · Page 2Linked to original sources

Alteration in regulation of myocardial blood flow in one-vessel coronary artery disease determined by positron emission tomography.

The behavior of myocardial blood flow (MBF) regulation in territories supplied by angiographically normal vessels of patients with coronary artery disease (CAD) has been poorly investigated. Resting MBF and coronary reserve were evaluated in 32 patients with stable angina, no previous myocardial infarction, and isolated left anterior descending or left circumflex coronary artery stenosis (> or = 50% diameter narrowing). MBF was measured, in the absence of any medical therapy, by means of dynamic positron emission tomography and 13N-ammonia. MBF measurements at baseline and after intravenous dipyridamole (0.56 mg/kg administered over 4 minutes), were obtained both in the stenosis-related regions and in contralateral territories. As a control group, 14 normal subjects were evaluated according to the same protocol. At rest, the 32 patients with CAD had similar MBF values in the stenotic and remote regions (0.76 +/- 0.21 and 0.77 +/- 0.19 ml/min/g, respectively, p = NS); both these values were significantly (p < 0.01) reduced with respect to mean MBF in normal subjects (1.03 +/- 0.25 ml/min/g). The dipyridamole study was completed in 30 patients; these patients had lower values of maximal MBF in the stenotic than in the remote regions (1.52 +/- 0.65 vs 1.76 +/- 0.68 ml/min/g, p < 0.05); however, both these values were significantly reduced (p < 0.01) with respect to mean dipyridamole MBF in normal subjects (3.66 +/- 0.92 ml/min/g). Thus, in patients with CAD, resting and maximal MBF can be reduced not only in myocardial territories supplied by stenotic arteries, but also in territories supplied by angiographically normal arteries.

Aged↗

Does the myocardium become "stunned" after episodes of angina at rest, angina on effort, and coronary angioplasty?

To assess whether myocardial stunning occurs after brief periods of ischemia, global and regional ventricular function assessed by radionuclide angiography was studied in 52 patients. Patients were divided into 3 groups according to the type of ischemic episodes. Group 1 consisted of 15 patients studied before, during and after episodes of angina at rest. Seventeen patients studied immediately before and after coronary angioplasty constituted group 2. Group 3 consisted of 20 patients with stable angina studied before, during and after exercise-induced ischemia. Medical therapy was discontinued 48 hours before the study in all patients except those undergoing coronary angioplasty who were receiving diltiazem 180 mg/day. No difference in baseline ejection fraction was found between groups, whereas peak filling rate was statistically lower in group 3 patients. Evidence of left ventricular dysfunction during ischemia was seen in patients in groups 1 and 3, whereas transient ischemia was documented by ST-segment displacement and/or typical chest pain during balloon inflation in group 2. Persistence of systolic or diastolic dysfunction was not observed in any of the 3 groups in the recovery phase after ischemia. In conclusion, transient ischemia caused either by a primary reduction in oxygen supply (angina at rest, coronary angioplasty) or by an increase in oxygen demand (angina on effort) did not reproduce the phenomenon of systolic and diastolic stunning observed in animal experiments, although in all patients the ischemia was of sufficient duration and severity to induce marked ventricular dysfunction. The search for stunned myocardium should be extended to other different clinical models characterized by prolonged ischemia such as unstable angina or myocardial infarction.

Aged↗

Non-invasive assessment of residual viability in post-myocardial infarction patients. Role of nuclear techniques.

The failure of non-imaging techniques in identifying viable segments has favoured the clinical application of nuclear imaging. The main pathways that support radionuclide imaging are cell membrane integrity, persistence of intermediary metabolism and demonstration of a residual coronary reserve. Thallium-201 reinjection or rest protocols allow the identification of viable myocardium in most of patients with wall motion abnormalities and appear to be the most diffuse, low-cost and available method to detect viable myocardium. More complex approaches use positron emission tomography and matched flow/metabolic information. Flow/metabolic 'mismatch' usually identifies most of hypoperfused regions that show post-operative improvement of regional wall motion. The last promising approach is represented by the demonstration of a maintained regional coronary reserve in dyssynergic areas. Technetium-99m-microspheres (or Teboroxime in the future) can be successfully used for this purpose. The clinical application of radionuclides appears to be one of the principal imaging tools able to identify residual viability.

Blood Flow Velocity↗

Regional myocardial blood flow and coronary reserve in hypertensive patients. The effect of therapy.

Patients with essential arterial hypertension demonstrate abnormal vasodilator capacity either during increased cardiac metabolic demand or during pharmacological vasodilation. Structural and functional damage to the coronary microcirculation has been proposed as one of the major causes of impaired coronary reserve in this disease. To assess the role of microvascular impairment in regional myocardial blood flow (MBF), 27 patients with essential hypertension were evaluated by dynamic positron emission tomography (PET) at rest, during atrial pacing and after dipyridamole infusion and compared with 13 healthy subjects. All patients had normal coronary arteries, 17 had moderate to severe hypertension and 10 had mild hypertension. Baseline mean MBF of 0.97 +/- 0.25 ml/min/g was significantly increased to 1.60 +/- 0.38 during atrial pacing and 2.35 +/- 0.95 after dipyridamole infusion (p < 0.01); however, mean flow during atrial pacing and after dipyridamole infusion was significantly lower than in healthy subjects (2.15 +/- 0.73 and 3.71 +/- 0.86 ml/min/g, p < 0.05 and p < 0.01, respectively). The MBF response to atrial pacing and dipyridamole infusion was similarly depressed in patients with mild and severe hypertension. The study was repeated after 6 months of antihypertensive treatment with the calcium antagonist verapamil or the angiotensin converting enzyme (ACE) inhibitor enalapril in a subgroup of 20 patients as part of a randomised, single-blind clinical trial. This study is still in progress; the initial 16 patients treated with verapamil or enalapril showed an obvious improvement in MBF values during atrial pacing and after dipyridamole infusion after 6 months of therapy (mean MBF: 2.10 +/- 0.64 and 2.99 +/- 1.63 ml/min/g, respectively, p < 0.05 vs pretreatment values). In conclusion, obvious impairment of MBF during atrial pacing and after dipyridamole infusion was observed in hypertensive patients with normal coronary arteries and this appeared unrelated to the severity of hypertension. Therapy with verapamil or enalapril improved coronary reserve and MBF response to an increase in myocardial oxygen demand.

Adult↗

Right coronary artery disease. Pathophysiology, clinical relevance, and methods for recognition.

Among the clinical manifestations of ischemic heart disease, right coronary artery (RCA) disease offers a wide variety of right and left ventricular ischemic involvement, including prevalent right ventricular dysfunction and severe cardiac failure. Whether the right ventricular impairment is dependent primarily on ischemia of the right ventricle or requires a concomitant left ventricular dysfunction remains debatable. To assess the pathophysiology and clinical relevance of RCA-related ischemia, a systematic study of patients with single RCA disease (either vasospastic angina at rest or typical stable angina) was undertaken by radionuclide ventriculography. A high incidence of ischemia-induced right ventricular dysfunction was observed (93% and 95% in angina at rest and on effort, respectively), either alone or associated with left ventricular impairment. These results were compared with those obtained in a control population with isolated left anterior descending artery disease and either primary or secondary angina pectoris. We infer that the impairment of the right ventricle was related primarily to right ventricular ischemia and that left ventricular dysfunction alone did not cause an important depression of right ventricular systolic function. In conclusion, the clinical manifestations of RCA disease can be protean; the right ventricle can be the target of ischemia, and recognition of its impairment poses diagnostic problems. Radionuclide ventriculography and two-dimensional echocardiography, together with stressors of coronary flow reserve, are reliable techniques for assessing RCA-related ischemia.

Angina Pectoris↗

Novel organ-specific circulating cardiac autoantibodies in dilated cardiomyopathy.

To determine whether organ-specific cardiac autoantibodies are present in dilated cardiomyopathy, indirect immunofluorescence on human heart and skeletal muscle was used to test sera from 200 normal subjects and from 65 patients with dilated cardiomyopathy, 41 with chronic heart failure due to myocardial infarction and 208 with other cardiac disease. Three immunofluorescence patterns were observed: diffuse cytoplasmic on cardiac tissue only (organ-specific), fine striational on cardiac and, to a lesser extent, skeletal muscle (cross-reactive 1) and broad striational on both cardiac and skeletal muscle (cross-reactive 2). Cardiac specificity of the cytoplasmic pattern was confirmed by absorption studies with homogenates of human atrium, skeletal muscle and rat liver. Organ-specific cardiac antibodies (IgG; titer range 1/10 to 1/80) were more frequent in patients with dilated cardiomyopathy (17 [26%] of 65) than in those with other cardiac disease (2 [1%] of 208, p less than 0.0001) or heart failure (0 [0%] of 41, p less than 0.001) or in normal subjects (7 [3.5%] of 200, p less than 0.0001). Organ-specific cardiac antibodies were more common in patients with dilated cardiomyopathy and in those with fewer symptoms (8 of 15 in New York Heart Association functional class I versus 9 of 50 in classes II to IV, p less than 0.01) and more recent (less than 2 years) onset of disease (9 of 19 versus 8 of 46, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Behavior of right and left ventricles during episodes of variant angina in relation to the site of coronary vasospasm.

The effects of single-vessel coronary occlusion on simultaneously evaluated right (RV) and left ventricular (LV) performance were assessed and compared with LV perfusion patterns in 25 patients with variant angina. Coronary spasm involved the right coronary artery in 15 patients (group 1) and the left anterior descending coronary artery in 10 patients (group 2). Biventricular function was assessed by radionuclide angiography under basal conditions, during spontaneous or ergonovine-induced ischemia, and after resolution of the ischemic attack. Myocardial perfusion was assessed by thallium 201 scintigraphy in 21 patients of this series during superimposable ischemic episodes. In group 1, ischemia caused RV (14 of 15 patients) and LV (13 of 15 patients) regional dysfunction with significant reduction in RV and LV ejection fractions. The interventricular spetum was involved in six of 15 patients, causing a more pronounced LV impairment. In group 2, all patients showed septal dyssynergies associated with a reduction of LV ejection fraction; absent or trivial RV involvement was observed. In both groups, LV perfusion defects were present in all patients with LV wall motion abnormalities during ischemia, matching the site of regional dyssynergies. Thus, in a group of patients with variant angina and single-vessel disease, transient occlusion of the right coronary artery directly caused RV and LV impairment; in these patients, the extent of LV but not RV dysfunction appeared related to the presence of septal ischemia. Vasospasm of the left anterior descending coronary artery consistently caused LV dysfunction not associated with secondary effects on RV systolic function.

Angina Pectoris, Variant↗

Frequent occurrence of silent ischaemia in patients with isolated right coronary artery stenosis: a radioisotopic study.

Silent ischaemia has been widely investigated limiting the diagnostic approach to the left ventricle. To date, no systematic study on silent ischaemia in patients with demand-induced right ventricular dysfunction has been reported. The occurrence of painless ischaemic episodes was evaluated by atrial pacing and radionuclide angiography in 20 consecutive patients with single right coronary artery stenosis and without previous myocardial infarction. At the peak pacing rate all patients showed transient myocardial dysfunction (reduction of ejection fraction and/or development of wall-motion abnormalities) localized to the right, the left, or to both ventricles in 9, 1 and 10 patients, respectively. Eight patients experienced chest pain (group 1) and 12 were asymptomatic (group 2) at the maximal pacing rate. Basal left ventricular ejection fraction (55 +/- 4% vs. 55 +/- 5%), basal right ventricular ejection fraction (48 +/- 4% vs. 46 + 8%), peak pacing left (52 +/- 9% vs. 50 +/- 11%) and right (38 +/- 7% vs. 37 +/- 9%) ventricular ejection fractions, and maximal pacing pressure rate product (17,289 +/- 2880 vs. 19,244 +/- 3806) were not significantly different in the two groups. This study demonstrates a high prevalence of silent ischaemia in patients with single right coronary artery stenosis and pacing-induced dominant right ventricular dysfunction. Painful episodes do not appear to be related to the magnitude of changes in ejection fraction.

Coronary Disease↗

[Right ventricular dysfunction in demand-induced ischemia in patients with isolated right coronary artery disease: a radioisotope study].

In ischemic heart disease, the left ventricle has been considered the main target of an imbalance between myocardial oxygen supply and demand. Accordingly, the approach to ischemia has been directed at the evaluation of the left ventricle. The aim of this study was to assess the relative involvement of the left and right ventricle in patients with isolated right coronary artery stenosis. We studied 20 patients with a clinical history of effort angina (15 male, 5 female, mean age 54.1 +/- 6.2) using radionuclide angiography and atrial pacing. Findings were compared with those of 6 normal subjects that were paced at the maximal heart rate of 150 beats/min. Atrial pacing was interrupted because of diagnostic ST segment depression in 8 patients, Wenckebach type atrioventricular block in 1, chest pain without electrocardiographic changes in 4 and the achievement of the maximal prefixed heart rate of 150 beats/minute in 7. With respect to control conditions, during atrial pacing right ventricular ejection fraction declined from 46.8 +/- 6.8% to 37.4 +/- 8.1% (p less than 0.001), while no significant change was observed in left ventricular ejection fraction values (55.2 +/- 4.5% and 51.1 +/- 10.2% respectively). During atrial pacing, left ventricular peak filling rate increased from 1.77 +/- 0.53 to 4.71 +/- 1.8 end-diastolic volumes/second (p less than 0.0001). Qualitative analysis of regional wall motion showed a right ventricular dysfunction in 19/20 patients; this was prevalent in 9 and involving also the left ventricle in 10; an isolated impairment of the left ventricle was observed in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Role of myocardial scintigraphy with thallium-201 in the characterization of episodes of transient ischemia at rest. Clinical and electrocardiographic correlates].

UNLABELLED: In the past ten years we studied 80 patients with angina at rest by 201-Thallium perfusion scintigraphy. According to ECG changes during episodes of transient ischemia at rest, the patients were divided into three groups. Thirty six patients showed transient ST segment elevation (Group 1); 33 ST segment depression (Group 2) and 11 normalization of negative T waves (Group 3). 201-TI scintigraphy was performed during spontaneous or ergonovine induced episodes of ischemia and at redistribution. Group 1 showed localized and severe perfusion defects, well correlated to the site of ECG changes. Group 2 showed more diffuse and less severe perfusion defects, less correlated to the site of ECG changes. Group 3 showed perfusion defects similar to those observed in Group 1 and associated in 54% with basal perfusion defects due to previous myocardial infarction. IN CONCLUSION: A) three main perfusion patterns are associated with the three types of ECG changes; B) relative to ECG, myocardial scintigraphy provides a more accurate definition of the site and extension of ischemia, particularly in Group 2 patients.

Adult↗

Clinical application of monitoring techniques: radioisotopic methods.

The availability of mobile gamma cameras or the nearness of nuclear medicine devices to the coronary care unit make the assessment of transient myocardial ischemia by radioisotopic techniques practical. Nuclear cardiology provides information on the presence, site and extent of ischemia and helps the clinician in the evaluation of myocardial functional impairment and recovery. Monitoring of myocardial wall motion by radionuclide ventriculography demonstrates that during angina at rest; global ejection fraction is not always sensitive to regional ischemia; episodes of angina with undetectable electrocardiographic signs of ischemia can be associated with severe myocardial dysfunction; separate left and right phase analysis of radionuclide ventriculography is a sensitive tool to assess segmental dyssynergy localized to the left or the right ventricle; a prevalent right ventricular impairment during ischemia, not measurable by Thallium scintigraphy, is possible; the recovery of function after ischemia is usually fast and apparently complete. In addition, useful diagnostic information can be derived by left ventricular injection of radioactive microspheres during cardiac catheterization followed by gated acquisitions of the intramyocardial radioactivity. Gated microsphere acquisitions, providing diastolic and systolic images, avoid blurring of images due to cardiac motion and enhance contrast between myocardium and background: the overall result is an improved detection and definition of small perfusion defects. Furthermore, this technique permits simultaneous assessment of regional perfusion and wall motion. An appraisal of potential mismatches between flow and function after revascularization procedures can be recognized by this approach. The development of technology is improving the performance of nuclear medicine instrumentation, hampered, at present, by limited spatial and temporal resolution.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

Clinical application of monitoring techniques: hemodynamic monitoring.

In the diagnosis of myocardial ischemia continuous hemodynamic monitoring may contribute to detection of transient ischemia, to definition of location and to elimination of its pathogenesis, and to characterization of hemodynamic response to ischemia. It can be helpful in investigating the significance of negligible, non specific and/or short-lasting electrocardiographic changes accompanying typical anginal symptoms. Simultaneous right ventricular and left ventricular pressure monitoring gives information regarding biventricular interaction during episodes of transient ischemia: an early left ventricular dysfunction, with or without a late right ventricular impairment, a selective right dysfunction, and a simultaneous left ventricular and right ventricular impairment all represent the hemodynamic patterns associated with left, right and biventricular ischemia respectively. Monitoring of hemodynamic parameters related to myocardial oxygen consumption and the study of their changes preceding the onset of ischemia during both spontaneous and provoked episodes of ischemia, may help in identifying whether functional or organic factors or both are involved in the pathogenesis of transient ischemia in individual patients. Two principal hemodynamic patterns appear to be associated with transient ischemia: a) left ventricular and/or right ventricular impairment, usually beginning shortly before the onset of electrocardiographic changes, followed by a rapid recovery and often an overshooting, b) a sudden and sustained increase in systolic pressure and heart rate, simultaneous with the onset of ST-T changes. In both cases, the 'excitatory' pattern appears to be unrelated to pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗

When the electrocardiogram fails to define site and extent of myocardial ischemia.

Information on the anatomical site of myocardial ischemia and infarction is commonly derived from the 12-lead electrocardiogram; however, correspondence between an electrocardiogram lead, showing ischemic changes and actual location of ischemia is not always present. In our experience, a good correspondence between the electrocardiogram and perfusion defects was found in patients with angina at rest and anterior ST segment elevation or normalization of negative T wave while patients with transient ST segment depression showed perfusion defects which correlated less with electrocardiographic changes. In addition, patients with ischemic episodes at rest and with inferior ST segment elevation, right or left ventricular ischemia were indistinguishable on the basis of the electrocardiogram as documented by Thallium-201 scintigraphy and radionuclide ventriculography. In effort angina, the site and extension of ST segment depression, even in patients with single vessel disease, failed to localize the actual anatomical location of myocardial ischemia. In patients with persistent ST segment depression and/or negative T waves, and clinically documented myocardial necrosis, transmural and non-transmural persistent perfusion defects were found in spite of absence of Q waves. In these patients, late normalization of the electrocardiogram did not correspond to normalization of flow. In conclusion, electrocardiographic changes do not always provide correct information regarding the presence, location and extent of myocardial ischemia and a multiparametric approach is often required in order to characterize ischemic and/or necrotic areas.

Angina Pectoris↗

Transient predominant right ventricular ischemia caused by coronary vasospasm.

This study describes the clinical experience with four patients with variant angina caused by spasm of the right coronary artery who were assessed for evidence of right ventricular involvement. The patients were suspected of having predominant right ventricular ischemia on the basis of normal thallium-201 scans, left ventricular ejection fraction, regional wall motion assessed by equilibrium radionuclide angiography (RNA), two-dimensional echocardiographic findings, and left ventricular hemodynamics; all procedures were performed during transient ST segment elevation in the inferior leads. Right ventricular ischemia was documented in four patients by first-pass radionuclide studies and phase analysis of RNA, and in three patients by simultaneous right and left hemodynamic monitoring. The clinical findings from these four patients are compared with those from four other patients with similar electrocardiographic changes, coronary anatomic distribution, and documented right coronary spasm but with evidence of left ventricular involvement as documented by abnormal thallium-201 scintigraphy, RNA, two-dimensional echocardiography, and left hemodynamics during ischemic episodes. Although preliminary, these data indicate the existence of prevalent right ventricular ischemia during variant angina caused by right coronary vasospasm. This condition should be suspected whenever typical anginal symptoms and/or ischemic electrocardiographic changes are accompanied by normal thallium-201 scintigraphic findings and/or normal left ventricular function as assessed by RNA, echocardiography, and left hemodynamic monitoring. Among noninvasive procedures, first-pass radionuclide study and phase analysis of RNA represent suitable techniques for detecting transient right ventricular dysfunction.

Angina Pectoris, Variant↗

Improved diagnostic yield of radionuclide angiography by quantitative phase analysis during resting angina and following isosorbide dinitrate.

The reliability of quantitative phase analysis of radionuclide angiography in the detection of wall motion abnormalities has been investigated in 15 patients with angina at rest. All patients have been studied in the basal state, during spontaneous or ergonovine-induced ischemia and following isosorbide dinitrate acute i.v. administration in the resolution phase. Quantitative phase analysis provided a more sensitive index of impaired wall motion as compared to global ejection fraction changes. Isosorbide dinitrate rapidly and completely solved ischemic dyssynergies caused by coronary vasospasm.

Adult↗

[Myocardial imaging with 99mTC albumin microspheres for the simultaneous assessment of contraction and perfusion in man].

Radiolabeled human albumin microspheres (HAM) have been used in the past, in order to visualize coronary flow distribution in man. In order to obtain information both on myocardial perfusion and contractility, we applied R-wave synchronized reconstruction of the cardiac cycle in cine mode to HAM imaging. In 20 patients with angina pectoris and coronary stenosis of variable severity and in 1 patient with congestive cardiomyopathy we injected 4 millions of HAM (mean diameter 15 microns) labeled with 15-20 mCi of 99mTc, into the left ventricle during routine cardiac catheterization. Data were collected by a gamma camera, and by the use of a high resolution collimator and were electronically restricted to the cardiac area (64 X 64 matrix). The reconstruction of the cardiac cycle was made according to the technique developed in our laboratory for gated blood pool imaging. From the displayed images we evaluated myocardial flow distribution at the time of injection and regional wall motion (by cine mode) at any subsequent time, with a temporal resolution of 2 to 4 mins. The patterns of contractility of myocardial walls with normal or reduced perfusion were in agreement with those observed by means of contrast ventriculography. Advantages of the technique are: a) simultaneous information on flow and contractility; b) prolonged time for wall motion observation (4 to 6 hours); c) high quality pictures, since the signal to background ratio is much more favourable than with other isotope techniques. The technique appears to be promising from the results obtained in the number of patients included in this study.

Adult↗

Myocardial blood flow and perfusion reserve in infarcted patients with stress-induced normalization of previously negative T waves: a positron emission tomography study.

BACKGROUND: The clinical correlations between stress-induced normalization of previously negative T waves (NTW) and regional myocardial blood flow (MBF) regulation and tissue viability remain debatable. METHODS AND RESULTS: To confirm these correlations, 14 patients with previous anterior myocardial infarction (13 Q waves) and NTW on baseline electrocardiographic precordial leads and 10 healthy subjects were studied by means of positron emission tomography (PET). The MBF values were obtained in the anterior infarcted myocardial regions in either resting condition or during dipyridamole infusion, using N-13 ammonia as a flow tracer. Seven subjects had normalization of NTW (Group 1) and 7 had persistent NTW (Group 2) during dipyridamole infusion. The resting MBF values were similar for both Group 1 and Group 2 (0.43+/-0.13 versus 0.51+/-0.15 mL.min(-1).g(-1), respectively; P = not significant) and were significantly lower than in the anterior myocardial regions of healthy subjects (1.03+/-0.23 mL.min(-1).g(-1), P < .001). After administration of dipyridamole, the MBF was significantly higher in Group 1 than in Group 2 (0.88 +/- 0.37 versus 0.55 +/- 0.17 mL.min(-1).g(-1), respectively; P < .05) and markedly lower than in healthy subjects (3.78+/-0.64 mL.min(-1).g(-1), P < .001). Coronary reserves (dipyridamole/resting MBF) were 2.03+/-0.40 and 1.14+/-0.44 in Group 1 and Group 2, respectively (P < .002). CONCLUSION: Despite similar values of resting perfusion, infarcted dysfunctional areas with or without NTW during stress may present different regional MBF responses; normalization of NTW demonstrates higher coronary flow reserve than persistent NTW, suggesting a better preserved coronary microcirculatory function in the former, indicative of the presence of myocardial viability.

Adult↗