No abstract

Objective: The purpose of the present study was to provide evidence regarding the safety of real-time flashcontrast echocardiography combined with dobutamineatropine stress echo (DASE). Background: The combination of perfusion assessment using myocardial contrast echocardiography (MCE) with DASE has shown very promising results for the diagnosis of coronary artery disease. Concerns have, however, been expressed regarding the safety of the use of echocontrast agents in echocardiography. Design: 5250 individuals (70.8% men, aged 64.6 years (SD 10.6)) were submitted to DASE, with concurrent MCE using a low mechanical index technique with the administration of high-energy impulses in order to assess replenishment time. Results: No deaths or myocardial infarctions were observed. Sustained ventricular tachycardia (VT) or fibrillation requiring resuscitation occurred in two cases (0.04%). The incidence of other arrhythmic events was: sustained VT not requiring resuscitation, 10 (0.18%); nonsustained VT, 18 (0.34%); atrial tachycardia, 4 (0.08%); atrial fibrillation, 25 (0.48%). Other observed adverse events included: intense headache, 52 (1%); intense back pain, 26 (0.5%). Vagal reactions with marked systolic blood pressure falls were observed in 45 cases (0.9%). Hypersensitivity reactions were reported in 23 cases (0.44%), although no serious cases of hypersensitivity requiring hospitalisation were recorded. The sensitivity, specificity and overall accuracy of DASE/MCE were 92%, 61% and 85%, respectively. Conclusions: This report of safety data regarding stresscontrast echocardiography in a large series of subjects suggests that this is an exceptionally safe technique, given that in 5250 studies no study-related deaths or myocardial infarctions were encountered, whereas serious adverse events requiring hospitalisation were extremely rare (one in 2625 studies).

Objective: To compare real-time three-dimensional echocardiography (RT3DE) with two-dimensional dobutamine stress echocardiography (2DE) for the detection of myocardial ischaemia, with angiographic validation of the results. Methods: 56 patients (mean (SD) age 64.5 (6.2) years, 38 males), referred for coronary angiography, were examined by 2DE and RT3DE during the same dobutamine stress protocol. Results: All 56 patients completed the stress protocol uneventfully. The mean (SD) acquisition time for the necessary views to evaluate all segments was 26.3 (2.5) s for RT3DE and 58.8 (3.7) s for 2DE (p,0.001). At peak stress, RT3DE had a higher wall-motion score index (1.25 (0.24) by 2DE, 1.30 (0.27) by RT3DE; p = 0.014). The regional wall-motion score for the four apical segments at peak stress was compared; it was 1.35 (0.55) by 2DE and 1.52 (0.69) by RT3DE (p = 0.003). The diagnostic parameters of 2DE versus RT3DE were: sensitivity 73% vs 78%, specificity 93% vs 89% and overall accuracy 86% vs 85%, respectively. In the left anterior descending artery territory, in particular, where RT3DE had higher regional wall-motion scores, it showed a tendency towards higher sensitivity (85% vs 78%), although this difference did not achieve statistical significance. Conclusion: RT3DE identifies wall-motion abnormalities more readily in the apical region than 2DE, which may explain the tendency towards higher sensitivity in the left anterior descending artery territory. RT3DE results were validated using angiography as reference and findings indicate diagnostic equivalence to 2DE, with the advantage of considerable shorter acquisition times. D obutamine stress echocardiography has become a well established method of myocardial functional assessment in the diagnosis of coronary artery disease and in evaluation of its prognosis.1-4 The advent of echocardiography machines integrating all necessary systems for performing realtime three-dimensional echocardiography (RT3DE) holds promise as a new useful tool in cardiovascular ultrasonographic imaging. However, the clinical utility of this tool has yet to be adequately investigated. Particularly in the field of diagnosis of coronary artery disease, there is a marked lack of data regarding the usefulness of RT3DE. Our aim was to evaluate RT3DE in detecting myocardial wall-motion abnormalities during a standard dobutamine stress protocol, in comparison to twodimensional echocardiography (2DE), with coronary angiography as the reference method for assessing the diagnostic power of this modality (fig 1). METHODS Study populationThe study population included 56 patients (mean (SD) age 64.5 (6.2) years, 38 males), referred for coronary angiography to the cardiac catheterisation laboratory of a tertiary hospital. All patients were in sinus rhythm. Exclusion criteria included the presence of symptoms of heart failure, a suspected or proven acute coronary event within the previous month, history of sustained ventricular tachycardia, moderate or severe valvular disease, uncontrolled hypertension...

Objective: Increased resting heart rate as well as increased arterial stiffness are both independent predictors of cardiovascular events and mortality. Results of previous studies have failed to converge concerning the association between heart rate and arterial stiffness, regardless of other potential confounders, such as age, gender and particularly blood pressure (BP). We aimed to investigate: (a) the degree of association (if any) between resting heart rate and carotid-to-femoral pulse wave velocity (PWV), the gold standard index of arterial stiffness, (b) if the relationship between heart rate and PWV is mediated by BP levels and (c) whether their association is affected by the levels of aortic stiffening. Approach: Demographic, hemodynamic, laboratory and clinical data of 1566 subjects from the cross-sectional observational 'Corinthia' study were analyzed using univariate and multivariate regression models. Mediation analysis was performed to test whether mean arterial pressure (MAP) is a significant mediator in the heart rate-PWV relationship. The total population was divided in two groups of low and high arterial stiffness according to the median PWV value (8.6 m s −1 ). Main results: We found that (i) there is a significant association between heart rate and PWV, regardless of other confounding factors. An increase in heart rate by 20 b.p.m. can increase PWV by 0.5 m s −1 . However, this association was significant only for subjects with increased aortic stiffness (PWV > 8.6 m s −1 ) and not for those with PWV ⩽ 8.6 m s −1 . Further, (ii) heart rate-PWV association was partially mediated by MAP. Significance: Increased resting heart rate is related to increased aortic stiffness, only in subjects with stiffer aortas, regardless of BP and other risk factors and subjects' characteristics. The synergistic prognostic effect of increased arterial stiffness and elevated heart rate on target organ damage, cardiovascular events and mortality should be explored in future studies.