Doppler-derived Variables Research Articles

Effect of sildenafil on stable chronic heart failure: a prospective randomized-controlled clinical trial

Background Patients with systolic heart failure (HF) who develop secondary pulmonary hypertension have reduced exercise capacity and increased mortality compared with HF patients without pulmonary hypertension. A defective nitric oxide signaling is involved in left ventricular (LV) diastolic abnormalities and remodeling. Phosphodiesterase type 5 inhibition, by blocking degradation of nitric oxide second-messenger cyclic guanosine monophosphate, might be beneficial. Aim of the study In our study, we tested the effects of phosphodiesterase type 5 inhibition (sildenafil) on LV ejection fraction, diastolic function, pulmonary artery pressure, and clinical status. Patients, methods, and results One hundred HF patients (New York Heart Association classes II–IV) were assigned randomly to placebo or sildenafil (50 mg three times per day) for 6 months, with assessment at the first and 6 months of LV ejection fraction, diastolic function, pulmonary artery systolic pressure, and exercise performance (using 6 min walk test). The two groups studied were similar in terms of age, sex distribution, etiology of cardiomyopathy, the prevalence of chronic atrial fibrillation, LVEDD, LA dimensions, and pulmonary artery pressure as well as drug therapy is given to each group all through the study period (P > 0.05). After 1 month of therapy, there was a significant increase in LV ejection fraction and a decrease in pulmonary artery systolic pressure in the sildenafil group (P 0.05). Doppler-derived variables of LV diastolic function improved significantly in the sildenafil group (P 0.05). Over 6 months of therapy and follow-up, LV ejection fraction increased from 31.5 ± 5.4 to 36.4 ± 3.5 and the difference was not significant between the two groups (P > 0.05), whereas in the sildenafil group, ejection fraction % increased significantly from 30.6 ± 4.5% at baseline to 45.6 ± 5.4% (P 0.05), whereas in the sildenafil group, it decreased significantly from 48.3 ± 17.7 to 28.4 ± 6.4 mmHg (P Conclusion In patients with HF, long-term use of sildenafil was well tolerated. This therapeutic regimen (50 mg three times per day) promoted a sustained significant improvement in LV systolic and diastolic function properties in comparison with placebo.

Abstract 17934: Normal Doppler Hemodynamics of Pulmonary Valve Prostheses in Adults

Introduction: Pulmonary valve (PV) replacement is rare, so data regarding normal hemodynamics are limited. We sought to determine the normal Doppler-derived hemodynamic profiles of various PV prostheses (PVPs) in adults. Hypothesis: Doppler-derived hemodynamic profiles of normal PVPs will vary according to prosthesis type in adult patients. Methods: We performed a retrospective review of comprehensive two dimensional and Doppler echocardiographic examinations of 327 patients (median age, 35; range 18 -83 years) with normal PVPs performed early after implantation. Data were analyzed to determine mean±SD. Results: Parasternal short axis was the most commonly used window (96%) for assessment of PVPs. For the 327 PVPs, peak instantaneous gradient was 25±11 mmHg, mean systolic gradient was 13.1±6.1 mmHg, and mean right ventricular outflow tract velocity was 0.8±0.6 m/s. Results for selected variables analyzed by prosthesis type are listed in the Table. Pericardial prostheses had significantly lower peak gradient (21±10.1 mmHg; P=0.002) compared with porcine (25±9.7 mmHg), mechanical (26±16.6 mmHg), bovine venous (34±15.5 mmHg) and homograft PVPs (35±8.4 mm Hg). Conclusions: This is the largest series reporting normal Doppler-derived hemodynamic profiles of PVPs. This study establishes normative values for Doppler-derived variables for normal PVPs implanted in adults. Pericardial prostheses had the optimal hemodynamic profile in this patient population.

Left Atrial Size: An Underappreciated Perioperative Cardiac Risk Factor

LEFT ATRIAL (LA) VOLUME MEASUREMENT has been shown to have a role in the prognosis of long-term cardiovascular mortality in the community setting as well as in the prediction of adverse perioperative events. Different clinical methods have been described for LA size measurement, including magnetic resonance imaging (MRI), computerized tomography (CT), and echocardiography. In recent literature, the LA size has been shown to positively predict the risk of several pathologies (Table 1), including the recurrence of atrial fibrillation (AF), cerebrovascular accidents (CVA), myocardial infarction (MI), and overall mortality. As a result, assessment of LA size recently has received significant clinical attention as a prognostic marker as well as a tool for following response to therapy. In this regard, the value of LA size as a prognostic marker also can be extrapolated to the perioperative assessment of diastolic function. Since the Doppler-derived variables for assessment of diastolic function are extremely load-dependent, LA size provides an alternative marker of the chronicity and significance of elevated left ventricular end-diastolic pressure (LVEDP). Commonly termed as the “HbA1c” for assessment of diastolic dysfunction, the role of LA size in the recognition of long-standing diastolic dysfunction is well recognized. The presence of perioperative diastolic dysfunction has been shown to be an independent predictor of outcome in cardiac and noncardiac surgery. Therefore, knowledge of the LA size possibly can be used for perioperative risk stratification and has the potential to impact intraoperative decision-making. In this article, the authors review the physiologic importance of LA size and its impact on the assessment of diastolic dysfunction, the evidence for its use as a perioperative marker

Meta-analysis of standard, restrictive and supplemental fluid administration in colorectal surgery

Optimal fluid therapy for colorectal surgery remains uncertain. A simple model was applied to define standard, restrictive and supplemental fluid administration. These definitions enabled pooling of data from different trials. Randomized controlled trials on fluid amount (standard versus restrictive or supplemental amount) and on guidance for fluid administration (goal-directed fluid therapy by oesophageal Doppler-derived variables versus conventional haemodynamic variables) in patients with colorectal resection were eligible for inclusion. The primary outcome measure was postoperative morbidity. Secondary endpoints were mortality, cardiopulmonary morbidity, wound infection, anastomotic failure, recovery of bowel function and hospital stay. A random-effects model was applied. Nine randomized controlled trials were included. Restrictive fluid amount (odds ratio (OR) 0.41 (95 per cent confidence interval (c.i.) 0.22 to 0.77); P = 0.005) and goal-directed fluid therapy by means of oesophageal Doppler-derived variables (OR 0.43 (95 per cent c.i. 0.26 to 0.71); P = 0.001) significantly reduced overall morbidity. There were no significant differences in the secondary endpoints analysed. Using standardized definitions, this meta-analysis suggests that restrictive rather than standard fluid amount according to current textbook opinion, and goal-directed fluid therapy rather than fluid therapy guided by conventional haemodynamic variables, reduce morbidity after colorectal resection.

Doppler Echocardiography of 240 Normal Carpentier-Edwards Duraflex Porcine Mitral Bioprostheses: A Comprehensive Assessment Including Time Velocity Integral Ratio and Prosthesis Performance Index

Normal Doppler-derived echocardiographic data for Carpentier-Edwards Duraflex (Edwards Lifesciences, Irvine, CA) porcine bioprosthesis function in the mitral position are limited to 2 small series that did not include all Doppler-derived variables. The purpose of this study was to provide a comprehensive Doppler echocardiographic assessment of normal Carpentier-Edwards Duraflex mitral bioprosthesis function in a large number of patients assessed in the early postoperative phase. All of the important Doppler-derived hemodynamic variables reported to date were used. All patients had either a mitral valve prosthesis time velocity integral to left ventricular outflow tract time velocity integral ratio < 3.9 or an E velocity < 2.8. The pressure half-time was < 130 msec in all patients. Nearly all patients (97%) had an E velocity < 2.8 msec and a mitral valve prosthesis time velocity integral to left ventricular outflow tract time velocity integral ratio < 3.9 regardless of bioprosthesis size, left ventricular function, heart rate, hemoglobin, or hematocrit. With increasing bioprosthesis size, effective orifice area significantly increased, whereas the prosthesis performance index significantly decreased.

Association of Age and Heart Rate with Pulsed‐Wave Doppler Measurements in Healthy, Nonsedated Cats

Associations of age and heart rate with blood flow velocities and durations assessed by pulsed-wave (PW) Doppler echocardiography in cats are incompletely understood. To determine the effects of age and heart rate on blood flow velocities and durations of cardiac events obtained by PW Doppler echocardiography in healthy, nonsedated cats. A convenience sample of 87 healthy, nonsedated cats aged 3 months to 19 years. Prospective, observational study. PW Doppler measurements were obtained by echocardiography. Association of age and heart rate with PW Doppler values was evaluated by simple and multiple linear regressions and ANCOVA. Significant weak positive relationships were found between age and isovolumic relaxation time (IVRT) (R2= 0.18; P< or = .001), and between age and duration of pulmonary venous retrograde flow (R2= 0.07; P= .041). There was a significant weak negative relationship between age and transmitral peak early diastolic velocity (R2= 0.19; P< or = .001). Age and heart rate were significantly related to pulmonary venous peak systolic velocity (R2= 0.13; P= .008). Heart rate affected transmitral peak late diastolic velocity (R2= 0.11; P= .006). After adjusting for heart rate effect, the PW Doppler variables that were significantly different between age groups were transmitral peak early diastolic velocity (P< or = .001), duration of transmitral late diastolic flow (P< or = .001), IVRT (P< or = .001), and the ratio of duration of transmitral late diastolic flow to duration of pulmonary venous retrograde flow (P= .029). The association of several PW Doppler-derived variables and age and heart rate is weak and not clinically important.

Evaluation of the Hemodynamic Performance of St.Jude Mitral Prostheses: A Pilot Study by Dobutamine-Stress Doppler Echocardiography

In contrast to the widespread use of dobutamine stress Doppler echocardiography in the hemodynamic evaluation of the prosthetic valves in aortic position, it has been rarely, if ever, used for assessment of these valves in mitral position. Therefore, this pilot study was done to assess the hemodynamic performance of St. Jude prosthetic mitral valves (functional orifice area 25-31) with dobutamine-stress Doppler echocardiography. Twenty consecutive patients (13 women and 7 men, aged 23 to 42 years) who had undergone mitral valve replacement 6 to 4745 days previously and 16 healthy volunteers (5 women and 11 men, aged 18 to 42 years) underwent dobutamine-stress Doppler echocardiography. Dobutamine infusion was started at a rate of 5 microg/kg per minute and was increased by 5 microg increments at 3-minute intervals. Maximum and mean gradients as well as pressure halftime were measured at rest and at the end of each stage. The correlation between Doppler-derived variables versus the heart rate was assessed and a regression equation was obtained for each of them. A significant increase in blood pressure, heart rate, maximum and mean gradients was noted during dobutamine infusion in both groups. There was a significant positive linear correlation between the increasing transprosthetic mitral valvular maximum and mean gradients and the increments in the heart rate (G(max) = 4.47 + 0.093 [HR], r= 0.474, p<0.05) and (G(mean) = 3.0+0.003 [HR], r=0.2697, p<0.05), respectively, indicating the heart rate dependency of these parameters. Pressure halftime, on the other hand, had an inverse but linear relationship with the heart rate (PHT = 142 - 0.55 [HR], r= -0.577, p<0.05). Similar findings were found for the control group as well. Standard dobutamine-stress echocardiography can safely be performed in patients with St. Jude mitral valve prostheses. Single Doppler measurements of the pressure gradients and pressure halftime may yield erroneous conclusions regarding the function and size of these valves unless corrected for the patients simultaneous, online heart rate. The use of the regression equations obtained in this pilot study may help to partly overcome some of these difficult issues.

A simple method for noninvasive estimation of pulmonary capillary wedge pressure

Background: Various Doppler echocardiographic indices were postulated for evaluation of cardiac performance, however, a reliable index for estimation of pulmonary capillary wedge pressure (PCWP) is unavailable. Objectives: We hypothesize the Doppler-derived variables in right ventricle provides a clinically reliable index to estimate PCWP and to assess the severity of congestive heart failure. Methods: Forty five patients with ischemic or idiopathic dilated cardiomyopathy underwent simultaneous BNP measurement, right-side catheterization and Doppler echocardiographic examination. We measured isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) in each ventricles (LV, RV) and analyzed the correlations with PCWP. Results: LVICT, LVET, LVIRT and RVIRT correlated poorly with PCWP. On the other hand, both RVICT and RVET had definite correlation (r = 0.75 and −0.71, respectively). And, we attempted to calculate a novel Doppler index defined as RVICT divided RVET (RVICT/ RVET) and found a good correlation with PCWP. (r = 0.83, p < 0.0001, PCWP = 4.15 + 50.5∗(RVICT/ RVET)). A RVICT/RVET cut off value of 0.20 had a sensitivity of 95.5% and a specificity of 91.3% to determine PCWP > 15mmHg. In addition, a RVICT/RVET value correlated well with plasma BNP level (r = 0.86, p < 0.001). Conclusions: Novel right ventricular Doppler index (RVICT/RVET) provides a simple and accurate means of estimating PCWP that is useful for assessment of the severity of congestive heart failure.

Temporal Variability of Exercise Doppler Echocardiography in Patients with Nonstented Aortic Bioprostheses

Temporal variability and reproducibility of Doppler-derived variables obtained during supine symptom-limited exercise was investigated in 26 patients who were in clinically and hemodynamically stable condition with normally functioning nonstented aortic bioprostheses (stentless porcine, n = 13; cryopreserved homografts, n = 13). All patients had normal systolic left ventricular function and underwent 2 similar exercise tests within 12 months (mean time interval 7.2 ± 1.9 months). The coefficient of variation was 8% to 9% for primary Doppler-derived variables (ie, velocities and velocity time integrals) at rest and during exercise. The coefficient of variation for calculated maximal pressure difference was 16% at rest and 15% at peak exercise. Measurement variability assessed from repeated measurements from the same videotaped recording was approximately 2%. High reproducibility was shown for most variables with intraclass correlation coefficients of 0.85 or more. We conclude that Doppler echocardiography can be used in patients with nonstented aortic bioprostheses with the same high reproducibility during exercise as at rest. The results provide clinically useful information regarding temporal variability for Doppler-derived variables. (J Am Soc Echocardiogr 1999;12:484-91.)

Feasibility and accuracy of Doppler echocardiographic estimation of pulmonary artery occlusive pressure in the intensive care unit

Mitral inflow and pulmonary vein inflow variables have been shown to relate to left ventricular filling pressures. However, the feasibility and accuracy of Doppler estimation of pulmonary artery (PA) occlusive pressure in the intensive care unit have not been previously assessed. Accordingly, 67 consecutive patients in intensive care units who had PA catheters underwent Doppler recordings of mitral inflow, pulmonary vein flow, and isovolumic relaxation time (IVRT). Thirty-six patients met Doppler inclusion criteria. Most exclusions were due to atrial fibrillation, merging of peak velocity during early diastole (E) and atrial contraction (A) mitral flow velocities, and inadequate recordings. Mean age (±SD) was 65 ± 12 years, ejection fraction varied between 19% and 80%, and 45% of patients were on mechanical ventilation. Doppler-derived variables were related to occlusive pressure (mean 16 ± 6 mm Hg, range 6 to 40), and the most significant variables were entered into a multiple linear regression analysis. The derived relation was tested in 30 repeat studies after a variety of hemodynamic interventions and in a prospective group of 32 additional patients (mean age 63 ± 11.6 years, pressure range 7 to 28 mm Hg). The highest correlations with occlusive pressure were observed with the E/A ratio (r = 0.75), IVRT (r = −0.55), atrial filling fraction (r = −0.65), and deceleration time (r = −0.50). Pulmonary venous recording could be obtained in only 16% of patients. The best model was with E/A and IVRT: PA occlusive pressure = 17 + (5.3 E/A) − (0.11 IVRT), r = 0.79. In the group with repeat studies, a significant correlation was observed between predicted and observed changes in occlusive pressure (r = 0.87), with a mean difference between pressure changes of 0.4 ± 3 mm Hg. Similarly, in the prospective group, a significant correlation was observed between measured and Doppler-derived occlusive pressures (r = 0.88). Of the total 112 patients screened, Doppler estimation of occlusive pressure could be performed in 63%. Estimation of PA occlusive pressure is therefore feasible by Doppler in approximately two thirds of adult patients in intensive care units and may significantly contribute to management of the critically ill patient.

Effects of exercise on left ventricular diastolic performance in trained athletes

Dynamically trained athletes develop increased left ventricular (LV) wall mass. To determine whether this increased wall mass impaired characteristics of LV diastolic filling, serial Doppler echocardiograms were obtained from 10 trained athletes (mean age 21 years) at rest, during supine graded bicycle exercise and during recovery at heart rates of 80, 120 and 140 beats/min, respectively. Similar studies were obtained in 10 age-matched control subjects. Studies at rest showed significant increases in athletes in LV end-diastolic dimension and indexed LV wall mass. Differences in peak filling rates and in normalized peak lengthening rates between athletes and control subjects were seen at heart rates of 140 beats/min during exercise and recovery. Differences in Doppler-derived variables between athletes and control subjects were seen in total time-velocity integral, early peak filling velocity and E A ratio. In athletes, time-velocity integral was increased during recovery at heart rates of 120 beats/min and 80 beats/min, early peak filling velocity was increased during exercise at 120 beats/min and during recovery at 120 beats/min and 80 beats/min, and E A ratio was higher at all heart rates during both exercise and recovery. Although no significant differences were found in LV diastolic filling indexes at rest, a significant enhancement was found in these parameters in dynamically trained athletes during exercise, particularly at higher levels of dynamic exercise.

Factors Influencing Doppler Echocardiographie Assessment of Left Ventricular Diastolic Function in Aortic Valve Stenosis

The present study evaluates by Doppler echocardiography the peak early and late atrial (A) mitral valve inflow velocities and their ratio (E/A) in adults with aortic valve stenosis. By multivariate analysis, clinical, echocardiographic, and hemodynamic factors were analyzed in order to find those with potential independent influence on the Doppler-derived variables

Impairment of left ventricular diastolic function during coronary artery bypass grafting

Twelve patients were studied by transoesophageal Doppler echocardiography to determine diastolic function during coronary artery bypass grafting. Haemodynamic and Doppler-derived variables were measured after induction of anaesthesia and after closure of the sternum. Early diastolic filling of the left ventricle decreased from 55% to 35% during surgery. The contribution of atrial contraction to left ventricular filling increased from 41% to 62% (p less than 0.001). We conclude that coronary artery bypass grafting results in impairment of diastolic function during the operation.

Continuous-Wave Doppler Echocardiographie Evaluation of Patients with Coronary Artery Disease

To investigate the usefulness of continuous-wave Doppler echocardiography from the suprasternal notch in the evaluation of patients with coronary artery disease (CAD) during exercise, ascending aortic blood flow was recorded using the Doppler method during treadmill exercise testing. Doppler-derived peak aortic velocity, stroke volume, and cardiac output were compared in patients with CAD (n = 34, mean age 57 years) with that of normal subjects (n = 21, mean age 35 years). Coronary angiography was performed in all 34 patients with CAD; supine ergometer exercise testing with simultaneous measurement of pulmonary artery wedge pressure (PAWP) was conducted in 18. The patients were classified according to (1), the extent of CAD (single-vessel disease, n = 22; multivessel disease, n = 12) and (2) to the extent of exercise-induced elevation in PAWP (marked elevation ≥ 20 mm Hg, n = 8; < 20 mm Hg, n = 10) at peak exercise. There were no significant differences between Doppler-derived variables in normal subjects and those in patients with single-vessel disease with and without ischemic ECG changes. In contrast, patients with multivessel disease or patients with marked elevation in PAWP induced by exercise showed a significantly lower increase in Doppler-derived variables than the other groups. These findings suggest that exercise-induced changes in continuous-wave Doppler-derived variables can be used to distinguish between patients with and without multivessel CAD and patients with and without abnormal elevations in left ventricular filling pressure during dynamic upright exercise testing.

Role of left ventricular function and Doppler-derived variables in predicting hemodynamic benefits of rate-responsive pacing

Cardiac hemodynamics were studied in 22 patients (mean age 55 ± 2 years, range 22 to 73) with rateresponsive pacemakers using the continuous-wave Doppler method to assess ascending aortic blood flow. Compared with constant rate ventricular (VVI) pacing, rate-responsive pacing conferred improvements in exercise capacity (39 ± 9%, p < 0.001) and cardiac output (41 ± 8%, p < 0.001). Cardiac output increased by 141 ± 21% over the resting value and 56% of this increase was mediated by the ability of these pacemakers to increase their pacing rate. Doppler-derived peak aortic flow velocity, acceleration and stroke distance were lower during maximal exercise in the rate-responsive mode and there was a trend toward a higher systolic blood pressure response. Neither age nor echocardiographic and Doppler-derived variables (at rest and during peak exercise in the VVI mode) could predict the hemodynamic and functional benefits conferred by rate-responsive pacing during exercise, although left ventricular function had a weak correlation. It was concluded that rate-responsive pacing significantly benefits patients with bradycardia, although the extent of the benefit is not predictable, and that advanced age alone should not be a barrier to the use of a rate-responsive pacemaker.

Effect of coronary artery disease on Doppler-derived parameters of aortic flow during upright exercise

Recent advances in Doppler echocardiography have made possible noninvasive determination of stroke volume, cardiac output and peak ejection velocity at rest. To determine the ability of Doppler to measure these variables and the effect of altered left ventricular (LV) function during upright treadmill exercise, 20 normal subjects (group I) and 17 patients with coronary artery disease (CAD) (group II) were studied. Stroke index response was similar in both groups. The increase in cardiac index was more rapid in group I subjects and reached a higher peak value at maximal exercise (8.6 ± 2.5 vs 5.5 ± 2.2 liters/min, p < 0.001). Peak ejection velocity increased rapidly during exercise in group I subjects; it increased much less in group II patients. Differences were significant at each stage of exercise. Peak ejection velocity was 1.56 ± 0.32 and 0.89 ± 0.26 m/s in group I vs group II patients, respectively, at maximal exercise. Three responses were seen in group II subjects. Three patients, all with 1-vessel CAD and normal LV function at rest, showed a normal response, with an increase in peak ejection velocity of at least 80% (type I response). In 8 patients peak ejection velocity increased less than 80% (type II response) and in 6 patients it decreased at maximal exercise (type III). Type II and III responses were seen in patients with more severe CAD and LV dysfunction at rest. These data show a progressive difference in Doppler-derived variables in exercise between normal subjects and patients with CAD, which is greatest in patients with LV dysfunction at rest and multivessel CAD.