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BACKGROUND The purpose of this study was to determine the predictive value of dobutamine stress echocardiography for perioperative cardiac events in patients scheduled for elective major noncardiac vascular surgery. METHODS AND RESULTS Patients (n = 136; mean age, 68 years) unable to exercise underwent a dobutamine stress test before surgery (incremental dobutamine infusion [10-40 micrograms.kg-1.min-1] continued with atropine [0.25-1 mg i.v.] if necessary to achieve 85% of the age-predicted maximal heart rate without symptoms or signs of ischemia). The clinical risk profile was evaluated by Detsky's modification of Goldman's risk factor analysis. Echocardiographic images were evaluated by two observers blinded to the clinical data of the patients, and results of the test were not used for clinical decision making. Technically adequate images were obtained in 134 of 136 patients, one major complication occurred (ventricular fibrillation), and three tests were discontinued prematurely because of side effects. Finally, data from 131 patients were analyzed with univariate and multivariate methods. The dobutamine stress test was positive (new or worsened wall motion abnormality) in 35 of 131 patients. In the postoperative period, five patients died of myocardial infarction, nine patients had unstable angina, and one patient developed pulmonary edema. All patients with cardiac complications (15 patients) had a positive dobutamine stress test. No cardiac events occurred in patients with negative tests. Five patients with a technically inadequate or prematurely stopped test were operated on without complications. By multivariate analysis (logistic regression), only age > 70 years and new wall motion abnormalities during the dobutamine test were significant predictors of perioperative cardiac events. CONCLUSIONS Dobutamine stress echocardiography is a feasible, safe, and useful method for identifying patients at high or low risk of perioperative cardiac events. The test yields additional information, beyond that provided by clinical variables, in patients who are scheduled for major noncardiac vascular surgery.

The case of a 72-year old patient with acute heart failure due to thrombosis of the mechanical mitral prosthesis is presented. The diagnosis was made by transthoracic echocardiography. The patient refused reoperation, and systemic thrombolysis was administered. After thrombolytic infusion we observe the disappearance of the echocardiographic signs of thrombosis, with concomitant improvement of symptoms.

In the management of heart failure the general practitioner (GP) plays an important role. However, international studies proved that the GP differs in the management of these patients from the cardiologist. This pilot study aims at investigating if such differences persist in the Italian community.Seventy patients with heart failure have been enrolled prospectively by 10 GPs in the Udine district (ASL 4). All of them have been evaluated at the first and subsequent visits, both with respect to clinical and instrumental parameters, overall resource consumption and quality of life.We observed a high degree of heterogeneity in the follow up patterns; a low coordination between GP and cardiologists in managing patients; several co-morbidities; high social burden; a good adherence to treatment guidelines; a moderate workload, subjectively evaluated from the GP.This experience motivated the need of further research in the field, and, from the point of view of the daily practice, the need of integrating hospital and community management of patients with heart failure.

We describe a new technique to treat stenoses of coronary bifurcations. The aim of this technique, called "side balloon stenting," is to treat the bifurcation lesions with the kissing balloon technique, implanting one or more stents without removing the guidewires which remain in place during the whole procedure, avoiding potential problems of access to the vessels jailed by stent struts. In addition, implanting the stent using the kissing balloon technique would prevent the "snow-plow" phenomenon (plaque shifting) in the side branch. The "side balloon stenting" technique was applied in 29 cases at various levels of coronary artery segments involving bifurcations (Table 1). The technical success rate of the side balloon stenting was 90% (25 procedures). The elective placement of one stent in the main vessel was done in 20/25 procedures (80%), and in only 5/25 (20%), it was also necessary to insert a second one in the side branch (due to suboptimal results), using the "culotte" technique in two and the T-technique in the other three. We were unable to advance the system to the right position in 4 patients (13%): in 2 due to twisting of the guidewires and in the other due to vessel tortuosity and insufficient backup of the system (guiding catheter and guidewires). In these four last cases, the delivery system was retrieved and a stent was successfully implanted in the right position in the main branch. Angiographic success (residual stenoses30% and TIMI 3 flow in both branches) was obtained in 100% of the cases. The post-intervention period was uneventful. These preliminary results show that the side balloon stenting technique is both feasible and safe in th treatment of coronary bifurcations with a satisfactory rate of procedural success and often (82%) positioning only one stent in the parent vessel, thus avoiding stenting the side branch. It will be necessary, however, to assess, based mainly on restenosis rate, whether these promising immediate results will persist in the long run.

The quality of cardiac imaging plays a pivotal role in clinical decision-making and depends mainly on the technical performance of the imaging system and on angiographic technique. The Italian Society of Invasive Cardiology and The Italian Society of Physics in Medicine have set quality criteria giving precise guidelines regarding how an angiogram should appear provided that good equipment and correct angiographic technique are used. The criteria have been reviewed by the European Concerted Action DIMOND Cardiology group and are reported here to provide a reference standard for images for the most common procedures in daily practice.

In interventional cardiology (IC) the PTCA (percutaneous transluminal coronary angioplasty) procedure is the most frequent procedure with the highest dose to the patient. The procedure is usually performed by cardiologists having, in general, insufficient knowledge of radiation physics, radiation technology and radiation protection. The need for radiation protection is of paramount importance in this field of interventional radiology. Correlation between the complexity of PTCA procedure and irradiation parameters (fluoroscopy time, number of images and dose-area product--DAP) has been demonstrated. The presence of severe tortuosity and occlusion of > or = 3 months play a major role. Fluoroscopy time is better correlated with technical factors than DAP, which also includes the influence of patient size, collimation, operation modes, and X ray beam orientation. The number of acquired images is less correlated with the complexity of the PTCA procedure. A complexity index was conceived and procedures were divided into three groups, defined as: simple, medium and complex, which were significantly different in terms of patient dose.

A 60-year-old woman referred to our hospital because of increasing dyspnea and angina. Her past history included an anterior myocardial infarction, associated with a large coronary dissection of the proximal left anterior descending coronary artery. The infarction resulted in a ventricular aneurysm which was treated with surgical excision without coronary revascularization. Coronary angiography showed a linear filling defect involving the left anterior descending coronary artery. Intracoronary ultrasound revealed a long intimal tear dividing the artery into two separated lumens. A kissing-stent technique was used to preserve the anatomical and functional integrity of the main vessel as well as of the diagonal branch. Two premounted stents were positioned covering the origin of both branches of the bifurcation. Simultaneous inflation of the two balloons created a metallic new-carina, 1 cm proximal to the bifurcation. Five months later the patient was readmitted with chest pain and repeat coronary angiography demonstrated a severe in-stent restenosis. Re-coronary angioplasty resulted in a good angiographic result. At 4 months from the last procedure there is no complaint of angina.

Evaluation of the long-term functional outcome assessed by exercise myocardial perfusion imaging following excimer laser angioplasty compared to balloon angioplasty in coronary lesions10 mm in length.Previous randomized studies evaluating the effect of coronary interventions mainly focused on the long-term clinical and angiographic outcome. The functional outcome, assessed by myocardial perfusion scintigraphy, has not been evaluated in a randomized setting.A total of 308 patients with stable angina and a longer coronary lesion (10 mm) were randomized to excimer laser angioplasty or balloon angioplasty. A 99mTechnetium-2-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography (SPECT) study was performed in 139 patients before the initial angioplasty procedure and at 6 months follow-up (73 patients in the laser group versus 66 patients in the balloon group, respectively). Exercise tolerance at follow-up was compared to baseline values by means of exercise duration and double product at peak exercise. Myocardial perfusion of the randomized vascular bed was assessed semi-quantitatively on the MIBI SPECT images. The reversible defects were graded as mild, moderate or severe. Myocardial perfusion at follow-up was expressed as a percentage reduction in incidence and grading of the reversible defects compared to baseline values.Forty-four (61%) patients assigned to laser angioplasty were asymptomatic at 6 months follow-up compared to 34 (52%) patients assigned to balloon angioplasty (p = NS). Improvement in exercise duration and double product were 0.7 +/- 2.1 min and 4.3 +/- 6.2 min/mmHg/l,000, respectively, in the laser group, versus 0.3 +/- 2.5 min and 3.1 +/- 5.5 min/mmHg/1,000, respectively, in the balloon group (both p = NS). The percentage reduction of reversible defects was 23% in patients assigned to laser angioplasty vs. 29% in patients assigned to balloon angioplasty (Relative risk [RR]: 0.79, 95% confidence interval [CI]: 0.40-1.57; p = 0.50). The mild, moderate and severe reversible defects improved in 44.4, 63.6 and 66.6%, respectively, in the laser angioplasty group vs. 66.6, 53.8 and 90%, respectively, in the balloon angioplasty group. None of the comparisons were significantly different.Excimer laser angioplasty compared to balloon angioplasty in coronary lesions10 mm in length yields a similar long-term functional outcome assessed by anginal status, exercise tolerance and myocardial perfusion.

The presence of myocardial viability is predictive of improvement in regional left ventricular (LV) function after revascularization. Studies on predicting improvement in global LV function are scarce, and the amount of viable myocardium needed for improvement in LV ejection fraction (LVEF) after revascularization is unknown. Moreover, whether the presence of viability is associated with relief of heart failure symptoms after revascularization is uncertain. Hence, the aims were to define the extent of viable myocardium needed for improvement in LVEF and to determine whether preoperative viability testing can predict improvement in heart failure symptoms.Patients (n = 47) with ischemic cardiomyopathy (mean LVEF +/- SD, 30% +/- 6%) undergoing surgical revascularization were studied with 18F-FDG SPECT to assess viability. Regional and global function were measured before and 3-6 mo after revascularization. Heart failure symptoms were graded according to the New York Heart Association (NYHA) criteria, before and 3-6 mo after revascularization.The number of viable segments per patient was directly related to the improvement in LVEF after revascularization (r = 0.79, P0.01). Receiver operating characteristic curve analysis revealed that the cutoff level of four viable segments (representing 31% of the left ventricle) yielded the highest sensitivity and specificity (86% and 92%, respectively) for predicting improvement in LVEF. Furthermore, the presence of four or more viable segments predicted improvement in heart failure symptoms after revascularization, with positive and negative predictive values of 76% and 71%, respectively.The presence of substantial viability (four or more viable segments, 31% of the left ventricle) on FDG SPECT is predictive of improvement in LVEF and heart failure symptoms postoperatively.

Over the past two decades the use of angioplasty has rapidly expanded. As technology and experience have advanced, operators are increasingly faced with two-vessel and three-vessel disease. Coronary artery bypass graft surgery and coronary balloon angioplasty are two possible approaches for patients with multivessel coronary disease. Randomized trials comparing these two different procedures have found no difference in early as well as late mortality between assigned treatment groups. The Bypass Angioplasty Revascularization Investigation (BARI) showed a better long-term outcome with coronary artery bypass in the subgroup of patients with treated diabetes (35% died within 5 years after angioplasty compared with 19% who underwent surgery). Repeat revascularization was more common after angioplasty. Surgery offers more complete revascularization, but morbidity is higher; angioplasty is less invasive but patients are more likely to need another revascularization procedure mainly related to the occurrence of restenosis. Restenosis is often associated with the recurrence of symptoms requiring further revascularization. The use of stents and inhibitors of glycoprotein IIb/IIIa, minimally invasive surgical techniques and all-arterial grafting have the potential to change the scenery of coronary artery revascularization in the next few years.

Increased myocardial uptake of 18F-fluorodeoxyglucose (FDG) in regions with perfusion defects (perfusion-FDG mismatch) has been shown to predict functional recovery after revascularization; conversely, a concordant decrease in perfusion and FDG uptake (perfusion-FDG match) represents scar tissue (varying from subendocardial to transmural scar) that will not improve in contractile function after revascularization. Several recent studies have used a mild reduction in perfusion or FDG uptake (or both) as an indicator of viable tissue. To our knowledge, this criterion has not been validated against functional outcome after revascularization. This study aimed to compare the predictive value for functional recovery of these different perfusion-metabolism criteria.Forty-two patients referred for revascularization were studied with early resting 201Tl SPECT (to evaluate perfusion) and FDG SPECT. Contractile function was evaluated before and 3-4 mo after revascularization using two-dimensional echocardiography. Angiography was not repeated.Two hundred six dysfunctional segments were identified; functional recovery occurred in 71 segments. The 206 dysfunctional segments were divided into five groups: group I, segments (n = 37) with normal perfusion; group II, segments (n = 69) with a mild reduction in perfusion (or =60% of normal 201Tl uptake) without increased FDG uptake (mild match); group III, segments (n = 29) with a mild reduction in perfusion and increased FDG uptake (mild mismatch); group IV, segments (n = 46) with a more severe reduction in perfusion (60% of normal 201Tl uptake) without increased FDG uptake (severe match); and group V, segments (n = 25) with a 201Tl activity60% and increased FDG uptake (severe mismatch). The mean wall motion score improved significantly in groups I, III and V but not in groups II and IV. Improvement of function was observed in 76% of group I segments, in 69% of group III segments and in 68% of group V segments. In contrast, only 13% of group II segments and 7% of group IV segments improved after revascularization.The results indicate that normal perfusion and mismatch patterns (either mild or severe) are predictive of functional recovery, whereas match patterns (either mild or severe) are predictive of absence of recovery. Match patterns are likely to represent different degrees of scar tissue, ranging from subendocardial to transmural scars. To identify segments with a high likelihood of improvement of function after revascularization, integration of information on perfusion and FDG uptake appears mandatory.

The assessment of myocardial viability has gained a lot of attention over the past few years. Various imaging techniques, mainly nuclear and echocardiographic approaches, have been developed for this purpose. From the existing data, it has become clear that the presence of dysfunctional yet viable myocardium can predict improvement of regional and global left ventricular (LV) function after revascularization. This issue is most relevant in patients with severely depressed LV function, since in these patients revascularization carries a high (peri-)procedural risk on the one hand, but may substantially improve LV function in some patients. Besides the improvement of resting LV function after revascularization, other end-points may also be clinically relevant, including the response during stress, improvement of exercise capacity, the quality of life and the prevention of LV remodeling. These issues have not been studied extensively thusfar. Finally, several retrospective studies have shown the prognostic value of viability assessment; patients with viable but jeopardized myocardium were significantly more prone to experience cardiac events than patients with viability who underwent revascularization. The different aspects of viability assessment (including pathophysiology, available techniques, current implications and unresolved issues) will be addressed in this manuscript.

This study sought to evaluate the time course of improvement of left ventricular (LV) dysfunction in stable patients and its implications on the accuracy of dobutamine echocardiography for predicting improvement after surgical revascularization.Little is known about the optimal timing for evaluation of postrevascularization recovery of the contractile function of viable myocardium.Sixty-one patients with chronic ischemic LV dysfunction scheduled for elective surgical revascularization were prospectively selected. They underwent dobutamine echocardiography (5 to 40 microg/kg body weight per min) and radionuclide ventriculography both preoperatively and at 3-month follow-up. At 14 months, another evaluation of LV function was obtained. To analyze echocardiograms, a 16-segment model and a five-point scoring system were used. Dyssynergic segments were considered likely to recover in the presence of a biphasic contractile response to dobutamine. Improvement of global function was defined as aor =5% increase in LV ejection fraction (LVEF).Of the 61 patients, LVEF improved in 12 at 3 months and in 19 at late follow-up (from 32+/-8% to 42+/-9%, p0.0001). The frequency and time course of improvement of LVEF were similar in patients with mild and severe LV dysfunction. A biphasic response, identified in 186 of the 537 dyssynergic segments, was predictive of recovery in 63% at 3 months and in 75% at late follow-up. The positive predictive value was best in the most severe dyssynergic segments (90% vs. 67%). Other responses were highly predictive for nonrecovery (92%). The sensitivity and specificity for improvement of global function on a patient basis (or =4 biphasic segments) were 89% and 81%, respectively, at late follow-up.Serial postoperative follow-up studies demonstrate incomplete recovery of contractile function at 3 months. The diagnostic accuracy of dobutamine echocardiography for predicting recovery is dependent on three factors: the combining of low and high dobutamine dosages, the severity of regional dyssynergy and the timing of evaluation.

Closed-loop arbutamine stress echocardiography has been shown to be safe and effective for detecting coronary artery disease (CAD) using a standardized infusion protocol and centralized core laboratory analyses. However, the accuracy of arbutamine stress echocardiography using local test interpretation has not been previously tested in a large population. The present study reports the safety, sensitivity, and specificity of arbutamine stress echocardiography in a multicenter trial allowing user-defined, nonstandardized protocols and local test interpretation. In all, 1,070 patients underwent arbutamine stress testing at 81 sites. Heart rate increased from 73 +/- 13 to 124 +/- 15 beats/min, systolic blood pressure from 144 +/- 24 to 174 +/- 25 mm Hg, and pressure rate product x 10(3) from 10.5 +/- 2.8 to 19.6 +/- 3.9. Among 1,070 patients, there were only 2 (0.2%) significant adverse events related to arbutamine, both of which resolved completely with appropriate therapy. There were no incidents of ventricular fibrillation, sustained ventricular tachycardia, or death related to testing. Among 242 patients who underwent arbutamine stress echocardiography and diagnostic coronary angiography within 12 weeks, sensitivity and specificity for detection of CAD were 71% (95% confidence interval 64% to 77%) and 67% (95% confidence interval 52% to 80%), respectively. Closed-loop arbutamine stress echocardiography is a safe and effective method for evaluating CAD in clinical practice.

The application of 18-F-fluorodeoxyglucose (FDG) imaging with single photon emission computed tomography (SPECT) to detect tissue viability has been introduced recently in several centers, both in Europe and the USA. This paper summarizes the available data on FDG SPECT. Three studies have performed a direct comparison between FDG SPECT and FDG PET, showing good agreement between these techniques. Preliminary data in patients with poor left ventricular function undergoing revascularization suggest that FDG SPECT can predict improvement of ventricular function after revascularization. Comparative studies between FDG SPECT and low-dose dobutamine echocardiography also showed close agreement. Although the initial results are promising, larger studies are needed to determine the precise role of FDG SPECT in the assessment of myocardial viability.

Doppler tissue imaging is one of the most recent technical achievements of clinical echocardiography. Different Doppler modes are encompassed by Doppler tissue imaging: tissues velocity, pulsed wave-doppler, acceleration, phase, synchronicity and energy modes. With the exception of the energy mode, all modes are based on the Doppler shift, according to the strength of the Doppler signals from the tissues. The most widely used mode is tissue velocity, in which the velocity of moving tissue is calculated in relation to the transducer from the Doppler shift and is displayed as colour-encoded velocity maps in M-mode and two-dimensional imaging formats. Both curved M-mode, applied on two-dimensional images, and three-dimensional reconstruction appear among the most promising applications of velocity mode for the quantitative assessment of regional left ventricular function. A second Doppler mode, pulsed wave-doppler tissue imaging, displays the velocity profile of a region of interest versus time. The velocity data are displayed with a high temporal resolution, but with the disadvantage of a low spatial resolution. A third Doppler mode, tissue acceleration, displays the differences in velocity between subsequent frames in colour-encoded maps. A clinical application has been found in the electrophysiologic field. Other Doppler modes, phase and synchronicity, still require clinical assessment. Lastly, the tissue energy or power mode displays the strength of the Doppler signal from the tissues as gradations of the colour intensity in colour-encoded maps. One of its fields of application appears to be the study of myocardial perfusion with contrast agents. The development of new dedicated algorithms for colour quantification, along with the beginning of the new era of digital echocardiography, should help bring Doppler tissue imaging into the clinical arena.

Over the past 10 years, F18-fluorodeoxyglucose (FDG) imaging with positron emission tomography (PET) has emerged as an important technique in the delineation of myocardial viability. Using this technique it has become possible to predict recovery of ventricular function after revascularization in patients with chronic coronary artery disease. Data from long-term (although retrospective) follow-up studies have demonstrated that patients with viable myocardium on FDG PET who do not undergo revascularization are prone to cardiac events, including cardiac death and non-fatal infarction. The same studies have pointed out that patients with viable tissue on FDG PET, who do undergo revascularization, improve substantially in symptoms related to congestive heart failure. To allow FDG imaging in centers without PET equipment, recent studies have evaluated the use of FDG imaging with single photon emission computed tomography (SPECT) and 511 keV collimators. Preliminary data using this alternative approach are promising, but need further confirmation. In this review the experience with FDG imaging (using either PET or SPECT) in the assessment of tissue viability in patients with coronary artery disease will be discussed.

The aim of this study was to evaluate the value of thallium-201 chloride (201Tl) reinjection imaging following dobutamine stress (DRi) to identify viable myocardium in comparison with a rest-redistribution 201Tl protocol (RR). The identification of viable myocardium bears important consequences for adequate selection of patients with poor left ventricular function, often unable to exercise, who are considered for revascularization. Twenty-six patients with chronic coronary artery disease and depressed left ventricular function (ejection fraction 36 +/- 10%) were studied by both DRi and RR single photon emission computed tomography (SPECT). Semi-quantitative analysis of regional 201Tl activity (5-point score) and wall motion by echocardiography using a 16-segment model was performed. Regions were classified as viable (normal/reversible/fixed moderate defects) or non-viable (fixed severe defects) and related to regional wall motion. Target heart rate was reached in 25 patients. Myocardial viability was demonstrated in 353/416 (85%) by DRi SPECT and in 346/416 (83%) by RR SPECT. The agreement between the 2 protocols was 98% with a K-value of 0.94; similar results were obtained when the analysis was limited to dyscontractile segments. In conclusion, this study demonstrates the feasibility and diagnostic value of DRi SPECT to identify viable myocardium.

This study assessed the value of dobutamine 201Tl scintigraphy for detecting significant disease of infarct-related and remote coronary arteries in myocardial infarction patients.Dobutamine (up to 40 micrograms/kg/min)/atropine (up to 1 mg) stress test in conjunction with stress-reinjection 200Tl SPECT was performed in 71 symptomatic patients with left ventricular dysfunction3 mo after myocardial infarction. Ischemia was defined as reversible perfusion defects.Significant coronary artery stenosis (or = 50% luminal diameter stenosis) was detected in all patients. Sensitivity, specificity and accuracy of regional ischemia for the diagnosis of remote coronary artery stenosis were 74% (95% Cl 63-86), 80% (Cl 70-90) and 76% (Cl 65-87), respectively. Those for infarct-related artery stenosis were 71% (Cl 60-81), 83% (Cl 75-92) and 72% (Cl 61-82), respectively. Ischemic perfusion score was higher in patients with multiversus single-vessel disease (1056 +/- 1021 versus 423 +/- 633, p0.01).Dobutamine thallium scintigraphy is valuable for assessing the extent of coronary stenosis on the basis of reversible hypoperfusion in symptomatic patients late after myocardial infarction.

Akinesis becoming dyskinesis at high-dose dobutamine stress echocardiography (DSE) has been disregarded as a marker of myocardial ischemia. However, to our knowledge, the relationship between this pattern and myocardial viability has not been assessed.We studied 42 patients with myocardial infarction who underwent DSE (up to 40 micrograms/kg/min) before coronary artery bypass surgery, and resting echocardiogram 3 months after surgery. Viability in akinetic segments was considered to be present if systolic thickening occurred with low-dose dobutamine (LDD).During high-dose DSE, dyskinesis occurred in 35 of the 164 akinetic segments (group A). The remaining 129 segments comprised group B. Segments of group B had a higher prevalence of viability pattern with LDD (18% vs 0%; p0.01) and a higher prevalence of functional improvement (20% vs 0%; p0.005) compared with group A. In absence of viability pattern with LDD, postoperative improvement occurred in 10% of segments in group B and in none of segments in group A, resulting in a higher negative predictive value of LDD in group A vs B (100% vs 90%; p0.05).The phenomenon of akinesis becoming dyskinesis with high-dose DSE is associated with absence of viability pattern with LDD and poor functional outcome after surgical revascularization. Observation of this pattern provides additional data to those obtained only with LDD echocardiography.

Exercise 201TI SPECT has been used as a useful method for the assessment of patients with anomalous left coronary artery communicating to the pulmonary artery (ALCAPA syndrome). In this study, we described an adult patient with this anomaly who was evaluated by dobutamine stress testing in conjunction with simultaneous 201Tl SPECT and echocardiography before and after surgery. A large perfusion defect in the anterior wall, septum and apex was detected on the preoperative stress scan with partial reversibility on reinjection scan. Worsening of wall motion abnormalities in the septum and anterior wall was detected by stress echocardiography. In the studies performed 3 mo and 1 yr after reimplantation of the left coronary artery in the aorta, a smaller fixed perfusion defect in the anterior wall and apex was detected without reversibility. No stress-induced wall motion abnormalities were detected. Despite the improvement of perfusion, there was no improvement of regional or global left ventricular function at rest. We report that both dobutamine 201Tl SPECT and echocardiography were useful for the detection of reversible ischemia and for the assessment of the surgical outcome of an adult patient with ALCAPA syndrome.

The aim of this study was to analyze whether left ventricular dysfunction affects the safety and feasibility of high-dose dobutamine-atropine stress echocardiography. We examined the results of the test in 318 consecutive patients who were referred for high-dose dobutamine-atropine stress echocardiography and also underwent diagnostic cardiac catheterization. Forty-four patients had a left ventricular ejection fraction of 25% or less (mean, 21%; range, 15% to 25%). In the entire group of 318 patients, no serious complications (death, myocardial infarction, or ventricular fibrillation) occurred. The overall feasibility of completing the test was excellent (97%). A trial fibrillation occurred in four patients, nonsustained ventricular tachycardia in 12, and sustained ventricular tachycardia in one. A decrease in systolic blood pressure of greater than 40 mm Hg or a peak systolic pressure of less than 80 mm Hg was present in eight cases. In the group with an ejection fraction of 25% or less, there was a higher rate of significant tachyarrhythmias (14% versus 5%; p = 0.03), whereas the feasibility of the test was slightly lower (89%; p0.01), but no difference for hypotension was found. By multivariate analysis, a history of tachyarrhythmias was the only predictor of stress-induced arrhythmias. Advanced left ventricular dysfunction does not represent a contraindication for dobutamine-atropine stress testing.

Dobutamine-atropine stress echocardiography is used for the non-invasive diagnosis of coronary artery disease, but stress test results may be influenced by beta-blockers. The aim of this study was to assess if the addition of atropine can compensate for the presence of beta-blockers in dobutamine stress echocardiography. Twenty-six patients referred for evaluation of chest pain were studied twice, on and off metoprolol 100 mg b.i.d. (in random order sequence) with a wash-out period of at least 48 h. Dobutamine stress echocardiography was performed using up to 40 micrograms.kg-1.min-1, followed, if necessary, by the addition of atropine to achieve 85% of the age-predicted maximal heart rate, unless symptoms or markers of ischaemia appeared. Atropine was given to patients on beta-blockers more often [(22/26) vs (6/26)] than to those off beta-blockers (P0.001). Heart rate at every stage of the test was lower on beta-blockers. Chest pain occurred in patients on beta-blockers significantly less than in those off beta-blockers (8% vs 46%), and the addition of atropine made no significant difference (31% vs 46%). During dobutamine stress, new wall motion abnormalities occurred in three patients on beta-blockers (12%); this number increased to 15 after the addition of atropine (57%). New or worsened wall motion abnormalities occurred in 12 patients (46%) off beta-blockers with dobutamine alone and in 14 patients after adding atropine (53%).(ABSTRACT TRUNCATED AT 250 WORDS)

Sestamibi is a Tc labeled radiotracer particularly suitable for myocardial perfusion studies, providing similar information as thallium scintigraphy for the diagnosis of coronary artery disease. In comparison with thallium, sestamibi has the advantage of improved imaging properties due to its higher gamma emission. This is particularly relevant when SPECT imaging is considered. The myocardial uptake of sestamibi is partially passively, related to the myocardial flow, and is also related to the metabolic cellular activity, as it is proportional to the electrochemical gradient generated at cell membrane level. While the role for sestamibi in diagnosing coronary artery disease is well accepted, it is still controversial for the assessment of myocardial viability. Clinical studies reported by others and results from our own institution will be described both in the setting of a recent myocardial infarction (myocardial stunning) and of longstanding left ventricular dysfunction (hibernating myocardium). The results concordantly suggest that sestamibi underestimates myocardial viability, compared to the accepted standards of thallium (rest-redistribution or stress-reinjection protocols), 18-F FDG PET and also in the prediction of left ventricular functional recovery after revascularisation. However, the data available at present are very limited, particularly after revascularisation. Furthermore, according to new promising results, the role of sestamibi in the setting of myocardial viability has potential for improvement, if the injection at rest will be performed during nitrates. It is also foreseen that the combined use of sestamibi perfusion/wall motion scan (first pass and/or gated perfusion studies) and the development of new softwares for attenuation correction might improve the results in the setting of myocardial viability.

The rationale of exercise echocardiography for the diagnosis of coronary artery disease is based on the detection of exercise-induced wall motion abnormalities by ultrasound. Some of the problems that had previously limited the widespread application of the test have been solved by the development of digital recording and side by side cine loop display of two-dimensional echocardiograms: thus, respiratory artifacts can be eliminated, the examination is faster, and the comparison between rest and stress images has become practical and reliable improving sensitivity. The sensitivity and specificity of exercise echocardiography vary from 70 to 100%, according to patient selection, the protocol, and the gold standard used. Few studies studied the value of exercise echocardiography as compared to the more established nuclear cardiology imaging. Data from these comparative evaluations show a strong correlation between the two techniques for identifying and localizing myocardial ischemia. With good equipment and after proper training, exercise echocardiography can provide both diagnostic and prognostic information for routine clinical care.

We have assessed the value of dobutamine stress echocardiography for the diagnosis of myocardial ischemia in 20 consecutive patients referred for chest pain, without a previous myocardial infarction and with a normal left ventricular wall motion at rest. The test was considered positive when wall motion abnormalities appeared during dobutamine infusion (from 5 to a maximum of 40 micrograms/Kg/min). The results were compared to the % diameter stenosis (%DS) quantitatively measured on coronary arteriography. "Significant" coronary artery disease was defined as greater than or equal to 50% DS. No significant side effects occurred in any patients during the test. Transient wall motion abnormalities were detected in 8 of the 12 patients with significant coronary artery disease (sensitivity = 66%) and in 1 of the 8 patients without significant coronary artery disease (specificity = 88%). All the patients with false-negative dobutamine stress echocardiography had distal stenosis or stenosis in a collateral vessel; moreover, all the patients with true-positive dobutamine stress echocardiography had proximal (7 patients) or middle (1 patient) stenosis. The results of this study show that dobutamine stress echocardiography is a safe and feasible test for the noninvasive diagnosis of myocardial ischemia.

Using the presence of stress induced ischemia with dobutamine-atropine stress echocardiography (DSE) for predicting perioperative cardiac events (CE) in patients undergoing major vascular surgery has a high negative but low positive predictive value (PPV). Aim of the study to improve the PPV of DSE by combining the value of clinical markers and DSE. Methods in 300 consecutive patients clinical risk factors (diabetes, angina, Q waves on ECG, ageg 70 years, and history of ventricular arrhythmias) where assessed. DSE results were analyzed by quantifying the extent and severity of new wall motion abnormalities (NWMA) at peak stress. Also, heart rate threshold (HR-Thres) at which NWMA occurred was noted. Low HR-Thres was defined as NWMA at l70% of maximal age and sex related heart rate. Results 27 CE occurred of which 5 cardiac deaths, 12 myocardial infarctions and 10 patients with unstable angina. One-hundred patients had no clinical risk factors, 200 one or more. All but 1 CE occurred in patients with 1 Or more risk factors. In 27 of 72 patients with a positive DSE a CE occurred (PPV 38%). Quantifying the extent and severity of NWMA at peak stress provided no additional information. The HR-Thres at which ischemia occurred improved PPV In 30 patients with a low HR-Thres, 20 CE occurred (PPV 67%). In the remaining 42 patients with a high HR-Thres, only 7 CE occurred (16%). The improvement of PPV from 38% to 67% is statistically highly significant (P l 0.01). All patients with a fatal CE and 8 of 12 patients with a myocardial infarction had a low HR-threshold. Conclusions 1) in patients with no clinical risk factors additional stress testing is not efficient. 2) in patients with one or more risk factors semiquantitative DSE allows stratification of patients in low, intermediate, and high risk groups for CE.

Purpose: It is possible to simultaneously evaluate wall thickening and perfusion abnormalities with radionuclide techniques that use tracers such as Tc-99m MIBI. We presumed that detection of wall thickening by gated MIBI SPECT imaging in the presence of a stress-induced perfusion defect correlates with reversibility of that defect on resting images. Therefore, the aim of our study was to analyze, in patients without myocardial infarction, resting wall thickening and stress perfusion imaging as an alternative to conventional stress-rest imaging. Methods and Results: The patients (n = 44) underwent an exercise (n = 37) or pharmacologic (n = 7) stress protocol. All patients had previous coronary angiography within 3 months. Stress-rest MIBI SPECT and gated MIBI SPECT studies were analyzed by visual scoring. The sensitivity and specificity of segmental analysis of both stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies for the overall detection of coronary artery disease were, respectively, 71% and 96%. For patient evaluation for detection of coronary artery disease, stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies showed a sensitivity rate of 96% for both and specificity rates of 84% and 79%, respectively. Conclusions: Our data revealed close agreement between reversible perfusion defects on stress-rest MIBI SPECT scans and significant wall thickening on gated MIBI SPECT stress images in patients without previous myocardial infarction (95%). Gated MIBI SPECT stress, without resting studies, which provide an assessment of wall motion and wall thickening, potentially allows stress defect reversibility to be evaluated in patients without previous myocardial infarction.