Rapid cardiovascular effects of growth hormone treatment in short prepubertal children: impact of treatment duration.

Objective: Previous studies show that growth hormone (GH) treatment increases cardiac dimensions in short children with GH deficiency (GHD) and has diverse cardiac effects in children with idiopathic short stature (ISS). This study was performed to assess the effect of GH on the cardiovascular system in short children with a broad range of GH secretion and GH sensitivity/responsiveness.

Design And Patients: In this prospective, multicentre study, short prepubertal children diagnosed with isolated GHD (89) or ISS (38) were followed during 2 years of GH treatment.

Long-term follow-up of mitral valve regurgitation--importance of mitral valve pathology and left ventricular function on survival.

Background: Timing of surgery for mitral regurgitation (MR) is one of the more difficult decisions for the practicing cardiologist.

Methods And Results: In order to determine useful clinical cut-offs, we investigated the influence of baseline echocardiographic predictors for survival in a long-time follow-up cohort. Data from 144 patients with MR were collected between 1989 and 1993.

Heart rate variability in children with Fontan circulation.

Heart rate variability (HRV) can be used to study cardiovascular autonomic control. This study examines HRV in children with Fontan circulation and its change over time. Thirty-four children in two groups were examined.

Electrocardiographic ST segment depression and clinical function in children with Fontan circulation.

Previous studies noted that Fontan patients have electrocardiographic ST depressions during exercise tests and on 24-hour ambulatory electrocardiographic (ECG) monitoring. This study investigated whether the ST depressions were correlated to clinical function (NYHA Functional Classification). Forty-five children in two groups were examined--15 patients with Fontan circulation and 30 with a structurally normal heart, matched for sex, height, and weight.

Electrocardiographic ST-segment depression in children with fontan circulation.

Despite successful operation, many patients palliated with a Fontan-type procedure continue to show effort limitation. We previously observed that these children showed electrocardiographic ST depression during exercise tests. The purpose of the study was to investigate whether electrocardiographic ST depression is a common finding in children with Fontan circulation.

Flow convergence flow rates from 3-dimensional reconstruction of color Doppler flow maps for computing transvalvular regurgitant flows without geometric assumptions: An in vitro quantitative flow study.

Objective: This study was designed to develop and test a 3-dimensional method for direct measurement of flow convergence (FC) region surface area and for quantitating regurgitant flows with an in vitro flow system.

Background: Quantitative methods for characterizing regurgitant flow events such as flow convergence with 2-dimensional color flow Doppler imaging systems have yielded variable results and may not be accurate enough to characterize those more complex spatial events.

Method: Four differently shaped regurgitant orifices were studied: 3 flat orifices (circular, rectangular, triangular) and a nonflat one mimicking mitral valve prolapse (all 4 orifice areas = 0.

The abnormal contralateral atrioventricular valve in mitral and tricuspid atresia in neonates: An echocardiographic study.

Abnormalities of the mitral valve (MV) or the tricuspid valve (TV) morphology and/or function in patients with functional single ventricle may result in early morbidity and death. The purpose of this study was to determine the incidence of contralateral atrioventricular valve (AVV) pathologies in mitral valve atresia (MA) and tricuspid valve atresia (TA). We retrospectively reviewed the echocardiographic data of 50 neonates with MV and 20 with TA.

Late fenestration closure in the hypoplastic left heart syndrome: comparison of hemodynamic changes.

Background And Objectives: Although survival of patients with the hypoplastic left heart syndrome treated by staged surgical palliation has improved, hemodynamic data after fenestrated Fontan operation and after fenestration closure have not been reported in this patient population. We sought to describe the hemodynamic status of these patients at cardiac catheterization performed for the purpose of fenestration closure and to compare these data with data from contemporary patients with other forms of univentricular heart.

Methods And Results: Hemodynamic responses to fenestration closure during cardiac catheterization were reviewed in 40 consecutive patients, including 20 with the hypoplastic left heart syndrome and 20 with other forms of univentricular heart defects.

Pulmonary venous blood flow pattern in patients with univentricular hearts following total cavo-pulmonary connection.

The objective of the study was evaluation of the pulmonary venous blood flow (PVF) pattern and the influence of ventricular function and atrioventricular valve regurgitation on this flow in patients with univentricular hearts post total cavo-pulmonary connection (TCPC). Transthoracic or transoesophageal echocardiographic studies were performed in 24 children with normal hearts (group A) and in 24 patients with univentricular hearts (group B). Ventricular function and atrioventricular valve regurgitation was semiquantitatively assessed.

Computer simulation of circulation in patient with total cavo-pulmonary connection: inter-relationship of cardiac and vascular pressure, flow, resistance and capacitance.

The aim is to develop a computer model representative of the circulation in a patient with a uni-ventricular heart surgically palliated by a total cavo-pulmonary connection (TCPC). The effects of known hazardous exposures on this type of circulation are investigated. A model of the cardiovascular system is built using standard components such as transmission lines, restrictors and capacitances.

Left ventricular stroke work in mitral regurgitation: an animal experimental study.

Background And Aims Of The Study: Most studies on mitral regurgitation have focused on evaluating the regurgitant volume. The effects of mitral regurgitation and its associated cardiac workload on left ventricular function and mechanics may be equally important both in assessing the impact of regurgitation as well as in planning and evaluating therapy. The present study was undertaken to investigate the interrelationships of the regurgitant volume, hemodynamics and left ventricular work in an experimental animal model of chronic mitral regurgitation in which the regurgitant volume could be measured directly with electromagnetic flow probes.

Vena contracta imaged by Doppler color flow mapping predicts the severity of eccentric mitral regurgitation better than color jet area: a chronic animal study.

Objectives: This study sought to evaluate the relation between the color Doppler-imaged vena contracta and the severity of mitral regurgitation (MR) in a chronic animal model of MR.

Background: The vena contracta, which is defined as the smallest connection between the laminar flow acceleration zone and the turbulent regurgitant jet, has been reported to be a clinically useful marker for evaluating the severity of valvular regurgitation.

Methods: Six sheep with chronic MR produced by previous operation severing the chordae tendineae were examined.

Invasive evaluation of mitral regurgitation: the importance of hemodynamic measurements during exercise.

Background And Aims Of The Study: In patients with mitral regurgitation, left ventricular angiography is usually performed to grade the regurgitation. This is a semi-quantitative method which gives some information related to the regurgitant volume at a certain time. The aim of our study was to evaluate the benefits of invasive hemodynamic examinations during stress.

Evaluation of mitral regurgitation by pulmonary venous blood flow patterns. Relation to angiographic and haemodynamic parameters in subgroups of patients.

Objectives: To study the relationship between pulmonary venous systolic flow fraction (PVSFfr) recorded using pulsed Doppler transesophageal echocardiography and angiographic grading and haemodynamic parameters in subgroups of patients with mitral regurgitation.

Background: Reversed systolic pulmonary venous flow is a sensitive sign of severe mitral regurgitation. Scarse data are available regarding the effects of atrial fibrillation and coronary artery disease.

Quantification of mitral flow by Doppler color flow mapping.

This study was performed to develop and validate Doppler color flow methods for quantifying forward transmitral flow rates and volumes with isovelocity aliasing contours. We undertook computer modeling of flows and studied an animal model with strictly controlled mitral flows. Finite element analysis was first used to establish the isovelocity surface contours reconstructed from the magnitudes and directions of the velocity vectors proximal to the normal mitral orifice.

Three-dimensional reconstruction of color Doppler flow convergence regions and regurgitant jets: an in vitro quantitative study.

Objectives: This study sought to investigate the applicability of a current implementation of a three-dimensional echocardiographic reconstruction method for color Doppler flow convergence and regurgitant jet imaging.

Background: Evaluation of regurgitant flow events, such as flow convergences or regurgitant jets, using two-dimensional imaging ultrasound color flow Doppler systems may not be robust enough to characterize these spatially complex events.

Methods: We studied two in vitro models using steady flow to optimize results.

Long term follow up of patients with anterior myocardial infarction complicated by left ventricular thrombus in the thrombolytic era.

Objectives: To examine the appearance and resolution of left ventricular thrombi and to study the relation between thrombus and mortality during long term follow up after anterior myocardial infarction.

Design: Ninety nine consecutive patients were prospectively studied until the last included patient had been followed for one year. Streptokinase and aspirin were used routinely, anticoagulants only after a decision by the attending physician.

Dynamics of left ventricular thrombi in patients with acute anterior myocardial infarction treated with thrombolytics.

Background: Limited data exist concerning left ventricular thrombi during and after hospitalization in patients treated according to modern principles. The purpose of the present study was to examine the formation and resolution of left ventricular thrombi during the first month in patients with acute anterior myocardial infarction treated with streptokinase and aspirin.

Methods: Seventy-seven consecutive patients were studied prospectively during the hospital stay and 1-month follow-up study.

Dynamic change in mitral regurgitant orifice area: comparison of color Doppler echocardiographic and electromagnetic flowmeter-based methods in a chronic animal model.

Objectives: The aim of the present study was to investigate dynamic changes in the mitral regurgitant orifice using electromagnetic flow probes and flowmeters and the color Doppler flow convergence method.

Background: Methods for determining mitral regurgitant orifice areas have been described using flow convergence imaging with a hemispheric isovelocity surface assumption. However, the shape of flow convergence isovelocity surfaces depends on many factors that change during regurgitation.

Left ventricular thrombosis after anterior myocardial infarction with and without thrombolytic treatment.

Objectives: To examine the incidence of left ventricular thrombus in patients with anterior myocardial infarction, with and without streptokinase treatment. To identify predictors of thrombus development.

Design: Consecutive patients prospectively studied during the hospitalized period.

Pulmonary venous systolic flow fraction in patients with mitral regurgitation: transoesophageal echocardiographic findings in relation to haemodynamic and angiographic evaluation.

In patients with mitral regurgitation (MR), pulmonary venous systolic flow fraction (PVSFfr) recorded using pulsed Doppler transoesophageal echocardiography (TEE) was compared with PVSFfr in normal subjects, to angiographic grading and to haemodynamic parameters. PVSfr was calculated as the systolic flow velocity integral divided by total inflow integral. PVSfr is negative when systolic flow is reversed.

Relation of left atrial V-wave/left ventricular systolic pressure ratio to mitral regurgitant volume.

Evaluation of mitral regurgitation is difficult whether invasive or noninvasive methods are used. The determination of the regurgitant volume itself cannot be done in clinical practice with reasonable accuracy. In six sheep with chronic mitral regurgitation, left ventricular and left atrial pressures were recorded with high-fidelity catheters.

Doppler evaluation of severity of mitral regurgitation: relation to pulmonary venous blood flow patterns in an animal study.

Objectives: This study examined the influence of regurgitant volume on pulmonary venous blood flow patterns in an animal model with quantifiable mitral regurgitation.

Background: Systolic pulmonary venous blood flow is influenced by atrial filling and compliance and ventricular output and by the presence of mitral regurgitation. The quantitative severity of the regurgitant volume itself is difficult to judge in clinical examinations.

Color Doppler regurgitant jet area for evaluating eccentric mitral regurgitation: an animal study with quantified mitral regurgitation.

Objectives: The purpose of the present study was to rigorously evaluate the accuracy of the color Doppler jet area planimetry method for quantifying chronic mitral regurgitation.

Background: Although the color Doppler jet area has been widely used clinically for evaluating the severity of mitral regurgitation, there have been no studies comparing the color jet area with a strictly quantifiable reference standard for determining regurgitant volume.

Methods: In six sheep with surgically produced chronic mitral regurgitation, 24 hemodynamically different states were obtained.