Cardiovascular Ultrasound - Latest Articles

The impact of aging and atherosclerotic risk factors on transthoracic coronary flow reserve in subjects with normal coronary angiography

Maurizio Galderisi — 2012-05-14T00:00:00Z

Age may affect coronary flow reserve (CFR) especially in subjects with atherosclerotic risk factors (ARFs). The aim of this prospective, multicenter, observational study was to determine the effects of aging on CFR in patients with normal epicardial coronary arteries and ARFs. Three-hundred-thirty-five subjects (mean age = 61 years) with at least one ARF but normal coronary angiography underwent high-dose dipyridamole stress-echo with Doppler evaluation of left anterior descending artery. CFR was calculated as the ratio between hyperemic and resting coronary diastolic peak velocities. Patients were divided in age quartiles. CFR was progressively reduced with aging (1st quartile: 3.01 +/- 0.69, 4th quartile: 2.39 +/- 0.49, p<0.001). This was mainly due to a gradual increase of resting velocities (1st quartile = 26.3 +/- 6.1 cm/s, 4th quartile = 30.2 +/- 6.4 cm/s, p<0.001) while the reduction of hyperemic velocities remained unaffected (1st quartile = 77.7 +/- 18.9 cm/s, 4th quartile = 70.9 +/- 18.4 cm/s, NS). When age quartiles and ARFs were entered into a regression model, third and fourth age quartile (p<0.0005 and p<0.0001 respectively), left ventricular mass index (p<0.0001), diastolic blood pressure (p<0.001), total cholesterol (p<0.002), fasting blood glucose (p<0.01) and male gender (p<0.05) were independent determinants of CFR in the whole population. Aging reduces coronary flow reserve in patients with angiographically normal coronary arteries due to a gradual increase of resting coronary flow velocity. CFR is also affected by atherosclerotic risk factors and left ventricular hypertrophy

Fetal cardiac muscle contractility decreases with gestational age: a color-coded tissue velocity imaging study

Nina Elmstedt — 2012-05-09T00:00:00Z

Background: Present data regarding how the fetal heart works and develops throughout gestation is limited. However, the possibility to analyze the myocardial velocity profile provides new possibilities to gain further knowledge in this area. Thus, the objective of this study was to evaluate human fetal myocardial characteristics and deformation properties using color-coded tissue velocity imaging (TVI). MethodsTVI recordings from 55 healthy fetuses, at 18 to 42 weeks of gestation, were acquired at a frame rate of 201-273 frames/s for offline analysis using software enabling retrieval of the myocardial velocity curve and 2D anatomical information. The measurements were taken from an apical four chamber view, and the acquired data was correlated using regression analysis. Results: Left ventricular length and width increased uniformly with gestational age. Atrioventricular plane displacement and the E'/A' ratio also increased with gestational age, while a longitudinal shortening was observed. Conclusions: Fetal cardiac muscle contractility decreases with gestational age. As numerous fetal- and pregnancy-associated conditions directly influence the pumping function of the fetal heart, we believe that this new insight into the physiology of the human fetal cardiovascular system could contribute to make diagnosis and risk assessment easier and more accurate.

Correction: Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry

Konstantinos Lampropoulos — 2012-04-26T00:00:00Z

Following publication of our article [Lampropoulos et al., Cardiovascular Ultrasound 2012, 10:5] the authors noted that the legends for Figure 1 and Figure 2 were incorrect.The correct legend for Figure 1 is:Sequence analysis of systemic ventricular flow during systole and diastole in Fontan patients. The vortex from the Fontan group was consistently shorter, wider and rounder. The vortices were located at the centre of the left ventricle throughout diastole and systole and did not redirect flow in a coherent, sequential fashion as in controls. The location, shape and sphericity of the main vortices differ clearly from controls in all cardiac cycle [early diastole(A), late diastole(B), ejection (C)].The correct legend for Figure 2 is:Sequence analysis of systemic ventricular flow during systole and diastole in controls. The vortex from the control group was compact, elliptically shaped, and located apically. The location, shape and sphericity of the main vortices differ clearly from the Fontan group in all cardiac cycle [early diastole(A), late diastole(B), ejection (C)].It was also noted the legends for the Additional file 1 and Addition file 2 were also incorrect:The correct legend for Additional file 1 is:The flow patterns of a 38 year old female without cardiac abnormalitiesThe correct legend for Additional file 2 is:The flow pattern of a 29 year old male with Fontan circulation.The authors would like to apologize for any inconvenience caused by this error.

Value of segmental myocardial strain by 2-dimensional strain echocardiography for assessment of scar area induced in a rat model of myocardial infarction

Shu-sheng Liao — 2012-04-03T00:00:00Z

ObjectivesTwo-dimensional strain echocardiography (2DSE) technique has enabled accurate quantification of regional myocardial function. This experimental study was aimed to investigate the value of 2DSE in detection of segmental regional myocardial dysfunction induced by fibrosis following myocardial infarction in a small animal (rat) model. Methods: A rat model of myocardial infarction was established by ligation of the proximal left anterior descending coronary artery in 17 SD rats. Regional myocardial function was detected by 2DSE at baseline and 4-weeks post-infarction, including end-systolic radial strain and strain rate (SR and SrR) and end-systolic circumferential strain and strain rate (SC and SrC) of each of six segments at papillary level. According to the size of scar found by histologic Masson staining, the optimal cutoff points of parameters for detecting scar area were analyzed and the sensitivity and specificity of every parameter to detect myocardial scar were obtained using ROC. Results: (1) Comparing with parameters measured at baseline, there were significant decreases in SR, SrR, SC and SrC of each segment at 4 weeks post-infarction, with the worst in the infarct area (32.90 ± 8.79 vs 11.18 ± 3.89, 6.28 ± 1.35 vs 3.18 ± 0.47, -14.46 ± 2.21 vs -6.30 ± 2.17 and 4.93 ± 0.95 vs 2.59 ± 1.16, respectively) (all P < 0.05). (2)By 4 weeks, the myocardium of infarct area (anteroseptum, anterior and anterolateral) had fibrosis (31.33 ± 9.89, 73.42 ± 13.21 and 13.99 ± 3.24%, respectively) with minimal fibrosis in inferoseptal segment (0.32 ± 0.19%), no fibrosis was found in the inferior and inferolateral segments. (3)Significant negative correlations were found between the size of segmental scar and 2DSE parameters (r-value -0.61 ~ -0.80, all P < 0.01) with the strongest correlation in SR. SR less than 10% has 84% sensitivity and 98% specificity for detecting segments of scar area greater than 30% with AUC = 0.97. Conclusions: 2DSE is able to assess regional myocardial dysfunction in a rat model of myocardial infarction and has high accuracy in detecting infarct segments with scar area greater than 30%.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Carla Contaldi — 2012-03-27T00:00:00Z

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of echocardiography.

Acute regional improvement of myocardial function after interventional transfemoral aortic valve replacement in aortic stenosis: A speckle tracking echocardiography study

Sebastian Schattke — 2012-03-26T00:00:00Z

Background: Transcatheter aortic valve implantation (TAVI) is a promising therapy for patients with severe aortic stenosis (AS) and high perioperative risk. New echocardiographic methods, including 2D Strain analysis, allow the more accurate measurement of left ventricular (LV) systolic function. The goal of this study was to describe the course of LV reverse remodelling immediately after TAVI in a broad spectrum of patients with symptomatic severe aortic valve stenosis. Methods: Thirty consecutive patients with symptomatic aortic valve stenosis and preserved LVEF underwent transfemoral aortic valve implantation. We performed echocardiography at baseline and one week after TAVI. Echocardiography included standard 2D and Doppler analysis of global systolic and diastolic function as well as 2D Strain measurements of longitudinal, radial and circumferential LV motion and Tissue Doppler echocardiography. Results: The baseline biplane LVEF was 57 ± 8.2%, the mean pressure gradient was 46.8 ± 17.2 mmHg and the mean valve area was 0.73 ± 0.27 cm2. The average global longitudinal 2D strain of the left ventricle improved significantly from -15.1 (± 3.0) to -17.5 (± 2.4) % (p < .001). This was reflected mainly in improvement in the basal and medial segments while strain in the apex did not change significantly [-11.6 (± 5.2) % to -15.1 (± 5.5) % (p < .001), -13.9 (± 5.1) % to -16.8 (± 5.6) % (p < .001) and -19.2 (± 7.0) % to -20.0 (± 7.2) % (p = .481) respectively]. While circumferential strain [-18.1 (± 5.1) % vs. -18.9 (± 4.2) %, p = .607], radial strain [36.5 (± 13.7) % vs. 39.7 (± 17.2) %, p = .458] and the LVEF remained unchanged after one week [57.0 (± 8.2) % vs. 59.1 (± 8.1) %, p = .116]. Conclusion: There is an acute improvement of myocardial longitudinal systolic function of the basal and medial segments measured by 2D Strain analysis immediately after TAVI. The radial, circumferential strain and LVEF does not change significantly in all patients acutely after TAVI. These data suggest that sensitive new echo methods can reliably detect early regional changes of myocardial function after TAVI before benefits in LVEF are detectable.

Real-time three-dimensional transthoracic echocardiography in daily practice: initial experience

Ashraf Anwar — 2012-03-26T00:00:00Z

Aim of the workTo evaluate the feasibility and possible additional value of transthoracic real-time three-dimensional echocardiography (RT3D-TTE) for the assessment of cardiac structures as compared to 2D-TTE. Methods: 320 patients (mean age 45 ± 8.4 years, 75% males) underwent 2D-TTE and RT3D-TTE using 3DQ-Q lab software for offline analysis. Volume quantification and functional assessment was performed in 90 patients for left ventricle and in 20 patients for right ventricle. Assessment of native (112 patients) and prosthetic (30 patients) valves morphology and functions was performed. RT3D-TTE was performed for evaluation of septal defects in 30 patients and intracardiac masses in 52 patients. Results: RT3D-TTE assessment of left ventricle was feasible and reproducible in 86% of patients while for right ventricle, it was (55%). RT3D-TTE could define the surface anatomy of mitral valve optimally (100%), while for aortic and tricuspid was (88% and 81% respectively). Valve area could be planimetered in 100% for the mitral and in 80% for the aortic. RT3D-TTE provided a comprehensive anatomical and functional evaluation of prosthetic valves. RT3D-TTE enface visualization of septal defects allowed optimal assessment of shape, size, area and number of defects and evaluated the outcome post device closure. RT3D-TTE allowed looking inside the intracardiac masses through multiple sectioning, valuable anatomical delineation and volume calculation. Conclusion: Our initial experience showed that the use of RT3D-TTE in the assessment of cardiac patients is feasible and allowed detailed anatomical and functional assessment of many cardiac disorders.

Physiological aspects of the determination of comprehensive arterial inflows in the lower abdomen assessed by Doppler ultrasound

Takuya Osada — 2012-03-26T00:00:00Z

Non-invasive measurement of splanchnic hemodynamics has been utilized in the clinical setting for diagnosis of gastro-intestinal disease, and for determining reserve blood flow (BF) distribution. However, previous studies that measured BF in a "single vessel with small size volume", such as the superior mesenteric and coeliac arteries, were concerned solely with the target organ in the gastrointestinal area, and therefore evaluation of alterations in these single arterial BFs under various states was sometimes limited to "small blood volumes", even though there was a relatively large change in flow. BF in the lower abdomen (BFAb) is potentially a useful indicator of the influence of comprehensive BF redistribution in cardiovascular and hepato-gastrointestinal disease, in the postprandial period, and in relation to physical exercise. BFAb can be determined theoretically using Doppler ultrasound by subtracting BF in the bilateral proximal femoral arteries (FAs) from BF in the upper abdominal aorta (Ao) above the coeliac trunk. Prior to acceptance of this method of determining a true BFAb value, it is necessary to obtain validated normal physiological data that represent the hemodynamic relationship between the three arteries. In determining BFAb, relative reliability was acceptably high (range in intra-class correlation coefficient: 0.85-0.97) for three arterial hemodynamic parameters (blood velocity, vessel diameter, and BF) in three repeated measurements obtained over three different days. Bland-Altman analysis of the three repeated measurements revealed that day-to-day physiological variation (potentially including measurement error) was within the acceptable minimum range (95% of confidence interval), calculated as the difference in hemodynamics between two measurements. Mean BF (ml/min) was 2951 +/- 767 in Ao, 316 +/- 97 in left FA, 313 +/- 83 in right FA, and 2323 +/- 703 in BFAb, which is in agreement with a previous study that measured the sum of BF in the major part of the coeliac, mesenteric, and renal arteries. This review presents the methodological concept that underlies BFAb, and aspects of its day-to-day relative reliability in terms of the hemodynamics of the three target arteries, relationship with body surface area, respiratory effects, and potential clinical usefulness and application, in relation to data previously reported in original dedicated research.

Spatial orientation of cross-sectional images of coronary arteries: point of view in intracoronary imaging

Troels Thim — 2012-03-22T00:00:00Z

Background: In studies where cross-sectional images of coronary arteries obtained with different imaging modalities are compared, the importance of correct co-localization and matching of images along the coronary artery longitudinal axis is obvious. However, it appears neglected that correct spatial orientation of the cross-sectional plane may not be obtainable just by rotating the images to ensure co-localization of identifiable landmarks such as sidebranches. A cross-section has two sides, one facing proximally and the other distally, and pairs of images reconstructed corresponding to these opposite points of view are mirror images of each other and not superimposable. This may be difficult if not impossible to recognize and unrecognized it will give rise to flawed results in the development and validation of imaging technologies aimed at plaque characterization (tissue mapping). We determined the imagined point of view for three commercially available intracoronary imaging systems used by invasive cardiologists and illustrate its importance in imaging modality validation.Methods and ResultsWe made an asymmetric phantom and investigated it with two different intravascular ultrasound (IVUS) systems and one optical coherence tomography (OCT) system. The asymmetry of the phantom allowed determination of the spatial orientation of the cross-sectional images. On all tested systems, an observer should imagine herself/himself standing proximal to the cross-section when looking at the intravascular images. Conclusions: The tested intracoronary imaging modalities displayed cross-sectional images with a spatial orientation corresponding to a proximal point of view. Knowledge of the spatial orientation is mandatory when comparing and validating different imaging modalities aimed at plaque characterization.

Could successful cryoballoon ablation of paroxysmal atrial fibrillation prevent progressive left atrial remodeling?

Tamas Erdei — 2012-03-19T00:00:00Z

Background: Radiofrequency catheter ablation of atrial fibrillation (AF) has been proved to be effective and to prevent progressive left atrial (LA) remodeling. Cryoballoon catheter ablation (CCA), using a different energy source, was developed to simplify the ablation procedure. Our hypothesis was that successful CCA can also prevent progressive LA remodeling. Methods: 36 patients selected for their first CCA because of nonvalvular paroxysmal AF had echocardiography before and 3, 6 and 12 months after CCA. LA diameters, volumes (LAV) and LA volume index (LAVI) were evaluated. LA function was assessed by: early diastolic velocities of the mitral annulus (Aasept, Aalat), LA filling fraction (LAFF), LA emptying fraction (LAEF) and the systolic fraction of pulmonary venous flow (PVSF). Detailed left ventricular diastolic function assessment was also performed. Results: Excluding recurrences in the first 3-month blanking period, the clinical success rate was 64%. During one-year of follow-up, recurrent atrial arrhythmia was found in 21 patients (58%). In the recurrent group at 12 months after ablation, minimal LAV (38 +/- 19 to 44 +/- 20 ml; p < 0.05), maximal LAV (73 +/- 23 to 81 +/- 24 ml; p < 0.05), LAVI (35 +/- 10 to 39 +/- 11 ml/m2; p = 0.01) and the maximal LA longitudinal diameter (55 +/- 5 to 59 +/- 6 mm; p < 0.01) had all increased. PVSF (58 +/- 9 to 50 +/- 10%; p = 0.01) and LAFF (36 +/- 7 to 33 +/- 8%; p = 0.03) had decreased. In contrast, after successful cryoballoon ablation LA size had not increased and LA function had not declined. In the recurrent group LAEF was significantly lower at baseline and at follow-up visits. Conclusions: In patients whose paroxysmal atrial fibrillation recurred within one year after cryoballoon catheter ablation left atrial size had increased and left atrial function had declined. In contrast, successful cryoballoon catheter ablation prevented progressive left atrial remodeling.