Systolic Forward Flow Research Articles

Comparison Between Transcranial Color Doppler Ultrasonography and Angiography in the Confirmation of Brain Death

Objective Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Angiography has been considered the gold standard in the diagnosis of BD but is invasive. We validated transcranial color Doppler ultrasonography (TCD) to confirm BD by comparing it to angiography. Patients and methods Forty patients experienced the clinical diagnosis of brain death due to head injury in 19 cases (47.5%), cerebral hemorrhage in 11 (27.5%), subarachnoid hemorrhage in 7 (17.5%), and cerebral infarction in 3 (7.5%). Blood pressure, heart rate, S PO2, and P CO2 were monitored throughout the study. Patients were excluded if episodes of hypoxia, arrhythmia, and hypotension occurred during examinations, or if the TCD was not technically feasible. Results Both angiography and TCD confirmed BD in all patients. The agreement between the above methods to confirm BD was 100%. Angiography showed the absence of filling of intracranial arteries, while TCD revealed: (1) brief systolic forward flow or systolic spikes and diastolic reversed flow (50%); (2) brief systolic forward flow or systolic spikes and no diastolic flow (25%); (3) no demonstrable flow in a patient in whom flow had been clearly documented on a previous TCD examination (12.5%). Five patients required repeated TCD examinations, because of initial detection of a diastolic to-and-fro flow pattern. BD was confirmed by TCD in the above patients after 30 hours of clinical BD. Conclusion TCD was a sensitive tool to diagnose BD, affording a reliable alternative examination to standard angiography.

Atypical ductus venosus blood flow pattern in fetuses with severe tricuspid valve regurgitation

We observed seven cases of atypical ductus venosus (DV) blood flow velocity waveform pattern with impairment of systolic forward flow resulting in a notch or a significant reduction in peak velocity during the S-wave in systole. All affected fetuses had severe tricuspid valve regurgitation associated with congestive heart failure and/or cardiac malformations. The decrease in venous systolic forward flow modulates the venous pulsatility indices towards more favorable values and should be considered when fetuses with tricuspid regurgitation are followed by Doppler assessment of the DV. Detection of these changes in the DV flow profile should prompt detailed color Doppler echocardiography with special emphasis on right atrioventricular valve regurgitation.

Pulmonary resistance in cardiovascular context

Comparison of the human cardiovascular system with arrangements of circulatory systems found in lower vertebrates and invertebrates allows appreciation of the functional elegance of our double circulation with systemic and pulmonary vascular trees served by a single looped and septated heart. In the pulmonary part of the circulation, consideration of the nature of alveolar microvessels in relation to the system as a whole may throw light on the pathophysiology of pulmonary regurgitation and pulmonary hypertension. Pulmonary microvessels impose remarkably little resistance to flow compared with the systemic. This may be attributed to their delicate, compliant structure, with tissue support on one side only, their respiratory walls remaining relatively free to expand in alveolar air. Low resistance may also depend on the branch pattern of alveolar capillaries, with almost immediate proximity between bifurcations and confluences in a uniquely dense, interconnected network. In the presence of free pulmonary regurgitation, pulmonary microvessels probably play a valve-like role, representing a low-resistance boundary or watershed between pulmonary arteries and veins. This microvascular watershed imposes little resistance to systolic forward flow, but in diastole, with venous pressures being kept low by function of the left heart, there is presumably little or no reversal of gradient to move blood back through the capillaries. The delicacy and potential vulnerability of alveolar capillaries to elevation of flow and pressure is likely, however, to go with a protective feedback circuit which, in abnormal circumstances, could contribute to development of arteriolar medial hypertrophy and pulmonary arterial hypertension.

P01.14: Atypical reduction of ductus venosus systolic forward flow in three fetuses with severe tricuspid regurgitation

P01.14: Atypical reduction of ductus venosus systolic forward flow in three fetuses with severe tricuspid regurgitation

Myocardial blood supply through a direct left ventricle–coronary artery shunt is not aided by augmented coronary capacitance

Objectives Left ventricle–coronary artery shunting is proposed as an alternative means of myocardial revascularization when standard methods are not an option. During diastole, however, regurgitant coronary flow to the left ventricle decreases the efficacy of the left ventricle–coronary artery shunt. We investigated whether augmented coronary compliance would improve net forward shunt flow. Methods In 11 anesthetized pigs a specially designed stent was placed through the lateral wall of the left ventricle. Through an arterial graft, it was connected to the proximal left anterior descending coronary artery. A blind stump of the right internal thoracic artery (15 cm) was anastomosed to the distal left anterior descending coronary artery to serve as added coronary compliance chamber. Blood flow was measured in the coronary artery just distal from the left ventricle–coronary artery shunt, as well as in the shunt and in the compliance chamber entrance-exit. Results The left ventricle–coronary artery shunt decreased the net forward midcoronary flow to 53% ± 18% (mean ± SD) of native flow (8 ± 4 vs 16 ± 5 mL/min at baseline, P < .01). The augmented compliance did not significantly increase net forward coronary flow (61% ± 25% of native flow, P < .01 vs baseline and P = .21 vs left ventricle–coronary artery shunt with normal compliance). The increase in systolic forward flow (53 ± 23 vs 37 ± 19 mL/min with normal compliance) was accompanied by a similar increase in diastolic regurgitant flow (−26 ± 20 vs −16 ± 16 mL/min). Conclusion In healthy pigs a left ventricle–coronary artery shunt decreased net forward coronary flow to 53% ± 18% of native flow. Augmentation of coronary artery compliance did not improve shunt performance.

Respiratory variation in superior vena cava flow in patients with chronic obstructive pulmonary disease: Estimation of pulmonary hypertension using Doppler flow index

Patients with chronic obstructive pulmonary disease (COPD) are difficult to assess by conventional transthoracic echocardiography (TTE) because of emphysematous lungs or mediastinal deviation. We hypothesized that superior vena cava (SVC) flow is related to pulmonary circulation and may be useful for the detection of pulmonary hypertension (PH) in patients with COPD that cannot been assessed by direct evaluation using the tricuspid regurgitant Doppler velocity. SVC Doppler flow velocities were examined in 46 patients with COPD and the pressure gradient between the right ventricular and right atrial pressure (RV-RAΔP) was calculated by tricuspid regurgitant Doppler velocities. The patients were divided into 2 groups: 11 patients with PH (RV-RAΔP > 25 mm Hg) were compared with 35 without PH. There was no significant difference in the maximal SVC peak systolic forward flow velocity during inspiration (INS) between these 2 groups. However, the minimal SVC peak systolic forward flow velocity during expiration (EXP) in the group with PH was significantly higher than that in the group without PH (37.4 ± 20.0 cm/s vs 26.4 ± 8.5 cm/s, P = .01). Linear regression analysis revealed a significant correlation between RV-RAΔP and the EXP/INS ratio ( r = 0.61, P < .001). In COPD patients with PH, the increased expiratory SVC systolic flow supplemented the preload for the impaired right ventricular filling flow caused by PH, thereby maintaining the transtricuspid driving pressure. Our observation suggests that respiratory variation in SVC systolic forward flow may be a sensitive Doppler flow index for evaluating severity of PH in patients with COPD that cannot been assessed by conventional TTE. (J Am Soc Echocardiogr 2002;15:1165-9.)

Prediction of mean pulmonary wedge pressure using Doppler pulmonary venous flow variables in hypertrophic cardiomyopathy

We examined whether pulmonary venous flow variables, assessed by transthoracic Doppler echocardiography, could predict mean pulmonary wedge pressure in hypertrophic cardiomyopathy. Forty-four patients with no left ventricular systolic dysfunction (left ventricular fractional shortening ≥25%) were studied. Forty patients with systolic dysfunction (dilated cardiomyopathy group) served as control. Mitral and pulmonary venous flow velocity curves were recorded with the pulsed-Doppler method and were related to mean pulmonary wedge pressure obtained by right heart catheterization. In hypertrophic cardiomyopathy group, the systolic ( r=−0.15, P=0.335) and diastolic ( r=0.35, P=0.022) forward flow velocity were poorly related to mean pulmonary wedge pressure, whereas the velocity of atrial reversal ( r=0.68, P<0.001) correlated well with mean pulmonary wedge pressure. In dilated cardiomyopathy group, the systolic ( r=−0.51, P=0.001) and diastolic ( r=0.60, P<0.001) forward flow velocity were strongly related to mean pulmonary wedge pressure. With the cut-off value set at the velocity of atrial reversal >30 cm/s in hypertrophic cardiomyopathy group, the sensitivity for predicting mean pulmonary wedge pressure >15 mmHg was 79% and the specificity was 73%. In conclusion, the atrial component of the pulmonary venous flow can be used to predict mean pulmonary wedge pressure in hypertrophic cardiomyopathy.

Diastolic ventricular interaction in normal and dilated heart during head-up tilting.

The normal human heart behaves as a single functional unit during preload reduction; adaptations of the left ventricle to head-up tilting is mediated through ventricular interdependence and biventricular-lung interaction. We hypothesized that reduction of venous return in dilated cardiomyopathy is likely to have a great effect on ventricular chamber geometry and filling. The aim of this study was to evaluate the effects of gradual head-up tilting in normal subjects and in patients with dilated cardiomyopathy, addressing special attention to right (RV) and left ventricular (LV) dimensions, geometry, and filling, and to biventricular-lung interaction. Twenty normal subjects and 23 patients with moderate heart failure due to dilated cardiomyopathy were studied with two-dimensional and Doppler echocardiography in supine position and after 20 degrees, 40 degrees, and 60 degrees tilting. Right ventricular and LV dimensions, LV geometry, and tricuspid, mitral, and pulmonary venous flow patterns were recorded at each step of the study. Geometric changes of the LV were evaluated by measurements of volumes and diameters in the apical four-chamber view (which identifies the interventricular septum and lateral wall) and apical two-chamber view (which identifies the inferior and anterior wall of the LV). In the two groups, tilting was associated with reduction of RV area and LV diameter and volumes; percent variations in LV diameter and volumes recorded in four-chamber view were lower at each step of tilting than with those derived from the two-chamber view in controls and in patients. In normal subjects, mitral and tricuspid peak early flow velocities were decreased at any tilting level; peak late velocities were unchanged; peak velocity of systolic forward flow of the pulmonary vein was reduced, diastolic forward flow was unchanged, and the difference in duration between reverse pulmonary flow and forward mitral A wave was reduced. Doppler findings were qualitatively similar in patients, but tilting induced a more marked redistribution of LV filling to late diastole because of a significant increase in atrial contribution. Preload reduction by tilting induces profound effects on left and right dimensions, geometry, and filling in normal and dilated heart; reduction or RV dimensions are associated with changes in LV ventricular geometry (minimal reduction in septal-lateral diameter, marked reduction in anterior-posterior diameter), redistribution of right and left diastolic filling to late diastole, and redistribution of pulmonary venous flow to early diastole. These mechanisms are probably due to a favorable interaction between heart and lungs, which increases compliance within the pericardial space and facilitates redistribution of flow from the lungs. Even a minimal amount of preload reduction causes more marked effects in LV filling patterns in dilated cardiomyopathy than in normal hearts, confirming that ventricular interaction and pericardial constraint are increased when heart volume enlarges.

Ductus venosus flow velocity in newborn lambs during increased pulmonary artery pressure.

The aim of the present study was to assess with ultrasound the ductus venosus flow velocity in newborn lambs with increasing pulmonary artery pressures and to evaluate whether this is a useful method to detect elevated pulmonary artery pressure. The ductus venosus flow velocity was studied with pulsed-wave Doppler echocardiography in nine newborn lambs < or = 30 h old. The lambs were anesthetized, mechanically ventilated, and instrumented to measure mean airway pressure and pulmonary artery and arterial blood pressures. A vascular occluder was placed around the main pulmonary artery. With mean pressures ranging from 20 to 50 mm Hg in the pulmonary artery, the ductus venosus flow velocity was examined. In seven lambs, the mean portal pressure and central venous pressure were also measured. With a stepwise increase in the pulmonary artery pressure, the minimum ductus venosus flow velocity during atrial systole decreased to a reversed flow, and the duration of this reversed flow component increased. The systolic forward peak flow velocity signal also gradually decreased. No changes were detected in the mean central venous or in the portal pressure with increasing pulmonary artery pressure or changes in ductus venosus flow. The flow velocity in the ductus venosus, which is higher than in other precordial veins, shows a reduction and even reversal of the nadir and an increase of the duration of reversed flow during atrial systole as a response to increased pulmonary artery pressure. Thus, Doppler ultrasound of the ductus venosus flow velocity may be a useful noninvasive diagnostic supplement to detect pulmonary hypertension of the newborn.

Effect of Atrial Fibrillation on Pulmonary Venous Flow Patterns Assessed by Doppler Transesophageal Echocardiography

To investigate the effect of atrial fibrillation (AF) on pulmonary venous flow (PVF) patterns in a cohort with nonrheumatic AF. A prospective and controlled study undertaken at a tertiary referral medical center. The echocardiographic parameters of left superior PVF as assessed by Doppler transesophageal echocardiography in 40 patients with chronic AF (group 1) were compared to those of 33 volunteers with sinus rhythm (group 2) and well-matched baseline characteristics. : All group 1 patients presented with single systolic forward flow (SFF) patterns. In contrast, single and double SFF patterns were found equally in group 2. With regard to reverse flow (RF), most group 1 patients (33 of 40) had an early systolic RF and none had atrial RF; however, most group 2 subjects (29 of 33) had an atrial RF. Some of the group 1 patients (17%) had a late systolic RF in the absence of significant mitral regurgitation. In group 1, the SFF appeared later and disappeared earlier than in group 2. The mean systolic peak velocity and time-velocity integral (TVI) of the SFF were significantly lower in group 1 compared to group 2. The diastolic peak velocity and TVI were not significantly different between groups. : Our data indicate that AF independently and significantly affects the PVF and leads to characteristic flow patterns different from sinus rhythm. The presence of AF reduces SFF in addition to the absence of atrial RF. These changes in the flow patterns should be taken into account while interpreting the implications of PVF in the presence of AF.

Assessment of Right Atrial Pressure With 2-Dimensional and Doppler Echocardiography: A Simultaneous Catheterization and Echocardiographic Study

To derive a clinically useful, noninvasive determination of right atrial pressure. Noninvasive assessment of right ventricular systolic pressure from Doppler-derived tricuspid regurgitant velocity requires an accurate assumption of right atrial pressure. Seventy-one patients were studied in the cardiac catheterization laboratory, comparing right atrial pressure (measured at mid systole) with simultaneous 2-dimensional echocardiographic measurement of inferior vena cava diameter and Doppler recordings of hepatic vein systolic, diastolic, and atrial reversal velocities. The initial 28 patients were used to derive a clinical algorithm to predict right atrial pressure, which was tested in the subsequent 43 patients. Inferior vena cava dimension correlated directly with right atrial pressure (r2=0.74; P<.001). The systolic filling fraction of the hepatic vein velocity curves correlated poorly with right atrial pressure. However, the correlation between the hepatic vein Doppler sum of systolic forward flow velocity and atrial reversal velocity and right atrial pressure was inverse (r2=0.32; P=.002). With a combination of variables from both inferior vena cava diameter and hepatic vein velocity curves, patients can be divided into those with normal right atrial pressure, mildly increased right atrial pressure, and severely increased right atrial pressure. The combined information from inferior vena cava diameter and hepatic vein velocity curves can be used to assess right atrial pressure.

Correlation of the Flow Patterns among the Four Pulmonary Veins as Assessed by Transesophageal Echocardiography: Influence of Significant Mitral Regurgitation

Aims: To evaluate the correlation of the flow patterns of the four pulmonary veins as assessed by transesophageal echocardiography and the influence of significant mitral regurgitation on this correlation. Methods and Results: Eighty-eight patients with normal sinus rhythm and variable underlying cardiovascular diseases underwent transthoracic and transesophageal echocardiographic studies. Doppler flow of the four pulmonary veins could not be adequately interpreted in 19 patients (22%). The left atrial dimension of these patients was significantly larger than that of the patients with complete study of the flow in the four pulmonary veins (49 ± 6 vs. 43 ± 7 mm; p < 0.05). Of the 69 patients with complete evaluation of the four pulmonary veins, 48 patients without significant mitral regurgitation were analyzed as group A, and the remaining 21 patients as group B. The peak systolic and diastolic forward flow velocities of the four pulmonary veins were measured and the ratio of peak systolic (S) to diastolic (D) flow velocity was calculated. Group A had a significantly larger S/D ratio in all four pulmonary veins than group B (p < 0.05 in each pulmonary vein measurement). There was good correlation of the flow pattern represented as S/D ratio between left upper and lower pulmonary veins (r = 0.90) and between right upper and lower pulmonary veins (r = 0.89) in group A. The correlation of the flow pattern among the four pulmonary veins deteriorated in group B. Conclusion: Pulmonary veins on the same side share rather similar flow patterns in comparison with pulmonary veins on the opposite sides. The correlation of flow patterns among the four pulmonary veins is good in subjects without significant mitral regurgitation, but it worsens in patients with significant mitral regurgitation. Therefore, cautious interpretation of flow patterns of the four pulmonary veins in patients with significant regurgitation is indicated for grading the severity of mitral regurgitation.

Influence of gravity on pulmonary venous flow velocity patterns: Analysis of left and right pulmonary venous flow velocities in left and right decubitus positions

Background The pulmonary venous flow signal measured by transesophageal echocardiography is generally recorded from the left upper pulmonary vein in the left lateral decubitus position, whereas that by transthoracic echocardiography is from the right upper pulmonary vein in the left semi–lateral decubitus position. The purpose of this study was to evaluate the influence of the postural change on the peak flow velocities of the left and right pulmonary veins and whether the parameters of the left and right pulmonary venous flow can be used interchangeably. Methods and Results The study group consisted of 37 patients with normal left ventricular filling pressure and in whom the systolic forward flow signals from both pulmonary veins recorded in the left and right lateral decubitus positions were clear enough to differentiate as biphasic. The peak early systolic (peak S1) and diastolic velocities were significantly increased when the pulmonary vein was on the recumbent subject’s upper side, whereas the peak late systolic velocity (peak S2) was significantly increased when the pulmonary vein was on the recumbent subject’s lower side. The peak S1 was higher than the peak S2 when the pulmonary vein was on the recumbent subject’s upper side, whereas the reverse relation was seen when the pulmonary vein was on the recumbent subject’s lower side. Conclusions We should take into consideration the body position and the side on which the pulmonary vein is situated in evaluating the peak flow velocities of the pulmonary veins. (Am Heart J 1999;137:419-26.)

Left ventricular diastolic function in normal human pregnancy.

Little information is available about changes in left ventricular diastolic function during pregnancy. We used mitral inflow and pulmonary venous flow profiles to evaluate left ventricular diastolic function in 37 healthy pregnant women 26 to 41 years old (mean, 32 years). Echocardiographic studies were performed at the end of each trimester. Eight subjects (control group) underwent similar testing 1 to 3.5 months (mean, 1.7 months) postpartum. During pregnancy, the cardiac output increased significantly as a result of an increased heart rate and, to a lesser degree, stroke volume. Significantly decreased systemic vascular resistance and increased left ventricular mass were also noted. Peak mitral flow velocity in early diastole (E) increased 13. 3% during the first trimester and remained at the high end of normal throughout pregnancy. Peak A-wave velocity (A) increased maximally in the third trimester. Compared with control subjects, first-trimester subjects had a significantly increased E/A ratio. The ratio subsequently decreased, reflecting the augmented A-wave velocity. Pulmonary venous peak systolic forward flow velocity increased, peaking in the second trimester (nonsignificant), but returned to baseline levels postpartum. The pulmonary venous diastolic time-velocity integral decreased significantly from the first to the third trimester. Peak pulmonary venous reverse flow velocity at atrial contraction increased significantly, without being markedly changed in duration. Pregnancy, a chronic, natural volume-overload state, has important effects on hemodynamic and echocardiographic variables. Based on pulmonary venous flow and left ventricular inflow velocities, our results provide a standard reference concerning diastolic filling dynamics by trimester.

Phasic flow events at the aortic isthmus–ductus arteriosus junction and branch pulmonary artery evaluated by multimodal ultrasonography in fetal lambs

Objectives: We assessed the phasic flow and interaction between the pulmonary trunk and aortic isthmus flow at their junction in the lamb fetus in late gestation and also assessed the interaction of the left pulmonary artery branch. Study Design: With echocardiographic and Doppler ultrasonographic and saline-contrast techniques, we studied 7 fetal lambs with arterial and venous catheters in place to assess direction, velocity, and timing of flow at the aortic isthmus, ductus arteriosus, and proximal left pulmonary artery. Results: At the isthmus-ductus junction, ductus systolic flow occurred later (0.048 ± 0.006 second, mean ± SD) and accelerated more slowly than isthmus flow but with higher velocities (peak 70.7 ± 7.1 vs 63.1 ± 6.3 cm/s, velocity time integral 5.7 ± 1.2 vs 4.5 ± 1.3 cm, respectively; P < .001). There was a small degree of late systolic flow reversal and admixture from both sources. Signals from the left pulmonary arterial branch showed a sharp, brief systolic forward flow with a peak velocity of 48.8 ± 9.1 cm/s, followed by late systolic and diastolic flow reversal with a peak velocity of 23.5 ± 8.7 cm/s. Conclusion: The differences in the flow timing may be the result of different timing of ventricular contraction, resistances in the vascular beds, and ductus constriction, both anatomic and physiologic. (Am J Obstet Gynecol 1998;179:1338-47.)

Pulmonary Venous Flow Doppler Velocities in Children

We report the results of a prospective study of pulmonary venous (PV) flow Doppler velocities in 68 normal children. We sought to establish the normal PV flow velocities in the broad pediatric population, compare these velocities to heart rate and age. In normal children, there is a wide range of PV flow velocities, most of which correlate with age and heart rate. However, the PV flow velocities and their durations do not distinguish the age groups. The peak velocity of systolic forward flow and atrial reversal flow in the pulmonary vein were independent of heart rate. The PV flow peak systolic velocity showed a weak correlation with the velocity of the mitral inflow early wave. However, the velocity of atrial reversal flow showed no correlation with the mitral inflow A velocity (late wave), which is generated by the same force of atrial contraction.(J Am Soc Echocardiogr 1998;11:132–7.)

Evaluation of Right Ventricular Function During CABG: Transesophageal Echocardiographic Assessment of Hepatic Venous Flow Versus Conventional Right Ventricular Performance Indices.

The vulnerability of right ventricle (RV) to ischemic insult during cardiac surgery is being increasingly recognized. This study aims to evaluate right ventricular function by measuring hepatic venous flow (HVF) patterns using intraoperative transesophageal echocardiography (TEE), and to compare HVF with other conventional two-dimensional echocardiographic and hemodynamic indices of RV performance. Patients undergoing coronary artery bypass grafting (CABG) were studied intraoperatively using a multiplane dual frequency 5/3.7-MHz phased array transducer, a pulmonary artery catheter, and an arterial catheter. Peak velocities and time velocity integrals of HVF pattern were studied. Peak systolic-diastolic ratio (S/D) of biphasic HVF and reverse flow ratio (% reverse flow/forward flow = % RF/FF) were also examined. Two-dimensional echocardiographic measurements included: (1) transverse plane long-axis (LA) and short-axis (SA) planimetered areas expressed as ratios; LA maximum major and minor-axis shortening fractions; (2) tricuspid annular plane systolic excursion (TAPSE) ratio. All data were obtained after induction of anesthesia (stage 1), after sternotomy (stage 2), aftercardiopulmonary bypass (CPB) (stage 3), and after sternal closure (stage 4). Pre-CPB all 35 patients had biphasic HVF by Doppler. In 31 patients peak S/D ratio was >1. After CPB, there was significant reduction in systolic forward flow (S wave), along with an increase in late systolic reverse flow (V wave) and an increase in % RF/FF. At this stage TAPSE ratio decreased (pre CPB 0.33 +/- 0.12 vs post CPB 0.30 +/- 0.11). There was simultaneous decrease in 2-D long-axis LA (pre CPB 0.52 +/- 0.11 vs post CPB 0.31 +/- 0.01) and max major axis LA (pre CPB 0.38 +/- 0.06 vs post CPB 0.31 +/- 0.11). Max major axis LA correlated significantly with changes in right atrial pressure (P < 0.05). Tricuspid annular motion diminished significantly at sternal closure. Hepatic systolic forward flow and TAPSE ratio can be an indirect measure of RV systolic functions in correlation with maximum major axis LA changes. Evaluation of HVF provides unique insight into right ventricular dynamics. It is an easy, safe, and sensitive method for assessing RV functions intraoperatively.

Pulmonary venous flow in normal dogs recorded by transthoracic echocardiography: techniques, anatomic validations and flow characteristics.

To observe pulmonary venous flow in dogs, the echocardiographic imaging planes and the techniques for examination, and the validations of anatomic location were investigated. Then, the velocity pattern of pulmonary venous flow was recorded in normal conscious dogs. Six imaging planes were available for observing the right or left caudal lobe pulmonary venous flow with two-dimensional or pulsed Doppler echocardiography. Of these, the left lateral apical 4-chamber view can be applied as standard view, because the pulmonary venous flow and transmitral flow could be recorded in this view simultaneously with small sampling angle. The velocity pattern of pulmonary venous flow demonstrated two forward waves in 19 of 20 dogs examined, with one peak occurring during ventricular systole and another during ventricular diastole. A reversed flow during atrial contraction was also seen in 11 dogs. In the two forward waves, the mean peak velocity and velocity-time integral of ventricular diastolic forward flow were significantly higher than those of systolic forward flow (46.49 +/- 6.79 vs. 31.13 +/- 4.92 cm/s, p < 0.0001 and 8.18 +/- 1.84 vs. 5.14 +/- 0.82 cm, p < 0.0001, respectively). The deceleration time of diastolic forward flow shortened with the increase of heart rate (r = -0.87, p < 0.0001). Pulmonary venous flow in dogs can be observed under transthoracic two-dimensional or pulsed Doppler echocardiography.

Estimating Mean Pulmonary Wedge Pressure in Patients With Chronic Atrial Fibrillation From Transthoracic Doppler Indexes of Mitral and Pulmonary Venous Flow Velocity

Objectives. We sought to obtain a noninvasive estimation of mean pulmonary wedge pressure (MPWP) in patients with chronic atrial fibrillation (AF).Background. It has previously been demonstrated that MPWP can be reliably estimated from Doppler indexes of mitral and pulmonary venous flow (PVF) in patients with sinus rhythm. Doppler estimation of MPWP has not been validated in patients with AF.Methods. MPWP was correlated with variables of mitral and pulmonary venous flow velocity as assessed by Doppler transthoracic echocardiography in 35 consecutive patients. The derived algorithm was prospectively tested in 23 additional patients.Results. In all patients the mitral flow pattern showed only a diastolic forward component. A significant but relatively weak correlation (r = −0.50) was observed between MPWP and mitral deceleration time. In 12 (34%) of 35 patients, the pulmonary vein flow tracing demonstrated only a diastolic forward component; a diastolic and late systolic forward flow was noted in the remaining 23 patients (66%). A strong negative correlation was observed between MPWP and the normalized duration of the diastolic flow (r = −0.80) and its initial deceleration slope time (r = −0.91). Deceleration time >220 ms predicted MPWP ≤12 mm Hg with 100% sensitivity and 100% specificity. When estimating MPWP by using the equation MPWP= −94.261 PVF deceleration time− 9.831 Interval QRS to onset of diastolic PVF− 16.337 Duration of PVF+ 44.261, the measured and predicted MPWP closely agreed with a mean difference of −0.85 mm Hg. The 95% confidence limits were 4.8 and −6.1 mm Hg.Conclusions. In patients with chronic AF, MPWP can be estimated from transthoracic Doppler study of PVF velocity signals.(J Am Coll Cardiol 1997;30:19–26)

Influence of aging on left atrial appendage flow velocity patterns in normal subjects

Transesophageal pulsed Doppler echocardiography was performed to examine changes with age in the left atrial appendage flow velocity patterns in 50 normal subjects (15 to 80 years) in sinus rhythm. There was a significant negative correlation between the peak early diastolic forward and backward left atrial appendage flow velocities and age, as well as a significant positive correlation between the peak early diastolic forward left atrial appendage flow velocity and the peak early diastolic transmitral and pulmonary venous flow velocities. Although there was a significant positive correlation between the peak atrial systolic transmitral flow velocity and age, there was a negative correlation between the peak atrial systolic forward and backward left atrial appendage flow velocities and age. There was a positive correlation between both the maximum left atrial diameter and the amplitude of the interatrial septal motion during atrial systole and age. There was a significant negative correlation between the left atrial appendage ejection fraction during atrial systole and age. Left atrial appendage thrombi and spontaneous echo contrast were detected in two subjects with low peak early diastolic and atrial systolic left atrial appendage flow velocities. In conclusion, both peak early diastolic and atrial systolic left atrial appendage flow velocities decreased with age. A decrease in the peak atrial systolic flow velocity appeared to be an important sign of left atrial appendage thrombus formation even in normal elderly subjects in sinus rhythm.