Continuous wave Doppler determination of right ventricular pressure: a simultaneous Doppler-catheterization study in 127 patients

Simultaneous continuous wave Doppler echocardiography and right-sided cardiac pressure measurements were performed during cardiac catheterization in 127 patients. Tricuspid regurgitation was detected by the Doppler method in 117 patients and was of adequate quality to analyze in 111 patients. Maximal systolic pressure gradient between the right ventricle and right atrium was 11 to 136 mm Hg (mean 53 +/- 29) and simultaneously measured Doppler gradient was 9 to 127 mm Hg (mean 49 +/- 26); for these two measurements, r = 0.96 and SEE = 7 mm Hg. Right ventricular systolic pressure was estimated by three methods from the Doppler gradient. These were 1) Doppler gradient + mean jugular venous pressure; 2) using a regression equation derived from the first 63 patients (Group 1); and 3) Doppler gradient + 10. These methods were tested on the remaining 48 patients with Doppler-analyzable tricuspid regurgitation (Group 2). The correlation between Doppler-estimated and catheter-measured right ventricular systolic pressure was similar using all three methods; however, the regression equation produced a significantly better estimate (p less than 0.05). Use of continuous wave Doppler blood flow velocity of tricuspid regurgitation permitted determination of the systolic pressure gradient across the tricuspid valve and the right ventricular systolic pressure. This noninvasive technique yielded information comparable with that obtained at catheterization. Approximately 80% of patients with increased and 57% with normal right ventricular pressure had analyzable Doppler tricuspid regurgitant velocities that could be used to accurately predict right ventricular systolic pressure.     

Noninvasive estimation of pulmonary artery diastolic pressure in patients with tricuspid regurgitation by Doppler echocardiography.

OBJECTIVES: The purpose of this study was to determine whether Doppler echocardiographic assessment of right ventricular pressure at the time of pulmonary valve opening could predict pulmonary artery diastolic pressure. BACKGROUND: Doppler echocardiography has been used to estimate right ventricular systolic pressure noninvasively. Because right ventricular and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening, Doppler echocardiographic estimation of right ventricular pressure at this point might provide an estimate of pulmonary artery diastolic pressure. METHODS: We studied 31 patients who underwent right heart catheterization and had tricuspid regurgitation. Pulmonary flow velocity was recorded by pulsed wave Doppler echocardiography, and tricuspid regurgitant velocity was recorded by continuous wave Doppler echocardiography. The time of pulmonary valve opening was determined as the onset of systolic flow in the pulmonary artery. Tricuspid velocity at the time of pulmonary valve opening was measured by superimposing the interval between the onset of the QRS complex on the ECG and the onset of pulmonary flow on the tricuspid regurgitant envelope. The tricuspid gradient at this instant was calculated from the measured tricuspid velocity using the Bernoulli equation. This gradient was compared to the pulmonary artery diastolic pressure obtained by right heart catheterization. MEASUREMENTS AND RESULTS: The pressure gradient between the right atrium and right ventricle obtained at the time of pulmonary valve opening ranged from 9 to 31 mm Hg (mean, 19+/-5) and correlated closely with invasively measured pulmonary artery diastolic pressure (range, 9 to 36 mm Hg; mean, 21+/-7 mm Hg; r = 0.92; SEE, 1.9 mm Hg). CONCLUSION: Doppler echocardiographic measurement of right ventricular pressure at the time of pulmonary valve opening is a reliable noninvasive method for estimating pulmonary diastolic pressure.     

Noninvasive estimation of both systolic and diastolic pulmonary artery pressure from Doppler analysis of tricuspid regurgitant velocity spectrum in patients with chronic heart failure

Background Noninvasive estimation of pulmonary artery systolic and diastolic pressures usually requires the investigation of both tricuspid and pulmonary regurgitant jets and an estimate of right atrial pressure. A new, noninvasive method to obtain pulmonary diastolic pressure (based on the hemodynamic demonstration that right ventricular systolic pressure and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening) from the analysis of tricuspid regurgitation alone has been described in a small cohort of patients. We sought to verify the accuracy of this method in a large population of patients with heart failure. Methods An estimate of pulmonary artery diastolic pressure was obtained by transposing the pulmonary opening time (from the onset of the R wave on the electrocardiographic tracing to the beginning of pulmonic forward flow on Doppler examination) onto the tricuspid regurgitant velocity curve and calculating the pulmonary artery diastolic pressure value as the pressure gradient between the right ventricle and right atrium at this time. The study group included 86 consecutive patients (64 men, aged 52 ± 11 years) with heart failure (New York Heart Association class ≥II, 94%) who were in stable clinical condition with a chiefly idiopathic (57%), ischemic (24%), or other form (13%) of dilated cardiomyopathy. Noninvasive, right-sided pressures were compared with invasive measurements obtained during right heart catheterization performed within 24 hours. The Bland and Altman graphic method was used together with the calculation of the Lin concordance correlation coefficient and its 95% CI to assess the agreement between hemodynamic and echocardiographic measurements. Results Catheter-derived pulmonary artery systolic pressure ranged from 8 to 119 mm Hg (mean 42 ± 21 mm Hg), pulmonary artery diastolic pressure from 1 to 59 mm Hg (mean 20 ± 11 mm Hg), and right atrial pressure from −5 to 20 mm Hg (mean 6 ± 5 mm Hg). Tricuspid regurgitation was detected in 75 of 86 patients (87%). Pulmonary artery systolic pressure ranged from 13 to 110 mm Hg (mean 44 ± 21 mm Hg); the pressure gradient between the right ventricle and right atrium at time t of the pulmonary valve opening on the tricuspid regurgitation velocity curve was measurable in 70 of 75 (93%) cases and ranged from 3.5 to 64 mm Hg (mean 22 ± 11 mm Hg). Good agreement was observed not only for pulmonary artery systolic pressure but also for pulmonary artery diastolic pressure, based on the analysis of the tricuspid regurgitation velocity jet, with a slight difference between measurements (−1.8 and 0.1, respectively), no evident pattern of point scattering, and a high concordance correlation coefficient that was elicited by the virtually total overlapping of lines on the graph. Overall results were not significantly different whether patients with depressed right ventricular function (right ventricular ejection fraction ≤35%), with a tricuspid regurgitation grade ≥2 and atrial fibrillation were included in the analysis. Conclusions The narrow paired difference for the estimate of pulmonary artery systolic pressure and the even better difference for pulmonary artery diastolic pressure using the tricuspid regurgitation velocity curve analysis indicates that this new method reliably estimates invasive right-sided pressures over a wide range of pressure values in patients with heart failure. The overall good correlation with invasive values indicates that Doppler examination of tricuspid regurgitation alone may provide a simple and comprehensive new method for the noninvasive evaluation of right ventricular and pulmonary hemodynamics in patients with heart failure. (Am Heart J 2002;144:1087-94.)     

Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation

We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2). Adding the transtricuspid gradient to the mean right atrial pressure (estimated clinically from the jugular veins) gave predictions of right ventricular systolic pressure that correlated well with catheterization values (r = .93, SEE = 8 mm Hg). The tricuspid gradient method provides an accurate and widely applicable method for noninvasive estimation of elevated right ventricular systolic pressures.     

Comparison of three Doppler ultrasound methods in the prediction of pulmonary artery pressure

Pulmonary artery pressure was noninvasively estimated by three Doppler echocardiographic methods in 50 consecutive patients undergoing cardiac catheterization. First, a systolic transtricuspid gradient was calculated from Doppler-detected tricuspid regurgitation; clinical jugular venous pressure or a fixed value of 14 mm Hg was added to yield systolic pulmonary artery pressure. Second, acceleration time from pulmonary flow analysis was used in a regression equation to derive mean pulmonary artery pressure. Third, right ventricular isovolumic relaxation time was calculated from Doppler-determined pulmonary valve closure and tricuspid valve opening; systolic pulmonary artery pressure was then derived from a nomogram. In 48 patients (96%) at least one of the methods could be employed. A tricuspid pressure gradient, obtained in 36 patients (72%), provided reliable prediction of systolic pulmonary artery pressure. The prediction was superior when 14 mm Hg rather than estimated jugular venous pressure was used to account for right atrial pressure. In 44 patients (88%), pulmonary flow was analyzed. Prediction of mean pulmonary artery pressure was unsatisfactory (r = 0.65) but improved (r = 0.85) when only patients with a heart rate between 60 and 100 beats/min were considered. The effect of correcting pulmonary flow indexes for heart rate was examined by correlating different flow indexes before and after correction for heart rate. There was a good correlation between corrected acceleration time and either systolic (r = -0.85) or mean (r = -0.83) pulmonary artery pressure. Because of a high incidence of arrhythmia, right ventricular relaxation time could be determined in only 11 patients (22%). Noninvasive prediction of pulmonary artery pressure is feasible in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive determination of pulmonary arterial systolic pressure by continuous wave Doppler

We evaluated the accuracy of continuous wave Doppler for estimating pulmonary arterial systolic pressure in patients with tricuspid regurgitation. Of 44 patients with a variety of cardiac disorders, 39 (89%) had Doppler-detected tricuspid regurgitation. Adequate spectral profiles of the flow signals were obtained in 34 of them (87%), representing 77% of the entire group. Continuous wave Doppler ultrasound was used to measure the maximum velocity of the regurgitant jet, and by applying the modified Bernoulli equation, the systolic pressure gradient between the right ventricle and the right atrium was calculated. Pulmonary arterial systolic pressure was estimated by adding the transtricuspid gradient to the mean right atrial pressure, and correlated well with catheterization values (r = 0.96). The correlation coefficient was not significantly modified if mean right atrial pressures were excluded in the calculations (r = 0.91). Continuous wave Doppler constitutes a sensitive method for the detection of tricuspid regurgitation. The method using the tricuspid gradient provides an accurate estimation of pulmonary arterial systolic pressure. Combined with other available methods (pulsed wave Doppler), this noninvasive technique can yield information comparable with that obtained at catheterization.     

Can echocardiographic evaluation of cardiopulmonary hemodynamics decrease right heart catheterizations in end-stage heart failure patients awaiting transplantation?

Candidacy for heart transplantation is influenced by the severity of pulmonary hypertension. In this study, invasive hemodynamics from right-sided cardiac catheterization were compared with values obtained by validated equations from Doppler 2-dimensional transthoracic echocardiography. This prospective study was conducted in 40 patients with end-stage heart failure evaluated for heart transplantation or ventricular assist device implantation. Transthoracic echocardiography and right-sided cardiac catheterization were performed within 4 hours. From continuous-wave Doppler of the tricuspid regurgitation jet, pulmonary artery systolic pressure was calculated as the peak gradient across the tricuspid valve plus right atrial pressure estimated from inferior vena cava filling. Mean pulmonary artery pressure was calculated as (0.61 × pulmonary artery systolic pressure) + 2. Pulmonary vascular resistance (PVR) was calculated as (tricuspid regurgitation velocity/right ventricular outflow tract time-velocity integral × 10) + 0.16. Pulmonary capillary wedge pressure was calculated as 1.91 + (1.24 × E/E'). Pearson's correlation and Bland-Altman analysis of mean differences between echocardiographic and right-sided cardiac catheterization measurements were statistically significant for all hemodynamic parameters (pulmonary artery systolic pressure: r = 0.82, p < 0.05, mean difference 3.1 mm Hg, 95% confidence interval [CI] -0.2 to 6.3; mean pulmonary artery pressure: r = 0.80, p < 0.05, mean difference 2.5 mm Hg, 95% CI 0.3 to 4.6; PVR: r = 0.52, p < 0.05, mean difference 0.8 Wood units, 95% CI 0.3 to 1.4; pulmonary capillary wedge pressure: r = 0.65, p < 0.05, mean difference 2.2 mm Hg, 95% CI 0.1 to 4.3). Compared with right-sided cardiac catheterization, PVR by Doppler echocardiography identified all patients with PVR > 4 Wood units (n = 4), 73% of patients with PVR <2 Wood units (n = 8), and 52% of patients with PVR from 2 to 4 Wood units (n = 10). In conclusion, echocardiographic estimation of cardiopulmonary hemodynamics is reliable in patients with end-stage cardiomyopathy. The noninvasive assessment of hemodynamics by echocardiography may be able to decrease the number of serial right-sided cardiac catheterizations in selected patients awaiting heart transplantation. However, in patients with borderline PVR, right-sided cardiac catheterization is indicated to assess eligibility for transplantation.     

Feasibility of generating hemodynamic pressure curves from noninvasive Doppler echocardiographic signals

Objectives. This study was designed to determine the feasibility of Doppler generation of accurate, complete right ventricular and pulmonary artery pressure curves in patients with Dopplermeasurable tricuspid and pulmonary regurgitation.Background. Doppler-derived flow velocities have been used to assess right ventricular systolic pressure; pulmonary artery systolic, diastolic and mean pressures, and left ventricular systolic and diastolic pressures. Instantaneous gradient across any area of discrete narrowing is accurately derived using the simplified Bernoulli equation (4V²). Invasive catheterization is currently the only means of generating intracardiac pressure curves. Noninvasively derived pressure curves using Doppler echocardiography would be a considerable advance in the assessment of normal and pathologic cardiac hemodynamics.Methods. Right ventricular and pulmonary artery pressure curves were generated in 18 of 22 patients with measurable tricuspid and pulmonary valve regurgitation using superimposition of Doppler-measured tricuspid and pulmonary valve blood flow velocities on an assumed right atrial pressure. Dopplermeasured right ventricular and pulmonary artery pressure curves were compared with simultaneous catheterization-measured curves.Results. Doppler-derived pulmonary artery systolic pressure (Doppler PAP) correlated with simultaneous catheter-measured pulmonary artery pressure (Cath PAP) by the equation Doppler PAP = 0.92(Cath PAP) + 4.5, r = 0.98. Other Doppler-derived pressure measurements that correlated at near identity with the catheterization-measured corresponding measurement include Doppler-derived pulmonary artery mean pressure (Doppler mean PAP) [Doppler mean PAP = 0.85(Cath mean PAP) + 2.6, r = 0.97], and Doppler-derived right ventricular pressure (Doppler RVP) [Doppler RVP = 0.84(Cath measured RVP) + 7.9, r = 0.98]. Doppler-derived pulmonary artery diastolic pressure (Doppler PAP diast) did not correspond as well in this study [Doppler PAP diast = 0.45(Cath PAP diast) + 6.6, r = 0.83].Conclusions. Clinically usable right ventricular and pulmonary artery pressure curves can be derived by superimposing Dopplermeasured tricuspid and pulmonary valve blood flow velocities in patients with tricuspid and pulmonary valve regurgitation.     

Comparison of Doppler derived haemodynamic variables and simultaneous high fidelity pressure measurements in severe pulmonary hypertension.

OBJECTIVE--To assess relations between right ventricular pressure measured with a high fidelity transducer tipped catheter and the characteristics of tricuspid regurgitation recorded with Doppler echocardiography. DESIGN--A prospective non-randomised study of patients with severe pulmonary hypertension referred for consideration of lung transplantation. SETTING--A tertiary referral centre for cardiac and pulmonary disease, with facilities for invasive and non-invasive investigation, and assessment for heart and heart-lung transplantation. PATIENTS--10 patients with severe pulmonary hypertension being considered for lung transplantation. ENDPOINTS--Peak right ventricular, pulmonary artery, and right atrial pressures; peak positive and negative right ventricular dP/dt; peak Doppler right ventricular-right atrial pressure drop; Doppler derived peak positive and negative right ventricular dP/dt; and time intervals of Q to peak right ventricular pressure and to peak positive and negative right ventricular dP/dt. RESULTS--The mean (SD) pulmonary artery systolic pressure was 109 (29) mm Hg. The peak Doppler right ventricular-right atrial pressure drop underestimated peak right ventricular pressure by 38 (21) mm Hg, and by 21 (18) mm Hg when the Doppler value was added to the measured right atrial pressure (P values < 0.05). This discrepancy was greater for higher pulmonary artery pressures. The timing of peak right ventricular pressure differed, with the Doppler value consistently shorter (mean difference 16 ms, P < 0.05). Values of peak positive and negative right ventricular dP/dt and the time intervals Q-peak positive right ventricular dP/dt and pulmonary closure to the end of the pressure pulse differed between the two techniques in individual patients, but not in a consistent or predictable way. CONCLUSIONS--Doppler echocardiography significantly underestimates the peak right ventricular pressure and the time interval to peak right ventricular pressure in pulmonary hypertension, particularly when severe. These differences may be related to orifice geometry. Digitisation of Doppler records of tricuspid regurgitation provides useful semiquantitative estimates of absolute values and timing of peak positive and negative right ventricular dP/dt. Clinically significant differences may exist, however, and must be considered in individual patients.     

Quantitative assessment of pulmonary hypertension in patients with rheumatic heart disease using continuous wave Doppler ultrasound

The accuracy of Doppler ultrasound in estimating pulmonary arterial systolic pressure non-invasively was evaluated in 50 patients with rheumatic heart disease. In all cases, the maximal velocity of the tricuspid regurgitation jet was measured by continuous wave Doppler ultrasound and the systolic pressure gradient between right ventricle and the right atrium was calculated by the modified Bernoulli equation. There was a close correlation between Doppler estimated and hemodynamically measured transtricuspid systolic gradient (r = 0.86, P less than 0.001). Right ventricular systolic pressure, which equals pulmonary arterial systolic pressure in the absence of right ventricular outflow obstruction, was calculated by adding a constant of 10 to the Doppler gradient and also by using a regression equation. Right ventricular systolic pressure obtained by both of these Doppler methods correlated closely with values at cardiac catheterization (r = 0.82 and 0.83, respectively). Our study suggests that pulmonary arterial systolic pressure can be determined non-invasively with accuracy, by Doppler ultrasound, in patients with rheumatic heart disease.     

Prospective Doppler echocardiographic evaluation of pulmonary artery diastolic pressure in the medical intensive care unit

To test the hypothesis that the noninvasive evaluation of pulmonary regurgitation can provide accurate estimates of pulmonary artery (PA) diastolic pressures and PA wedge pressures, Doppler echocardiographic studies were performed immediately before bedside PA catheterization in 29 medical intensive care unit patients. The characteristic color flow Doppler signal of pulmonary regurgitation was detected in 19 (66%) patients. In 17 of the 29 patients (59%), the gradient between the right ventricle and PA at end-diastole could be calculated from the pulsed-wave Doppler signal of pulmonary regurgitation using the simplified Bernoulli equation. Right atrial pressure was then estimated by examination of the jugular venous pulse or by electronic transduction of the pressure signal from a previously placed central venous catheter. A noninvasive estimate of PA diastolic pressure was made by adding the clinical estimate of right atrial pressure to the end-diastolic pressure gradient across the pulmonary valve. Pulmonary artery catheterization was then performed and stripchart recordings were interpreted by a physician who was unaware of the noninvasively-estimated PA diastolic pressure. The PA diastolic pressure estimated by Doppler echocardiography correlated closely with that found at catheterization (r = 0.94, mean absolute difference 3.3 mm Hg). The noninvasive estimate of PA diastolic pressure also correlated with the PA wedge pressure (r = 0.87, mean absolute difference 3.8 mm Hg). Therefore, in 59% of medical intensive care unit patients, Doppler echocardiographic evaluation of pulmonary regurgitation allowed accurate noninvasive estimation of PA diastolic pressure.     

Doppler echocardiographic evaluation of pulmonary artery pressure in chronic obstructive pulmonary disease. A European multicentre study. Working Group on Noninvasive Evaluation of Pulmonary Artery Pressure. European Office of the World Health Organization, Copenhagen

The feasibility, reproducibility and reliability of Doppler echocardiography in evaluation of pulmonary artery pressure in patients with chronic obstructive pulmonary disease (COPD) were determined in a multicentre study. In 100 COPD patients with mean pulmonary artery pressure ranging from 10 to 62 mmHg at cardiac catheterization, pulmonary pressure estimation was attempted by four Doppler echocardiographic methods. These methods comprised the calculation of transtricuspid and transpulmonary pressure gradients from Doppler-detected tricuspid or pulmonary regurgitation, the evaluation of right ventricular outflow tract velocity profiles with the measurement of right ventricular systolic time intervals and the measurement of the right ventricular isovolumic relaxation time. In 98 (98%) patients at least one of the methods could be employed. A tricuspid regurgitation jet was detected in 47 (47%) patients but its quality was adequate for measurement in 30 (30%). Pulmonary regurgitation jet velocity was measured only in five cases. The standard error of estimate in testing intra- and interobserver reproducibility of Doppler systolic time intervals was less than 5%. The predictive value of right ventricular outflow tract acceleration time less than 90 ms in the identification of patients with mean pulmonary artery pressure greater than 20 mmHg was 80%. Of Doppler echocardiographic data, best correlations with mean pulmonary artery pressure were found for the transtricupid gradient (r = 0.73, SEE = 7.4 mmHg), for the right ventricular acceleration time (r = 0.65, SEE = 8 mmHg) and right ventricular isovolumic relaxation time (r = 0.61, SEE = 8.5 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of combined two-dimensional echocardiography and continuous wave Doppler recordings in the estimation of pressure gradient in right ventricular outlet obstruction

Fifteen patients (median age 8.5 years) with fixed right ventricular outflow tract obstruction were evaluated by two-dimensional echocardiographically directed continuous wave Doppler ultrasound within 24 hours of cardiac catheterization. Pulmonary artery blood velocity measurements were determined from a real time spectral display of pulmonary artery flow profile and converted to pressure drop utilizing a modified Bernoulli equation. Use of both parasternal and subcostal imaging permitted more accurate detection of maximal flow velocity than did use of either approach alone. Gradients estimated from Doppler recordings correlated well with those measured at cardiac catheterization (correlation coefficient = 0.95, standard error of the estimate = 7.9 mm Hg) with a trend to slight underestimation of gradient in more severe obstruction. In three patients with combined valvular and subvalvular stenosis and one patient with right ventricular outlet obstruction due totally to a ventricular septal aneurysm, Doppler estimation of gradient provided an accurate assessment of total right ventricular-pulmonary artery gradient. Thus, continuous wave Doppler ultrasound combined with two-dimensional echocardiography provides a reliable noninvasive method of estimating pressure gradient in patients with right ventricular outflow tract obstruction.     

Early reversal of right ventricular dysfunction in patients with acute pulmonary embolism after treatment with intravenous tissue plasminogen activator

To assess abnormalities of right heart function and their reversal with thrombolysis in pulmonary embolism, serial imaging and Doppler echocardiographic studies were performed before and after a 6 hour intravenous infusion of 80 to 90 mg of recombinant tissue-type plasminogen activator (rt-PA) in seven patients with segmental or lobar acute pulmonary embolism. None of the five men and two women had known prior pulmonary hypertension. Substantial clot lysis and improvement in pulmonary blood flow, as determined by serial pulmonary angiography and perfusion lung scanning, were achieved in all. Coincident with clot lysis, pulmonary artery systolic pressure decreased (from 42 +/- 11 to 26 +/- 7 mm Hg, p less than 0.005), right ventricular diameter decreased (from 3.9 +/- 1.0 to 2.0 +/- 0.5 cm, p less than 0.005) and left ventricular diameter increased (from 3.7 +/- 0.9 to 4.4 +/- 0.6 cm, p less than 0.01). Right ventricular wall movement, initially mildly, moderately or severely hypokinetic in one, two and four patients, respectively, normalized in five and improved to mild hypokinesia in two. Tricuspid regurgitation was present before lytic therapy in six patients. In five, flow velocity in the tricuspid regurgitant jets indicated a peak systolic right ventricular minus right atrial pressure gradient of 25 to 52 mm Hg. Tricuspid regurgitation was detected early after lytic therapy in only two patients. Systolic septal flattening was noted before but not after lysis. These findings confirm that pulmonary emboli may result in appreciable right ventricular dysfunction and dilation, resultant tricuspid regurgitation, abnormal septal position and decreased left ventricular size.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive Estimation of Diastolic Pulmonary Artery Pressure by Doppler Analysis of Tricuspid Regurgitation Velocity in Pediatric Patients

Purpose. Diastolic pulmonary artery pressure (dPAP) is equal to right ventricular pressure at the time of pulmonary valve opening. We studied the accuracy of dPAP estimated from Doppler profile of tricuspid regurgitation (TR) jet in pediatric patients. Methods. Echocardiograms were prospectively performed on consecutive pediatric heart transplant recipients undergoing right‐heart catheterization and endomyocardial biopsy. An estimate of dPAP was obtained by superimposing the pulmonary valve opening time, indexed to the electrocardiogram, onto the TR Doppler tracing. Echocardiographic estimates of dPAP from end‐diastolic pulmonary regurgitation (PR) were obtained for comparison. Catheter‐derived right atrial pressure was added to the Doppler gradient in both groups. Doppler estimates and catheter‐derived measurements of dPAP were compared using Lin correlation and Bland–Altman analysis. Results. Sixty‐five catheterization studies were performed on 35 patients (20 males): median age at enrollment: 12.1 years (4 months to 18 years); median time: since transplant of 1.2 years (21 days to 16.1 years). Adequate TR signal was obtained in a significantly higher proportion of patients than an adequate PR signal (65% vs. 43%, respectively, P= .007). Median catheter‐derived dPAP was 12 mm Hg (6–30 mm Hg) and right atrial pressure was 6 mm Hg (1–17 mm Hg). Median estimated dPAP from TR was 15 mm Hg (range: 7–29 mm Hg), with the Lin correlation coefficient of 0.74 (95% confidence interval [CI]: 0.6–0.87). Median estimate for dPAP from PR was 10 mm Hg (range: 2–25 mm Hg), with the Lin correlation coefficient of 0.74 (95% CI: 0.58–0.9). There was excellent interobserver agreement for dPAP from TR with the Lin correlation coefficient of 0.946 (95% CI: 0.803–0.986). Conclusion. Doppler estimation of dPAP from TR is a novel, reliable, noninvasive method and compares favorably with estimation from PR. Adequate TR signal for estimation of dPAP can be obtained more frequently in children than adequate PR signal, thereby increasing the proportion of patients in whom dPAP can be estimated noninvasively.     

Left ventricular filling characteristics in pulmonary hypertension: a new mode of ventricular interaction.

OBJECTIVE--To examine the effects of pulmonary hypertension on left ventricular diastolic function and to relate the findings to possible mechanisms of interdependence between the right and left sides of the heart in ventricular disease. DESIGN--A retrospective and prospective analysis of echocardiographic and Doppler studies. SETTING--A tertiary referral centre for both cardiac and pulmonary disease. PATIENTS--29 patients with pulmonary hypertension (12 primary pulmonary hypertension, 10 pulmonary fibrosis, five atrial septal defect (ASD), and two scleroderma) were compared with a control group of 10 patients with an enlarged right ventricle but normal pulmonary artery pressure (six ASD, one after ASD closure, one ASD and pulmonary valvotomy, one tricuspid valve endocarditis and repair, and one pulmonary fibrosis). None had clinical or echocardiographic evidence of intrinsic left ventricular disease. MAIN OUTCOME MEASURES--M mode echocardiographic measurements were made of septal thickness, and left and right ventricular internal cavity dimensions. Doppler derived right ventricular to right atrial pressure drop, and time intervals were measured, as were isovolumic relaxation time, and Doppler left ventricular filling characteristics. RESULTS--The peak right ventricular to right atrial pressure gradient was (mean (SD)) 60 (16) mm Hg in pulmonary hypertensive patients, and 18 (5) mm Hg in controls. The time intervals P2 to the end of the tricuspid regurgitation, and P2 to the start of tricuspid flow were both prolonged in patients with pulmonary hypertension compared with controls (115 (60) and 120 (40) v 40 (15) and 45 (10) ms, p values less than 0.001). Pulmonary hypertensive patients commonly had a dominant A wave on the transmitral Doppler (23/29); however, all the controls had a dominant E wave. Isovolumic relaxation time of the left ventricle was prolonged in pulmonary hypertensive patients compared with controls, measured as both A2 to mitral valve opening (80 (25) v 50 (15) ms) and as A2 to the start of mitral flow (105 (30) v 60 (15) ms, p values less than 0.001). The delay from mitral valve opening to the start of transmitral flow was longer in patients with pulmonary hypertension (30 (15) ms) compared with controls (10 (10) ms, p less than 0.001). At the time of mitral opening there was a right ventricular to right atrial gradient of 12 (10) mm Hg in pulmonary hypertensive patients, but this was negligible in controls (0.4 (0.3) mm Hg, p less than 0.001). CONCLUSIONS--Prolonged decline of right ventricular tension, the direct result of severe pulmonary hypertension, may appear as prolonged tricuspid regurgitation. It persists until after mitral valve opening on the left side of the heart, where events during isovolumic relaxation are disorganised, and subsequent filling is impaired. These effects are likely to be mediated through the interventricular septum, and this right-left ventricular asynchrony may represent a hitherto unrecognised mode of ventricular interaction.     

Hemodynamics in endomyocardial fibrosis

Nine patients with endomyocardial fibrosis have been studied. The clinical diagnosis was confirmed by right ventricular angiography in all of them. They were submitted to right and left ventricular catheterization and had the cardiac pressures, the pulmonary arteriolar resistance, and the cardiac index measured. The ratio between the end-diastolic and systolic ventricular pressures has been taken as an index of the degree of impairment to ventricular filling, and, based on this, patients were classified into two groups: I, predominant or isolated right ventricular disease (seven patients); and II, predominant left ventricular disease (two patients).Group I patients were characterized by a right ventricular $\text{D}{}_2\text{S}$ ratio above 60 per cent, severe tricuspid regurgitation, a diastolic pulmonary artery pressure slightly lower than the right ventricular plateau and end-diastolic pressures, and a reversal of the gradient between the left ventricular end-diastolic pressure and the right atrial mean pressure; these two latter findings strongly suggesting a diastolic blood flow between the right atrium and the left ventricle.The two patients in Group II did not show evidences suggestive of tricuspid regurgitation or of an early opening of the pulmonic valve. Even presenting high values for the left ventricular $\text{D}{}_2\text{S}$ ratio, the pulmonary arteriolar resistance was normal in one patient and mildly elevated in the other patient.     

Tetralogy of Fallot in adults. A report on 147 patients.

Presented here is the clinical and hemodynamic profile of 147 patients, above the age of 18 with tetralogy of Fallot. Cardiac catheterization and selective cineangiocardiography were performed in all. Infundibular pulmonary stenosis, a subaortic large infracristal ventricular septal defect, mitral-aortic fibrous continuity and equal pressures in both the ventricles and aorta were considered mandatory for the diagnosis of tetralogy of Fallot. Cardiac enlargement was seen in 25.8 per cent of the patients, and 15.6 per cent were in congestive cardiac failure; 9.5 per cent had systemic hypertension, and aortic regurgitation was present in 6.7 per cent. A reticular pattern in the lung fields due to bronchial collaterals was seen in 23.1 per cent. The incidence of right aortic arch (19.9 per cent), absent left pulmonary artery (2.8 per cent), absent right pulmonary artery (0.7 per cent) and dextrocardia (1.4 per cent) is brought out. The right atrial mean pressure was increased in 4.8 per cent and a prominent "a" wave greater than 10 mm Hg was present in 10.9 per cent. The right ventricular end-diastolic pressure was increased in 23.8 per cent and the left ventricular end-diastolic pressure in 25.9 per cent of the patients.     

Doppler assessment of interventricular pressure gradient across isolated ventricular septal defect

Continuous wave Doppler ultrasound was used to estimate the pressure gradient between the right and left ventricle for assessment of pulmonary arterial systolic pressure in 30 patients with isolated ventricular septal defect and for subsequent comparison with similar data obtained on cardiac catheterization. The age of the patients ranged from 8 months to 45 years (6.8 +/- 8.6 years). No patient had right or left ventricular outflow tract obstruction. Doppler measurements were done within 24 h of cardiac catheterization. Pressure gradient across ventricular septal defect on cardiac catheterization ranged from 7 to 95 mmHg (48 +/- 24 mmHg) and that on Doppler assessment ranged from 8 to 78 mmHg (42 +/- 20 mmHg). Doppler measurements of interventricular pressure gradient correlated well with those obtained on cardiac catheterization (r = 0.90, p less than 0.001). Correlation was better in patients with pressure gradient across ventricular septal defect less than 75 mmHg (r = 0.96). Correlation was poor in three of five patients with very small ventricular septal defects (interventricular pressure gradient greater than 75 mmHg) because the jet used was not ideal. Thus continuous wave Doppler ultrasound is an accurate noninvasive means of measuring pressure gradient across ventricular septal defect, which is a useful parameter for assessment of pulmonary artery systolic pressure in patients with isolated ventricular septal defect without right and left ventricular outflow tract obstruction.     

Observations suggesting a high incidence of exercise-induced severe mitral regurgitation in patients with mild rheumatic mitral valve disease at rest

Objectives. The aim of this study was to determine the hemodynamic effects of upright bicycle ergometry in symptomatic patients with mild, mixed mitral stenosis and regurgitation.Background. Patients with seemingly mild rheumatic mitral valve disease often complain of exertional dyspnea or fatigue. These symptoms are usually ascribed to flow-dependent increases in the gradient across the stenotic mitral valve. Although catheterization studies in these patients may demonstrate an increase in mitral valve gradient proportional to an increase in cardiac output, this approach does not specifically address the underlying mechanism of any observed increases in mitral gradient or left atrial (i.e., pulmonary capillary wedge) pressure. Exercise echocardiography is uniquely suited to the dynamic assessment of exercise-induced hemodynamic changes.Methods. Fourteen symptomatic patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest performed symptom-limited upright bicycle ergometry with quantitative two-dimensional, Doppler and color Doppler echocardiographic analysis.Results. Average pulmonary artery systolic pressure in the 13 patients with adequate spectral signals of tricuspid regurgitation increased from 36 ± 5 mm Hg (mean ± SD) at rest to 63 ± 14 mm Hg at peak exercise (p < 0.001). The mean transmitral pressure gradient in all patients increased from 4.5 ± 1.4 mm Hg at rest to 12.7 ± 2.7 mm Hg at peak exercise (p < 0.001). Five patients developed severe mitral regurgitation during exercise.Conclusions. Patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest demonstrate a marked increase in pulmonary artery systolic pressure and mean transmitral pressure gradient during dynamic exercise. In a subset of these patients, marked worsening of mitral regurgitation appears to be the underlying mechanism of this hemodynamic deterioration. Because of the small sample size, this novel observation must be considered preliminary with respect to the true prevalence of exercise-related development of severe mitral regurgitation. If additional studies confirm the importance of this phenomenon, it has important implications for the management of patients with rheumatic mitral valve disease.