[Mitochondrial cardiomyopathies: a new entity in cardiology research and diagnosis].
Explore the source record for details and available documents.
Aging↗
Biomedical subjects
F Fedele
Publications and source records attributed to F Fedele.
Stress echocardiography: comparison of exercise, dipyridamole and dobutamine in detecting and predicting the extent of coronary artery disease.
OBJECTIVES: This study was designed to compare exercise, dipyridamole and dobutamine echocardiography in the same patients and to evaluate, by measuring physiologic and echocardiographic variables, the mechanisms by which exercise and dobutamine induce ischemia. BACKGROUND: The diagnostic value of stress echocardiography has been widely reported, but the specific effects of exercise, dipyridamole and dobutamine have not been directly compared. Furthermore, no echocardiography study has evaluated left ventricular volume changes at ischemic threshold during exercise and dobutamine administration. METHODS: One hundred patients with suspected (Group A, n = 60) or known (Group B, n = 40) coronary artery disease underwent all three tests in random order. RESULTS: In Group A, the sensitivities of exercise (mean 76%, 95% confidence interval [CI] 58% to 94%) and of dobutamine echocardiography (72%, 95% CI 53% to 91%) were higher than that of dipyridamole (52%, 95% CI 31% to 73%; p = 0.01 and p = 0.02, respectively). Specificity did not differ significantly among tests (94% for exercise [95% CI 86% to 100%] and 97% for dipyridamole and dobutamine [95% CI 91% to 100%]). Accuracy was identical for exercise and dobutamine (87%) and higher than that for dipyridamole (78%, p = 0.06). In Group B, the accuracy in predicting coronary disease extent was 71% for exercise, 33% for dipyridamole and 75% for dobutamine. At ischemic threshold, end-systolic volume index and the ratio of systolic blood pressure to end-systolic volume, a variable related to myocardial contractility, were significantly lower and higher, respectively, with dobutamine than during exercise (p < 0.05). CONCLUSIONS: In a clinical setting, exercise echocardiography should represent the first diagnostic approach because it has high diagnostic efficacy and provides additional information on exercise capacity; pharmacologic stress, particularly that of dobutamine, provides a pivotal diagnostic tool when exercise is not feasible or its results are nondiagnostic. Our preliminary data on echocardiographic evaluation at ischemic threshold support the view that myocardial contractility is a major factor in inducing ischemia during dobutamine infusion.
Coronary Disease↗
A reexamination of the hemodynamic effects of digitalis relative to ventricular dysfunction.
The available data suggest that digitalis improves symptoms of a failing heart in the presence of sinus rhythm as well as supraventricular arrhythmias. Intravenous digitalis administration in patients with chronic heart failure and baseline hemodynamic deterioration increases cardiac index and reduces heart rate. These beneficial effects are maintained with long-term oral therapy and are comparable with those obtained using dobutamine in patients with chronic severe heart failure. The addition of digoxin to therapy with vasodilators and diuretics confers clinical benefit in patients with moderate to severe heart failure symptoms because of systolic ventricular dysfunction. Digoxin effects on diastolic function appear to be different in patients with preserved systolic function in comparison to patients with overt heart failure and systodiastolic dysfunction. In patients with right ventricular dysfunction digoxin does not appear to influence hemodynamic measurements unless concomitant left ventricular dysfunction is present.
Digoxin↗
[Usefulness of stress echocardiography in the evaluation of clinical and functional success of coronary angioplasty and prognostic stratification].
The present study, selecting 39 patients undergoing elective coronary angioplasty (PTCA) with signs of myocardial ischemia during supine bicycle exercise stress test (EST) before PTCA and on medical therapy, was designed: to evaluate the efficacy of angiographically successful PTCA on functional capacity, in terms of work load, time of exercise and rate-pressure product (RPP), by comparing pre- and post-PTCA-EST performed in patients with post-PTCA disappearance (Group I, 44%) or persistence (Group II, 56%) of myocardial ischemia, and in the latter, to evaluate the effects of medical therapy, by repeating EST after its addition; to investigate the influence of PTCA on regional function, assessed by a 11 segment model and graded as usual, in the 25 patients group with pre-PTCA exercise-induced wall motion abnormalities, disappearing (Group A, 64%) or persisting (Group B, 36%) after the interventional procedure; to examine by a 12-month follow-up the eventuality of recurrent anginal symptoms, in the presence of myocardial ischemic signs in the territory supplied by the dilated vessel and/or of angiographic restenosis, in relation to the result of post-PTCA-EST. The results of our study showed a significant improvement in functional capacity after PTCA only in Group I patients, whereas in Group II patients effort tolerance significantly increased only after medical therapy, which was associated with the disappearance of myocardial ischemia. With regard to follow-up, exercise echocardiography showed a positive and negative predictive value for angina recurrence with angiographic restenosis of 78 and 92%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Angioplasty, Balloon, Coronary↗
[Comparison of provocation tests based on physiopathologic mechanisms: suggestions for the clinician].
Explore the source record for details and available documents.
Echocardiography↗
[The use of stress echocardiography in the assessment of results of myocardial revascularizations interventions].
Explore the source record for details and available documents.
Angioplasty, Balloon, Coronary↗
[Assessment of contractile reserve in dilated cardiomyopathy].
Explore the source record for details and available documents.
Adult↗
Dipyridamole myocardial contrast echocardiography in patients with single-vessel coronary artery disease: perfusion, anatomic, and functional correlates.
The aim of this study was to examine whether myocardial contrast echocardiography (MCE) may be used to study regional myocardial blood flow distribution during dipyridamole-induced hyperemia. MCE was performed before and after dipyridamole infusion in 11 patients with a proximal, significant left anterior descending (LAD) coronary artery stenosis. The relation between contrast-derived parameters and the degree of coronary narrowing and the occurrence of transient regional wall motion abnormalities was also investigated. In the territory supplied by left circumflex coronary artery, mean peak contrast intensity increased after dipyridamole from 50 +/- 18 to 76 +/- 27 IU (p < 0.001). In contrast, a significant reduction in mean peak intensity was observed after dipyridamole in the LAD territory (from 41 +/- 27 to 13 +/- 13 IU, p < 0.01). Similar results were obtained with the use of the area under the time-intensity curve. An increase in peak intensity > or = 10 IU after dipyridamole administration separated normal regions from those supplied by a significant coronary artery lesion with a sensitivity of 91% and a specificity of 91%. Perfusion abnormalities were always detected by contrast echocardiography when septal motion abnormalities developed and, in five patients they were detected in the absence of clinical, electrocardiographic, and echocardiographic signs of ischemia. A weak correlation was found between both peak intensity and area under the curve and percent coronary diameter stenosis and cross-sectional area. In conclusion, dipyridamole MCE can be used during routine coronary angiography to assess myocardial blood flow distribution in patients with coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction: role of magnetic resonance imaging.
Nineteen patients (16 men and 3 women, mean age 51 years) with previous anterior myocardial infarction and severe stenosis (> or = 90%) of the left anterior descending coronary artery were studied by magnetic resonance imaging (MRI) without and with contrast media to verify the capability of MRI in identifying viable myocardium in areas of severe systolic dysfunction. In corresponding left ventricular segments, a comparison was made between regional signal intensities (SI) determined on MRI images before and 4, 8, 12, and 30 minutes after administration of paramagnetic contrast media (gadolinium diethylenetriaminepentaacetic acid, 0.4 mmol/kg intravenously) and metabolic parameters determined by iodine 123 phenylpentadecanoic acid (IPPA) scintigraphy. The SI and the time of maximum postcontrast enhancement were analyzed by dividing the left ventricle into 11 segments. Each segment was classified as normal (group 1, n = 116), hibernating (group 2, n = 50), or necrotic (group 3, n = 43) on the basis of the IPPA washout rate (> 30%, 10% to 30%, and < 10%, respectively). Regional SI demonstrated significant differences in absolute values at 12 minutes (group 3: 1.62 +/- 0.58 vs group 1: 1.32 +/- 0.52, p < 0.01, and vs group 2: 1.34 +/- 0.48, p < 0.05) and at 30 minutes (group 3: 1.71 +/- 0.47 vs group 1: 1.21 +/- 0.55, p < 0.01, and vs group 2: 1.49 +/- 0.57, p < 0.05) and in temporal distribution. These results suggest that MRI has a potential role in differentiating viable from necrotic myocardium in patients with chronic severe systolic dysfunction.
Contrast Media↗
Influence of residual perfusion within the infarct zone on the natural history of left ventricular dysfunction after acute myocardial infarction: a myocardial contrast echocardiographic study.
OBJECTIVES: This study used myocardial contrast echocardiography to investigate the extent of residual perfusion within the infarct zone in a select group of patients with recently reperfused myocardial infarction and evaluated its influence on the ultimate infarct size. BACKGROUND: Limited information is available on the status of myocardial perfusion within postischemic dysfunctional segments at predischarge and on its influence on late regional and global functional recovery. METHODS: Twenty patients with acute myocardial infarction were selected for the study. Patients met the following inclusion criteria: 1) single-vessel coronary artery disease; 2) patency of infarct-related artery with persistent postischemic dysfunctional segments at predischarge; 3) stable clinical condition up to 6 months after hospital discharge. All selected patients underwent coronary angiography and myocardial contrast echocardiography before hospital discharge and repeated the echocardiographic examination 6 months later. Patients were grouped according to the pattern of contrast enhancement in predischarge dysfunctional segments. RESULTS: In nine patients (group I), the length of segments showing abnormal contraction coincided with that of the contrast defect segments. In the remaining 11 patients (group II), postischemic dysfunctional segments were partly or completely reperfused. There was no difference between the two groups in asynergic segment length at predischarge (7.3 +/- 2.5 vs. 7.2 +/- 4.3 cm, p = NS). At follow-up study, asynergic segment length was significantly reduced in group II patients, whereas no changes were observed in group I patients (from 7.2 +/- 4.3 to 4.7 +/- 3.7 cm, p < 0.005; and from 7.3 +/- 2.5 to 7.5 +/- 2.9 cm, p = NS, respectively). CONCLUSIONS: Among patients with a predischarge patent infarct-related artery, further improvement in regional and global function may be expected during follow-up when residual perfusion in the infarct zone is present.
Adult↗
[Transesophageal stress echocardiography].
The Authors analyze the literature data on transesophageal stress echocardiography and personal experience with dipyridamole echocardiography. Advantages and limitations for the clinical application of this method are discussed taking into account computer-aided echocardiographic images. Transesophageal stress echocardiographic results are compared with those obtained by other stress test imaging techniques.
Echocardiography, Transesophageal↗
[ACE-inhibitors after infarction: current knowledge and future prospects].
Experimental and clinical findings showing a beneficial effect on ventricular remodelling have led to a widespread use of ACE-inhibitors in myocardial infarction. Recent trials (SAVE, AIRE, GISSI 3, ISIS 4) have clearly demonstrated that in patients with left ventricular dysfunction and/or heart failure the treatment with ACE-inhibitors is mandatory, although several questions remain unanswered. Recent experimental observations on the relationship between ACE and endothelial function, and between ACE and intimal proliferation have gone forward leading to new perspectives on the potential use of ACE-inhibitors in all patients with acute myocardial infarction.
Angiotensin-Converting Enzyme Inhibitors↗
Characterization of reversible myocardial dysfunction by magnetic resonance imaging.
Some recent cardiovascular applications of nuclear magnetic resonance imaging (MRI) are discussed, on the basis of both literature and personal data. Management of coronary patients has become directed to strategies aiming at salvaging the ischemic myocardium, and MRI can play an important role in providing the necessary data leading to an appropriate assessment. Due to its capability in showing morphofunctional information on wall thickness and thickening, cine-MRI technique can be used to detect myocardial ischemia and infarction, since it allows the acquisition of 16 or more frames of the cardiac cycle which can be displayed in a cine loop format. In an Italian Cooperative Study the role of MRI in discriminating stunned from necrotic areas has been investigated. Comparison of fractional area change by echo versus cine-MR turned out to be almost completely overlapping, but cine-MRI allowed a more accurate measurement of systolic wall thickening due to better visualization of endo- and epicardial borders (more sensitive marker of kinetic damage than wall motion). Other studies have also been performed in order to determine the capability of contrast agents of allowing differentiation between reperfused reversible and irreversible myocardial injury and allowing distinction between reperfused and occlusive myocardial infarction. In a recent study we investigated the MRI possibility of identifying viable myocardium in severely chronic systolic dysfunctioning areas by comparing, in corresponding left ventricular segments, regional perfusion and metabolism at IPPA scintigraphy and regional signal intensity at MR images obtained before and after paramagnetic contrast media administration. The potential role of MRI was shown in the identification of viable myocardium with the use of contrast medium, that is of crucial importance in this respect.
Diagnosis, Differential↗
Influence of reperfusion induced by thrombolytic treatment on natural history of left ventricular regional wall motion abnormality in acute myocardial infarction.
Although several studies have investigated left ventricular (LV) function after reperfusion interventions, it is still unclear whether benefits result from successful therapy or whether such benefits only reflect the natural history of a subgroup of patients with acute myocardial infarction (AMI). This study evaluates the unique effect of thrombolytic therapy on the natural history of regional LV wall motion dysfunction. One hundred seventy-six patients with AMI were studied: 82 patients (group A) underwent conventional treatment and 94 (group B) thrombolytic therapy. LV regional improvement, evaluated by changes in echo score between admission and predischarge examination, was present more frequently in group B (28%) than in group A (17%). Furthermore, improved patients in group B had higher admission echo scores (7.5 +/- 3.5 vs 6.3 +/- 3.1), a prevalence of anterior AMI (68 vs 30.1%) and a higher rate of coronary patency (92 vs 58% in patients who had no improvement). In group A patients the rate of coronary patency was similar in those who did (46.1%) and did not have (36.1%) improvement. Observations at 12 to 18 months showed similar data in group A patients and in group B patients without improvement, whereas a marginal additional improvement was observed in group B patients who had in-hospital improvement. These observations demonstrate that LV function recovery is more frequent and marked in treated than in untreated patients. Follow-up results suggest a prolonged beneficial effect of thrombolytic treatment on LV function. The highest rate of coronary patency in improved group B patients underline the role of reperfusion on natural history of LV dysfunction after AMI.
Coronary Angiography↗
Effectiveness of thrombolysis is associated with a time-dependent increase of malondialdehyde in peripheral blood of patients with acute myocardial infarction.
By using a highly sensitive, high-performance liquid chromatographic technique, plasma values of malondialdehyde (MDA), adenosine and oxypurines were determined in 10 healthy subjects, 10 patients with noncardiac illness, and 20 patients with acute myocardial infarction (AMI) observed within 6 hours from the onset of symptoms. Patients with AMI received fibrinolytic treatment. Peripheral blood was obtained before and serially after thrombolysis (1, 2, 3, 6 and 24 hours). Coronary patency was assessed by timing of peak creatine phosphate kinase and by predischarge angiography. MDA (mean +/- SD) in healthy subjects, noncardiac patients, and immediately before thrombolytic treatment in patients with AMI was 0.051 +/- 0.013, 0.066 +/- 0.020 and 0.397 +/- 0.326 mumol/liter of plasma, respectively. A progressive increase in plasma MDA after thrombolysis was observed only in reperfused patients, whose values at the third, sixth and 24th hours were also significantly greater than those of nonreperfused patients. Time-dependent variations of xanthine and adenosine were also observed in the same group after thrombolysis. The data appear to indicate that a relevant increase in plasma MDA, mostly originating due to phospholipid derangement of postischemic myocytes, occurs only in patients with successful thrombolysis, thus suggesting that if properly assayed, it may represent reliable biochemical evidence of tissue injuries after myocardial reperfusion in humans.
Adenosine↗
[Role of the endogenous opioid system in the modulation of anginal pain].
The Authors make an analysis of the complex interactions occurring between peripheral and central factors in the regulation of anginal pain. As for the role of the endogenous opioid system, results obtained in a study using a particular methodological approach have demonstrated that patients with asymptomatic ischemic heart disease have a higher endogenous opioid tone at the level of the central nervous system.
Angina Pectoris↗
[Evaluation of aortic distensibility using cine-MR before and after antihypertensive treatment with calcium antagonists and ACE-inhibitors].
Several studies have been performed in the last years to evaluate arterial distensibility, particularly of the aorta, in hypertension and to estimate the changes of this distensibility after anti-hypertensive treatment. The aim of this study was to assess the aortic distensibility in a group of 10 patients with essential hypertension in comparison with a control group, with regard to the vascular effects of a long-term anti-hypertensive treatment with calcium-antagonists and ACE-inhibitors. All patients were studied using cine-MR imaging, a technique with several peculiarities (multiplanar scanning, intrinsic contrast, etc) that allows simple and quick assessment of the aortic vascular parameters in the ascending and descending tracts. The results of our study show the absence of a significant improvement of aortic vascular areas, and therefore of vessel distensibility, even in the presence of a complete blood pressure normalization in all patients after a 3-month treatment. These data do not confirm previous reports in this setting, based on the ultrasonographic techniques (2D and Doppler echocardiography). Two major reasons may explain our results: first, the rigorous criteria of patient enrollment that we have stated in order to avoid any influence of age and/or other pathologies; second, the ability of MR imaging to allow accurate estimation of aortic vascular parameters and to achieve an excellent intraobserver and interobserver reproducibility in comparison with other techniques. We conclude that MR imaging is the method of choice for the assessment of cardiovascular function and morphology.
Angiotensin-Converting Enzyme Inhibitors↗
Rheological features of erythrocytes in acute myocardial infarction.
There is evidence that oxidative insult plays a role in the development of acute myocardial infarction. Significance has also been attributed to changes in viscosity of the blood and in the deformability and aggregation of erythrocytes affecting their rheological behavior. In a group of patients with myocardial infarction we found a decreased erythrocyte filtration and an increased blood viscosity with no significant change in plasma viscosity. These changes were accompanied by alterations in the microviscosity of the erythrocyte membrane assessed by measuring the polarization of specific fluorescent molecules. From our data it is evident that there is an increase in the rigidity of the membrane at the lipid/protein boundary, with an associated increase in the fluidity of the deep lipid core of the membrane, while no changes were observed in the dynamic behavior of the membrane proteins. These physico-chemical perturbations in the membrane could be the basis for the decreased filtration of erythrocytes. We found, however, no evidence of lipid peroxidation in the erythrocyte membrane.
Adenosine Triphosphate↗