INTRODUCTION: Conservative fluid management in patients with acute lung injury (ALI) increases time alive and free from mechanical ventilation. Vascular pedicle width (VPW) is a non-invasive measurement of intravascular volume status. The VPW was studied in ALI patients to determine the correlation between VPW and intravascular pressure measurements and whether VPW could predict fluid status. METHODS: This retrospective cohort study involved 152 patients with ALI enrolled in the Fluid and Catheter Treatment Trial (FACTT) from five NHLBI ARDS (Acute Respiratory Distress Syndrome) Network sites. VPW and central venous pressure (CVP) or pulmonary artery occlusion pressure (PAOP) from the first four study days were correlated. The relationships between VPW, positive end-expiratory pressure (PEEP), cumulative fluid balance, and PAOP were also evaluated. Receiver operator characteristic (ROC) curves were used to determine the ability of VPW to detect PAOP <8 mmHg and PAOP ≥18 mm Hg. RESULTS: A total of 71 and 152 patients provided 118 and 276 paired VPW/PAOP and VPW/CVP measurements, respectively. VPW correlated with PAOP (r = 0.41; P < 0.001) and less well with CVP (r = 0.21; P = 0.001). In linear regression, VPW correlated with PAOP 1.5-fold better than cumulative fluid balance and 2.5-fold better than PEEP. VPW discriminated achievement of PAOP <8 mm Hg (AUC = 0.73; P = 0.04) with VPW ≤67 mm demonstrating 71% sensitivity (95% CI 30 to 95%) and 68% specificity (95% CI 59 to 75%). For discriminating a hydrostatic component of the edema (that is, PAOP ≥18 mm Hg), VPW ≥72 mm demonstrated 61.4% sensitivity (95% CI 47 to 74%) and 61% specificity (49 to 71%)(area under the curve (AUC) 0.69; P = 0.001). CONCLUSIONS: VPW correlates with PAOP better than CVP in patients with ALI. Due to its only moderate sensitivity and specificity, the ability of VPW to discriminate fluid status in patients with acute lung injury is limited and should only be considered when intravascular pressures are unavailable.

Left ventricular (LV) diastolic dysfunction (DD) is diagnosed by Doppler echocardiography (DE) and Tissue Doppler imaging (TDI). Velocity vector imaging (VVI) evaluates myocardial deformation (strain). We studied left atrial (LA) deformation and volumes by VVI in relation to established Doppler-derived indices of LV diastolic function in diabetic patients. MATERIAL: Using DE and TDI , 87 patients (males 49%; age 60+/-7 years) with type 2 diabetes mellitus were classified as having no (n=60), mild (n=13) or moderate (n=14) DD. RESULTS: LA volume was larger in moderate (72.3+/-22.4 ml) than in mild DD (58.8+/-16.1 ml; p=0.01) and no DD (57.9+/-16.0 ml; p=0.01). LA roof strain distinguished no DD from mild and moderate DD (p=0.0073). Systolic LA strain correlated to total emptying fraction (r=0.70, p<0.0001), and inversely to LA volume (r=-0.35, p=0.0009). A cross-validated analysis of no versus mild or moderate DD expressed by LA strain revealed a positive predictive value of 48% and negative of 84%. CONCLUSION: LA strain by VVI is impaired in patients with type 2 diabetes mellitus and mild or moderate LV DD. LA strain seems of value in distinguishing normal from abnormal diastolic function. VVI offers new information on regional LA function and LA volumes but has too limited discriminative power to detect early LV DD.

Sudden cardiac death (SCD) is a field of continuous research. In order to answer various questions regarding SCD, several animal models have been developed. The aim of the present study is to describe our experimental model of inducing cardiac arrest in Landrace/Large White pigs, and then resuscitated according to the International Guidelines on resuscitation. Fifteen Landrace/Large White pigs were anaesthetized and intubated while spontaneously breathing. The left and right jugular veins, as well as the femoral and the carotid arteries, were surgically prepared. Induction of cardiac arrest was achieved by using an ordinary rechargeable lithium battery, through a pacemaker wire inserted into the right ventricle. The typical Advanced Life Support (ALS) protocol was followed, and in case of restoration of spontaneous circulation, the animals were further evaluated for 30 min. Seven animals were successfully resuscitated using this protocol, whereas eight failed resuscitation efforts. Successful resuscitation was contingent on the restoration of the levels of coronary perfusion pressure and PETCO(2) during chest compressions. Among the different ways of inducing cardiac arrest, the ordinary lithium battery is a simple, safe and valuable technique. Landrace/Large White pigs' baseline haemodynamics closely resemble human haemodynamics, making the breed a favourable model for resuscitation.

Left ventricular end diastolic (LVEDP) and mean right atrial (RAP) pressures were recorded simultaneously in 30 patients with shock (14 acute myocardial infarction, 10 acute pulmonary embolism or severe bronchopulmonary disease, and 6 sepsis). Myocardial infarction was characterized by a predominant increase in LVEDP, pulmonary disease by a predominant increase in RAP, and sepsis by a normal relationship between LVEDP and RAP. In all three groups a significant positive correlation was noted between RAP and LVEDP, with the regression line in cor pulmonale deviated significantly toward the RAP axis and the regression line in myocardial infarction exhibiting a zero RAP intercept at an elevated LVEDP.Low cardiac outputs with elevated LVEDP in myocardial infarction indicated severe left ventricular failure. Low outputs with elevated RAP in cor pulmonale were consistent with right ventricular overload. Although cardiac outputs often were normal in sepsis, low outputs with elevated cardiac filling pressures in some patients were consistent with a hemodynamic or humoral-induced generalized depression of cardiac performance.Vasoconstrictor and inotropic drugs often produced a functional disparity between the two ventricles, with the gradient between LVEDP and RAP increasing, apparently because of an increase in left ventricular work or an inadequacy of left ventricular oxygen delivery. Acute plasma volume expansion with dextran in patients with pulmonary vascular disease resulted in a somewhat more rapid rise in RAP than in LVEDP. In septic and myocardial infarction shock, however, LVEDP and RAP usually rose proportionally, with the absolute rise of LVEDP surpassing that of RAP. Although the absolute level of the central venous pressure thus may not be a reliable indicator of left ventricular function in shock, changes in venous pressure during acute plasma volume expansion should serve as a fairly safe guide to changes in LVEDP.

OBJECTIVE Pulmonary artery occlusion pressure and central venous pressure have been considered to be reliable measures of left and right ventricular preload in patients requiring invasive hemodynamic monitoring. Studies in recent years have questioned the correlation between these estimates of ventricular filling pressures and ventricular end-diastolic volumes/cardiac performance variables in specific patient groups, but clinicians have continued to consider the relationship valid in the broader context. The objective of this study was to assess the relationship between pressure estimates of ventricular preload (pulmonary artery occlusion pressure, central venous pressure) and end-diastolic ventricular volumes/cardiac performance in healthy volunteers. DESIGN Prospective, nonrandomized, nonblinded interventional study. SETTING Cardiac catheterization and echocardiography laboratories. SUBJECTS Normal healthy volunteers (n = 12 group 1, n = 32 group 2). INTERVENTIONS Pulmonary catheterization and radionuclide cineangiography (group 1) and volumetric echocardiography (group 2) during 3 L of normal saline infusion over 3 hrs. MEASUREMENTS AND MAIN RESULTS In group 1, the initial pulmonary artery occlusion pressure and central venous pressure did not correlate significantly with initial end-diastolic ventricular volume indexes or cardiac performance (cardiac index and stroke volume index). Changes in pulmonary artery occlusion pressure and central venous pressure following saline infusion also did not correlate with changes in end-diastolic ventricular volume indexes or cardiac performance. In contrast, initial end-diastolic ventricular volume indexes and changes in these ventricular volume indexes in response to 3 L of normal saline loading correlated well with initial stroke volume index and changes in stroke volume index, respectively. The relationship between left ventricular end-diastolic volume index and stroke volume index was confirmed in group 2 subjects using mathematically independent techniques to measure these variables. In addition, initial central venous pressure, right ventricular end-diastolic volume index, pulmonary artery occlusion pressure, and left ventricular end-diastolic volume index failed to correlate significantly with changes in cardiac performance in response to saline infusion in group 1 subjects. CONCLUSIONS Normal healthy volunteers demonstrate a lack of correlation between initial central venous pressure/pulmonary artery occlusion pressure and both end-diastolic ventricular volume indexes and stroke volume index. Similar results are found with respect to changes in these variables following volume infusion. In contrast, initial end-diastolic ventricular volume indexes and changes in end-diastolic ventricular volume indexes in response to saline loading correlate strongly with initial and postsaline loading changes in cardiac performance as measured by stroke volume index. These data suggest that the lack of correlation of these variables in specific patient groups described in other studies represents a more universal phenomenon that includes normal subjects. Neither central venous pressure nor pulmonary artery occlusion pressure appears to be a useful predictor of ventricular preload with respect to optimizing cardiac performance.

Myocardial oxygen consumption was measured in 11 anesthetized, open-chest dogs in order to compare in the same heart the relative influence on oxygen usage of tension development and the contractile or inotropic state, as reflected in V(max.) the maximum velocity of shortening of the unloaded contractile elements. The isovolumetrically contracting left ventricle was studied with left ventricular volume, heart rate, and systemic perfusion rate controlled. Wall tension, contractile element velocity, and V(max) were calculated. Peak developed tension was increased at a constant V(max) by increasing ventricular volume, and the effect on oxygen consumption was determined. Oxygen utilization was then redetermined at an increased V(max) but at a constant peak developed tension by infusing norepinephrine (0.76 to 7.6 mug/min) and decreasing ventricular volume to match the tension existing before norepinephrine infusion. Oxygen consumption consistently increased with increases in both developed tension and V(max) with the following multiple regression equation relating these variables: myocardial oxygen consumption (mul/beat per 100 g in LV)= K + 0.25 peak developed tension (g/cm(2))+ 1.43 V(max)(cm/sec). These data indicate that the oxygen cost of augmentation of contractility is substantial, can be independent of any change in fiber shortening, and is similar in order of magnitude to the effect of alterations in tension development

Transseptal (TS) catheterization was introduced in 1959 as a strategy to directly measure left atrial (LA) pressure. Despite acceptable feasibility and safety, TS catheterization has been replaced by indirect measurements of LA pressure using the Swan-Ganz catheter. Today, TS puncture is rarely performed for diagnostic purposes but continues to be performed for procedures such as balloon mitral valvuloplasty, antegrade balloon aortic valvuloplasty, and ablation of arrhythmias in the LA. Thus, the "art" of TS puncture has been lost, except in centers that perform these procedures with regularity. Recently, there has been a renewed interest in the TS technique because of emerging therapeutic procedures for structural heart disease and atrial fibrillation ablation. Invasive cardiologists will have to refamiliarize themselves with the TS technique, newer TS devices, and advanced ultrasound imaging for guidance of the procedure.

Development in the 1950s of the transseptal technique for left heart catheterization is described. Initial studies in animals and human cadavers were followed up by left atrial puncture with measurements of left atrial and left ventricular (LV) pressure (the latter using a small plastic catheter) in patients with cardiac disease. Many such procedures were performed safely without complications. Subsequent modification of the original technique for percutaneous catheter insertion allowed placement of a larger taper-tipped catheter in the LV chamber for selective LV angiography. Early clinical research studies at the National Heart Institute were performed using the transseptal method; these included investigation of the effects of increasing afterload on the normal and failing left ventricle by means of a graded angiotensin infusion to induce a progressive increase in aortic pressure. A marked decrease in the stroke volume occurred with increased afterload in the failing heart. This finding later led to the concept of afterload mismatch with limited pre-load reserve. Another early transseptal catheterization study in which measurements of LV pressure were made at different locations within the left ventricle as well as in the left atrium confirmed the presence of cavity obliteration in some patients and true obstruction in the LV outflow tract in many others. In addition, left ventriculography showed that obstruction was caused by abnormal anterior position during systole of the anterior mitral valve leaflet. With growing acceptance of retrograde catheterization of the left ventricle, the use of the transseptal technique for diagnostic purposes declined. However, in recent years, substantial renewed application of the transseptal method has occurred for special diagnostic and therapeutic purposes, including balloon valvuloplasties and electrophysiologic ablation procedures within the left heart.

BACKGROUND It is known that a spectrum of changes in structure, size and function of the different chambers of the heart occur in individuals with hypertension. The earliest changes and the sequence of these changes are still being studied. AIMS The present study aimed to assess early changes in the left atrial size and function in hypertension, and its relationship with left ventricular geometry and other factors that may influence left atrial size. METHODS One hundred consecutive subjects who were newly diagnosed with hypertension and 50 apparently normal individuals were recruited into the study. Standard M-mode, two-dimensional and Doppler echocardiography were performed. The endocardial border of the left atrium was traced to obtain the atrial area and left atrial volumes and emptying fractions were derived from measured areas. RESULTS The hypertensive patients and the controls were comparable by age, sex and body mass index. Thirty-seven (37%) of the hypertensive subject had increased left ventricular mass versus eight subjects (16%) in the normal controls. The patients with hypertension had a higher linear left atrial dimension (3.5 +/- 0.48 cm versus 3.1 +/- 0.47 cm, P < 0.0001), longer pre-atrial contraction length (3.8 +/- 0.56 cm versus 3.6 +/- 0.45 cm; P = 0.02) and higher peak late mitral inflow velocity (0.64 +/- 0.19 m/s versus 0.56 +/- 0.15 m/s; P = 0.010). CONCLUSIONS Changes in the geometry of the left ventricle occur early in hypertension and precede deterioration in left ventricular systolic function. The corresponding left atrial changes are marginal and are indicative of increased left atrial length and accentuated atrial systolic function.

The images and videos presented in this article illustrate a diagnostic transseptal left heart catheterization for a patient with a prosthetic mitral valve guided by live three-dimensional (3D) transesophageal echocardiography. This method provided high-quality 3D imaging that was useful in guiding transseptal puncture and demonstrating prosthetic valve function during this evaluation.

AIMS Transseptal puncture (TP) can be a difficult procedure and is not without risk of complications. The purpose of this study was to evaluate the use of three-dimensional multi-detector row computed tomography (MDCT) to localize the fossa ovalis (FO) and facilitate TP in patients undergoing left atrial catheter ablation. METHODS AND RESULTS Fourteen consecutive patients were studied. Thirteen patients underwent pulmonary vein isolation and one patient had ablation for left atrial flutter. All patients underwent cardiac MDCT imaging pre-ablation for use in conjunction with electroanatomic mapping. Prior to puncturing the interatrial septum, standard fluoroscopic views of the transseptal sheath were compared with corresponding MDCT images tagging the FO. Successful, uncomplicated TP was achieved in all 14 patients. The mean duration of TP was 15.6 +/- 10.0 min. The average fluoroscopy time was 8.5 +/- 7.4 min. The MDCT images were deemed helpful in facilitating TP in 13 patients (93%). CONCLUSION This study demonstrates the feasibility of MDCT to localize the FO and aid TP. For patients undergoing left atrial ablation in whom MDCT imaging is undertaken pre-ablation, tagging the FO can be easily performed and is a novel tool for guiding transseptal catheterization without additional risk.

BACKGROUND Arterial hypertension determines distinct adaptive left ventricular geometric responses, which may differently affect left ventricular function and left atrial performance. OBJECTIVES In this study, the effect of left ventricular geometry on left atrial size and function, and the relationship between left atrial size and left ventricular mass were assessed in 336 patients with systemic arterial hypertension who had undergone Doppler echocardiography. METHODS AND RESULTS Patients were classified into concentric (110 patients with concentric left ventricular geometry defined as relative wall thickness > or = 0.44) and eccentric groups (226 patients with relative wall thickness < 0.44). Comparison to the latter, the former had greater left atrial size, left atrial ejection force, left ventricular mass and lower left ventricular midwall fractional shortening. Left ventricular concentric, rather than eccentric, geometry emerged by multivariate analysis as a factor independently associated with the highest degree of left atrial ejection force. Left atrial size was positively related to left ventricular mass in the whole population (r = 0.65, SEE = 6 ml, P < 0.00001). This relationship was maintained in the subgroups with concentric (r = 0.65, SEE = 6 ml, P < 0.00001) or eccentric geometry (r = 0.59, SEE = 6 ml, P < 0.00001). CONCLUSIONS Our results indicate that the relationship of left ventricular geometry to both left atrial size and ejection force in hypertensive patients is relevant. Concentric left ventricular geometry is associated with greater left atrial size and ejection force than eccentric geometry, suggesting that increased left ventricular stiffness has a greater effect in stimulating left atrial performance than left ventricular end-systolic stress. The degree of left atrial enlargement similarly depends on left ventricular mass in patients with concentric and eccentric geometry.

Although modeling the four-chambered heart as a constant-volume pump successfully predicts causal physiological relationships between cardiac indexes previously deemed unrelated, the real four-chambered heart slightly deviates from the constant-volume state by ventricular end systole. This deviation has consequences that affect chamber function, specifically, left atrial (LA) function. LA attributes have been characterized as booster pump, reservoir, and conduit functions, yet characterization of their temporal occurrence or their causal relationship to global heart function has been lacking. We investigated LA function in the context of the constant-volume attribute of the left heart in 10 normal subjects using cardiac magnetic resonance imaging (MRI) and contemporaneous Doppler echocardiography synchronized via ECG. Left ventricular (LV) and LA volumes as a function of time were determined via MRI. Transmitral flow, pulmonary vein (PV) flow, and lateral mitral annular velocity were recorded via echocardiography. The relationship between the MRI-determined diastolic LA conduit-volume (LACV) filling rate and systolic LA filling rate correlate well with the relationship between the echocardiographically determined average flow rate during the early portion of the PV D wave and the average flow rate during the PV S wave (r = 0.76). We conclude that the end-systolic deviation from constant volume for the left heart requires the generation of the LACV during diastole. Because early rapid filling of the left ventricle is the driving force for LACV generation while the left atrium remains passive, it may be more appropriate to consider LACV to be a property of ventricular diastolic rather than atrial function.

OBJECTIVE To establish normal values of left atrial and left ventricular volumes and function in children and young adults using three dimensional echocardiography (3DE). METHODS 169 healthy subjects aged 2 to 27 years were studied by digitised 3DE. 3DE was achieved using rotational acquisition of planes at 18 degrees intervals from the parasternal view for the left atrium and from the transthoracic apical view for the left ventricle with ECG gating and without respiratory gating. Left atrial and left ventricular volumes could be calculated throughout the heart cycle, and the respective time-volume curves were reconstructed in each subject. RESULTS For the analysis the subjects were divided into five groups according to body surface area: 0.5-0.75 m2, 0.75-1.0 m2, 1.0-1.25 m2, 1.25-1.5 m2, and over 1.5 m2. Mean (SD) left atrial maximum volume/body surface area was 19.6 (3.5), 21.7 (3.7), 22.0 (4.7), 24.5 (4.8), and 27.4 (6.4) ml/m2; left ventricular maximum volume/body surface area was 50.1 (8.8), 54.9 (10.1), 56.4 (9.9), 58.7 (11.0), and 64.4 (10.3) ml/m2. Left atrial active emptying increased from 19% to 35% with age (r = 0.34, p < 0.001) and with decreasing heart rate (r =-0.28, p < 0.001). CONCLUSIONS Transthoracic 3DE is well suited for studying the phasic changes in left atrial and left ventricular volumes in young children as well as in adults. The data obtained from 169 healthy subjects will serve as a reference for further studies in patients with various cardiac abnormalities.

OBJECTIVE To evaluate the prevalence of left atrial enlargement and the correlates of left atrial size in children and adolescents with essential hypertension. BACKGROUND Left atrial enlargement has been associated with increased risk of cardiovascular disease, including stroke in adults. Risk factors for left atrial size in adults with hypertension include age, race, and obesity. METHODS AND RESULTS Patients (n =112; average age, 14.2 years) with essential hypertension were studied with echocardiography. The average left atrial dimension was 2.8 (+/- 0.5) cm; 51% patients had left atrial dimension >95% upper confidence limit. The patients with left atrial enlargement had greater body mass index (P <.05) than those without left atrial enlargement. In multiple regression analysis, height, body mass index, systolic blood pressure, and left ventricular geometry were significant independent correlates of left atrial size. Children with eccentric left ventricular hypertrophy were more likely to have a larger left atrial dimension. CONCLUSIONS Left atrial enlargement is prevalent in children and adolescents with essential hypertension. This may indicate an increased risk of cardiovascular disease morbidity and mortality. Control of obesity and blood pressure elevation offer two approaches for treatment that may prevent left atrial enlargement.