Assessment of cardiac viability by thallium 201 redistribution and dobutamine echocardiography.

OBJECTIVE: Dobutamine echocardiography and thalium 201 are useful in the assessment of myocardial viability, but both techniques frequently yield conflicting results. The objective of this study was to determine the minimum mass of viable myocardium that each test could detect and compare the agreement of dobutamine echocardiography and thallium 201 to detect viability. METHODS: Dobutamine echocardiography and thallium 201 were performed in 10 patients scheduled for cardiac transplantation. In each patient, 15 segments were studied. After transplantation these segments were analyzed by the pathologist measuring by a computer system the total area of each segment, the necrotic + fatty mass, and area (%) of viable myocytes per segment. The percentage of viable tissue was estimated ([Total mass - (Necrotic + Fatty tissue)]/Total mass x 100) on each segment, which was compared with the result (viable or not viable) obtained by echocardiography or thallium 201. RESULTS: Dobutamine echocardiography defined 90 segments (60%) as viable versus 117 (78%) in thallium (kappa 0.49, 95% CI 0.36-0.63). The minimum percent of viable tissue per segment defined as viable by thallium was 43% versus 49% by echocardiography. With use of thallium, the highest accuracy of the test to detect viability was when the percent of necrotic tissue of the segment analyzed was 40% (positive and negative likelihood ratio 2.2 and 3.6, respectively). By use of echocardiography, the highest accuracy of the test was observed when the percent of necrotic tissue of the segment analyzed was 31% (positive and negative likelihood ratio 5.5 and 7.7, respectively). CONCLUSION: The discrepant results of dobutamine echocardiography and thallium 201 are due to differences in the minimum mass of live myocytes required by each technique to detect viability.

Reason for discrepancies in identifying myocardial viability by thallium-201 redistribution, magnetic resonance imaging, and dobutamine echocardiography.

Dobutamine echocardiography (DE), magnetic resonance imaging (MRI), and thallium redistribution (TS) are used to assess cardiac viability. However, these modalities sometimes yield contradictory results. Our aim was to establish the degrees of agreement among DE, MRI, and TS in identifying myocardial viability and to analyze the minimum critical mass of live (viable) cells required for each test to identify viability. A prospective study was done in which DE, MRI, and TS were consecutively performed in 10 ischemic patients scheduled for heart transplantation. The explanted heart was analyzed to quantify the amount of live cells per segment. The pathologic data were compared with the test results to analyze the minimum mass of viable cells required by each technique to identify viability. Mean age was 58 +/- 8 years (8 men). The mean ejection fraction was 0.27 +/- 0.04. Seven patients had severe cardiac failure (New York Heart Association functional class IV) and 6 patients had refractory angina. A total of 150 cardiac segments were analyzed. Among the 150 segments, 107 (71.3%) showed some degree of myocardial necrosis. Mean total area, mean fatty area, and mean necrotic area per segment were 2.53 +/- 0.7, 0.13 +/- 0.2, and 0.55+/-0.5 cm(2), respectively. As expected, a higher amount of necrotic tissue was found in nonviable segments. From the 150 segments, DE identified 90 as viable and 60 as nonviable. These data were similar to that of MRI (98 viable and 52 nonviable). A higher proportion of viable segments was found by TS (117 viable vs 33 nonviable). The concordance between DE and TS was only moderate (kappa 0.49). The agreement between MRI and TS also showed moderate concordance (kappa 0.56). The highest agreement was found between DE and MRI (kappa 0.73). Thus, discrepancies in assessing viability by DE, MRI, and TS may be due to differences in the minimum critical mass of live myocytes required by each technique to diagnose viability. Thallium requires a lesser amount of live tissue than DE or MRI to detect viability; also, its maximum diagnostic efficiency is obtained with lesser amounts of live tissue on each segment. These considerations should be taken into account when these diagnostic tests are used for the detection of viability before revascularization procedures.

Better prognosis of elderly patients with infectious endocarditis in the era of routine echocardiography and nonrestrictive indications for valve surgery.

OBJECTIVE: It has been reported that endocarditis in the elderly may have a poor outcome. Our aim was to assess the different features and prognosis, if any, in the present time. METHODS: Of 103 patients with proven endocarditis, 31 were 65 years or older and 72 were younger than 65 years. Degenerative heart disease was seen more frequently in the elderly (22.5% vs 2.7%, P =.003). Drug abuse and immunodeficiency virus infection were more common in the younger group, as was tricuspid endocarditis (26.3% vs 0%, P <.001). At clinical presentation cardiac failure (41.9 vs 19.4%, P =.02) and leukocytosis (61.2% vs 40.2%, P =.049) were seen more frequently in the elderly. RESULTS: Despite other similar clinical features, it took longer to diagnose older patients (7.2 +/- 6.2 vs 3.2 +/- 3.5 days, P <.001). Enterococcus infected the aged more often (32.2% vs 13.1%, P =.001). During hospitalization, heart failure and embolization tended to be more common in the elderly and the younger group, respectively. There were no significant differences in the incidence of anatomic complications, the need for operation, and overall mortality. CONCLUSION: Although a worse prognosis has been reported in elderly patients with infective endocarditis, the early use of transesophageal echocardiographic examinations and equal therapeutic options provides a similar outcome when compared with younger subjects.

Chlamydia pneumoniae in the atherosclerotic plaques of patients with unstable angina undergoing coronary artery bypass grafting: does it have prognostic implications?

OBJECTIVE: This study sought to evaluate the prognostic significance of the presence of DNA of Chlamydia pneumoniae in the coronary atherosclerotic lesions of patients with unstable angina. BACKGROUND: C. pneumoniae has been implicated in the pathogenesis of coronary artery disease by serological and pathological studies, but whether antichlamydial antibodies and the presence of this pathogen in the coronary atherosclerotic tissue are related to prognosis in unstable angina remains unclear. METHODS: A total 76 coronary specimens from 45 patients with unstable angina undergoing bypass surgery were subjected to nested polymerase chain reaction (PCR) for C. pneumoniae. Antichlamydial immunoglobulin G (IgG), A (IgA) and M (IgM) were also examined by an enzyme immunoassay. Patients were followed during a 2-year period to determine the incidence of adverse cardiovascular events. RESULTS: DNA of C. pneumoniae was detected in 57 (75%) of 76 atherosclerotic lesions: 39 patients showed a positive PCR result in at least one plaque. Of the 45 patients, 44 (97.7%) showed a positive serological result: IgG was positive in 39 (86.6%) patients, IgM in five (11.1%) patients and IgA in 42 (93.3%). Clinical characteristics and serologic results were similarly distributed in patients with and without infected lesions at enrollment. At least one adverse event occurred in 21 (46.6%) of the 45 patients at 2 years: death in nine (20%), recurrent angina in 12 (26.6%), revascularization in six (13.3%) and myocardial infarction in two (4.4%) patients. The composite endpoint of death, myocardial infarction, recurrent angina and revascularization at 2-year follow-up did not differ according to the PCR or serologic results. CONCLUSIONS: The presence of C. pneumoniae in coronary atherosclerotic plaques of patients with unstable angina undergoing coronary bypass grafting does not have prognostic significance. In addition, serology does not allow us to differentiate those patients with plaque infection by C. pneumoniae and also does not provide any prognostic information in these patients.

Prevalence of Chlamydia pneumoniae in the atherosclerotic plaque of patients with unstable angina and its relation with serology.

BACKGROUND: Chlamydia pneumoniae has been associated with coronary artery disease by both seroepidemiological studies, and by direct detection of the micro-organism in atherosclerotic lesions. This bacteria could play a potential role in the development of acute coronary events. We examined coronary arteries from patients with unstable angina in order to verify an endovascular presence of C. pneumoniae, and to determine if there is any relationship between serology of acute infection by this pathogen and its presence inside the atherosclerotic plaque of these patients. METHODS: We analysed a total of 76 atherosclerotic plaques obtained from 45 patients who underwent coronary artery bypass surgery. In all patients unstable angina was present within the prior 3 weeks. The presence of C. pneumoniae in the plaque was determined by nested polymerase chain reaction (PCR). Antichlamydial immunoglobulin G (IgG), A (IgA) and M (IgM) was examined by microimmunofluorescence and compared to the PCR result. FINDINGS: DNA of C. pneumoniae was detected in 57 (75%) of 76 atherosclerotic lesions. In most cases (74/76: 97%) a positive IgA, IgM or IgG result was seen. Seven (12%) and 54 (94%) of the 57 PCR positive plaques came from patients with a positive IgM and IgA result, respectively. There was no statistical significant difference between PCR positive and PCR negative plaques in patients with a positive or negative serological result. Clinical characteristics were similarly distributed in patients with and without infected lesions. INTERPRETATION: C. pneumoniae organisms are frequently found in the atherosclerotic lesions of patients undergoing coronary surgery for unstable angina. Neither serological results of acute or recent infection by C. pneumoniae nor clinical characteristics are useful in predicting the individual risk of harbouring C. pneumoniae in the coronary lesions of patients with unstable angina.

Myocardial perfusion in real-time using power modulation. In vivo evidence for microcirculatory damage after acute myocardial infarction.

BACKGROUND AND OBJECTIVES: In addition to the myocardium, the microvasculature may be also damaged in acute myocardial infarction. The aim was to evaluate the capability of myocardial contrast echocardiography in the detection of microvasculature damage after myocardial infarction. PATIENTS AND METHODS: Twelve patients with recent acute myocardial infarction and five control subjects with normal coronary arteries and without history of myocardial infarction were studied. Myocardial contrast echocardiography with power modulation was performed, and quantitative data were measured off-line. Power modulation uses a combination of low (0.1) and high (1.7) mechanical indexes, allowing a real-time evaluation of myocardial perfusion. Contrast agent was administered as a 3-min bolus. The quantitative analysis was performed off-line by a different blinded investigator. The refilling velocity was calculated as the difference between the peak myocardial refilling value and the value at 1 s after the impulse divided by the time from the first second after the impulse to the peak refilling value. RESULTS: Eighty-one myocardial segments (75%) were analysed qualitatively and quantitatively in AMI patients, and 18 (60%) in control subjects (P=NS). The peak refilling intensity was not significantly different in patients and control subjects (6.62+/-5.85 vs. 7.53+/-4.06 dB, respectively). However, time to peak refilling intensity was significantly longer (5.25+/-1.57 vs. 4.00+/-0.53, P=0.004) and the velocity of refilling was significantly lower (2.74+/-5.34 vs. 6.58+/-8.02, P=0.028) in patients with myocardial infarction. CONCLUSION: There is microvasculature damage after myocardial infarction that is reflected as a delayed velocity of refilling in myocardial contrast echocardiography.

Evaluation of myocardial perfusion with grey-scale ultra-harmonic and multiple-frame triggering. The need for quantification.

BACKGROUND AND OBJECTIVE: Contrast echocardiography has been recently introduced as a new technique for evaluating myocardial perfusion in a qualitative basis. The objective of this study was to test whether a visual subjective evaluation of myocardial perfusion by myocardial contrast echocardiography adequately matches the data obtained with an off-line quantification of myocardial perfusion. METHODS: Sixty-one myocardial segments were evaluated by myocardial contrast echocardiography with Ultra-harmonic and Multiframe Triggering in 11 patients 3-7 days after an anterior myocardial infarction, using SH-U 563A (Levovistâ, Schering AG, Berlin, Germany) as contrast agent. Myocardial perfusion was classified as grade 1 (absent), 2 (patchy or incomplete) and 3 (complete) in each segment. The quantitative analysis was performed off-line by a different investigator blinded to the qualitative evaluation, using a commercially available software. The quantitative data on grey-scale obtained were compared between grade 1, 2 and 3 segments. RESULTS: Of the 61 segments, 45 (73.8%) were classified as grade 3, whereas the remaining 16 (26.2%) were considered to be abnormally perfused (grade 2: n=12, 19.6%; grade 1: n=4, 6.6%). Segments with grade 1 perfusion had a significantly higher grey-scale value (123.6 +/- 41.3 vs. 70.1 +/- 34.3, p=0.004). However, there were no significant differences between segments with perfusion grade 2 and 3 (76.8 +/- 33.2 vs. 68.3 +/- 34.8, p=0.452). CONCLUSION: Qualitative assessment of myocardial perfusion by Ultra-harmonic and Multiframe Triggering is of limited value, since only myocardial segments with absent perfusion may be reliably identified. This findings support the need of quantification in the evaluation of myocardial perfusion by contrast echocardiography.

Value of automated segmental motion analysis in the assessment of aortic stenosis severity.

BACKGROUND AND AIMS OF THE STUDY: Left ventricular (LV) contraction is slowed in patients with aortic stenosis (AS). Although the possible role of LV systolic function abnormalities in the assessment of AS severity has been evaluated, current echocardiographic techniques cannot offer precise quantification of LV motion velocity. The study aim was to evaluate an automated segmental motion analysis (ASMA) system to assess AS severity. METHODS: Twenty-two patients with AS, sinus rhythm and preserved LV ejection fraction were studied prospectively. Patients underwent both conventional Doppler echocardiography to measure transaortic gradient and aortic valve area by the continuity equation, and ASMA of the interventricular septum. The ASMA line graph mode displays changes in area through the cardiac cycle. The RR interval and time from the R-wave to peak maximum area shortening were measured, and an ASMA index was calculated. RESULTS: A significant and strong inverse correlation was found between aortic valve area and ASMA index (r = -0.78; 95% CI -0.90 to -0.55; p <0.001). The area under the ROC curve in the diagnosis of severe AS (aortic valve area < or =0.8 cm2) was 0.97 (95% CI 0.90-1.0). Sensitivity, specificity, positive and negative predictive values and overall accuracy for an ASMA index >0.40 were 100, 91.7, 92.3, 100 and 95.8%, respectively. CONCLUSION: The ASMA system may be valuable in evaluating AS, as it offers a strong correlation with aortic valve area calculated by the continuity equation, and very high sensitivity and specificity in the diagnosis of severe AS.

Influence of diabetes mellitus on short- and long-term outcome in patients with active infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: The incidence and severity of certain infections appear to be increased in patients with diabetes mellitus (DM). The study aim was to evaluate the effect of DM on short- and long-term outcome in patients with active infective endocarditis (IE). METHODS: A total of 151 patients with IE was included and followed up for a mean of 3.1 years. Of these patients, 13 (9%) were diabetics. The outcome of patients with or without DM was compared at short-term (in-hospital) and long-term follow up. RESULTS: Patients with DM were older (66 +/- 11 versus 50 +/- 19 years, p < 0.01) and had a lower frequency of intravenous drug abuse (0 versus 30%, p <0.01) and tricuspid valve involvement (0 versus 20%, p = 0.02) than non-DM patients. Mortality was higher in DM patients both in hospital (31% versus 15%, p = NS) and at a mean follow up of 3.1 years (54% versus 31%, p = 0.002). DM patients also had a significantly higher rate of cardiac failure (69% versus 38%, p = 0.03) and renal failure (62% versus 20%, p <0.01) during hospitalization. Incidences of anatomic complications (abscess, pseudoaneurysm) (15.4% versus 20.3%), valve rupture or perforation (7.7% versus 16.7%) and need for surgical repair (46.2% versus 45.7%) were similar in both DM and non-DM patients. DM, without secondary pathology like renal failure, did not appear to be an independent risk factor for mortality at either short- or long-term follow up. CONCLUSION: Although mortality and morbidity in IE were greater in DM than in non-DM patients, diabetes itself does not constitute an independent risk factor.

Transesophageal Doppler Analysis of Coronary Sinus Flow A New Method to Assess the Severity of Tricuspid Regurgitation.

BACKGROUND: Severe mitral regurgitation induces reversal of flow in the pulmonary veins. We hypothesized that severe tricuspid regurgitation may disrupt normal coronary sinus flow. The purpose of this study was to analyze the Doppler flow pattern of the coronary sinus and to determine its value in the assessment of the severity of tricuspid regurgitation. METHODS: The coronary sinus flow was analyzed in 70 consecutive patients with some degree of tricuspid regurgitation (27 mild, 14 moderate, and 29 severe) and in 35 patients without tricuspid regurgitation. The coronary sinus flow was obtained by pulsed-Doppler transesophageal echocardiography in a transverse plane, which showed its drainage into the right atrium. RESULTS: The number of patients with adequate studies of the coronary sinus tended to increase with the severity of the tricuspid regurgitation. In patients without or with only mild tricuspid regurgitation the coronary sinus Doppler flow pattern was formed by two negative waves, a late systolic wave and another diastolic one with higher velocity and longer duration. The systolic wave became reversed in 21 (96%) of the patients with severe tricuspid regurgitation. The sensitivity, specificity, and diagnostic accuracy of the presence of a reversed systolic wave in the coronary sinus for the diagnosis of severe tricuspid regurgitation was 95%, 82%, and 80%, respectively. CONCLUSIONS: Significant tricuspid regurgitation modifies the coronary sinus flow pattern as assessed by transesophageal echocardiography. The presence of a reversed systolic flow in the coronary sinus appears to be a reliable new sign with good sensitivity, specificity, and diagnostic accuracy for the diagnosis of severe tricuspid regurgitation.

Impact of Beta Blockers on Dobutamine-Atropine Stress Echocardiography.

Dobutamine increases oxygen demand in the myocardium and is used in conjunction with echocardiography to detect coronary artery disease. Beta blockers (BB) are partial antagonists of dobutamine and, therefore, offset dobutamine effects. Still, the impact of BB therapy on dobutamine stress echocardiography is not clear. One hundred forty-one dobutamine-atropine echocardiographic studies have retrospectively been analyzed: 27 patients were on BB (19%; group I); and 114 off BB (81%; group II). Coronary angiography was performed in a similar percentage of patients (97% and 85%, respectively; P = NS). No differences in clinical and angiographic profile were found between the groups. Sensitivity (83% vs 71%; P = NS) and specificity (100% vs 95%; P = NS) for coronary artery disease were similar in both groups. Atropine was infused more frequently to patients from group I (67% vs 46%; P = 0.04). Limiting side effects and prolonged ischemia presented with the same frequency in both groups. When the dobutamine test was positive, severe extent of ischemia appeared more often in patients from group I than in patients from group II (66% vs 33%; P = 0.03). The majority of patients from group I (55%) with severe extent of ischemia and only 12% from group II received atropine (P = 0.02). No differences were found in dobutamine time and extent of ischemia in patients from group I who had a positive response to dobutamine. On the contrary, patients from group II with one vessel disease had a dobutamine time longer (10.5 +/- 3.8 vs 7.8 +/- 3.7 min; P < 0.05) and extent of ischemia smaller (1.8 +/- 0.4 vs 2.6 +/- 0.5 segments; P < 0.05) than patients from group II with multivessel disease. We conclude that: 1) sensitivity of dobutamine-atropine echocardiography for diagnosis of coronary artery disease remains even if patients are on BB; 2) patients with significant coronary artery disease who are taking BB often develop severe myocardial ischemia during dobutamine-atropine stress echocardiography; and 3) BB therapy precludes stratification of a positive echocardiographic response. These conclusions should be confirmed in a prospective study to be considered as definitive. (ECHOCARDIOGRAPHY, Volume 13, July 1996)

[Left ventricular free wall rupture during dobutamine stress echocardiography]. / Rotura de la pared libre del ventrículo izquierdo durante prueba de estrés con dobutamina.

Dobutamine stress echocardiography is associated with a very low rate of serious complications, lower than 0.5% (death, infarction or sustained ventricular tachycardia). We report the case of a 75 year-old female patient that suffered a fatal left ventricular free wall rupture during a dobutamine stress echocardiography after acute myocardial infarction.

[Stress echocardiography in the pre-operative evaluation of patients undergoing major vascular surgery. Are results comparable with dypiridamole versus dobutamine stress echo?]. / Ecocardiografía de estrés en el preoperatorio de cirugía vascular: son comparables los resultados con dipiridamol y dobutamina?

INTRODUCTION: [corrected] Perioperative cardiovascular complications are an important cause of post-surgical morbility and mortality in patients undergoing major vascular surgery. Dobutamine Stress Echo is considered one of the methods of choice in the detection of coronary artery disease in this subgroup of patients. OBJECTIVES: . Our aim was to analyze if dipyridamole stress echocardiography could be used as an alternative to Dobutamine Stress Echo in the perioperative evaluation of patients in need of major vascular surgery. PATIENTS AND METHOD: The result of consecutives dypiridamole and dobutamine stress exams prior to vascular surgery were reviewed. We analyzed if those patients with a positive stress echo presented a higher number of cardiac events during and after surgery than those with negative stress echo. The negative and positive predictive values were calculated for both techniques. RESULTS: 133 stress exams were analysed: 39 with dobutamine and 94 with dipyridamole. Of the 39 dobutamine studies 2 were positive, 29 negatives and 8 non conclusive. Of the 94 dypiridamole studies 13 were positive and 81 negatives. None of the patients with a positive dobutamine echo underwent surgery. The negative predictive value for dobutamine echo was 96.5%, quite similar to that of dypiridamole stress echo (97.5%). CONCLUSION: Dipyridamole stress echocardiography is a valid alternative to dobutamine echocardiography in the pre-surgical evaluation of patients undergoing major vascular surgery.

Perioperative mortality and long-term outcome of infective endocarditis.

INTRODUCTION AND OBJECTIVES: Infective endocarditis (IE) is a disease with a high morbidity and mortality during the active phase and a considerable risk of complications during follow-up. The aim of this study is to describe the clinical features of IE associated with perioperative mortality in patients undergoing surgery and the short- and long-term prognosis of this disease after surgical treatment. PATIENTS AND METHODS: The clinical files of 150 patients (pts) admitted to our institution between 1989 and 2001 and whose final diagnosis was IE (Duke criteria) were retrospectively reviewed. Thus all patients included underwent at least 1 transthoracic examination, and a transesophageal examination if indicated. The study population was 69 patients with IE, 62 of whom (90%) underwent prosthetic valve replacement and 7 (10%) underwent explanation of pacemaker electrocatheter. In the statistical analysis, quantitative variables are expressed as means +/- SD and qualitative variables as proportions (percentages). Differences in survival were determined using the Kaplan-Meier log rank method. Associations were considered statistically significant when the p value was < 0.05. RESULTS: The mean age was 56 +/- 15 years. Thirty-five cases (51%) had prosthetic valve endocarditis, 30 (39%) had native valve IE and 7 (10%) pacemaker electrocatheter IE. Fifty-two patients (75%) had positive blood cultures. The most frequent agents were S. epidermidis (14.5%), S. aureus (14.5%), Enterococci (13%) and S. viridans (10%). Total perioperative mortality was 17.4% (n = 12), and surgical mortality was 19.4%. Our study shows a statistical tendency for higher mortality in diabetic patients (50% vs. 14%, p = 0.052) and in women (29% vs. 11%, p = 0.065). In multivariate analysis, the presence of heart failure was an independent predictor of perioperative mortality (OR = 11.4; 95% CI: 2.0-215.2; p = 0.024). Accumulated mortality in the first year was 28% and 5-year mortality was 48%. CONCLUSIONS: Prosthetic valve replacement in patients with IE is associated with high perioperative mortality (17.4%). Despite good early postoperative results, the mortality rate increases during the first year as well as the need for reoperation.

Negative predictive value of dipyridamole vs. dobutamine stress echocardiography in the long-term follow-up of patients undergoing major vascular surgery.

INTRODUCTION: Perioperative cardiovascular complications are a significant cause of post-surgical morbidity and mortality in patients undergoing major vascular surgery (MVS). Dobutamine stress echocardiography is the most important method of detecting coronary artery disease in these patients. Although dipyridamole stress echocardiography (SE-DIP) and dobutamine stress echo (SE-DOB) have demonstrated similar negative predictive value (NPV) in the early postoperative period in patients undergoing MVS, there are few data concerning the negative predictive value of SE-DIP in the long-term follow-up of this subgroup of patients. OBJECTIVE: Our aim was to compare the long-term NPV of these two types of stress echocardiography and to compare it with perioperative NPV, based on the working assumption that they are similar. PATIENTS AND METHODS: A retrospective study was made of 157 patients based on preoperative evaluations for vascular surgery between February 1997 and February 2000. Clinical history and the results of consecutive stress exams were analyzed. We excluded patients with a positive stress echo and those that performed dobutamine stress echo which was considered inconclusive since they did not reach 85% of the maximum heart rate for their age. Therefore, 110 patients were included, 29 (26.4%) with dobutamine and 81 (73.6%) dipyridamole-atropine. The patients were followed after surgery for a period of 2.2 +/- 1 years. Cardiac events were defined as cardiac death, nonfatal acute myocardial infarction and hospitalization for unstable angina. The cumulative probability of event-free survival was compared. RESULTS: The patients' mean age was 65 +/- 10 years, and 108 (98.1%) were men. After 2.2 +/- 1 years of follow-up, 7 cardiac events occurred in the group with negative SE-DIP (8.6%) and 3 in patients with negative SE-DOB (10.3%). There were no statistically significant differences between the two groups concerning event-free survival (3.7 +/- 0.2 vs. 3.5 +/- 0.2 years for SE-DIP and SE-DOB respectively; p = 0.91). Negative predictive values for SE for perioperative and long-term cardiac events were 97.3% and 90.9% respectively. CONCLUSIONS: SE-DIP is a good alternative to SE-DOB in the preoperative evaluation of patients undergoing MVS, with the NPV of SE-DIP being similar to SE-DOB in the perioperative period and in long-term follow-up.

Relationship between the changes in myocardial perfusion and left ventricular ejection fraction after acute myocardial infarction. Study with myocardial contrast echocardiography.

BACKGROUND AND OBJECTIVE: Myocardial contrast echocardiography has recently been proposed as a valid technique in the evaluation of myocardial perfusion after myocardial infarction. The objective of this study was to evaluate the relation between changes in myocardial perfusion assessed by myocardial contrast echocardiography and left ventricular ejection fraction after myocardial infarction. PATIENTS AND METHODS: We prospectively studied 17 patients with acute myocardial infarction, on whom two echocardiographic studies were performed, at 48-72 hours and at 6 months. Left ventricular ejection fraction and myocardial perfusion were evaluated with myocardial contrast echocardiography (Multiple-Frame Triggering and Harmonic Angio). Basal, medial and distal segments of the interventricular septum (anterior location infarction) and inferior wall (inferior infarction) were assessed. Myocardial perfusion was classified semi-quantitatively as grade 0, 1 or 2 (absent, heterogeneous or homogeneous opacification, respectively), giving a perfusion score. RESULTS: Left ventricular ejection fraction improved in 9 patients (53%), the proportion of grade 0 segments decreasing by 11 +/- 17%; by contrast, this proportion increased by 9 +/- 13% in patients with no improvement in ejection fraction (p = 0.028). Additionally, a significant correlation was observed between changes in ejection fraction and both perfusion score (r = 0.625; p = 0.007) and the proportion of grade 2 segments (r = 0.649; p = 0.005). CONCLUSION: After myocardial infarction, there is a significant relation between changes in left ventricular ejection fraction and myocardial perfusion assessed by myocardial contrast echocardiography with i.v. agents.

Contrast agents provide a faster learning curve in dipyridamole stress echocardiography.

AIM: Interobserver variability is an important limitation of the stress echocardiography and depends on the echocardiographer training. Our aim was to evaluate if the use of contrast agents during dipyridamole stress echocardiography would improve the agreement between an experienced and a non-experienced observer in stress echo and therefore if contrast would affect the learning period of dypyridamole stress echo. METHODS AND RESULTS: Two independent observers without knowledge of any patient data interpreted all stress studies. One observer was an experienced one and the other had experience in echocardiography but not in stress echo. Two observers analysed 87 non-selected and consecutive studies. Out of the 87 studies, 46 were performed without contrast administration, whereas i.v. contrast (2.5 g Levovist by two bolus at rest and at peak stress) was administered in 41. In all cases, second harmonic imaging and stress digitalisation pack was used. The agreement between observers showed a kappa index of 0.58 and 0.83 without and with contrast administration, respectively. CONCLUSIONS: The use of contrast agents provides a better agreement in the evaluation of stress echo between an experienced and a non-experienced observer in stress echo. Adding routinely contrast agents could probably reduce the number of exams required for the necessary learning curve in stress echocardiography.

Influencia de la administración de ecopotenciadores sobre la variabilidad interobservador en la ecocardiografía de estrés con dobutamina / The use of contrast agents in dobutamine stress echocardiography and its influence on interobserver variability

Introducción. La ecocardiografía de estrés farmacológico es una técnica fiable en el estudio de la enfermedad coronaria. Sin embargo, una de sus principales limitaciones es la variabilidad interobservador, relacionada con diversos factores que incluyen la calidad de la imagen, así como la experiencia del examinador. Objetivos. Valorar si el empleo de ecopotenciadores durante la ecocardiografía con dobutamina mejoraría la variabilidad entre dos observadores, un observador experto en ecocardiografía de estrés y un segundo observador sin experiencia en la técnica, y si influiría sobre la curva de aprendizaje. Métodos. Los ecocardiogramas de estrés fueron interpretados por dos observadores independientes: el primero (A) con experiencia en ecocardiografía de estrés y el segundo (B) sin experiencia en la técnica. Todos los estudios se realizaron con segundo armónico y digitalización de las imágenes. El agente de contraste empleado fue Levograf/Levovist® 2,5 g en dos bolos, en reposo y en el máximo estrés. El grado de acuerdo interobservador fue evaluado mediante el coeficiente kappa. Resultados. Se han analizado 52 estudios realizados en 51 pacientes no seleccionados y consecutivos. Se utilizó contraste en 22 estudios. En la ecocardiografía con dobutamina sin contraste, el grado de acuerdo se estimó con un coeficiente kappa de 0,52, mejorando sólo ligeramente el acuerdo entre los dos observadores al emplear contraste (kappa = 0,58; sin diferencias significativas entre las kappa). Conclusiones. El empleo rutinario de contraste mejora ligeramente, sin alcanzar diferencias significativas, el grado de acuerdo en la interpretación de la ecocardiografía de estrés. Sin embargo, esta mejoría no sustituye el período de formación necesario en la técnica (AU)

Utilidad de la ecocardiografía de contraste con segundo armónico en un paciente con miocardiopatía hipertrófica y obstrucción mesoventricular / Utility of contrast echocardiography with harmonic imaging in a patient with hypertrophic cardiomyopathy and midventricular obstruction

La ecocardiografía es una técnica utilizada de rutina en la evaluación de la función cardíaca. La definición de los bordes endocárdicos es fundamental para valorar de forma correcta la contractilidad global y segmentaria del ventrículo izquierdo. En algunas ocasiones esto resulta difícil debido a la inadecuada ventana acústica de los pacientes. Las nuevas técnicas ecocardiográficas podrían ayudar a diagnosticar de forma precisa e incruenta determinadas enfermedades que pasaban inadvertidas con las técnicas tradicionales. Presentamos el caso de un paciente diagnosticado en el ecocardiograma basal de alteraciones en la contractilidad segmentaria, tipo hipocinesia lateral y apical, en el que la utilización de la imagen armónica con ecocardiografía de contraste permitió cambiar el diagnóstico inicial. El paciente presentaba realmente una miocardiopatía hipertrófica severa con obstrucción mesoventricular, sin alteraciones segmentarias de la contractilidad (AU)