Non-invasive assessment of pulmonary hypertension: Doppler-echocardiography

Diastolic ventricular function in persistent pulmonary hypertension of the newborn

Background

Persistent pulmonary hypertension of the newborn (PPHN) is usually considered a consequence of impaired pulmonary circulation. However, little is known regarding the role of cardiac dysfunction in PPHN. In this study, we hypothesized that the tolerance for pulmonary hypertension in newborn infants depends on the biventricular function. The aim of this study is to evaluate biventricular cardiac performance by using Tissue Doppler Imaging (TDI) in an healthy newborn infants with asymptomatic pulmonary hypertension and in newborn infants with PPHN.

Methods

Right and left cardiac function were investigated using conventional imaging and TDI in 10 newborn infants with PPHN ("PPHN") and 10 asymptomatic healthy newborn infants ("asymptomatic PH").

Results

Systolic pulmonary artery pressure (PAP) as assessed by TDI and the mean systolic velocity of the right ventricular (RV) free wall were similar in both groups. The isovolumic relaxation time of the right ventricle at the tricuspid annulus was significantly longer in the "PPHN" than in the "asymptomatic PH" group (53 ± 14 ms vs. 14 ± 4 ms, respectively; p < 0.05). Left ventricular (LV) function was normal in both groups with a systolic velocity (S'LV) at the LV free wall groups (6 ± 0.5 cm/s vs. 8.3 ± 5.7 cm/s, p > 0.05).

Conclusion

The present results suggest that high PAP with or without respiratory failure is not associated with altered right systolic ventricular function and does not affect LV function in newborn infants. PPHN is characterized by a marked right diastolic ventricular dysfunction. These data suggest that the hypoxic respiratory failure in PPHN results, at least in part, from diastolic RV dysfunction and right to left shunting across the foramen ovale. We propose that the severity of the respiratory failure is more related to the RV diastolic dysfunction than the pulmonary artery pressure.

Low serum 25-hydroxyvitamin D (vitamin D) level among children with ventricular septal defect: how big is the risk for pulmonary hypertension?

INTRODUCTION

Ventricular septal defect is the most common CHD, leading to pulmonary hypertension. Significantly lower 25-hydroxyvitamin D level was reported in children with CHD compared with healthy controls. The current study aimed to investigate the correlation between 25-hydroxyvitamin D level and pulmonary hypertension in children with ventricular septal defect.

METHODS

A cross-sectional study was conducted on ventricular septal defect paediatric patients from January to June, 2019. Serum 25-hydroxyvitamin D was measured using electrochemiluminescence. Pulmonary hypertension was defined as mean pulmonary artery systolic pressure > 20 mmHg for children >3 months of age at sea level, measured by Doppler echocardiography.

RESULTS

From forty-four subjects, the majority of the subjects were female (56.8%) with normal nutritional status and perimembranous ventricular septal defect. Bivariate analysis showed that 25-hydroxyvitamin D level was associated with pulmonary hypertension (p < 0.01), type and size of ventricular septal defect (p = 0.02), and heart failure (p < 0.01). Higher 25-hydroxyvitamin D level was correlated with better nutritional status (p = 0.04, r = 0.26), and lower 25-hydroxyvitamin D level was correlated with the occurence of perimembranous ventricular septal defect (p = 0.01, r = -0.39), larger defect size (p < 0.01, r = -0.70), history of pneumonia (p = 0.02, r = -0.31), and heart failure (p < 0.01, r = -0.64). Subjects with 25-hydroxyvitamin D deficiency had prevalence ratio of 24.0 times for pulmonary hypertension. Higher pulmonary artery pressure was correlated to the occurence perimembranous ventricular septal defect (p = 0.01, r = 0.47), larger defect size (p < 0.01, r = 0.78), history of pneumonia (p = 0.01, r = 0.38), and heart failure (p < 0.01, r = 0.75).

CONCLUSION

Children with ventricular septal defect who had low 25-hydroxyvitamin D level posed a higher risk of having pulmonary hypertension.

Comparative Assessment of Echocardiographic Patterns Among Chronic Myeloid Leukemia Patients on Tyrosine Kinase Inhibitor and Healthy Controls

PURPOSE

Chronic myeloid leukemia (CML) is one of the common hematological malignancies in Nigeria. Cardiac abnormalities are associated with CML irrespective of treatment with tyrosine kinase inhibitors such as imatinib, which is available gratis in Nigeria.

OBJECTIVE

To assess the prevalence and patterns of cardiac dysfunction among patients with CML irrespective of treatment with imatinib using transthoracic echocardiography, and 12-lead surface electrocardiography.

PATIENTS AND METHODS

CML patients without Imatinib, CML patients with imatinib, and apparently healthy (age- and sex-matched) controls were 70 each in the study. Various echocardiographic parameters were measured and data obtained were analyzed, and the level of significance was taken as p < 0.05.

RESULTS

Of 70 CML patients with imatinib, 54.3% were men and 45.7% were women, while the CML group without imatinib had 62.9% men and 37.1% women, non-CML control had 54.3% men and 45.7% women. The average hematocrit was significantly lower in the CML group without Imatinib compared with the other groups (p<0.001). And, 12.9% and 17.1% of CML groups with and without imatinib had LVH, respectively, and none of the non-CML controls had LVH (P<0.041). Impaired left ventricular relaxation in 25.71% and 28.57% of CML patients with and without imatinib respectively but only 8.57% of the non-CML control had impaired left ventricular relaxation (p=0.236). Mitral valve regurgitation was the most frequent valvular abnormality across the groups. Pulmonary hypertension in 17.4% and 20% of CML patients with and without imatinib, respectively, but none of the non-CML controls had pulmonary hypertension (p<0.001). Pericardial effusion in 32.86% and 45.71% of CML patients with and without imatinib, respectively, but none of the non-CML controls had pericardial effusion (p<0.001). There was no significant difference in the QTC interval across the three groups.

CONCLUSION

Cardiac abnormalities are present in CML patients with or without Imatinib treatment, with significant prevalence than what is seen in the non-CML control group.

Utility of Automated Cardiac Chamber Volumetry by Non-Gated CT Pulmonary Angiography for Detection of Pulmonary Hypertension Using the 2018 Updated Hemodynamic Definition

BACKGROUND: Noninvasive tests for pulmonary hypertension (PH) are needed to help select patients for diagnostic right heart catheterization (RHC). CT pulmonary angiography (CTPA) is commonly performed for suspected PH. OBJECTIVE: To assess the utility of CTPA-based cardiac chamber volumetric measurements for diagnosis of PH in comparison with echocardiographic and conventional CTPA parameters, using as reference the 2018 updated hemodynamic definition. METHODS: This retrospective study included 109 patients (median age, 68 years; 72 women, 37 men) who underwent non-gated CTPA, echocardiography, and RHC for workup of suspected PH between August 2013 and February 2016. Two radiologists independently used automated 3D segmentation software to determine volumes of the right ventricle (RV), right atrium (RA), left ventricle (LV), and left atrium (LA), and measured axial diameters of cardiac chambers, main pulmonary artery, and ascending aorta. Interobserver agreement was assessed, and mean values were obtained; one observer repeated volumetric measurements to assess intraobserver agreement. ROC analysis was used to assess diagnostic performance for detection of PH. A multivariable binary logistic regression model was established. RESULTS: A total of 60/109 patients had PH. Intra- and interobserver agreement were excellent for all volume measurements (intraclass correlation coefficients, 0.935-0.999). In patients with, versus without, PH, RV volume was 172.6 versus 118.1 ml, and RA volume was 130.2 versus 77.0 ml (both p<.05). Cardiac chamber measurements with highest AUC for PH were RV/LV volume ratio and RA volume (both 0.791). Significant predictors of PH after adjustment for age, sex, and body surface area included RV volume per 10 ml [odds ratio (OR)=1.21], RA volume per 10 ml (OR=1.27), RV/LV volume ratio (OR=2.91), and RA/LA volume ratio (OR=11.22). Regression analysis yielded a predictive model for PH containing two independent predictors, echocardiographic pulmonary arterial systolic pressure and CTPA-based RA volume; the model had AUC 0.898, sensitivity 83.3%, and specificity 85.7%. CONCLUSION: Automated cardiac chamber volumetry using non-gated CTPA, particularly of the RA, provides incremental utility relative to echocardiographic and conventional CTPA parameters for diagnosis of PH. CLINICAL IMPACT: Automated cardiac chamber volumetry on CTPA may facilitate early nonvinvasive detection of PH, identifying patients warranting further evaluation by RHC.

Comparative accuracy of non-invasive imaging versus right heart catheterization for the diagnosis of pulmonary hypertension: A systematic review and meta-analysis

BACKGROUND

Right heart catheterization (RHC) is the gold-standard in the diagnosis of pulmonary hypertension (PH) but at the cost of procedure-related complications. We sought to determine the comparative accuracy of RHC versus non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and transthoracic echocardiography (TTE).

METHODS

Pulmonary hypertension was defined as a mean pulmonary artery pressure (mPAP) of>20 mmHg. Multiple databases were queried for relevant articles. Raw data were pooled using a bivariate model to calculate the measures of diagnostic accuracy and to estimate Hierarchical Summary Receiver Operating Characteristic (HSROC) on Stata 13.

RESULTS

A total of 51 studies with a total patient population of 3947 were selected. The pooled sensitivity and specificity of MRI for diagnosing PH was 0.92(95% confidence interval (CI) 0.88-0.96) and 0.86 (95% CI, 0.77-0.95), respectively. The net sensitivities for CT scan and TTE were 0.79 (95% CI 0.72-0.89) and 0.85 (95% CI 0.83-0.91), respectively. The overall specificity was 0.82 (0.76-0.92) for the CT scan and 0.71 (95% CI 0.61-0.84) for TTE. The diagnostic odds ratio (DOR) for MRI was 124 (95% CI 36-433) compared to 30 (95% CI 11-78) and 24 (95% 11-38) for CT scan and TTE, respectively. Chi-squared (x2) test showed moderate heterogeneity on the test for equality of sensitivities and specificities.

CONCLUSIONS

MRI has the highest sensitivity and specificity compared to CT and TTE. MRI can potentially serve as a surrogate technique to RHC for the diagnosis of PH.

Improvement of Left Ventricular Ejection Fraction and Pulmonary Hypertension Are Significant Prognostic Factors in Heart Failure with Reduced Ejection Fraction Patients

BACKGROUND

We evaluated long-term prognosis according to improvement of pulmonary hypertension (PH) and left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF) and PH.

METHODS

We included all consecutive patients with HFrEF and PH who had a baseline and follow-up echocardiographic examinations from September 2011 to March 2017. PH was defined as maximal velocity of tricuspid regurgitation (TR Vmax) over 3.0 m/s, and LVEF improvement was defined as LVEF change ≥ 15% from the baseline echocardiography. Primary outcome was 5-year major adverse cardio-cerebrovascular events (MACCE).

RESULTS

We analyzed 271 patients. Mean LVEF was 28±8% and TR Vmax was 3.4±0.4 m/s. On follow-up, 183 (68%) showed improvement of LVEF, and 165 (61%) demonstrated improvement of PH. We classified patients into 4 groups according to improvement of PH and LVEF; group 1 (both improvement, 134 patients), group 2 (PH improvement only, 31 patients), group 3 (LVEF improvement only, 49 patients) and group 4 (no improvement, 57 patients). Group 4 had older age, higher incidence of myocardial infarction and aggravation of pre-existing HF. During the follow-up (31±20 months), 27% died and 40.8% experienced MACCE. Group 4 had the worst survival (HR=4.332, 95% CI=2.396-7.833, p<0.001), and group 3 had increased MACCE rate (HR=2.030, 95% CI=1.060-3.888, p=0.033) compared with group 1. Group 2 had similar long-term clinical events (HR=1.085, 95% CI=0.458-2.571, p=0.853) to group 1.

CONCLUSIONS

In patients with HFrEF and PH, persistence of PH and no LVEF improvement was associated with the worst long-term outcome.

Prediction of spontaneous closure of ventricular septal defect and guidance for clinical follow-up

AIM

To predict the spontaneous closure of ventricular septal defect (VSD) and assist pediatrician to manage VSD children.

METHODS

Between January 2008 and December 2016, 132 children diagnosed with isolated VSD by echocardiography were enrolled. All participating children were followed-up by echocardiography yearly until the closure of VSD or 6 years old. The clinical indicators and echocardiographic parameters of patients were collected. Statistically significant factors were used to establish a Logistic Regression model for predicting spontaneous closure of VSD. Receiver operating characteristic (ROC) analysis was used to assess the specificity and sensitivity of Logistic Regression model.

RESULTS

Spontaneous closure occurred in 60% of all patients; 57% in perimembranous VSD (p-VSD) and 64% in muscular VSD (m-VSD) patients. Initial diagnosis age, defect size, aneurysms tissue of the ventricular membranous septum (ATVMS), pulmonary hypertension (PH), and left ventricular diastolic dimension (LVDD) were statistically significant. Defect size, ATVMS and LVDD were determined by the Logistic Regression model as representative factor. P-VSD and m-VSD model had areas under the ROC curves 0.854 and 0.898, respectively.

CONCLUSION

We inferred that defect size, ATVMS and LVDD were characteristic and representative predictors for spontaneous closure of VSD. And we summarized the prognostic factors and recommended a follow-up criteria to assist the pediatrician managing VSD children.

Combined automated 3D volumetry by pulmonary CT angiography and echocardiography for detection of pulmonary hypertension

OBJECTIVES

To assess the diagnostic accuracy of automated 3D volumetry of central pulmonary arteries using computed tomography pulmonary angiography (CTPA) for suspected pulmonary hypertension alone and in combination with echocardiography.

METHODS

This retrospective diagnostic accuracy study included 70 patients (mean age 66.7, 48 female) assessed for pulmonary hypertension by CTPA and transthoracic echocardiography with estimation of the pulmonary arterial systolic pressure (PASP). Gold standard right heart catheterisation with measurement of the invasive mean pulmonary arterial pressure (invasive mPAP) served as the reference. Volumes of the main, right and left pulmonary arteries (MPA, RPA and LPA) were computed using automated 3D segmentation. For comparison, axial dimensions were manually measured. A linear regression model was established for prediction of mPAP (predicted mPAP).

RESULTS

MPA, RPA and LPA volumes were significantly increased in patients with vs. without pulmonary hypertension (all p < 0.001). Of all measures, MPA volume demonstrated the strongest correlation with invasive mPAP (r = 0.76, p < 0.001). Predicted mPAP using MPA volume and echocardiographic PASP as covariates showed excellent correlation with invasive mPAP (r = 0.89, p < 0.001). Area under the curves for predicting pulmonary hypertension were 0.94 for predicted mPAP, compared to 0.90 for MPA volume and 0.92 for echocardiographic PASP alone. A predicted mPAP > 25.8 mmHg identified pulmonary hypertension with sensitivity, specificity, positive and negative predictive values of 86%, 93%, 95% and 81%, respectively.

CONCLUSIONS

Automated 3D volumetry of central pulmonary arteries based on CTPA may be used in conjunction with echocardiographic pressure estimates to noninvasively predict mPAP and pulmonary hypertension as confirmed by gold standard right heart catheterisation with higher diagnostic accuracy than either test alone.

KEY POINTS

• This diagnostic accuracy study derived a regression model for noninvasive prediction of invasively measured mean pulmonary arterial pressure as assessed by gold standard right heart catheterisation. • This regression model using automated 3D volumetry of the central pulmonary arteries based on CT pulmonary angiography in conjunction with the echocardiographic pressure estimate predicted pulmonary arterial pressure and the presence of pulmonary hypertension with good diagnostic accuracy. • The combination of automated 3D volumetry and echocardiographic pressure estimate in the regression model provided superior diagnostic accuracy compared to each parameter alone.

Reliability of Echocardiographic Indicators of Pulmonary Vascular Disease in Preterm Infants at Risk for Bronchopulmonary Dysplasia

OBJECTIVES

To determine the assessment and inter-rater reliability of echocardiographic evaluations of pulmonary vascular disease (PVD) in preterm infants at risk for bronchopulmonary dysplasia.

STUDY DESIGN

We prospectively studied echocardiograms from preterm infants (birthweights 500-1250 g) at 7 days of age and 36 weeks postmenstrual age (PMA). Echocardiograms were assessed by both a cardiologist on clinical service and a single research cardiologist. Interpretations were reviewed for inclusion of determinants of PVD and assessed for inter-rater reliability using the Prevalence Adjusted Bias Adjusted Kappa Score (PABAK).

RESULTS

One hundred eighty and 188 matching research and clinical echocardiogram reports were available for the 7-day and 36-week PMA studies. At least one of the specific qualitative measures of PVD was missing from 54% of the clinical reports. PVD was diagnosed at 7 days in 31% and 20% of research and clinical interpretations, respectively (PABAK score of 0.54). At 36 weeks, PH was diagnosed in 15.6% and 17.8% of research and clinical interpretations, respectively (PABAK score of 0.80).

CONCLUSIONS

Although all qualitative variables of PVD are not consistently provided in echocardiogram reports, the inter-rater reliability of cardiologists evaluating measures of PVD revealed strong agreement, especially at 36 weeks PMA. We speculate that establishment of a protocol for echocardiographic evaluation may improve the identification of PVD in preterm infants.

Right ventricular systolic dysfunction and remodelling in Nigerians with peripartum cardiomyopathy: a longitudinal study

Background

The literature on right ventricular systolic dysfunction (RVSD) in peripartum cardiomyopathy (PPCM) patients is scanty, and it appears that RV reverse remodelling in PPCM has not been previously described. This study thus aimed to assess RVSD and remodelling in a cohort of PPCM patients in Kano, Nigeria.

Methods

A longitudinal study carried out in 3 referral hospitals in Kano, Nigeria. Consecutive PPCM patients who had satisfied the inclusion criteria were recruited and followed up for 12 months. RVSD was defined as the presence of either tricuspid annular plane systolic excursion (TAPSE) <16 mm or peak systolic wave (S’) tissue Doppler velocity of RV free wall <10 cm/s. For the purpose of this study, recovery of RV systolic function was defined as an improvement of reduced TAPSE to ≥16 mm or S’ to ≥10 cm/s, without falling to reduced levels again, during follow-up.

Results

A total of 45 patients were recruited over 6 months with a mean age of 26.6 ± 7.0 years. RV systolic function recovery occurred in a total of 8 patients (8/45; 17.8 %), of whom 6 (75.0 %) recovered in 6 months after diagnosis. The prevalence of RVSD fell from 71.1 % at baseline to 36.4 % at 6 months (p = 0.007) and 18.8 % at 1 year (p = 0.0008 vs baseline; p = 0.41 vs 6 month). Patients with RVSD had higher serum creatinine, and TAPSE accounted for 19.2 % (p = 0.008) of the variability of serum creatinine at 6 months. Although 83.3 % of the deceased had RVSD, it didn’t predict mortality in the regression models (p > 0.05).

Conclusion

RVSD and reverse remodelling were common in Nigerians with PPCM, in whom the first 6 months after diagnosis seem to be critical for RV recovery and survival.

Percutaneous CT guided lung biopsy in patients with pulmonary hypertension: Assessment of complications

PURPOSE

To assess the complications of CT-guided percutaneous transthoracic needle aspiration and/or core biopsy (PTNAB) of lung nodules in patients with pulmonary arterial hypertension (PHTN).

METHOD AND MATERIALS

We analyzed PTNAB of 74 lung lesions (mean size: 3.6 ± 2.1 cm) in 74 patients (M: F 38:36; age 68 ± 15 years) with documented PHTN on cardiac ultrasound. 39 patients with lung lesions (M: F 24:15; age 65 ± 14) who underwent PTNAB in the same period with right ventricle systolic pressure (RVSP) <35 mm Hg were selected as controls. Pulmonary arterial pressures were estimated on cardiac ultrasounds by using the tricuspid regurgitation jet method. Two thoracic radiologists reviewed the medical records and PTNAB images on a PACS station and documented nodule size, location, distance traversed in lung, technical success and complications.

RESULTS

Fine needle aspirates were obtained in all and core biopsy in 23% (17/74) of the nodules. 61% (45/74) of the nodules were in the middle and 39% (29/74) were in the outer third of lung. PHTN was mild, moderate and severe in 84% (62/74), 13% (10/74) and 3% (2/74) of the patients. Biopsy was complicated by hemorrhage in 26% (19/74), moderate hemoptysis in 1.3% (1/74), pneumothorax in 17% (12/74), chest tube in 1.3% (1/74) and hemothorax in 1.3% (1/74) of the patients. The complications rate in control group was similar, hemorrhage in 33% (19/39) (p=0.6), moderate hemoptysis in 5% (2/39) (p=0.3), pneumothorax in 28% (11/39) (p=0.2), chest tube in (0/39) (p=0.3), and hemothorax in 3% (1/39) of the patients (p=0.7).

CONCLUSION

Percutaneous needle biopsy of lung lesions in patients with mild to moderate PHTN can be performed without significant increase in complications.

The Role of Echocardiography in the Evaluation of Pulmonary Arterial Hypertension

The evaluation of pulmonary arterial hypertension (PAH) requires a multimodality approach that combines invasive and noninvasive imaging studies to ensure accurate diagnosis and classification. Given the complexity of the hemodynamic relationships between the left heart, pulmonary circulation, and right heart, the diagnosis of PAH is often a challenging task. Right heart catheterization is the gold standard for diagnosis, providing the hemodynamic information that defines the disease. Nonetheless, echocardiography continues to be a valuable tool in the approach to the patient with suspected PAH. Echocardiographic assessment generates a wealth of information about the response of the right heart to elevated pulmonary pressures and provides essential diagnostic and prognostic data to the clinician. Numerous measurements can be used to identify alterations in right heart morphology, pressure, and function; although each variable in isolation may have little utility, meaningful information is revealed when multiple parameters are considered together. In this article, we will review the echocardiographic measurements employed in assessment of the right heart and seek to clarify the role of echocardiography in the diagnostic workup of PAH.

Fibrinolytic system related to pulmonary arterial pressure and lung function of patients with idiopathic pulmonary fibrosis

OBJECTIVES AND AIMS

To investigate urokinase-(uPA) and tissue-type (tPA) plasminogen activator and plasminogen activator inhibitor type-1 (PAI-1) levels in patients with idiopathic pulmonary fibrosis (IPF) and to determine the relationship between fibrinolytic system and pulmonary arterial pressure and pulmonary function.

METHODS

Seventy-nine patients with IPF were included. Bronchoalveolar lavage fluid (BALF) and blood samples were collected. The concentrations of tPA, uPA and PAI-1 were measured using enzyme-linked immunosorbent assay. Doppler echocardiography was used to detect tricuspid regurgitation pressure gradient (TRPG) to estimate pulmonary arterial pressure.

RESULTS

BALF tPA elevated (P < 0.005), circulatory PAI-1 decreased (P = 0.05) and the ratio of uPA and PAI-1 decreased (P = 0.01) in BALF in IPF patients with pulmonary hypertension (PH) compared to those without PH. Positive linear correlations were found: BALF tPA and TRPG (r = 0.558, P = 0.013); the predicted percentage of diffusion capacity of lung for carbon monoxide adjustments for alveolar volume and BALF uPA (r = 0.319, P = 0.035). Negative linear correlations were as follows: BALF PAI-1 and the predicted percentage of VC_max (r = -0.325, P = 0.020), or total lung capacity (r = -0.312, P = 0.033); circulatory PAI-1 and TRPG (r = -0.697, P = 0.003).

CONCLUSIONS

The change of alveolar fibrolytic system in IPF, especially the uPA reduction and the PAI-1elevation, contributes to the deterioration of lung function. During the lung injury initiating fibrosis, tPA and PAI-1 might be leaked out of the pulmonary capillaries into alveoli, resulting in their elevation in alveoli and reduction in circulation, and finally contributing to the development of PH in IPF.

Hemodynamics and right-ventricle functional characteristics of a swine carotid artery-jugular vein shunt model of pulmonary arterial hypertension: An 18-month experimental study

The continuous changes in pulmonary hemodynamic properties and right ventricular (RV) function in pulmonary arterial hypertension (PAH) have not been fully characterized in large animal model of PAH induced by a carotid artery-jugular vein shunt. A minipig model of PAH was induced by a surgical anastomosis between the left common carotid artery and the left jugular vein. The model was validated by catheter examination and pathologic analyses, and the hemodynamic features and right-ventricle functional characteristics of the model were continuously observed by Doppler echocardiography. Of the 45 minipigs who received the surgery, 27 survived and were validated as models of PAH, reflected by mean pulmonary artery pressure ≥25 mmHg, and typical pathologic changes of pulmonary arterial remodeling and RV fibrosis. Non-invasive indices of pulmonary hemodynamics (pulmonary artery accelerating time and its ratio to RV ventricular ejection time) were temporarily increased, then reduced later, similar to changes in tricuspid annular displacement. The Tei index of the RV was elevated, indicating a progressive impairment in RV function. Surgical anastomosis between carotid artery and jugular vein in a minipig is effective to establish PAH, and non-invasive hemodynamic and right-ventricle functional indices measured by Doppler echocardiography may be used as early indicators of PAH.

Accuracy of Doppler echocardiographic estimates of pulmonary artery pressures in a canine model of pulmonary hypertension

OBJECTIVES

To compare noninvasive estimates of pulmonary artery pressure (PAP) obtained via echocardiography (ECHO) to invasive measurements of PAP obtained during right heart catheterization (RHC) across a range of PAP. To examine the accuracy of estimating right atrial pressure via ECHO (RAPECHO) compared to RAP measured by RHC (RAPRHC), and determine if adding RAPECHO improves the accuracy of noninvasive PAP estimations.

ANIMALS

14 healthy female beagle dogs.

METHODS

Comparison of ECHO and RHC measures of PAP, both at normal PAP and increased PAP generated by microbead embolization.

RESULTS

Noninvasive estimates of PAP were moderately but significantly correlated (r of 0.68-0.78; p < 0.0006) with invasive measurements of PAP. Wide variance was noted for all estimations, with increased variance at higher PAP. The addition of RAPECHO improved correlation and bias in all cases. RAPRHC was significantly correlated with RAPECHO (r = 0.38; p = 0.04) as estimated by the ellipse area method. Median RAPRHC was significantly different between 3 subjective assessments of right atrial size (p = 0.037).

CONCLUSIONS

Spectral Doppler assessments of tricuspid and pulmonic regurgitation are imperfect methods for predicting PAP as measured by catheterization despite an overall moderate correlation between invasive and noninvasive values. Noninvasive measurements may be better utilized as part of a comprehensive assessment of PAP in canine patients. RAPRHC appears best estimated based on subjective assessment of RA size. Including estimated RAPECHO in estimates of PAP improves the correlation and relatedness between noninvasive and invasive measures of PAP, but notable variability in accuracy of estimations persists.

A new scoring system for spontaneous closure prediction of perimembranous ventricular septal defects in children

Background

Perimembranous ventricular septal defect (PMVSD) is a congenital heart aberration, which is surgically treated by patch or device closure, but also can heal without operation as spontaneous closure (SC).

Methods

We analyzed data from 1873 PMVSD patients admitted to our hospital during September 2001 and December 2009, in order to establish a Cox regression model for PMVSD SC probability prediction (derivative cohort). Initial contact age, ventricular septal defect (VSD) diameter, shunt flow, aneurysmal tissue of the ventricular membranous septum (ATVMS) development, associated complications, and left ventricular end-diastolic dimension (LVDD) were analyzed for correlations with SC. The derived scoring system based on the coefficients of the model was developed and applied to another cohort with 382 PMVSD patients to evaluate the validity for SC probability forecast (validation cohort).

Results

Multivariate Cox regression analysis revealed that SC of PMVSD was associated with age at first contact, defect size, diffuse shunt flow, ATVMS formation, associated complication, as well as increased LVDD, which were used to establish a new scoring system. The area under the receiver operating characteristic (ROC) curve of our predictive scaling was 0.831 (95% CI 0.804–0.858, p<0.001) in the derivative cohort. The scoring system also accurately predicted SC with an area under the ROC curve of 0.863 (95% CI 0.785–0.941, p<0.001) in the validation cohort.

Conclusion

Our scoring system using factors affecting SC can predict the probability of SC in PMVSD patients.

Rationale and design of the Pan African Pulmonary hypertension Cohort (PAPUCO) study: implementing a contemporary registry on pulmonary hypertension in Africa

INTRODUCTION

Pulmonary hypertension (PH) is a devastating, progressive disease with increasingly debilitating symptoms and usually shortened overall life expectancy due to a narrowing of the pulmonary vasculature and consecutive right heart failure. Little is known about PH in Africa, but limited reports suggest that PH is more prevalent in Africa compared with developed countries due to the high prevalence of risk factors in the region.

METHODS AND ANALYSIS

A multinational multicentre registry-type cohort study was established and tailored to resource-constraint settings to describe disease presentation, disease severity and aetiologies of PH, comorbidities, diagnostic and therapeutic management, and the natural course of PH in Africa. PH will be diagnosed by specialist cardiologists using echocardiography (right ventricular systolic pressure >35 mm Hg, absence of pulmonary stenosis and acute right heart failure), usually accompanied by shortness of breath, fatigue, peripheral oedema and other cardiovascular symptoms, ECG and chest X-ray changes in keeping with PH as per guidelines (European Society of Cardiology and European Respiratory Society (ESC/ERS) guidelines). Additional investigations such as a CT scan, a ventilation/perfusion scan or right heart catheterisation will be performed at the discretion of the treating physician. Functional tests include a 6 min walk test and the Karnofsky Performance Score. The WHO classification system for PH will be applied to describe the different aetiologies of PH. Several substudies have been implemented within the registry to investigate specific types of PH and their outcome at up to 24 months. Data will be analysed by an independent institution following a data analyse plan.

ETHICS AND DISSEMINATION

All local ethics committees of the participating centres approved the protocol. The data will be disseminated through peer-reviewed journals at national and international conferences and public events at local care providers.

Synergic effects of renin and aldosterone on right ventricular function in hypertension: a tissue Doppler study

BACKGROUND

Right ventricular dysfunction (RVD) is associated with poor cardiovascular outcome. The renin-angiotensin-aldosterone system is involved in alterations of the left ventricular geometry and function. Detrimental effects of the renin-angiotensin-aldosterone system on the right ventricular function are being postulated, but data supporting this assumption are still lacking. The aim of the study was to assess the impact of hyperreninemia, hyperaldosteronism or their combination on right ventricular function in hypertensive individuals.

METHODS

Plasma renin activity (PRA) and plasma aldosterone concentrations (PACs) were measured in 116 hypertensive patients, divided as follows: normal PRA and PAC (n = 38); high PRA and normal PAC (hypereninemia) (n = 26); normal PRA and high PAC (hyperaldosternism) (n = 27); high PRA and PAC (HRA) (n = 25). Echocardiographic evaluation of the left and right ventricles (RV), including tissue Doppler imaging, was performed. RVD was identified by tissue Doppler Imaging-derived Myocardial Performance Index, calculated with a multisegmental approach.

RESULTS

Indices of the right ventricular structure and function, as well as the prevalence of RVD, were higher in hyperreninemia and hyperaldosternism groups as compared with the normal group, and a further increase was observed in the HRA patients. Regression models showed a similar risk of RVD in the hyperreninemia and hyperaldosternism patients, regardless of systemic and pulmonary pressure, as well as left ventricular dysfunction. Notably, patients with both hyperreninemia and hyperaldosternism exhibited the strongest association with RVD as compared with patients with only hyperreninemia or hyperaldosternism.

CONCLUSIONS

Isolated hyperreninemia or hyperaldosternism determines a similar impairment of the right ventricular function, whereas their combination is further detrimental. Renin and aldosterone may represent early biomarkers of right ventricular dysfunction in hypertension.

The effect of cilostazol on right heart function and pulmonary pressure

INTRODUCTION

Cilostazol is a PDE3 inhibitor and used to treat peripheral arterial disease. There are few reports on the influence of cilostazol on heart.

AIMS

The aim of this study was to assess this effect on right ventricular function and pulmonary artery pressure.

METHODS

Forty patients with normal left and right ventricular ejection fraction and mild or moderate pulmonary artery hypertension were enrolled in the study. Right ventricular function was assessed by tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), tissue Doppler imaging (TDI), and two-dimensional speckle-tracking echocardiography (2D-STE) before and after oral administration of cilostazol. Also pulmonary artery pressure assessed before and after administration of cilostazol.

RESULTS

After cilostazol administration, there were significant increases in the TAPSE (1.9 ± 0.3 cm vs. 2.2 ± 0.3 cm, P < 0.001). Peak longitudinal strain (-18.7 ± 4.5% vs. -21.3  ± 3.7%, P = 0.001), isovolumetric acceleration (IVA) (176.6 ± 62.7 cm/sec(2) vs. 200.6 ± 61.9 cm/sec(2) , P = 0.025), right ventricular FAC increased significantly (37.6 ± 8.0% vs. 41.5 ± 8.9%, P < 0.001). Pulmonary artery pressure decreased significantly (39.9 ± 7.9 vs. 36.6 ± 5.5 mmHg, P = 0.001) after cilostazol administration.

CONCLUSION

Our study demonstrated that cilostazol improved right ventricular systolic function and reduced pulmonary artery pressure.

Echocardiographic assessment of pulmonary artery systolic pressure and outcomes in ambulatory heart failure patients

Background

Pulmonary hypertension (PH) in patients with heart failure (HF) is associated with worse outcomes and is rapidly being recognized as a therapeutic target. To facilitate pragmatic research efforts, data regarding the prognostic importance of noninvasively assessed pulmonary artery systolic pressure (PASP) in stable ambulatory patients with HF are needed.

Methods and Results

We examined the association between echocardiographic PASP and outcomes in 417 outpatients with HF (age, 54±13 years; 60.7% men; 50.4% whites; 24.9% with preserved ejection fraction). Median PASP was 36 mm Hg (interquartile range [IQR]: 29, 46). After a median follow‐up of 2.6 years (IQR: 1.7, 3.9) there were 72 major events (57 deaths; 9 urgent heart transplants; and 6 ventricular assist device implantations) and 431 hospitalizations for HF. In models adjusting for clinical risk factors and therapy, a 10‐mm Hg higher PASP was associated with 37% higher risk (95% CI: 18, 59; P<0.001) for major events, and 11% higher risk (95% CI: 1, 23; P=0.039) for major events or HF hospitalization. The threshold that maximized the likelihood ratio for both endpoints was 48 mm Hg; those with PASP ≥48 mm Hg (N=84; 20.1%) had an adjusted hazard ratio of 3.33 (95% CI: 1.96, 5.65; P<0.001) for major events and 1.47 (95% CI: 1.02, 2.11; P=0.037) for major events or HF hospitalization. Reduced right ventricular systolic function had independent prognostic utility over PASP for adverse outcomes. Right atrial pressure and transtricuspid gradient both contributed to risk.

Conclusions

Elevated PASP, determined by echocardiography, identifies ambulatory patients with HF at increased risk for adverse events.

NT-proatrial natriuretic peptide as a possible biomarker of cardiopulmonary involvement in sarcoidosis

BACKGROUND

Lung diffusion for carbon monoxide (DLCO) has been shown to associate with the risk of pulmonary arterial hypertension development and, most likely, with right ventricular (RV) myocardial dysfunction in sarcoidosis patients. Besides its known role as a marker of left ventricular dysfunction, experimental evidence suggests a role of NT-proAtrial Natriuretic Peptide (NT-proANP) also in modulating pulmonary circulation. We therefore investigated possible relationships between NT-proANP, lung diffusion impairment and RV dysfunction.

METHODS

Thirty-two pulmonary sarcoidosis outpatients and eighteen volunteers underwent full clinical assessment, including full lung function tests and Doppler echocardiography integrated with tissue Doppler imaging (TDI) study. Resting circulating NT-proBNP and NT-proANP plasma levels were also determined.

RESULTS

NT-proANP and RV-myocardial performance index (RV-MPI) were significantly higher in those patients with the greatest DLCO impairment, whereas no differences were found for NT-proBNP values. At multivariable analysis, only DLCO (β: -0.496; standard error: 3.38; p=0.000) and RV-MPI (β: 0.373; standard error: 6.56; p=0.031) remained significantly associated with NT-proANP levels.

CONCLUSIONS

Our finding may support a key role of NT-proANP in the complex mechanisms underlying modulation of lung function. An early increase in pulmonary vascular resistance may stimulate NT-proANP increase, thus explaining its association with signs of early RV myocardial dysfunction. This hypothesis warrants further confirmation.

Portopulmonary hypertension in cirrhotic patients: Prevalence, clinical features and risk factors

The incidence and clinical features of portopulmonary hypertension (POPH) have not been adequately described and it is currently unknown whether an association exists between the severity of POPH and liver function. Additionally, POPH risk factors are yet to be identified. The aim of this study was to determine the prevalence, describe the clinical features and investigate the potential risk factors of POPH. We conducted a study of 100 cirrhotic patients hospitalized between March 2011 and May 2012 at Tongji Hospital in Shanghai. The clinical characteristics of patients with and without POPH were analyzed. Clinical variables with a possible association with POPH were measured and pulmonary artery systolic pressure (PASP) was determined by cardiac Doppler echocardiography. Of the 100 patients enrolled in this study, 10 were diagnosed with POPH. Seven of the cases were mild, two were moderate and only one was severe; eight were attributed to viral infections. POPH was not detected in patients with schistosomal or alcoholic cirrhosis. Hemoglobin (Hb) levels were lower in patients with POPH compared to those without POPH (P<0.01) and the severity of POPH was not significantly correlated with Child-Pugh grade (R=−0.06, P=0.09). Hb levels, incidence of hepatitis C virus (HCV) infection and portal vein thrombosis differed between the two groups (P<0.05). Hb levels were identified as an independent risk factor associated with POPH and portal vein thrombosis may play an important role during the development of POPH. However, the severity of POPH was not associated with liver function.

Right ventricular dysfunction in a hypertensive population stratified by patterns of left ventricular geometry

Introduction

The aim of this study was to assess the prevalence, determinants and correlates of right ventricular (RV) systolic and diastolic dysfunction (RVSD and RVDD, respectively) in hypertensives, stratified by left ventricular (LV) geometric patterns.

Methods

The study was carried out in Aminu Kano Teaching Hospital in Kano, Nigeria, and was cross-sectional in design. Hypertensive subjects referred for echocardiography were consecutively recruited after satisfying the inclusion criteria. RVSD was defined as either tricuspid annular plane systolic excursion (TAPSE) of < 16 mm, or peak velocity of the systolic wave (S_m) in tissue Doppler imaging (TDI) of the RV lateral tricuspid annulus of < 10 cm/s, or both. RVDD was defined as the ratio of < 1.0 of the peak velocities of the early (E_m) to late (A_m) diastolic waves in the TDI of the RV lateral tricuspid annulus. Subjects with normal LV geometry (NG) served as controls, and were compared with those who had eccentric (EH) or concentric (CH) LV hypertrophy or concentric LV remodelling.

Results

A total of 128 subjects were recruited. Overall, the prevalence of RVDD almost doubled that of RVSD in the studied subjects (61.72 vs 32.03%, respectively). Subjects with EH had the highest prevalence of RVSD (52.63%), while those with CH had the lowest prevalence (20.69%) (p < 0.01). By contrast, the prevalence of RVDD was high across the four groups without significant statistical difference; as high as 68.52% in subjects with NG and as low as 42.86% in those with CR. LVEF was the only independent determinant of RVSD after controlling for confounding variables, while age was the only determinant of RVDD. Likewise, age was the only correlate for E_m:A_m ratio, while the best correlate for both TAPSE and S_m was LVEF.

Conclusion

The study has revealed that about two-thirds of the hypertensives had RVDD while about one-third had RVSD. Subjects with EH had the highest prevalence of RVSD, while RVDD was common across all the groups. LVEF and age were the only independent determinants of RVSD and RVDD, respectively.

Fractal dimension analysis of MDCT images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension

Objective

The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH).

Materials and Methods

Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with ImageJ software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups.

Results

The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis).

Conclusion

The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.

[Role of echocardiography in suspected pulmonary hypertension]

Echocardiography is the non-invasive method of choice for the study of patients with suspected pulmonary hypertension. This technique allows systolic pulmonary artery pressure to be estimated and can also provide additional information on the cause and effects of the disease. To estimate systolic pulmonary pressure, equivalent to right ventricular systolic pressure, maximal flow velocity of tricuspid regurgitation and right atrial pressure--estimated on the basis of the degree of inferior vena cava dilation--can be employed. Other parameters that should be evaluated are those related to right cavity size and right ventricular function. Unlike the left ventricle, the anatomy and geometry of the right ventricle is complex, hampering calculation of its systolic function. Consequently, over the years, various indirect methods have been developed to estimate right systolic function, the most commonly used being tricuspid annular plane systolic excursion (TAPSE) and the Tei index. New echocardiographic methods such as study of myocardial deformation (strain) and three-dimensional echocardiography may soon provide data suggesting poor clinical course in the short and medium term. Consequently, accurate determination and characterization of these data are essential.

Echocardiographic abnormalities and their correlation with bronchiectasis score in primary antibody deficiencies

BACKGROUND

Primary antibody deficiencies are characterized by defective antibody production and recurrent infections. Patients usually present with recurrent respiratory tract infections with consequent chronic pulmonary damage and bronchiectasis, which could potentially influence cardiac function. Our aim was to assess noninvasively the cardiac complications due to pulmonary disease in patients with primary antibody deficiency.

METHODS

A cross-sectional series of patients with primary antibody deficiency syndromes from our referral immunology center were recruited. Individuals undergoing high-resolution computed tomography (HRCT) and transthoracic echocardiography were reviewed.

RESULTS

Thirty primary immunodeficient patients aged 5-55 years of age (21 males and 9 females) were enrolled in this study. Half of the patients (50%) were found to have bronchiectasis in HRCT imaging. In echocardiographic examination, 20 patients (67%) had at least one abnormality; among which pulmonary hypertension was the most common (33%). Patients with bronchiectasis had higher pulmonary artery pressures and HRCT bronchiectasis score was strongly correlated with pulmonary artery pressure (regression R = 0.59, P value = 0.001).

CONCLUSION

Echocardiographic evaluation of right ventricular function and noninvasive estimation of pulmonary artery pressure could have an important diagnostic role in the follow-up and therapeutic management of patients with primary immune deficiency.

Detection of pulmonary hypertension with multidetector CT and echocardiography alone and in combination

PURPOSE

To test the reliability of potentially new computed tomographic (CT) indicators of pulmonary hypertension (PH) and to establish whether a combination of CT and echocardiographic measurements was more predictive of PH than either test alone.

MATERIALS AND METHODS

The institutional review board approved this retrospective study; patient consent was not required. Seventy-seven patients undergoing right-sided heart catheterization were examined. CT diameters of the main pulmonary artery, ascending aorta, and thoracic vertebra and cross-sectional area of the main pulmonary artery were measured. Segmental and subsegmental arterial diameters were recorded, and segmental artery size was compared with adjacent bronchus size by using a semiquantitative scoring system. The relationship between CT measurements and mean pulmonary arterial pressure (mPAP) was tested with linear regression. Multivariate regression was used to establish a composite index of mPAP by using CT markers of PH with echocardiography-derived right ventricular systolic pressure (RVSP). Post hoc logistic regression and receiver operating characteristic curve analysis were performed to test the diagnostic ability of the CT-echocardiography composite.

RESULTS

The ratios of the diameter of the main pulmonary artery to the diameter of the ascending aorta (R(2) = 0.45; P < .001) and of the cross-sectional area of the pulmonary artery to the diameter of the ascending aorta (R(2) = 0.45; P < .001) correlated equally with mPAP. The ratio of the diameter of the main pulmonary artery to the diameter of the thoracic vertebra, the segmental arterial diameter, and the segmental artery-to-bronchus ratio were related to mPAP but did not strengthen correlations compared with the ratio of the diameter of the main pulmonary artery to the diameter of the ascending aorta alone. A composite index of the ratio of the diameter of the main pulmonary artery to the diameter of the ascending aorta and echocardiography-derived RVSP was more strongly related (R(2) = 0.55) to mPAP and was more significantly predictive of PH than either measure alone.

CONCLUSION

A combination of CT and echocardiographic markers of PH is more closely related to mPAP than either test in isolation.

Role of cardiac magnetic resonance imaging in the management of patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by abnormally elevated blood pressure of the pulmonary circulation that results, over time, from extensive vascular remodeling and increased pulmonary vascular resistance. Recent advances in magnetic resonance imaging (MRI) technology have led to the development of techniques for noninvasive assessment of cardiovascular structure and function, including hemodynamic parameters in the pulmonary circulation, which are superior in their identification of right ventricular morphologic changes. These advantages make cardiac MRI an attractive modality for following up and providing prognoses in patients with PAH. In this review, we summarize recent developments in the use of MRI for the diagnosis, assessment, and ongoing monitoring of patients with PAH. Over the coming decade, it can be anticipated that continued improvements in MRI image acquisition, spatial and temporal resolution, and analytical techniques will result in improved understanding of PAH pathophysiology, diagnosis, and prognostic variables, and will supplement, and may even replace, some of the invasive procedures currently applied routinely to the evaluation of PAH.

Early impairment of myocardial function in young patients with beta-thalassemia major

BACKGROUND AND OBJECTIVE

One of the chief causes of death in patients with beta-thalassemia major (TM) remains heart failure due to iron overload. We investigated possible differences in myocardial function between a population of young asymptomatic patients with TM and healthy controls all of whom underwent an echocardiographic study, including tissue Doppler (TDI) and strain imaging (SI) analysis and cardiac magnetic resonance imaging (MRI).

METHODS

30 young asymptomatic patients with TM (16 taking deferoxamine and 14 taking deferiprone) and 30 healthy subjects underwent a cardiac MRI with T2* technique and an echocardiographic evaluation including systolic myocardial velocities (Sm), early (Em) and late (Am) diastolic velocities and systolic strain (S) at the level of basal segments of the lateral left ventricle (LV), interventricular septum (Septal) and lateral right ventricle (RV) wall. The differences in T2* values and echocardiographic parameters were also compared in patients with TM subgrouped according to iron chelation therapy.

RESULTS

The following TDI and SI measures were lower in patients than in controls: LV-Sm (P < 0.05), S-LV (P < 0.001), Septal-Sm (P < 0.05), Septal-Em (P < 0.001), S-Septal (P < 0.001), RV-Sm (P < 0.001), RV-Em (P < 0.001), RV-Em/Am (P < 0.05) and S-RV (P < 0.05). Myocardial function was better in the patients receiving deferiprone than those receiving deferoxamine. T2* values were higher in controls than in patients with TM and in those treated with deferiprone than those treated with deferoxamine. MRI data well correlated with SI parameters.

CONCLUSIONS

Study underlines that, even in a population of young, asymptomatic and well-chelated patients with TM, there is an impairment of myocardial function and that this condition could be easily detected by more advanced ultrasound techniques such as TDI and SI. The better indices of myocardial function in patients treated with deferiprone clearly needs confirmation from larger prospective studies.

Acute Changes in Pulmonary Artery Pressures Due to Exercise and Exposure to High Altitude Do Not Cause Left Ventricular Diastolic Dysfunction

BACKGROUND

Altitude-induced pulmonary hypertension has been suggested to cause left ventricular (LV) diastolic dysfunction due to ventricular interaction. In this study, we evaluate the effects of exercise- and altitude-induced increase in pulmonary artery pressures on LV diastolic function in an interventional setting investigating high-altitude pulmonary edema (HAPE) prophylaxis.

METHODS

Among 39 subjects, 29 were HAPE susceptible (HAPE-S) and 10 served as control subjects. HAPE-S subjects were randomly assigned to prophylactic tadalafil (10 mg), dexamethasone (8 mg), or placebo bid, starting 1 day before ascent. Doppler echocardiography at rest and during submaximal exercise was performed at low altitude (490 m) and high altitude (4,559 m). The ratio of early transmitral inflow peak velocity (E) to atrial transmitral inflow peak velocity (A), pulmonary venous flow parameters, and tissue velocity within the septal mitral annulus during early diastole (E') were used to assess LV diastolic properties. LV filling pressures were estimated by E/E'. Systolic right ventricular to atrial pressure gradients (RVPGs) were measured in order to estimate pulmonary artery pressures.

RESULTS

At 490 m, E/A decreased similarly with exercise in HAPE-S and control subjects (HAPE-S, 1.5 +/- 0.3 to 1.3 +/- 0.3; control, 1.7 +/- 0.4 to 1.3 +/- 0.3; p = 0.12 between groups) [mean +/- SD], whereas RVPG increased significantly more in HAPE-S subjects (20 +/- 5 to 43 +/- 9 mm Hg vs 18 +/- 3 to 28 +/- 3 mm Hg, p < 0.001). Changes in RVPG levels during exercise did not correlate with changes in E/A (p > 0.1). From 490 to 4,559 m, no correlations between changes in RVPG and changes in E/A or atrial reversal (both p > 0.1) were observed. Neither of the groups showed an increase in E/E' from 490 to 4,559 m.

CONCLUSION

Increased pulmonary artery pressure associated with exercise and acute exposure to 4,559 m appears not to cause LV diastolic dysfunction in healthy subjects. Therefore, ventricular interaction seems not to be of hemodynamic relevance in this setting.