Effects of sample volume location, imaging view, heart rate and age on tricuspid velocimetry in normal subjects

Right Ventricular Myocardial Stiffness and Relaxation Components by Kinematic Model-Based Transtricuspid Flow Analysis in Children and Adolescents with Pulmonary Arterial Hypertension

We hypothesized that the kinematic model-based parameters obtained from the transtricuspid E-wave would be useful for evaluating the right ventricular diastolic property in pediatric pulmonary arterial hypertension (PAH) patients. The model was parametrized by stiffness/elastic recoil k, relaxation/damping c and load x. These parameters were determined as the solution of m⋅d²x/dt² + c⋅dx/dt + kx = 0, which is based on the theory that the E-wave contour is determined by the interplay of stiffness/restoring force, damping/relaxation force and load. The PAH group had a significantly higher k and c compared with the control group (182.5 ± 72.4 g/s vs. 135.7 ± 49.5 g/s², p = 0.0232, and 21.9 ± 6.5 g/s vs. 10.6 ± 5.2 g/s, p <0.0001, respectively). These results indicate that in the PAH group, the right ventricle had higher stiffness/elastic recoil and inferior cross-bridge relaxation. The present findings indicate the feasibility and utility of using kinematic model parameters to assess right ventricular diastolic function.

Transthoracic echocardiography in the evaluation of pediatric pulmonary hypertension and ventricular dysfunction

Transthoracic echocardiography (TTE) is the most accessible noninvasive diagnostic procedure for the initial assessment of pediatric pulmonary hypertension (PH). This review focuses on principles and use of TTE to determine morphologic and functional parameters that are also useful for follow-up investigations in pediatric PH patients. A basic echocardiographic study of a patient with PH commonly includes the hemodynamic calculation of the systolic pulmonary artery pressure (PAP), the mean and diastolic PAP, the pulmonary artery acceleration time, and the presence of a pericardial effusion. A more detailed TTE investigation of the right ventricle (RV) includes assessment of its size and function. RV function can be evaluated by RV longitudinal systolic performance (e.g., tricuspid annular plane systolic excursion), the tricuspid regurgitation velocity/right ventricular outflow tract velocity time integral ratio, the fractional area change, tissue Doppler imaging-derived parameters, strain measurements, the systolic-to-diastolic duration ratio, the myocardial performance (Tei) index, the RV/left ventricle (LV) diameter ratio, the LV eccentricity index, determination of an enlarged right atrium and RV size, and RV volume determination by 3-dimensional echocardiography. Here, we discuss the potential use and limitations of TTE techniques in children with PH and/or ventricular dysfunction. We suggest a protocol for TTE assessment of PH and myocardial function that helps to identify PH patients and their response to pharmacotherapy. The outlined protocol focuses on the detailed assessment of the hypertensive RV; RV-LV crosstalk must be analyzed separately in the evaluation of different pathologies that account for pediatric PH.

Echocardiographic Assessment of Right Atrial Pressure in a Pediatric and Young Adult Population

Right atrial pressure (RAP) reflects right-sided cardiac hemodynamics and is useful in management of patients with cardiac and systemic disease. Studies in older adults demonstrated that inferior vena cava (IVC) diameter, IVC collapsibility index, hepatic vein systolic filling fraction (SFF), and right atrial volume (RAV) correlated with mean RAP at catheterization. This study aimed to assess the utility of echocardiographic parameters for assessment of RAP in children and young adults. Patients with pulmonary hypertension or heart transplantation undergoing right heart catheterization were recruited for this prospective observational pilot study. Transthoracic echocardiographic assessment of RAP was performed simultaneously with catheterization. For each parameter, three consecutive cardiac cycles were recorded. Long- and short-axis images of the IVC were obtained. RAV was assessed by area-length and biplane methods. IVC diameters and RAV were indexed to body surface area (BSA)(0.5) and (BSA)(1.4), respectively. Relationships between echocardiographic parameters and mean RAP were correlated using "Pearson's r." Fifty subjects aged 0.3-23 years (median 13, mean 12.3 ± 7 years) were enrolled. Mean RAP correlated modestly with RAV (r = 0.51, p < 0.001). Long-axis IVCmax (r = 0.30, p < 0.05) and tricuspid E wave velocity (r = 0.36, p < 0.01) also correlated with mean RAP. RV free wall tissue Doppler velocities, IVC collapsibility index, and hepatic vein SFF had no relation to mean RAP. In a pediatric and young adult population with pulmonary hypertension or heart transplantation, echocardiographic assessment of RAV and long-axis IVCmax provided a reasonable estimate of mean RAP. IVC collapsibility index and hepatic vein SFF demonstrated no association with mean RAP.

Right ventricular Doppler echocardiographic study of indeterminate form of chagas disease

BACKGROUND

Patients with indeterminate form of Chagas disease/cardiac normality (ICD/CN) exhibited normal electrocardiograms and chest X-rays; however, more sophisticated tests detected some degree of morphological and functional changes in the heart.

OBJECTIVE

To assess the prevalence of systolic and diastolic dysfunction of the right ventricle (RV) in patients with ICD/CN.

METHODS

This was a case-control and prevalence study. Using Doppler two-dimensional echocardiography (2D), 92 patients were assessed and divided into two groups: group I (normal, n = 31) and group II (ICD/CN, n = 61).

RESULTS

The prevalence of RV systolic dysfunction in patients in groups I and II was as follows: fractional area change (0.0% versus 0.6%), mobility of the tricuspid annulus (0.0% versus 0.0%), and S-wave tissue Doppler (6.4% versus 26.0%, p = 0.016). The prevalence of global disorders such as the right myocardial performance index using tissue Doppler (16.1% versus 27.8%, p = 0.099) and pulsed Doppler (61.3% versus 68%, p = 0.141) and diastolic disorders such as abnormal relaxation (0.0% versus 6.0%), pseudonormal pattern (0.0% versus 0.0%), and restrictive pattern (0.0% versus 0.0%) was not statistically different between groups.

CONCLUSION

The prevalence of RV systolic dysfunction was estimated to be 26% (S wave velocity compared with other variables), suggesting incipient changes in RV systolic function in the ICD/CN group.

Echocardiography in pediatric pulmonary hypertension

Pulmonary hypertension (PH) can be a rapidly progressive and fatal disease. Although right heart catheterization remains the gold standard in evaluation of PH, echocardiography remains an important tool in screening, diagnosing, evaluating, and following these patients. In this article, we will review the important echocardiographic parameters of the right heart in evaluating its anatomy, hemodynamic assessment, systolic, and diastolic function in children with PH.

Right ventricular plasticity and functional imaging

Right ventricular (RV) function is a strong independent predictor of outcome in a number of distinct cardiopulmonary diseases. The RV has a remarkable ability to sustain damage and recover function which may be related to unique anatomic, physiologic, and genetic factors that differentiate it from the left ventricle. This capacity has been described in patients with RV myocardial infarction, pulmonary arterial hypertension, and chronic thromboembolic disease as well as post-lung transplant and post-left ventricular assist device implantation. Various echocardiographic and magnetic resonance imaging parameters of RV function contribute to the clinical assessment and predict outcomes in these patients; however, limitations remain with these techniques. Early diagnosis of RV function and better insight into the mechanisms of RV recovery could improve patient outcomes. Further refinement of established and emerging imaging techniques is necessary to aid subclinical diagnosis and inform treatment decisions.

Different prognostic significance of right and left ventricular diastolic dysfunction in heart failure

BACKGROUND

Left (LV) and right (RV) ventricular diastolic dysfunction is common in heart failure but the prognostic value of RV diastolic dysfunction is not known.

HYPOTHESIS

As a follow-up to a previously undertaken study, this study was carried out to investigate whether LV and RV diastolic dysfunction affect prognosis differently and, in addition, whether changes in diastolic filling patterns over time correlate with clinical outcome.

METHODS

We studied a cohort of 105 patients (mean age 62.7 +/- 1.3 years, 66% male) with heart failure (ejection fraction < 50%) by Doppler echocardiography in both RV and LV.

RESULTS

An LV restrictive filling pattern (RFP) was present in 48% of the patients and, when compared with non-RFP subgroups, it was associated with poorer systolic function, higher New York Heart Association functional class, and higher cardiac mortality at 1 year (all p < 0.001). The coexistence of an LV-RFP and poor LV systolic function (ejection fraction < 25%) markedly decreased the 1-year survival that was significant when compared with other subgroups (p = 0.001). In contrast, RV diastolic dysfunction that occurred in 21% of patients was not a prognostic factor for mortality either alone or in combination with LV diastolic dysfunction, but predicted nonfatal hospital admissions for heart failure or unstable angina (p = 0.016).

CONCLUSION

An LV restrictive filling pattern is a powerful predictor of a poor prognosis, especially when combined with low ejection fraction, but in this study RV diastolic dysfunction did not appear to be an independent predictor of subsequent mortality.

Echocardiographically estimated left ventricular end-diastolic and right ventricular systolic pressure in normotensive healthy individuals

AIM

To study the effect of aging on and the relationship between echocardiographically estimated left ventricular (LV) filling pressure and estimated right ventricular (RV) systolic pressure among healthy normotensive individuals.

METHODS

We analyzed 249 healthy individuals (aged 18-82 years, 52% men) with normal echocardiographic findings and reliably measurable tricuspid regurgitation gradients. Subjects with blood pressure >140/90 mmHg and/or LV hypertrophy were excluded. LV & RV dimensions and LV mass were measured with M-mode echocardiography. Atrial (A) volumes were determined with the area-length method. Diastolic function was assessed with transmitral Doppler and mitral annulus tissue Doppler. The ratio of transmitral early peak velocity to early diastolic mitral annulus velocity (E/E') was used as estimation of LV filling pressure. The transtricuspid Doppler gradient was used to estimate RV end-systolic pressure.

RESULTS

Even in normotensive individuals aging was accompanied by an increase in LV mass and LA dimensions and an increase in relaxation abnormalities. E/E' increased with every decade: from 7.8 for age 18-35 years to 10.9 for age > or =75 years (p<0.0001) as did the transtricuspid gradient: from 18.3 mmHg for age 18-35 years to 25.8 mmHg for age > or =75 years (p<0.0001). Linear regression showed that estimated RV systolic pressure was independently predicted by age, LA volume, LV systolic function and E/E'.

CONCLUSION

Among normotensive healthy individuals both E/E' and tricuspid regurgitation gradients increase significantly with aging. Moreover the E/E' ratio was independently predicting the tricuspid regurgitation gradient. These findings support the need for further studies defining age specific normal values.

Right ventricular myocardial performance index and exercise capacity in athletes

Right ventricular function is important for exercise capacity in athletes. The aim of this study was to investigate the effects of habitual exercise training on right ventricular global function. Fifty-two male athletes (25 runners, 27 wrestlers) and 43 age-matched sedentary male subjects were studied. All subjects in the study underwent an echocardiography examination and cardiopulmonary exercise test. Maximal oxygen consumption, right ventricular cavity diameters, and diastolic parameters were higher in the athletes than in controls. However, the right ventricular myocardial performance index was lower in athletes compared with controls. Therefore, the right ventricular myocardial performance index showed a negative correlation with maximal oxygen consumption (r=-0.61; P<0.001). The right ventricular myocardial performance index may reflect changes in right ventricular function and exercise capacity in athletes.

Right and left ventricular diastolic function in patients with and without heart failure: effect of age, sex, heart rate, and respiration on Doppler-derived measurements

Doppler echocardiography is widely used to assess right and left ventricular diastolic function. Although the factors affecting Doppler-derived measurements have been described in unaffected patients, there is little information available for patients with heart failure. Therefore we performed two-dimensional Doppler echocardiography studies of right and left ventricular function in 140 subjects, 88 with congestive heart failure and 52 age-matched normal subjects. The separate effects of age, sex, heart rate, and respiration were assessed by correlation analysis and multiple linear regression. In normal subjects both left and right ventricular parameters significantly correlated with age and heart rate. No significant effect of respiration was apparent in left ventricular function, but in the right ventricle inspiration caused a significant increase in transtricuspid peak E-wave velocity, E/A ratio, and shortening of the E-wave deceleration time. There was a significant correlation between left and right ventricular diastolic parameters. In heart failure, age correlated weakly with mitral valve peak A wave (r = 0.23, p = 0.03) and with tricuspid valve peak E-wave velocity (r = 0.37, p < 0.001), although in those with a restrictive filling pattern age was associated with a significant increased shortening of the mitral E-wave deceleration time (r = -0.8; p = 0.0015). Heart rate and deceleration time of mitral and tricuspid E wave significantly correlated, but heart rate did not correlate with either mitral or tricuspid peak E-wave or A-wave velocities or E/A ratio. In heart failure the effect of respiration was similar to normal subjects. Sex was not associated with Doppler variables in either normals or heart failure subjects. Thus this study demonstrates that age, heart rate, and respiration have important and separate associations with Doppler echo diastolic parameters of the right and left ventricle in normal subjects and similar, although weaker relations in patients with heart failure.

Right ventricular diastolic dysfunction in heart failure

BACKGROUND

Left ventricular (LV) diastolic dysfunction is common in heart failure and is an important predictor of prognosis and mortality. Less attention has been paid to right ventricular (RV) diastolic function. In this study, we compared RV diastolic function in a large cohort of patients with heart failure (HF) with two groups: patients with pulmonary hypertension and normal LV function (the PHT group) and normal subjects.

METHODS AND RESULTS

Transtricuspid and pulmonary artery flow were assessed by two-dimensional Doppler echocardiography at maximum inspiration and expiration in 185 subjects: 114 symptomatic HF patients (ejection fraction < 0.5), 31 PHT patients (pulmonary artery systolic pressure > 40 mm Hg), and 40 normal subjects. A subset was matched for age and heart rate. The results showed a high prevalence of RV diastolic abnormalities: HF patients had lower tricuspid E-A ratios, lower peak E-wave velocity, and prolonged RV isovolumic relaxation time (all P< .0001). Tricuspid E-wave deceleration time was significantly shorter only in those who had an LV restrictive filling pattern. The PHT group had similar findings. Compared with a normal range, more than half of the patients had lower tricuspid E-A ratios (HF, 55%; PHT, 69%), and 61% of HF and 58% of PHT patients had a prolonged RV isovolumic relaxation time. In the PHT group, RV diastolic parameters (E-wave deceleration time, E-A ratio, and isovolumic relaxation time) correlated significantly with pulmonary artery systolic pressure (P< .05). In the HF group, however, only tricuspid E-wave deceleration time correlated significantly with pulmonary artery systolic pressure, and HF patients with normal pulmonary artery systolic pressures had significantly lower tricuspid E-A ratios and prolonged RV isovolumic relaxation times compared with normal subjects. A close correlation existed between individual RV and LV diastolic parameters, suggesting that LV diastolic dysfunction may directly affect RV function, but there was no relation between LV size or systolic function and RV diastolic dysfunction.

CONCLUSIONS

RV diastolic function is frequently abnormal in HF patients, and this is not related to elevated pulmonary artery systolic pressure alone, although high pulmonary artery pressure by itself also is associated with impaired RV diastolic function. Assessment of the role of right ventricular diastolic function in determining the symptoms and prognosis of heart failure is warranted.

Relation of mean right atrial pressure to echocardiographic and Doppler parameters of right atrial and right ventricular function

BACKGROUND

A paucity of data exists as to the relation of mean right atrial pressure (RAP) to Doppler parameters of right atrial and ventricular filling. Furthermore, whether echocardiographic parameters of right atrial and right ventricular function and inferior vena cava improve the relation of Doppler filling dynamics with RAP has not been explored.

METHODS AND RESULTS

Doppler and echocardiographic studies were performed simultaneously with measurements of mean RAP in consecutive patients who either had a central venous catheter in the Intensive Care Unit or underwent catheterization of the right side of the heart. The initial population consisted of 35 patients with a mean age (+/-SD) of 60+/-15 years; 34% were on mechanical ventilation. Mean RAP averaged 9+/-5.7 mm Hg (range, 2 to 28 mm Hg). Among tricuspid inflow parameters, the strongest relation with RAP was observed with the ratio of early to late velocity (r=.66). For hepatic venous flow, systolic filling wave indexes had the best relation with atrial pressure, the highest being for systolic filling fraction (r=-.86). Weaker relations were noted with the use of right atrial volumes, right ventricular function, and inferior vena caval diameters. The addition of any of these variables did not improve the relation of systolic filling fraction with RAP. The regression equation (RAP=21.6-24 systolic filling fraction) was tested prospectively in the estimation of atrial pressure 50 patients. The correlation coefficient was .89 in the prospective group and .88 in the total group of 85 patients. The mean difference between predicted and actual pressures in the whole population was -0.2+/-2.6 mm Hg. The sensitivity and specificity for mean RAP>8 mm Hg were 86% and 92%, respectively.

CONCLUSIONS

Among echocardiographic and Doppler parameters of right atrial and right ventricular function, hepatic venous flow dynamics relate best to mean atrial pressure and can be used clinically to estimate mean RAP.

Optimal determination of right ventricular filling dynamics in systemic hypertension

To determine the optimal method of normalizing peak filling rate (PFR) determinations and apply it to the assessment of right ventricular (RV) and left ventricular (LV) filling characteristics and their interactions, 41 subjects with hypertension and 40 matched normals underwent echo-Doppler and nuclear study. Conventional normalization of PFR to end-diastolic volume (EDV) yielded poor correlations between nuclear- and echo-derived PFR (RV, r = 0.34; LV, r = 0.42), whereas nuclear and echo PFR normalized to stroke volume (SV) were closely correlated (RV, r = 0.87; LV, r = 0.92). Further, use of PFR normalized to SV revealed to close relation between RV and LV filling characteristics. Multivariate analysis confirmed that, in contrast to normalization to EDV or early to late filling-velocity ratios (E/A), peak filling rate normalized to SV was independent of ejection fraction and heart rate. In addition, RV filling impairment was related to LV filling impairment, and the effects of hypertension eliminated the independent influence of age on both LV and RV filling. In conclusion, normalization of PFR to SV may be preferable to use of EDV or E/A in evaluating RV and LV filling dynamics.

A study on left atrial transport function. Effect of age or left ventricular ejection fraction on left atrial storage fraction

Left atrial (LA) storage fraction is defined as the ratio of storage volume of the left atrium (LA) during ventricular systole to left ventricular (LV) stroke volume. To test their hypothesis that left atrial (LA) storage fraction is increased to compensate for impaired LV filling in the heart of aged subjects or with impaired LV ejection fraction, the authors studied 33 "normal" subjects and 25 patients with coronary artery disease. LA volume was measured by LA cineangiocardiography, and LV stroke volume and LV ejection fraction were measured by LV cineangiocardiography. To further evaluate the determinants of changes in LA storage fraction, they measured the ratio of LA active release volume to LV stroke volume, and the ratio of LA passive release volume to LV stroke volume. In "normal" subjects, LA storage fraction was increased with age (r = 0.584, P < 0.01). In patients with coronary artery disease, LA storage fraction was increased as LV ejection fraction was decreased (r = -0.525, P < 0.01). In both cases, LA active release fraction was significantly associated with changes in LA storage fraction rather than in LA passive release fraction. They conclude that LA storage fraction may be an important determinant of LV filling mainly through the LA active release fraction.

Age-related changes in left and right ventricular filling velocity profiles and their relationship in normal subjects

To confirm age-related changes in left and right ventricular filling velocity profiles and to compare left and right ventricular filling parameters in normal subjects, we performed pulsed Doppler echocardiographic studies in 108 normal subjects (72 men and 36 women) aged 15 to 78 years. An age-related decrease in peak early velocity (E velocity), an increase in peak atrial velocity (A velocity), and augmented ratio of A velocity to E velocity (A/E) were observed in left ventricle (r = -0.71, 0.63, and 0.83, respectively). Similar age-related changes were found in right ventricle (r = -0.71, 0.54, and 0.78). Aging had a greater effect on the filling of the left ventricle than the right one (i.e., a steeper slope). The difference between left and right ventricular filling increased with advancing age. Left ventricular filling indexes exceeded those of the right ventricle. Significant correlations were observed between the right and left ventricular filling parameters (r = 0.58 to 0.90). A strong relation was noted in A/E (r = 0.90). There was no significant relation between age and left ventricular mass. The left ventricular mass appeared to have little effect on left and right ventricular filling in normal individuals. Thus in clinical studies the age-related decrease in early diastolic filling and the increased atrial filling in both left and right ventricles should be considered. The atrial contribution to ventricular filling may be more pronounced in the left ventricle than the right ventricle in older subjects.

Long-term assessment of right ventricular diastolic filling in patients with pulmonic valve stenosis successfully treated in childhood

Patients with severe pulmonic stenosis (PS) have right ventricular (RV) diastolic filling abnormalities detectable by tricuspid valve pulsed Doppler examination. To determine if these abnormalities persist long term after successful therapy of PS, 19 patients were examined 8 +/- 3 years after PS therapy. At the time of follow-up Doppler examination, the PS gradient was 15 +/- 8 mm Hg. From the tricuspid valve inflow Doppler study, the following measurements were obtained at peak inspiration: peak velocities at rapid filling (peak E) and during atrial contraction (peak A), ratio of peak E to peak A velocities, RV peak filling rate normalized for stroke volume, deceleration time, the fraction of filling in the first 0.33 of diastole as well as under the E and A waves, and the ratio of E to A area. Data from PS follow-up patients were compared with our previously reported data from 12 age-related control subjects and 14 untreated patients with PS. Patients with PS who were followed up had higher peak E velocity (0.75 +/- 0.14 vs 0.59 +/- 0.21 m/s), lower peak A velocity (0.47 +/- 0.09 vs 0.64 +/- 0.28 m/s), higher E/A velocity ratio (1.65 +/- 0.33 vs 1.11 +/- 0.52), higher 0.33 area fraction (0.52 +/- 0.08 vs 0.34 +/- 0.14), lower A area fraction (0.29 +/- 0.06 vs 0.45 +/- 0.21) and higher E/A area ratio (2.48 +/- 0.82 vs 1.73 +/- 1.05) than PS patients without treatment (p less than 0.03). All Doppler indexes of the patients with PS who were followed up were the same as those of the control subjects except for the peak E velocity that was slightly higher (0.75 +/- 0.14 vs 0.63 +/- 0.11 m/s), the peak A velocity that was slightly higher (0.47 +/- 0.09 vs 0.38 +/- 0.09 m/s) and the E/A area ratio that was slightly lower (2.48 +/- 0.82 vs 3.50 +/- 1.25) (p less than 0.03). Thus, at long-term follow-up, all RV diastolic filling indexes in successfully treated patients with PS improved compared with the untreated patients and approached values found in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary venous flow velocity pattern as assessed with transthoracic pulsed Doppler echocardiography in subjects without cardiac disease

Pulmonary venous flow velocity pattern (PVFVP) was analyzed in 53 subjects (aged 25 to 77 years, mean 47) without cardiovascular disease who underwent transthoracic pulsed Doppler echocardiography. The forward flow velocity pattern was biphasic in 37 of the 53 subjects, with each of the 2 peaks in systole and diastole; flow was triphasic with 2 peaks in systole and the other peak in diastole in the remaining 16 subjects. Peak systolic and diastolic flow velocity ranged from 28 to 84 cm/s and from 27 to 71 cm/s, respectively. Mean systolic flow velocity was significantly greater than mean diastolic flow velocity (53 +/- 12 vs 47 +/- 11 cm/s, p less than 0.01). Systolic flow velocity and the ratio of systolic to diastolic flow velocity increased and diastolic flow velocity decreased with aging (r = 0.52, p less than 0.001, r = 0.70, p less than 0.001 and r = -0.49, p less than 0.001, respectively). Reverse flow occurred during the atrial contraction phase and its velocity (mean 20 cm/s) increased with aging (r = 0.56, p less than 0.001). The parameters of PVFVP were compared with the ratio of peak early diastolic filling velocity to peak filling velocity at atrial contraction (E/A ratio) measured in the transmitral flow velocity pattern. As E/A ratio increased, systolic flow velocity and systolic/diastolic flow ratio and peak reverse flow velocity decreased (r = -0.40, p less than 0.01, r = -0.67, p less than 0.001 and r = -0.68, p less than 0.001, respectively) and diastolic flow velocity increased (r = 0.58, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)