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) ν 40 (15) and 45 (10) ms, p values <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) ν 50 (15) ms) and as A₂ to the start of mitral flow (105 (30) ν 60 (15) ms, p values <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 < 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 < 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.

     

Doppler echocardiographic demonstration of the differential effects of right ventricular pressure and volume overload on left ventricular geometry and filling.

To compare the effects of isolated right ventricular pressure and volume overload on left ventricular diastolic geometry and filling, 11 patients with primary pulmonary hypertension, 11 patients with severe tricuspid regurgitation due to tricuspid valve resection and 11 normal subjects were studied with use of Doppler echocardiographic techniques. Right ventricular systolic overload in primary pulmonary hypertension resulted in substantial leftward ventricular septal shift that was most marked at end-systole and early diastole and decreased substantially by end-diastole. Right ventricular diastolic overload after tricuspid valve resection resulted in maximal leftward ventricular septal shift at end-diastole sparing end-systole and early diastole. The early diastolic distortion of left ventricular geometry associated with right ventricular pressure overload resulted in prolongation of isovolumetric relaxation of the left ventricle (129 +/- 39 ms) and a reduction in early diastolic filling compared with values in normal subjects. Late diastolic distortion of left ventricular geometry associated with right ventricular volume overload had no influence on the duration of left ventricular isovolumetric relaxation (52 +/- 32 ms) but caused a reduction in the atrial systolic contribution to late diastolic filling of the left ventricle compared with values in normal subjects. In patients with right ventricular pressure overload, 52 +/- 16% of left ventricular filling occurred in early diastole compared with 78 +/- 11% in patients with right ventricular volume overload (p less than 0.001). The differential effects of systolic and diastolic right ventricular overload on the pattern of left ventricular filling appear to be related to the timing of leftward ventricular septal displacement.     

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.     

Doppler assessment of right ventricular filling dynamics in systemic hypertension: comparison with left ventricular filling.

To assess right ventricular filling dynamics in systemic hypertension, pulsed Doppler echocardiographic studies were obtained at the tricuspid and mitral anuli in 43 untreated hypertensive patients, aged 23 to 66 years, and in 42 age-matched normotensive control subjects. In hypertensive patients, the ratio of late to early peak filling velocity and atrial filling fraction were higher, while normalized peak filling rate, one third and one half filling fractions were lower, compared with control values. Right ventricular filling dynamics correlated poorly with age in hypertensive patients, and were unrelated to left ventricular mass or left ventricular wall thickness. Weak correlations were only found between right ventricular wall thickness and right ventricular peak late inflow velocity, first half and first third filling fractions. However, right ventricular filling dynamics were closely related to left ventricular filling dynamics in both hypertensive patients (r = 0.49 to 0.82) and normal individuals (r = 0.55 to 0.86). Thus right ventricular filling dynamics are altered in hypertension, independently of left ventricular mass or blood pressure, are weakly related to right ventricular thickness, but remain closely correlated to left ventricular filling dynamics.     

The clinical spectrum of tricuspid regurgitation detected by pulsed Doppler echocardiography

The clinical diagnosis of tricuspid regurgitation (TR) is often difficult. Two-dimensional pulsed Doppler echocardiography offers a sensitive and specific method for detecting and semi-quantitating tricuspid regurgitation. The clinical, radiographic, radionuclide, echocardiographic, and when available, the right cardiac catheterization findings were evaluated in 36 patients with a diagnosis of tricuspid regurgitation by pulsed Doppler. Ten healthy subjects served as controls. The underlying cardiac cause was rheumatic heart disease in 7 (20%), ischemic heart disease in 12 (33%), dilated cardiomyopathy in 5 (14%), hypertensive heart disease in 2 (5%), aortic valve stenosis and/or regurgitation in 3 (8%), mitral valve prolapse with mitral regurgitation in 1 (3%), and congenital heart disease in 6 (17%). Seven patients (19%) had a temporary or permanent transvenous right ventricular pacing wire. A systolic murmur was heard in 29 patients (81%) with 16 (46%) having an elevated jugular venous pressure. Tricuspid regurgitation was clinically suspected in only 2 patients (6%). Isolated tricuspid regurgitation was uncommon, seen in 6 patients (17%), and usually secondary to congenital heart disease, ischemic heart disease, with the use of a transvenous pacing wire and following mitral valve replacement. Right cardiac catheterization was performed in 10 patients, of which 7 demonstrated elevated right atrial and pulmonary artery pressure. Pulsed Doppler echocardiography offers a practical and accurate method of detecting and evaluating the severity of tricuspid regurgitation. Tricuspid regurgitation is generally a functional disorder, and frequently occurs in association with left sided valvular heart disease, cardiomyopathy or congenital heart disease.     

Reduced atrial contribution to left ventricular filling in patients with severe tricuspid regurgitation after tricuspid valvulectomy: a Doppler echocardiographic study

Patients undergoing valvulectomy for isolated tricuspid valve endocarditis offer the unique opportunity to study the effects of acquired right ventricular volume overload on left ventricular filling in persons free of pulmonary hypertension and preexisting left heart disease. Eleven patients who had undergone total or partial removal of the tricuspid valve were compared with 11 age-matched control subjects; Doppler echocardiographic techniques were used to quantify changes in left ventricular filling and to relate them to changes in left ventricular and left atrial geometry caused by right ventricular and right atrial distension. The late diastolic fractional transmitral flow velocity integral, a measure of the left atrial contribution to left ventricular filling, was significantly decreased in patients undergoing tricuspid valvulectomy compared with control subjects (0.22 +/- 0.11 versus 0.32 +/- 0.09; p less than 0.04). Severe tricuspid regurgitation in these patients resulted in marked right atrial distension, reversal of the normal interatrial septal curvature and compression of the left atrium such that left atrial area was significantly smaller than in control subjects (5.9 +/- 2.2 versus 8.6 +/- 1.2 cm2/m2; p less than 0.005). Acting as a receiving chamber, the left ventricle was maximally compressed by the volume-overloaded right ventricle in late diastole, coincident with the timing of atrial systole, resulting in a significant increase in the left ventricular eccentricity index compared with that in control subjects (1.35 +/- 0.14 versus 1.03 +/- 0.1; p less than 0.001). Thus, right ventricular volume overload due to severe tricuspid regurgitation results in left heart geometric alterations that decrease left atrial preload, impair left ventricular receiving chamber characteristics and reduce the atrial contribution to total left ventricular filling.     

Comparisons between female and male patients with mitral stenosis.

OBJECTIVE--To compare Doppler, echocardiographic, and clinical variables in female and male patients with mitral stenosis. DESIGN--Observational study in consecutive patients with mitral stenosis of cross sectional and Doppler echocardiographic and clinical variables and a retrospective search for a history of systemic embolism. SETTING--A medical centre with 3000 beds, serving both urban and rural populations. PATIENTS--500 consecutive patients with an echocardiographic mitral valve area of 2 cm2 or less. 331 (66.2%) were female and 169 (33.8%) male (mean (SD) ages of 49 (13) and 48 (14) respectively). MAIN OUTCOME MEASURES--Mitral valve areas by echocardiographic planimetry and Doppler pressure half-time method, peak early diastolic mitral velocity and pressure gradient, echocardiographic score of mitral valve, left atrial end systolic diameter, frequency of left atrial thrombus and smoky echoes as well as various valve lesions detected with Doppler and echocardiography, cardiac rhythm, symptomatic functional class of heart failure, and history of systemic embolism. RESULTS--The prevalence of significant tricuspid (22% v 9%, P < 0.001) and pulmonary regurgitation (5% v 1%, P = 0.018) was higher in the female patients than in the male patients. Female patients also had a higher peak regurgitant velocity (3.2 (0.7) v 2.9 (0.7) m/s, P = 0.007) and pressure gradient (41 (21) v 36 (19) mm Hg, P = 0.010) across the tricuspid valve. However, the male patients had a higher echocardiographic score (9.7 (2.4) v 7.0 (2.3), P < 0.001) and a smaller Doppler-derived mitral valve area (0.9 (0.4) v 1.0 (0.4) cm2, P = 0.027). There were no differences between the female and the male patients in mitral valve area measured by planimetry, peak early diastolic mitral velocity and pressure gradient, and left atrial end systolic diameter or in the prevalence of atrial fibrillation, left atrial thrombus, left atrial smoky echoes, significant aortic stenosis, aortic regurgitation, or heart failure of New York Heart Association class III or IV. CONCLUSIONS--Female patients not only had a higher prevalence of mitral stenosis but also had a higher prevalence of associated tricuspid and pulmonary regurgitation along with a higher velocity and gradient of tricuspid regurgitation. The echocardiographic score was higher in male patients, however. These findings suggest that the pathophysiology of mitral stenosis is different in the two sexes and that gender should be taken into account when therapeutic strategies are formulated.     

Right ventricular diastolic function in chronic obstructive lung disease.

Early detection of diastolic dysfunction in chronic obstructive lung disease (COLD) patients could have great prognostic value. Echocardiography has been shown to be a useful technique in studying left ventricular diastolic function. A noninvasive method of studying right ventricular diastolic function has not yet been reported. Pulsed Doppler echocardiography was used to assess right ventricular diastolic function in three groups of subjects: Group I: 35 COLD patients with pulmonary hypertension; Group II: 32 COLD patients without pulmonary hypertension; and Group III: 18 control subjects. Ratios between peak atrial filling velocity (A) and peak early filling velocity (E) (A/E), deceleration half times of the right ventricular rapid filling wave (DHT), and the interval between pulmonary valve closure and tricuspid valve opening (isovolumic relaxation times) (Pc-To) were significantly different in Group I in comparison to Groups II and III. Sensitivity of A/E ratio and Pc-To were 82 and 77%, respectively, and specificity 90 and 72%, respectively; positive predictive values were 90 and 75%, respectively, and negative predictive value 82 and 74% respectively. The multiple correlation coefficient between A/E, acceleration time (ACT), DHT, Pc-To and mean pulmonary artery pressure was 0.75 for Groups I and II together. In conclusion 2D echo-Doppler proved to be useful in evaluating right ventricular diastolic function in all hypertensive COLD patients, revealing a high correlation between diastolic parameters and mean pulmonary artery pressure in both normotensive and hypertensive COLD patients.     

Effect of systemic hypertension on right ventricular morphology and function: an echocardiographic study

Background

Hypertension is an important cardiovascular risk factor worldwide. It is associated with left ventricular hypertrophy (LVH). Both diastolic and systolic dysfunction may occur in hypertensive heart disease. The ventricles are structurally and functionally interdependent on each other. This was an echocardiographic study intended to describe the impact of left ventricular pressure overload and hypertrophy due to hypertension on right ventricular morphology and function.

Methods

One hundred subjects with systemic hypertension and 50 age- and gender-matched normotensive control subjects were used for this study. Two-dimensional (2-D), M-mode and Doppler echocardiographic studies were done to evaluate the structure and function of both ventricles. Data analysis was done using the SPSS 16.0 (Chicago, Ill). Statistical significance was taken as p < 0.05.

Results

Age and gender were comparable between the two groups. Hypertensive subjects had significantly increased left ventricular end-diastolic dimensions, posterior wall thickness, interventricular septal thickness, left atrial dimensions and left ventricular mass and index. The mitral valve E/A ratio was reduced among hypertensive subjects when compared to normal controls (1.15 ± 0.75 vs 1.44 ± 0.31, respectively; p < 0.05). A similar pattern was found in the tricuspid E/A ratio (1.14 ± 0.36 vs 1.29 ± 0.30, respectively; p < 0.05). Hypertensive subjects also had reduced right ventricular internal dimensions (20.7 ± 8.0 vs 23.1 ± 3.1 mm, respectively; p < 0.001) but similar peak pulmonary systolic velocity. The mitral e/a ratio correlated well with the tricuspid e/a ratio.

Conclusion

Systemic hypertension is associated with right ventricular morphological and functional abnormalities. Right ventricular diastolic dysfunction may be an early clue to hypertensive heart disease.     

An echocardiographic study of perimembranous ventricular septal defect with left ventricular to right atrial shunting

Twenty nine patients with isolated perimembranous ventricular septal defects were investigated by M mode, cross sectional, and pulsed Doppler echocardiography. Tricuspid valve anomalies were present in all six patients with a left ventricular-right atrial shunt but in only six (26%) of 23 patients who had interventricular shunts only. Systolic flutter of the tricuspid valve was shown in five (83%) of the six patients with a ventriculoatrial shunt but not in the other patients. Systolic turbulence in both the right ventricle and right atrium was detected by Doppler echocardiography only in patients with ventriculoatrial shunting. A perimembranous ventricular septal defect with left ventricular to right atrial shunt can be diagnosed by its combined M mode, cross sectional, and pulsed Doppler echocardiographic features.     

An echocardiographic study of perimembranous ventricular septal defect with left ventricular to right atrial shunting.

Twenty nine patients with isolated perimembranous ventricular septal defects were investigated by M mode, cross sectional, and pulsed Doppler echocardiography. Tricuspid valve anomalies were present in all six patients with a left ventricular-right atrial shunt but in only six (26%) of 23 patients who had interventricular shunts only. Systolic flutter of the tricuspid valve was shown in five (83%) of the six patients with a ventriculoatrial shunt but not in the other patients. Systolic turbulence in both the right ventricle and right atrium was detected by Doppler echocardiography only in patients with ventriculoatrial shunting. A perimembranous ventricular septal defect with left ventricular to right atrial shunt can be diagnosed by its combined M mode, cross sectional, and pulsed Doppler echocardiographic features.     

A tale of two pressures: a case of pseudo-prosthetic mitral valve stenosis

We present a case of an 83-year-old female with past medical history of rheumatic fever associated mitral stenosis for which she underwent mitral commissurotomy 25 years prior to presentation. Subsequently, she underwent coronary artery bypass grafting and mitral valve replacement with a bio-prosthetic valve 8 years prior to presentation. Presently, she started experiencing worsening dyspnea and heart failure symptoms. Echocardiography showed mildly reduced left ventricular ejection fraction with severe aortic stenosis and pulmonary hypertension. The bioprosthetic mitral valve was functioning normally. We performed right and left heart catheterization for evaluation. Peak aortic gradient was 50 mm Hg with a mean gradient of 39 mm Hg. Aortic valve area was calculated to be 0.31 cm(2). However, simultaneous measurement of left ventricular and wedge pressures showed a significant gradient of 11 mm Hg across the mitral valve with a calculated mitral valve area of 0.4 cm(2). Because of discordant information between echocardiographic and hemodynamic data, we proceeded with trans-septal puncture to directly measure left atrial pressures. Simultaneous left atrial and left ventricular pressure measurement demonstrated a mean gradient of 4 mm Hg across the mitral valve with an area calculated at 1.9 cm(2). We review the tracings in detail and discuss the pitfalls of using pulmonary capillary wedge pressure as a surrogate for left atrial pressure.     

Doppler-echocardiographic assessment of the degree of pulmonary hypertension and right-ventricular pressure in patients with ventricular septal defects

The study was performed in 53 children aged 3 months to 4 years who had ventricular septal defect. Systolic pressure in the right ventricle, pulmonary artery and the severity of pulmonary hypertension were determined by two way: 1) from arteriovenous shunt via ventricular septal defect before its surgical closure; 2) from systolic regurgitation via the tricuspid valve after its seal. Right ventricular diastolic pressure was measured by Doppler echocardiography using diastolic blood flow through the tricuspid valve. Before ventricular septal defect closure, the correlation ratio of Doppler echocardiographic to cardiac catheterization values was 0.76 and that of Doppler echocardiographic to intrasurgical manometry was 0.79. In the postoperative period, a catheter was left in the right ventricle in 14 children and its pressure was simultaneously measured by the blind method. The correlation was 0.97 for right ventricular systolic pressure and 0.89 for diastolic one.     

M-mode echocardiographic features of endomyocardial fibrosis.

M-mode echocardiographic findings are described in 21 patients with endomyocardial fibrosis. Features associated with right ventricular endomyocardial fibrosis include: (i) exaggerated motion and thickening of the anterior right ventricular wall; (ii) increased right ventricular end-diastolic dimension; and (iii) paradoxical septal motion. Pericardial effusion (viz an echo-free space behind the posterior left ventricular wall) was shown in three patients. The tricuspid valve was easily recorded in all. Six patients with left ventricular endomyocardial fibrosis had diminished left ventricular end-diastolic dimension. Three had echo features of pulmonary hypertension (viz reduced e-f slope, absent a wave in sinus rhythm, and systolic notching of the pulmonary valve echogram). Fine fluttering of the anterior mitral valve and tricuspid valve echo was observed in two patients (one of whom was in sinus rhythm) with biventricular endomyocardial fibrosis, and no angiographic evidence of aortic regurgitation.     

Effect of patient age at surgical intervention on long-term right ventricular performance in atrial septal defect

Controversy exists about the influence of patient age on the benefit of surgery in atrial septal defect (ASD). Tissue Doppler echocardiography (TDE) when applied to atrioventricular annuli provides variables reliably reflecting the performance of the corresponding ventricle. We sought to investigate the effect of timing of surgery on biventricular functions by comparing the conventional echocardiography variables and TDE profiles of right and left atrioventricular annuli in patients treated at various ages. Conventional echocardiography and TDE analysis of mitral and tricuspid annuli were performed in 20 controls and 61 patients who underwent surgical ASD closure 2.8 +/- 2.5 years before the study. Standard parameters included were right and left-sided dimensions, estimated pulmonary artery pressure, ejection fraction, and tricuspid annular motion amplitude. TDE variables were systolic, early and late diastolic peak velocities at tricuspid lateral-and mitral-annulus at lateral and septal corners. Two subsets of patients who underwent surgery before (group 1, n = 20) and after 25 years (group 2, n = 41) formed our subgroups. Peak systolic TDE velocity and tricuspid annular motion amplitude had the lowest value in group 2 (P < 0.01 and <0.02, respectively). Late diastolic TDE velocity was significantly lower in group 2 compared to group 1 (P < 0.05). Increased right ventricular and atrial dimensions (P < 0.001 for both) and the estimated pulmonary artery pressure (P < 0.03) were the conventional measurements discriminating group 2 from group 1. The TDE profile of the mitral annulus was similar between the groups. These results suggest that delayed ASD closure is a relatively less effective procedure to restore secondary right ventricular dysfunction, as demonstrated by significantly different TDE measurements reflecting right ventricular longitudinal contraction and relaxation.     

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.     

Determinants of the relation between systolic pressure and duration of isovolumic relaxation in the right ventricle

Previous studies have suggested that right ventricular systolic pressure can be predicted from noninvasive estimates of the interval between pulmonary valve closure and tricuspid valve opening. To determine the basis for this relation, phonocardiograms and high fidelity right atrial and ventricular pressures were recorded in 29 patients with a right ventricular systolic pressure ranging from 20 to 149 mm Hg. In 22 patients with normal right atrial pressure (⩽ 8 mm Hg), both the time interval and the magnitude of pressure decrease from pulmonary valve closure to tricuspid valve opening were linearly related to systolic pressure (r = 0.89 and 0.96, respectively). Early pulmonary valve closure (decreased “hang-out” time) contributed to the greater magnitude of isovolumic pressure decrease at high systolic pressures, but correction for hang-out time did not eliminate the relation between systolic pressure and the pulmonary valve closure-tricuspid valve opening interval (n = 10).When patients with documented right coronary artery disease were excluded, the time constant for isovolumic pressure decrease also increased as a function of systolic pressure (r = 0.67, p < 0.01, n = 24), suggesting impaired relaxation at high systolic pressures. However, the mean rate of pressure decrease (mean negative dP/dt) still was greater in patients with a high pressure because of the exponential nature of the isovolumic pressure-time relation. The pulmonary valve closure-tricuspid valve opening interval accurately predicted normal systolic pressure in patients with right coronary artery disease despite markedly prolonged time constants, but was inappropriately short for the level of systolic pressure in patients with an elevated mean right atrial pressure because early opening of the tricuspid valve decreased the magnitude of isovolumic pressure fall.These findings indicate that 1) the magnitude of isovolumic pressure fall is the major determinant of the pulmonary valve closure-tricuspid valve opening interval, 2) pulmonary hypertension prolongs the interval by increasing both the magnitude and the time constant for pressure fall, and 3) the determinants of this interval can be altered by factors other than systolic pressure.     

Pulsed doppler echocardiographic detection of right-sided valve regurgitation: Experimental results and clinical significance

Pulsed Doppler echocardiography may allow noninvasive detection of tricuspid insufficiency as disturbed or turbulent systolic flow in the right atrium and pulmonary insufficiency as turbulent diastolic flow in the right ventricular outflow tract. Accordingly, six open chest mongrel dogs were examined with Doppler echocardiography before and after surgical creation of tricuspid and pulmonary insufficiency. The Doppler technique detected the appropriate lesion in all instances, with a specificity of 100 percent.In 121 patients (20 without heart disease, 101 with heart disease of various causes), pulsed Doppler echocardiography was used to detect right-sided valve regurgitation. Results were compared with right-sided pressure measurements and M mode echocardiographic findings in all, and with right ventricular angiography in 21 patients. Pulsed Doppler study detected tricuspid insufficiency in 61 of 100 patients, 12 (20 percent) of whom had clinical evidence of this lesion. Angiographic evidence of tricuspid regurgitation was present in 18 patients, 17 of whom had positive Doppler findings (sensitivity 94 percent), and absent in 3, all with negative Doppler findings. Pulmonary insufficiency was found on pulsed Doppler study in 47 of 91 patients, 3 of whom (all after pulmonary valvotomy) had clinical evidence of this lesion. Increased right ventricular systolic pressure (greater than 35 mm Hg) was noted more often in patients with (55 of 61 or 90 percent) than in those without (22 of 59 or 37 percent) tricuspid insufficiency (p <0.01). Pulmonary arterial mean pressure was elevated (22 mm Hg or less) more often in patients with (38 of 43 or 88 percent) than in those without (24 of 64 or 38 percent) pulmonary insufficiency (p <0.01).Thus, pulsed Doppler echocardiography appears to be an accurate noninvasive technique for detection of right-sided valve regurgitation. The absence of diagnostic physical findings in many of the patients indicates that the hemodynamic severity of the Doppler-detected valve insufficiency was probably insignificant. However, because of its high incidence rate (87 percent) and association with pulmonary hypertension (87 percent), pulsed Doppler detection of tricuspid or pulmonary insufficiency, or both (in the absence of pulmonary stenosis) was found superior to M mode echocardiographic measurements (right ventricular size, pulmonary valve motion) in the prediction of pulmonary hypertension.     

Doppler echocardiographic evaluation of left-to-right shunts in congenital heart disease

Doppler echocardiography enables the possibility of determining pulmonary to systemic flow ratios in patients with left to right shunts. Volume flow is calculated as the product of mean velocity over time, as evaluated by pulsed Doppler, and the cross-sectional area through which the flow passes. Appropriate sites for measurement of velocity and cross-sectional area of flow are the ascending aorta, right ventricular outflow tract and pulmonary artery as well as the tricuspid and mitral valve orifices. Velocity is always recorded as parallel as possible to the direction of flow. Echocardiographic measurements of the area of flow are carried out at the level of the sample volume. In the presence of an atrial or ventricular septal defect, the flow in the ascending aorta normally serves as systemic flow; alternatively, mitral or tricuspid flow may be used to cross-check these values. The latter serves for calculation of systemic flow in patent ductus arteriosus. In atrial or ventricular septal defect, the pulmonary flow is normally derived in the region of the pulmonary artery; in patent ductus arteriosus, however, in the region of the ascending aorta. As an alternative, or for confirmative use, in atrial septal defect the tricuspid flow and in ventricular septal defect and patent ductus arteriosus the mitral flow, can be taken into consideration. Studies we performed in 31 patients with atrial septal defect showed a close correlation between Doppler echocardiographic measurements and data obtained by cardiac catheterization and radionuclide studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral valve abnormalities in patients with right ventricular pressure overload. Analysis by real time cross sectional echocardiography

Abnormalities of the mitral valve in patients with pulmonary stenosis, tetralogy of Fallot, and pulmonary hypertension with right ventricular pressure overload were studied by real time cross sectional echocardiography. Dislocation of the anterior and posterior mitral leaflets at the coaptation zone in systole was present in 16 of 46 cases: nine of 11 (82%) cases of pulmonary hypertension, four of 20 (20%) cases of tetralogy of Fallot, and three of 15 (20%) cases of pulmonary stenosis. The incidence was highest in patients with pulmonary hypertension. In eight of the 16 patients with mitral valve lesions, mitral regurgitation was seen on left ventriculograms or cross sectional Doppler echocardiograms. The dislocation was located near the posteromedial commissure of the anterior mitral leaflet in all cases. These findings are similar to the mitral valve abnormalities seen in patients with secundum atrial septal defect, and therefore may be due to a common cause. No relation could be found between the left ventricular deformity index and the incidence of dislocation of the mitral leaflets. Thus, the reason why this mitral valve abnormality occurs in conditions with right ventricular pressure overload could not be established.