Three-dimensional echocardiography: the virtual reality in cardiology--luxury or useful technique?
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Echocardiography↗
Biomedical subjects
L Agati
Publications and source records attributed to L Agati.
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↗
Diagnosis of persistent left superior vena cava by multiplane transesophageal echocardiography.
Persistent left superior vena cava occurs in 2-4% of all congenital cardiac defects. The diagnosis is often missed if the lesion is not accurately looked for. Drainage to the coronary sinus is well tolerated, whereas drainage to the left atrium produces right to left shunt and may be associated with brain abscesses and/or embolization secondary to intravenous therapy administered through the left arm. This paper describes for the first time the diagnosis of persistent left superior vena cava by transesophageal contrast echocardiography. Echocardiography is the method of choice in the diagnosis of persistent left superior vena cava, because it can be used at the patient's bedside and allows easy detection of the drainage site.
Echocardiography, Transesophageal↗
[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↗
[New trends in the evaluation of myocardial viability by echocardiography].
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Coronary Circulation↗
[Prognostic stratification after acute myocardial infarction: usefulness and limitations of echocardiography in stress].
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Exercise Test↗
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↗
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↗
Apical transgastric echocardiography: new imaging projections.
New transgastric echocardiographic projections, obtained by monoplane transoesophageal echocardiography are presented. Starting from the transgastric short-axis view, the probe is first advanced 3-5 cm and slightly rotated clockwise. From this projection either a tricuspid valve long-axis or a subcostal-like 4-chamber view is obtained. Advancing the probe 48-55 cm from the incisor teeth and rotating it counter clockwise with maximal anterior flexion, an apical long-axis view is obtained. The left ventricle, including the apex, the left ventricular outflow tract, the aortic valve, the proximal ascending aorta and the left atrium are imaged. In this projection the Doppler beam is parallel to the left ventricular outflow tract, resulting in more accurate flow velocity measurements than from the oesophagus. Additional morphological and Doppler information on right ventricular outflow tract obstruction are obtained by slight changes in transducer position. The feasibility of these new transgastric imaging projections was assessed in 196 consecutive patients undergoing diagnostic TEE (104 conscious patients) or peroperative TEE monitoring (92 anaesthetized patients). Eighty-nine patients had coronary heart disease, 55 had valvular heart disease, nine had congenital heart disease, 22 had aortic aneurysm or dissection and 21 were studied for detection of cardiac sources of embolism. The morphology of the right ventricular outflow tract was visualized in detail in all patients, and high quality Doppler tracings parallel to the direction of flow were obtained. The subcostal-like view was successful in 86 out of 196 subjects (44%). The apical 4 and/or 5-chamber view was obtained in 139 subjects (71%).(ABSTRACT TRUNCATED AT 250 WORDS)
Echocardiography, Doppler↗
[Myocardial protection: a look to the future].
Three main types of damage induced by ischemia and reperfusion have been identified: lethal reperfusion injury, microvascular and macrovascular reperfusion injury, and myocardial stunning. Pathophysiological and therapeutic aspects of these ischemia/reperfusion sequelae are reviewed and discussed on the light of recent experimental and clinical results.
Adrenergic beta-Antagonists↗
Transesophageal dipyridamole echocardiography for diagnosis of coronary artery disease.
The value of transthoracic dipyridamole echocardiography has been extensively documented. However, in some patients, because of a poor acoustic window, the rest transthoracic examination is not always feasible and the transesophageal approach is more convenient. Therefore, transesophageal echocardiography with high dose dipyridamole (up to 0.84 mg/kg body weight over 10 min) was performed in 32 patients in whom the transthoracic dipyridamole test either was not feasible (n = 29) or yielded ambiguous results (n = 3). The transesophageal echocardiographic test results were considered abnormal when new dipyridamole-induced regional wall motion abnormalities were observed. All 32 patients underwent coronary angiography; significant coronary artery disease was defined as greater than or equal to 70% lumen diameter narrowing in at least one major vessel. All patients also performed a bicycle exercise test 1 day before transesophageal dipyridamole echocardiography. Transesophageal stress studies were completed in all patients, with a maximal imaging time (in tests with a negative result) of 20 min. No side effects or intolerance to drug or transducer was observed. The left ventricle was always visualized in the four-chamber and transgastric short-axis views. High quality two-dimensional echocardiographic images were obtained in all patients both at rest and at peak dipyridamole infusion and were digitally analyzed in a quad-screen format. Coronary angiography showed coronary artery obstruction in 24 patients: 6 had single-, 9 double- and 9 triple-vessel disease. The transesophageal dipyridamole test showed a specificity of 100% and an overall sensitivity of 92%. The sensitivity of this test for single-, double- and triple-vessel disease was 67%, 100% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary Angiography↗
Endogenous opioid system modulation in anginal pain: demonstration of its central activity.
Plasma beta-endorphin levels provide controversial results on the role of endogenous opioid system in modulation of anginal pain. As an alternative, the action of plasmatic luteinizing hormone after administration of naloxone was investigated: naloxone blocks the tonic endogenous opioid system inhibition of gonadotropin release; thus, the level of luteinizing hormone after naloxone administration is an index of central endogenous opioid system activity. Twenty patients with coronary artery disease and positive results of stress tests were selected: 10 had angina (group I) and 10 did not (group II). Ten healthy subjects were also studied as a control group (group III). In all patients basal plasma beta-endorphin levels, basal luteinizing hormone plasma levels (every 15 minutes for 1 hour) and luteinizing hormone plasma levels after administration of 0.1 mg/kg naloxone over 4 minutes (every 15 minutes for 2 hours) were determined. In 15 patients the test was performed after luteinizing hormone releasing hormone was given. The integral concentration time of luteinizing hormone plasma level during baseline (LHiB) and after administration of naloxone (LHiN) or luteinizing hormone releasing hormone (LHiRH), the ratio (LHiN:LHiB and LHiRH:LHiB) and the differences (LHiN-LHiB and LHiRH-LHiB) between the postinfusion period and baseline were calculated. No difference was found in beta-endorphin plasma levels and luteinizing hormone response after luteinizing hormone releasing hormone infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Analysis of Variance↗
Assessment of severity of coronary narrowings by quantitative exercise echocardiography and comparison with quantitative arteriography.
To determine the correlation of quantitative assessment of coronary narrowings with left ventricular functional impairment induced by exercise, 57 patients with 1-vessel coronary artery disease and without evidence of collateral flow were studied. A significant relation was observed between minimal cross-sectional area, percent area stenosis, minimal lumen diameter, percent diameter stenosis and the percentage of segmental area change from rest to peak exercise in a vascular distribution territory (r = 0.76, p less than 0.001; r = -0.55, p less than 0.001; r = 0.56, p less than 0.001; r = -0.75, p less than 0.001, respectively). For minimal cross-sectional area, the best cut-off value to separate significantly patients who had a decrease in contractility at peak exercise testing from those who had a normal response was 2 mm2 (p less than 0.001); for percent cross-sectional area stenosis, it was 75% (p less than 0.001); for minimal lumen diameter, it was 0.7 mm (p less than 0.001); and, for percent diameter stenosis, it was 85% (p less than 0.001). High cut-off values for angiographic variables are necessary to separate significantly patients who have a decrease in contractility at peak exercise testing from those who have a normal response. Several patients with mild coronary stenoses may have either normal or abnormal wall motion during exercise. Thus, exercise echocardiography is a useful tool in detecting the presence of fairly severe anatomic narrowing, whereas it is of limited clinical use in the assessment of intermediate coronary atherosclerotic lesions.
Cineangiography↗
[Noninvasive determination of anaerobic threshold: validation of an automatic computerized method].
The Authors propose a computerized method in order to automatically detect the anaerobic threshold by the analysis of ventilatory parameters (VE, VO2). The algorithm calculates all possible linear fits and the relative standard error of the relationship between VE and VO2 beginning from the first set of 4 data (excluding the first 2 min of exercise) and increasing of 1 pair of data until peak exercise. Subsequently the program chooses the line that fits the greatest number of data with the smallest error. The ventilatory anaerobic threshold (SA Ve) is then calculated as the point at which the relationship between VE and VO2 is no more linear (i.e. when the VE measured gets over of 2 standard errors the calculated value on the basis of the regression formula). During the first phase of the study the method was validated against invasive AT determination by arterial lactate concentration (SA La) in 14 patients (7 athletes, 7 healthy sedentary subjects) during a symptom-limited ergospirometric test (in supine position, 10 W/min until exhaustion). Subsequently we studied the method repeatability in 20 men (10 normals, 10 patients with congestive heart failure who performed 2 ergospirometric tests on separate days. The results showed a good correlation when comparing each other the VO2 (SA Ve 26.88 +/- 4.24, SA La 25.95 +/- 3.88 ml/kg/min; r = 0.88) or the onset time (SA Ve 11.8 +/- 2.42, SA La 11.61 +/- 1.8 min; r = 0.91) of anaerobic threshold determined by the 2 methods.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Role of endogenous opioids on nociceptive threshold in patients with exercise-induced myocardial ischemia.
To evaluate whether endogenous opioids (EO) play a role in the perception of anginal pain, a randomized double blind clinical trial, using naloxone (N) and placebo (P) and measuring beta-endorphin (beta-ep) plasma levels, was performed. We studied 10 patients with angiographically assessed coronary artery disease (CAD) and stable exercise-induced myocardial ischemia (established by 2 preliminary bicycle ergometric tests) of whom 5 symptomatic (SYM) and 5 asymptomatic (ASYM) and 5 subjects without CAD as a control group (CON). On a third exercise test the beta-ep plasma level (fmol/ml) was measured at rest (SYM 5.4 +/- 2.3 vs ASYM 7.2 +/- 2.3 vs CON 6.8 +/- 2.6, NS), at peak exercise (SYM 4.4 +/- 1.8 vs ASYM 8.0 +/- 4.2 and vs CON 6.2 +/- 2.7, NS) and during recovery (SYM 7.5 +/- 4.2 vs ASYM 7.2 +/- 3.0 vs CON 6.7 +/- 2.5, NS). On 2 subsequent tests patients received N (0.2 mg/kg) or P intravenously and chest pain was evaluated on an analogue scale (score from 1 to 10). After N compared to P we observed: an increased perception of chest pain in SYM (6.8 +/- 1.5 vs 4.2 +/- 1.0; p less than 0.01) without significant changes of the ischemic threshold (total work, heart rate-blood pressure product, ST segment changes, 2D-echocardiographic wall motion abnormalities); no modifications in ASYM and CON.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗