Dynamic fetal cardiovascular magnetic resonance imaging using Doppler ultrasound gating.

BACKGROUND: Fetal cardiovascular magnetic resonance (CMR) imaging may provide a valuable adjunct to fetal echocardiography in the evaluation of congenital cardiovascular pathologies. However, dynamic fetal CMR is difficult due to the lack of direct in-utero cardiac gating. The aim of this study was to investigate the effectiveness of a newly developed Doppler ultrasound (DUS) device in humans for fetal CMR gating. METHODS: Fifteen fetuses (gestational age 30-39 weeks) were examined using 1.5 T CMR scanners at three different imaging sites. A newly developed CMR-compatible DUS device was used to generate gating signals from fetal cardiac motion. Gated dynamic balanced steady-state free precession images were acquired in 4-chamber and short-axis cardiac views. Gating signals during data acquisition were analyzed with respect to trigger variability and sensitivity. Image quality was assessed by measuring endocardial blurring (EB) and by image evaluation using a 4-point scale. Left ventricular (LV) volumetry was performed using the single-plane ellipsoid model. RESULTS: Gating signals from the fetal heart were detected with a variability of 26 ± 22 ms and a sensitivity of trigger detection of 96 ± 4%. EB was 2.9 ± 0.6 pixels (4-chamber) and 2.5 ± 0.1 pixels (short axis). Image quality scores were 3.6 ± 0.6 (overall), 3.4 ± 0.7 (mitral valve), 3.4 ± 0.7 (foramen ovale), 3.6 ± 0.7 (atrial septum), 3.7 ± 0.5 (papillary muscles), 3.8 ± 0.4 (differentiation myocardium/lumen), 3.7 ± 0.5 (differentiation myocardium/lung), and 3.9 ± 0.4 (systolic myocardial thickening). Inter-observer agreement for the scores was moderate to very good (kappa 0.57-0.84) for all structures. LV volumetry revealed mean values of 2.8 ± 1.2 ml (end-diastolic volume), 0.9 ± 0.4 ml (end systolic volume), 1.9 ± 0.8 ml (stroke volume), and 69.1 ± 8.4% (ejection fraction). CONCLUSION: High-quality dynamic fetal CMR was successfully performed using a newly developed DUS device for direct fetal cardiac gating. This technique has the potential to improve the utility of fetal CMR in the evaluation of congenital pathologies.

Goal-Directed Fluid Therapy Guided by Cardiac Monitoring During High-Risk Abdominal Surgery in Adult Patients: Cost-Effectiveness Analysis of Esophageal Doppler and Arterial Pulse Pressure Waveform Analysis.

BACKGROUND: Several minimally invasive techniques for cardiac output monitoring such as the esophageal Doppler (ED) and arterial pulse pressure waveform analysis (APPWA) have been shown to improve surgical outcomes compared with conventional clinical assessment (CCA). OBJECTIVE: To evaluate the cost-effectiveness of these techniques in high-risk abdominal surgery from the perspective of the French public health insurance fund. METHODS: An analytical decision model was constructed to compare the cost-effectiveness of ED, APPWA, and CCA. Effectiveness data were defined from meta-analyses of randomized clinical trials. The clinical end points were avoidance of hospital mortality and avoidance of major complications. Hospital costs were estimated by the cost of corresponding diagnosis-related groups. RESULTS: Both goal-directed therapy strategies evaluated were more effective and less costly than CCA. Perioperative mortality and the rate of major complications were reduced by the use of ED and APPWA. Cost reduction was mainly due to the decrease in the rate of major complications. APPWA was dominant compared with ED in 71.6% and 27.6% and dominated in 23.8% and 20.8% of the cases when the end point considered was "major complications avoided" and "death avoided," respectively. Regarding cost per death avoided, APPWA was more likely to be cost-effective than ED in a wide range of willingness to pay. CONCLUSIONS: Cardiac output monitoring during high-risk abdominal surgery is cost-effective and is associated with a reduced rate of hospital mortality and major complications, whatever the device used. The two devices evaluated had negligible costs compared with the observed reduction in hospital costs. Our comparative studies suggest a larger effect with APPWA that needs to be confirmed by further studies.

Focused ultrasound of the pleural cavities and the pericardium by nurses after cardiac surgery.

OBJECTIVES: We aimed to study the feasibility and reliability of focused ultrasound (US) examinations to quantify pericardial (PE)- and pleural effusion (PLE) by a pocket-size imaging device (PSID) performed by nurses in patients early after cardiac surgery. DESIGN: After a 3-month training period, with cardiologists as supervisors, two nurses examined 59 patients (20 women) with US using a PSID at a median of 5 days after cardiac surgery. The amount of PE and PLE was classified in four categories by US (both) and chest x-ray (PLE only). Echocardiography, including US of the pleural cavities, by experienced cardiologists was used as reference. RESULTS: Focused US by the nurses was more sensitive than x-ray to detect PLE. The correlations of the quantification of PE and PLE by the nurses and reference was r (95% confidence interval) 0.76 (0.46-0.89) and 0.81 (0.73-0.89), both p < 0.001. PE and PLE were drained in one and six (eight cavities) patients, all classified as large amount by the nurses. CONCLUSIONS: Cardiac nurses were able to obtain reliable measurements and quantification of both PE and PLE bedside by focused US and outperform the commonly used chest x-ray regarding PLE after cardiac surgery.

True posttraumatic radial artery aneurysm / Aneurisma verdadeiro de arteria radial pos-traumatico

Radial artery aneurysms are rare and mostly secondary to traumatic events (posttraumatic pseudoaneurysms). Radial artery aneurysms should be treated due to the high risk of embolization, thrombosis, and compression of adjacent nerves. The authors describe a case of a 49-year-old patient complaining of a progressively growing tumor in the left wrist after a dog bite. The tumor proved to be a true posttraumatic aneurysm. Treatment consisted of removal of the aneurysm sac and ligation of the radial artery.

Os aneurismas de artéria radial são raros, sendo, na maioria das vezes, pseudoaneurismas pós-traumáticos. Os aneurismas de artéria radial devem ser tratados devido ao risco de embolização, trombose e compressão de estruturas nervosas adjacentes. Os autores relatam o caso de um paciente de 49 anos referindo tumoração de crescimento progressivo em punho esquerdo após mordedura canina, sendo diagnosticado aneurisma verdadeiro de artéria radial pós-traumático. Optou-se pela ressecção do saco aneurismático e ligadura da artéria radial.

Oclusión unilateral de la carótida interna con flujos reversos en ambas arterias oftálmicas: reporte de un caso / Unilateral internal carotid artery occlusion with bilateral ophthalmic arteries reverse flow: case report

El hallazgo de flujo reverso en una arteria oftálmica a través de la ventana transorbitaria en la evaluación de la oclusión carotidea, complementa el Doppler de vasos de cuello, demostrando la existencia de circulación colateral. En el siguiente caso, un paciente con oclusión carotidea derecha presenta flujo reverso en ambas arterias oftálmicas.

Transthoracic echocardiographic guidance of patent ductus arteriosus occlusion with an Amplatz® canine duct occluder.

Placement of an Amplatz canine duct occluder (ACDO) is usually performed by fluoroscopy (Nguyenba and Tobias, 2007). The latter technical approach presents limitations, mostly due to radiation exposure, making this practice dangerous for the patient and operators. In this study, we describe the successful placement of an Amplatz Canine Duct Occluder device by using transthoracic echocardiographic (TTE) guidance, performed on an 11-month-old female mongrel dog with a grade VI/VI continuous heart murmur diagnosed with patent ductus arteriosus (PDA). The TTE is useful in eliminating exposure to radiation and is more versatile than fluoroscopy in conveying real-time detailed information concerning the position of the ACDO.

Left ventricular filling and diastolic myocardial deformation in chronic primary mitral regurgitation.

AIMS: Chronic primary mitral regurgitation (MR) results in enhanced filling of the left ventricle (LV) during early diastole. Filling is impaired with the onset of LV systolic dysfunction, due to increased myocardial stiffness and reduced restoring forces. We investigated echocardiographic parameters of early diastolic function in relation to LV systolic function. METHODS AND RESULTS: Early diastolic transmitral flow and tissue Doppler velocities, propagation velocity of early filling (V(p)), and early diastolic strain rates (SR-E) were measured in 30 patients with chronic degenerative MR and 30 age-matched controls. MR subjects were further subdivided into group 1 (14 subjects) if they had well compensated LV, and group 2 (16 subjects) if they had one or more of the following: functional limitation (> NYHA class I), LV end-systolic diameter >or=4.0 cm, and LV ejection fraction

A new 15-50 MHz array-based micro-ultrasound scanner for preclinical imaging.

Most institutions now have a suite of imaging tools to follow mouse models of human disease. Micro-ultrasound is one of these tools and is second after whole-mouse fluorescence or bioluminescent imaging, in terms of installed systems. We report in this paper the first commercially available array transducer-based ultrasound imaging system that enables micro-ultrasound imaging at center frequencies between 15 and 50 MHz. At the heart of the new scanner is a laser-machined high-frequency 256 element, linear transducer array capable of forming dynamic diffraction limited beams. The power of the linear array approach is embodied in the uniform high resolution maintained over the full field of view. This leads to greatly expanded scope for real-time functional imaging that is demonstrated in this paper. The unprecedented images made with the new imaging system will enable many new applications not previously possible. These include real-time visualization of flow in the mouse placenta, visualization of flow development in the embryo, studies of embryonic to adult cardiac development/disease, and studies of real-time blood flow in mouse models of tumour angiogenesis.

Assessment of cardiac involvement in sarcoidosis by echocardiography.

The main objective of this study is to determine the prevalence of left ventricular systolic and diastolic dysfunction in patients with chronic sarcoidosis without clinical evidence of heart disease. The study includes 69 chronic sarcoidosis patients, 30 diagnosed by organ biopsy and 39 by clinical history, chest X-ray, high resolution computerized tomography (HRCT) and bronchoalveolar lavage (BAL), without suspected cardiac involvement. The control group consisted of 26 subjects selected from a population of hospital workers. The examination includes 12-lead ECG and echocardiographic examination. The results show that there were no differences in atrial size, left ventricular diameters, wall thickness, left ventricular ejection fraction or endocardial fractional shortening between the sarcoid group and controls. Signs of diastolic dysfunction were found in 33 (55%) patients, however, this group was significantly older than the others and had marginally higher blood pressure. Sarcoid patients had lower midwall fractional shortening (mFS) than controls; patients with diastolic dysfunction also had lower mFS but the difference was not significant. In conclusion, the results demonstrated an absence of left ventricular systolic dysfunction, evaluated by traditional echocardiographic methods, in our chronic sarcoidosis patients and an apparent absence of any relation between left ventricular diastolic dysfunction and sarcoidosis. Lower mFS was found among patients, particularly those with a long history of sarcoidosis. Further analysis is required to evaluate the significance of this index as a potential marker of heart involvement in chronic sarcoidosis.

Epicardial coronary artery Doppler: validation in the animal model.

The aim of the study was to validate a newly-designed epicardial coronary artery Doppler probe and test its detection of changes in coronary blood flow velocity. Left anterior descending (LAD) coronary blood flow and flow velocity were evaluated in four pigs with a pericoronary transit time flow (TTF) probe and a newly-designed epicardial Doppler micro-probe. Four consecutive measurements were taken for each of the following conditions: basal, partial stenosis, occlusion, and reperfusion of the LAD. Mean TTF value (ml/min) was 23.2+/-6.6 in basal condition, 16.2+/-5.7 after partial LAD stenosis, 0.1+/-0.3 during LAD occlusion, and 67.4+/-23.3 at reperfusion (P<0.001). Similar patterns were recorded in terms of Doppler velocity (cm/s) with values of 4.0+/-1.9 in basal condition, 3.5+/-2.3 after partial LAD stenosis, 0.5+/-1.4 during LAD occlusion, and 11.1+/-5.5 at reperfusion (P<0.001). No significant differences in both TTF and Doppler velocity were detected between basal condition and partial LAD stenosis (P=ns). Epicardial coronary arterial Doppler represents a valuable tool to detect coronary arterial flow velocity in basal condition. Although changes in flow velocity are easily recorded after coronary occlusion and reperfusion, modifications after partial coronary stenosis are not clearly defined.

Comparação dos valores de débito cardíaco obtidos por termodiluição e dopplerfluxometria transesofágica / Comparison between two methods for hemodynamic measurement: thermodilution and oesophageal doppler

OBJETIVO: A termodiluição (TD) é padrão de monitorização hemodinâmica. Alguns parâmetros hemodinâmicos podem ser medidos através do Doppler Transesofágico (DTE). Método simples, menos invasivo. Com o objetivo de avaliar a acurácia do DTE foram comparados TD e DTE na determinação de medidas de débito cardíaco (DC). MÉTODOS: Foram determinadas 192 medidas simultâneas, em diferentes situações clínicas em dez pacientes com idade entre 21 85 anos (cinco do gênero masculino e cinco do feminino), oito internados sépticos em uso de drogas vasoativas e dois monitorizados para laringectomia e transplante hepático; todas avaliadas ao longo de quatro horas, em intervalos de 30 minutos. Foram utilizados dois tipos de doppler: o DeltexR, e o ArrowR, introduzidos entre 35 e 45 cm da fossa nasal e localizados no ponto de maior diâmetro da aorta descendente. Na TD, foi utilizado cateter de artéria pulmonar (Swan Ganz BaxterR) e monitor DX-2001R, confirmado o posicionamento radiologicamente e através das curvas pressóricas geradas. As medidas do DC realizadas através da TD foram obtidas com soro fisiológico gelado, sendo considerada a média de quatro medidas não diferentes de 5 por cento. Foi aplicado o método estatístico de Bland e Altman, com utilização de gráfico de regressão linear. RESULTADOS: Não houve diferença estatisticamente significante entre esses dois métodos de medida hemodinâmica, com coeficiente de correlação de 0,88 para o DC (Doppler DeltexR X Swan Ganz BaxterR) e coeficiente de correlação de 0,99 DC (Doppler Arrow rR X Swan Ganz BaxterR) respectivamente, observando-se correlação. CONCLUSÃO: A medida das variáveis hemodinâmicas ao DTE foi obtida com facilidade nos dez pacientes estudados e revelou ter este dispositivo acurácia compatível à TD.

OBJECTIVES: Thermodilution (TD) is the "gold standard method" for hemodynamic monitoring. Some parameters can be measured by Oesophageal Doppler (OD), which is simpler and less invasive. To evaluate the accuracy of OD, we compared this method with TD in measurement of cardiac output (CO). METHODS: One hundred and ninety two simultaneous measurements were made in 10 patients (5 male and 5 female) with different clinical situations, 8 with sepsis using vasoactive drugs and 2 monitored for laryngectomy and liver transplantation. Measurements were taken during 4 hours at 30 minute intervals. The two oesophageal dopplers used DeltexR and ArrowR, were introduced between 35 and 45 cm from the nose and located at the point of largest diameter of the descending aorta. In TD, we used the pulmonary artery catheter (Swan Ganz BaxterR) and the DX- 2001 monitorR positioning was confirmed with support of radiology and of pressures curves. Measurements of CO carried out by means of TD were achieved using an iced saline solution considering the mean of four measurements with less than a 5 percent difference. The statistical method used was the Bland-Altman scatter plot and dispersion graphic. RESULTS: No statistically significant difference was found between the two methods for hemodyamic measurement with a correlation coefficient of 0.8 for CO (Deltex DopplerR and Baxter Swan GanzR) and a correlation coefficient of 0.99 for CO (Arrow DopplerR and Baxter Swan GanzR). CONCLUSION: Homodynamic measurements with OD have the same accuracy as those with TD and were easily obtained in the 10 patients.

Right ventricular performance in severe obesity. Effect of weight loss.

BACKGROUND: The effects of severe obesity on right ventricular function in the absence of associated cardiopulmonary disease are not well known. Right myocardial performance index (R-MPI) is an echocardiographic index to non-invasively assess the right ventricular function. The aim of our study was to assess R-MPI in individuals with severe but uncomplicated obesity before and after a significant weight loss induced by bariatric surgery. PATIENTS AND METHODS: Fifteen obese females (OB) without cardiovascular and pulmonary diseases were examined. In all subjects, R-MPI was calculated by Doppler echocardiography as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time. Furthermore, pulmonary function test (PFT) and 6-min walking test (6mWT) were performed. Ten healthy subjects with normal weight (HS) were also evaluated as controls. R-MPI, PFT and 6mWT were also re-evaluated one year later in 12 obese subjects treated with gastric banding after a consistent weight loss (> 20%). RESULTS: A prolongation of R-MPI was found in OB before bariatric surgery in comparison to the HS (0.47 +/- 0.04 and 0.29 +/- 0.05, respectively; P < 0.001). R-MPI significantly improved in OB 12 months after surgery (0.32 +/- 0.03) and was no longer different from HS. R-MPI positively correlated to body mass index (BMI). A significant association was found between the reduction of BMI after bariatric surgery and the distance walked during the 6mWT. CONCLUSIONS: These results show a right ventricular dysfunction in severe uncomplicated obesity, associated with an impaired functional capacity which recovers after consistent weight loss.

Intraoperative Doppler velocity measurements to locate patent ITA grafts at reoperation.

We are reporting a case of a patient who underwent an aortic valve replacement with previous coronary artery bypass grafting. During the operation we used a Doppler velocity probe to locate the exact position of the bilateral internal thoracic arteries. Once the vessels were identified, a suture was passed widely around each internal thoracic artery and a snare was positioned. With the aid of the Doppler velocity probe, we achieved a gentle occlusion of the vessels, applying enough traction on the snares to abolish the flow through the internal thoracic arteries.

Turbulent flow as a cause for underestimating coronary flow reserve measured by Doppler guide wire.

BACKGROUND: Doppler-tipped coronary guide-wires (FW) are well-established tools in interventional cardiology to quantitatively analyze coronary blood flow. Doppler wires are used to measure the coronary flow velocity reserve (CFVR). The CFVR remains reduced in some patients despite anatomically successful coronary angioplasty. It was the aim of our study to test the influence of changes in flow profile on the validity of intra-coronary Doppler flow velocity measurements in vitro. It is still unclear whether turbulent flow in coronary arteries is of importance for physiologic studies in vivo. METHODS: We perfused glass pipes of defined inner diameters (1.5-5.5 mm) with heparinized blood in a pulsatile flow model. Laminar and turbulent flow profiles were achieved by varying the flow velocity. The average peak velocity (APV) was recorded using 0.014 inch FW. Flow velocity measurements were also performed in 75 patients during coronary angiography. Coronary hyperemia was induced by intra-coronary injection of adenosine. The APV maximum was taken for further analysis. The mean luminal diameter of the coronary artery at the region of flow velocity measurement was calculated by quantitative angiography in two orthogonal planes. RESULTS: In vitro, the measured APV multiplied with the luminal area revealed a significant correlation to the given perfusion volumes in all diameters under laminar flow conditions (r2 > 0.85). Above a critical Reynolds number of 500--indicating turbulent flow--the volume calculation derived by FW velocity measurement underestimated the actual rate of perfusion by up to 22.5 % (13 +/- 4.6 %). In vivo, the hyperemic APV was measured irrespectively of the inherent deviation towards lower velocities. In 15 of 75 patients (20%) the maximum APV exceeded the velocity of the critical Reynolds number determined by the in vitro experiments. CONCLUSION: Doppler guide wires are a valid tool for exact measurement of coronary flow velocity below a critical Reynolds number of 500. Reaching a coronary flow velocity above the velocity of the critical Reynolds number may result in an underestimation of the CFVR caused by turbulent flow. This underestimation of the flow velocity may reach up to 22.5 % compared to the actual volumetric flow. Cardiologists should consider this phenomena in at least 20 % of patients when measuring CFVR for clinical decision making.

Usefulness of a hand-carried cardiac ultrasound device for bedside examination of pericardial effusion in patients after cardiac surgery.

To identify the incidence of pericardial effusion in patients after cardiac surgery using a hand-carried cardiac ultrasound device, 200 patients were assessed on postoperative day 3. If a pericardial effusion was found, patients were monitored for 3 consecutive days with a hand-carried cardiac ultrasound device. Within 72 hours after surgery, 43 patients (21.5%) had developed an effusion, of whom 2 patients had cardiac tamponade and 41 patients (21%) had a small pericardial effusion. No difference was found in the incidence of effusion based on the type of cardiac surgery. Of patients with a small pericardial effusion on day 3 after surgery, an additional 2 of 41 (5%) developed cardiac tamponade.

Ressincronização cardíaca total com marcapasso tetracâmara na insuficiência cardíaca refratária / Total cardiac resynchronization with four chamber pacemaker for refractory heart failure

A ressincronização cardíaca total, ou seja, interventricular, interatrial e atrioventricular, com intervalo atrioventricular ótimo, pode ser imperiosa nos casos de pacientes com indicação formal de ressincronização cardíaca com marcapasso biventricular para tratamento da insuficiência cardíaca refratária ao tratamento medicamentoso e que também apresentam evidências de distúrbios de condução interatrial. Neste artigo, apresentamos dois casos de pacientes portadores de miocardiopatia dilatada com dissincronia em todos os níveis(interatrial, interventricular e atrioventricular) que necessitaram de implante de marcapasso tetracâmara para obter os benefícios da terapia de ressincronização cardíaca

Use of a handheld epicardial ultrasonic Doppler flow detector to locate an intramyocardial coronary artery encased in inflamed neoplastic pericardium.

A 44-year-old man had severe stenosis of the left main coronary artery. The middle portion of the left anterior descending coronary artery was in an intramyocardial location. The pericardium, ascending aorta, epicardium, and coronary arteries were encased by a metastatic, poorly differentiated papillary adenocarcinoma. The left anterior descending artery was located with the aid of a handheld epicardial ultrasonic Doppler flow detector, and grafted with the left internal thoracic artery on a beating heart. Subsequently, the patient underwent 10 cycles of chemotherapy More than 22 months later, he was asymptomatic and in remission from neoplastic disease.