Cardiovascular Ultrasound - Latest Articles

Usefulness of an accelerated transoesophageal stress echocardiography in the preoperative evaluation of high risk severely obese subjects awaiting bariatric surgery

Sylvie Legault — 2010-07-28T00:00:00Z

Background: Severe obesity is associated with an increased risk of coronary artery disease (CAD). Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility, safety and utility of transesophageal dobutamine stress echocardiography (TE-DSE) using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia. Methods: Subjects with severe obesity [body mass index (BMI) >40 kg/m2] with known or suspected CAD and being evaluated for bariatric surgery were recruited. Results: Twenty subjects (9M/11F), aged 50+/-8 years (mean+/-SD), weighing 141+/-21 kg and with a BMI of 50+/-5 kg/m2 were enrolled in the study and underwent a TE-DSE. The accelerated dobutamine infusion protocol used was well tolerated. Eighteen (90%) subjects reached their target heart rate with a mean intubation time of 13+/-4 minutes. Mean dobutamine dose was 31.5+/-9.9 ug/kg/min while mean atropine dose was 0.5+/-0.3mg. TE-DSE was well tolerated by all subjects without complications including no significant arrhythmia, hypotension or reduction in blood arterial saturation. Two subjects had abnormal TE-DSE suggestive of myocardial ischemia. All patients underwent bariatric surgery with no documented cardiovascular complications. Conclusions: TE-DSE using an accelerated infusion protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery. Moreover, the absence of myocardial ischemia on TE-DSE correlates well with a low operative risk of cardiac event.

Reduced global longitudinal strain in association to increased left ventricular mass in patients with aortic valve stenosis and normal ejection fraction: a hybrid study combining echocardiography and magnetic resonance imaging

Wilfried Dinh — 2010-07-26T00:00:00Z

Background: Increased muscle mass index of the left ventricle (LVMi) is an independent predictor for the development of symptoms in patients with asymptomatic aortic stenosis (AS). While the onset of clinical symptoms and left ventricular systolic dysfunction determines a poor prognosis, the standard echocardiographic evaluation of LV dysfunction, only based on measurements of the LV ejection fraction (EF), may be insufficient for an early assessment of imminent heart failure. Contrary, 2-dimensional speckle tracking (2DS) seems to be superior in detecting subtle changes in myocardial function. The aim of the study was to assess these LV function deteriorations with global longitudinal strain (GLS) analysis and the relations to LVMi in patients with AS and normal EF. Methods: 50 patients with moderate to severe AS and 31 controls were enrolled. All patients underwent echocardiography, including 2DS imaging. LVMi measures were performed with magnetic resonance imaging in 38 patients with AS and indexed for body surface area. Results: The total group of patients with AST showed a GLS of -15,2+/-3,6% while the control group reached -19,5+/-2,7% (p <0,001). By splitting the group with AS in normal, moderate and severe increased LVMi, the GLS was -17,0+/-2,6%, -13,2+/-3,8% and -12,4+/-2,9%, respectively (p=0,001), where LVMi and GLS showed a significant correlation (r=0,6, p <0,001). Conclusions: In conclusion, increased LVMi is reflected in abnormalities of GLS and the proportion of GLS impairment depends on the extent of LV hypertrophy. Therefore, simultaneous measurement of LVMi and GLS might be useful to identify patients at high risk for transition into heart failure who would benefit from aortic valve replacement irrespectively of LV EF.

The value of hepatic diffusion-weighted MR imaging in demonstrating hepatic congestion secondary to pulmonary hypertension

Yuksel Dogan — 2010-07-21T00:00:00Z

Background: Congestive hepatomegaly might be the first sign for pulmonary hypertension. Apparent diffusion coefficient (ADC) value obtained with quantitative diffusion-weighted magnetic resonance imaging (DW-MRI) is affected by liver fibrosis and perfusion. We aimed to evaluate the diagnostic value of DW-MRI in cooperation with biochemical markers, ultrasonography (US) and echocardiography (ECHO) in determining the degree of hepatic congestion secondary to pulmonary hypertension (PHT). Methods: 35 patients with PHT and 26 control subjects were included in the study. PHT was diagnosed if pulmonary artery systolic pressure (PASP) was measured above 35 mmHg with ECHO. Study group was classified into mild and moderate PHT. DW-MRI was performed with b-factors of 0, 500 and 1000 sec/mm^2. Mean ADC, ADC-II (Average of the ADC values of right lobe anterior and posterior segments), US, ECHO and blood biochemical parameters of both groups were compared. Results: There exists a positive correlation between liver size and the diameters of vena cava inferior, right atrium, right hepatic vein(RHV), mid-hepatic vein(MHV), left hepatic vein(LHV) (p<0.01). There was a positive correlation between PASP and RHV, MHV, LHV. The patients had lower ejection fractions (p<0.01) and higher LDH (p<0.01) and ALP (p<0.05) levels than the control group. The ADC values of the patients with moderate PASP were higher than those with a mild PASP (p<0.05). Mean ADC was higher in patients with moderate PHT compared to control group (p=0.009). There was a positive correlation between PASP and ADC values of right lobe posterior segment of the liver (p<0.05). The ADC-II and mean ADC values of the patients with moderate PASP were higher than those of the control group (p<0.01). Conclusions: Congestion due to moderate PHT might be diagnosed with DW-MRI. As PASP increase; mean ADC and ADC-II values increase.

Echocardiography of isolated subacute left heart tamponade in a patient with cor pulmonale and circumferential pericardial effusion

Tomaz Mars — 2010-07-14T00:00:00Z

Patients with advanced idiopathic pulmonary artery hypertension have often a chronic pericardial effusion. It is the result of increased transudation and impaired re-absorption due to elevated venous pressure. These patients have pre-existent symptoms and signs of chronic right heart failure. High degree of suspicion is required to detect of development of an atypical form of tamponade with isolated compression of left heart chambers. Transthoracic echocardiography provides a rapid access to the correct diagnosis, a prompt relief of symptoms following the ultrasound guided pericardiocentesis and important diagnostic tool for regular follow up of patients thereafter as shown in our case report.

An isolated anterior mitral leaflet cleft: a case report

Giovanni Minardi — 2010-07-13T00:00:00Z

IntroductionThe anterior mitral leaflet cleft is an unusual congenital lesion most often encountered in association with other congenital heart defects. The isolated anterior leaflet cleft is quite a rare anomaly and is usually cause of mitral valve regurgitation. The importance of the lesion is that it is often correctable. When feasible, cleft suture and, eventually, annuloplasty are preferable to valve replacement. Echocardiography is the first choice technique in the evaluation of mitral valve disease, providing useful information about valve anatomy and hemodynamic parameters.Case presentationWe present a case of an isolated anterior mitral leaflet cleft producing moderate-severe mitral regurgitation correctly identified by echocardiography and successfully surgically corrected.. Conclusion: Isolated cleft is a rare aberration, that has to be known in order to be diagnosed. Transthoracic and transesophageal echocardiography is the most useful non invasive technique for cleft diagnosis and to indicate the right surgical correction.

Echocardiography may help detect pulmonary vasculopathy in the early stages of pulmonary artery hypertension associated with systemic sclerosis

Walter Serra — 2010-07-05T00:00:00Z

Background: Pulmonary arterial hypertension (PAH) in patients with systemic sclerosis is associated with a poor prognosis, but this can be improved by early disease detection. Abnormal pulmonary and cardiac function can be detected early by means of echocardiography, whereas right heart catheterization is usually performed later.ObjectivesThe purpose of this prospective study was to detect early the presence of pulmonary artery vasculopathy in patients with verified systemic sclerosis without significant pulmonary fibrosis, normal lung volumes and a mildly reduced lung diffusion capacity of carbon monoxide (DLCO). Methods: Nineteen consecutive female NYHA class I-II patients with scleroderma and a PAPs of < 35 mm/Hg measured by echocardiography, were enrolled between September 2007 and September 2009. They had a mean age of 51 ± 13 years, body mass index of 25 ± 5 kg/m2). They all underwent complete Doppler echocardiography, CPET, a pulmonary ventilation test (carbon monoxide lung diffusion, DLCO), HRCT. To investigate PAH by means of complete resting Doppler echocardiography estimates of systolic pulmonary artery pressure (PAPs) derived from tr icuspid regurgitation, mean PAP derived from pulmonary regurgitation, pulmonary vessel resistance (PVR) derived from the acceleration time of the pulmonary outflow tract (ACTpo), and right ventricular function derived from tricuspid annular plane systolic excursion (TAPSE). Right heart catheterisation was conducted only, if pulmonary hypertension was suggested by echocardiography and an abnormal ventilator test.The data are given as mean values ± SD, unless otherwise stated. The correlations between the variables were analysed using Pearson's r coefficient, and the predictive value of the variables was calculated using linear regression analysis. A p value of > 0.05 was considered significant. Results: Right heart catheterization detected PAH in 15/19 patients; mean PAP was 30.5 mm/Hg and RVP 3.6 UW. Coronary angiography of the patients aged more than 55 years showed some evidence of significant coronary artery disease. Echocardiography showed high systolic PAP values (46 ± 8 mmHg), whereas right ventricular function was normal (TAPSE 23 ± 3 mm), and in line with the NYHA class. ACTpo was reduced in the patients with a systolic PAP of < 46 mm/Hg (p > 0.001) and positively correlated with DLCO (p > 0.001) and the hemodynamic data.There was a good correlation between ACTpo and PVR (hemodynamic data) (r = -0615; p > 0.01). Conclusions: Although they need to be confirmed by studies of larger series of patients, our findings suggest that, in comparison with hemodynamic data, non-invasive echocardiographic measurements are an excellent means of identifying early-stage PAH.

Ultrasound-assessed perirenal fat is related to increased ophthalmic artery resistance index in HIV-1 patients

Pierfrancesco Grima — 2010-06-30T00:00:00Z

Background: The introduction of highly active antiretroviral therapy (HAART) has dramatically changed the prognosis of human immunodeficiency virus (HIV) infection, with a significant decline in morbidity and mortality.Changes in body fat distribution are a common finding in individuals with HIV infection being treated with antiretrovirals, and this condition (collectively termed lipodystrophy syndrome) is associated with depletion of subcutaneous fat, increased triglycerides and insulin resistance. Obesity, particularly visceral obesity, is associated with increased risk of cardiovascular disease. Therefore, estimating visceral fat distribution is important in identifying subjects at high risk for cardiovascular disease.The aim of our study was to evaluate whether perirenal fat thickness (PRFT), a parameter of central obesity, is related to ophthalmic artery resistance index (OARI), an index of occlusive carotid artery disease in HIV-1 infected patients. Methods: We enrolled 88 consecutive HIV-1-infected patients receiving highly active antiretroviral therapy for more than 12 months, in a prospective cohort study. Echographically measured PRFT and OARI, as well as serum metabolic parameters, were evaluated. PRFT and OARI were measured by 3.75 MHz convex and 7.5 MHz linear probe, respectively. Results: The means of PRFT and OARI in HIV-1-infected patients with visceral obesity was considerably higher than in patients without it (p < 0.0001 and p < 0.001, respectively). Using the average OARI as the dependent variable, total serum cholesterol level, HDL, triglycerides, glycemia, sex, blood pressure, age and PRFT were independent factors associated with OARI. A PRFT of 6.1 mm was the most discriminatory value for predicting an OARI > 0.74 (sensitivity 78.9%, specificity 82.8%). Conclusions: Our data indicate that ultrasound assessment of PRFT may have potential as a marker of increased endothelial damage with specific involvement of the ocular vascular region in HIV-1-infected patients.

Massive right atrial myxoma presenting as syncope and exertional dyspnea: case report

Olga Azevedo — 2010-06-18T00:00:00Z

Primary heart neoplasms are rare occurring with an estimated incidence of 0.0017-0.19%. Myxoma is the most prevalent primary heart tumor. The right atrium is an unusual localization, occurring only in 15-20% of myxoma cases. We report a rare case of a massive right atrial myxoma causing tricuspid valve obstruction and presenting as syncope and exertional dyspnea. This case illustrates the influence of myxoma's size, position and mobility as well as patient's body posture and respiration to the development of signs and symptoms. Three-dimensional echocardiography proved useful in surgery planning, allowing a better definition of the tumor outline and attachment.

Arterial elasticity imaging: comparison of finite-element analysis models with high-resolution ultrasound speckle tracking

DaeWoo Park — 2010-06-18T00:00:00Z

Background: The nonlinear mechanical properties of internal organs and tissues may be measured with unparalleled precision using ultrasound imaging with phase-sensitive speckle tracking. The many potential applications of this important noninvasive diagnostic approach include measurement of arterial stiffness, which is associated with numerous major disease processes. The accuracy of previous ultrasound measurements of arterial stiffness and vascular elasticity has been limited by the relatively low strain of nonlinear structures under normal physiologic pressure and the measurement assumption that the effect of the surrounding tissue modulus might be ignored in both physiologic and pressure equalized conditions. Methods: This study performed high-resolution ultrasound imaging of the brachial artery in a healthy adult subject under normal physiologic pressure and the use of external pressure (pressure equalization) to increase strain. These ultrasound results were compared to measurements of arterial strain as determined by finite-element analysis models with and without a surrounding tissue, which was represented by homogenous material with fixed elastic modulus. Results: Use of the pressure equalization technique during imaging resulted in average strain values of 26% and 18% at the top and sides, respectively, compared to 5% and 2%, at the top and sides, respectively, under physiologic pressure. In the artery model that included surrounding tissue, strain was 19% and 16% under pressure equalization versus 9% and 13% at the top and sides, respectively, under physiologic pressure. The model without surrounding tissue had slightly higher levels of strain under physiologic pressure compared to the other model, but the resulting strain values under pressure equalization were > 60% and did not correspond to experimental values. Conclusions: Since pressure equalization may increase the dynamic range of strain imaging, the effect of the surrounding tissue on strain should be incorporated into models of arterial strain, particularly when the pressure equalization technique is used.

Echocardiographic assessment of pulmonary vascular resistance in pulmonary arterial hypertension

Vincent Roule — 2010-06-07T00:00:00Z

Background: Echocardiographic ratio of peak tricuspid regurgitant velocity to the right ventricular outflow tract time-velocity integral (TRV/TVI rvot) was presented as a reliable non-invasive method of estimating pulmonary vascular resistance (PVR). Studies using this technique in patients with moderate to high PVR are scarce. Left ventricular outflow tract time-velocity integral (TVI lvot) can be easier to measure than TVI rvot, especially in patients with severe pulmonary hypertension (PH) with significant anatomical modifications of the right structures.AimsWe wanted to determine whether the TRV/TVI rvot and TRV/TVI lvot ratios would form a reliable non-invasive tool to estimate PVR in a cohort of patients with moderate to severe pulmonary vascular disease. Methods: Doppler echocardiographic examination and right heart catheterisation were performed in 37 patients. Invasive PVR was compared with TRV/TVI rvot and TRV/TVI lvot ratios using regression analysis. Two equations were modelled and the results compared with invasive measurements using the Bland-Altman analysis. Using receiver-operating characteristics curve analysis, a cut-off value for the two ratios was generated. Results: Correlation coefficients between invasive PVR and TRV/TVI rvot then TRV/TVI lvot were respectively 0.76 and 0.74. Two new equations were found but the Bland-Altman analysis showed wide standard deviations (respectively 3.8 and 3.9 Wood units). A TRV/TVI rvot then TRV/TVI lvot ratio cut-off value of 0.14 had a sensitivity of 93% and a specificity of 57% for the first and a sensitivity of 87% and a specificity of 57% for the second to determine PVR > 2 Wood units. Conclusion: Echocardiography is useful for the screening of patients with pulmonary hypertension and PVR > 2 WU. It remains disappointing for accurate assessment of high PVR. TVI lvot may be an alternative to TVI rvot for patients for whom accurate TVI rvot measurement is not possible.