Diagnosis and assessment of pulmonary vascular disease by Doppler echocardiography

An Update on the Diagnosis and Management of Acute Right Heart Failure

Right ventricular (RV) dysfunction and resultant acute right heart failure (ARHF) is a rapidly growing field of interest, driven by increasing appreciation of its contribution to heart failure morbidity and mortality. Understanding of ARHF pathophysiology has advanced dramatically over recent years and can be broadly described as RV dysfunction related to acute changes in RV afterload, contractility, preload, or left ventricular dysfunction. There are several diagnostic clinical signs and symptoms as well as imaging and hemodynamic assessments that can provide insight into the degree of RV dysfunction. Medical management is tailored to the different causative pathologies, and in cases of severe or end-stage dysfunction, mechanical circulatory support can be utilized. In this review, we describe the pathophysiology of ARHF, how its diagnosis is established by clinical signs and symptoms and imaging findings, and provide an overview of treatment options, both medical and mechanical.

Non-invasive imaging techniques for early diagnosis of bilateral cardiac dysfunction in pulmonary hypertension: current crests, future peaks

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease that eventually leads to heart failure (HF) and subsequent fatality if left untreated. Right ventricular (RV) function has proven prognostic values in patients with a variety of heart diseases including PAH. PAH is predominantly a right heart disease; however, given the nature of the continuous circulatory system and the presence of shared septum and pericardial constraints, the interdependence of the right and left ventricles is a factor that requires consideration. Accurate and timely assessment of ventricular function is very important in the management of patients with PAH for disease outcomes and prognosis. Non-invasive modalities such as cardiac magnetic resonance (CMR) and echocardiography (two-dimensional and three-dimensional), and nuclear medicine, positron emission tomography (PET) play a crucial role in the assessment of ventricular function and disease prognosis. Each modality has its own strengths and limitations, hence this review article sheds light on (i) ventricular dysfunction in patients with PAH and RV-LV interdependence in such patients, (ii) the strengths and limitations of all available modalities and parameters for the early assessment of ventricular function, as well as their prognostic value, and (iii) lastly, the challenges faced and the potential future advancement in these modalities for accurate and early diagnosis of ventricular function in PAH.

A better method to evaluate the reliability of echocardiography for assessment of pulmonary hypertension: comparison of tricuspid regurgitant spectrum quality grading and tricuspid valve regurgitation degree

Background

Transthoracic echocardiography (TTE) is recommended as the most important noninvasive screening tool for the diagnosis of pulmonary hypertension (PH), sonographers usually measure the volume of regurgitant flow rather than evaluating the spectral quality, so physicians will determine whether the ultrasound measurements of pulmonary arterial systolic pressure (US-PASP) are reliable based on the volume of tricuspid regurgitation (TR). Therefore, for the first time, we grade the quality of TR spectrum (TRS) based on its integrity and clarity, aiming to assess clinical application value of different tricuspid regurgitant spectrum quality grades (TR-SQG), and investigate whether the accuracy of US-PASP is more trustworthy than TR.

Methods

We retrospectively analyzed 108 patients with chronic thromboembolic PH (CTEPH) to compare the correlation and agreement between US-PASP and right heart catheterization measurements of PASP (RHC-PASP). TR area (TRA) and TRS were measured in each patient, and TR-SQG was performed.

Results

The correlation coefficients between US-PASP and RHC-PASP were r=0.622 (P<0.001), r=0.754 (P<0.001), r=0.595 (P<0.001) in mild, moderate, severe TR, and r=0.301 (P=0.135), r=0.747 (P<0.001), r=0.739 (P<0.001), r=0.828 (P<0.001) in TR-SQG I-IV, respectively. Bland-Altman analysis revealed the mean biases of 5.05, 3.06, 7.62 mmHg in mild, moderate, severe TR, and -16.47, -8.07, 1.82, 6.09 mmHg in TR-SQG I-IV, respectively. In mild TR with the TR-SQG III and IV, the correlation coefficients between US-PASP and RHC-PASP were r=0.779 (P<0.001), intraclass correlation coefficient (ICC) =0.774, paired t-test P=0.160, respectively; and the consistency was significantly higher than that of mild TR without considering TR-SQG. In moderate TR with the TR-SQG III and IV, the r=0.749, ICC =0.746, paired t-test P=0.298 between US-PASP and RHC-PASP.

Conclusions

The US-PASP with TR-SQG III or IV is trustworthy, and its accuracy and consistency are better than those predicted by the traditional severity of TR. The establishment of the ultrasound evaluation system of TR-SQG helps clinicians to judge whether the US-PASP is accurate, credible, and reliable.

Prevalence, risk factors and echocardiographic predictors of pulmonary hypertension in systemic lupus erythematosus: towards a screening protocol

BACKGROUND

Systemic lupus erythematosus (SLE) significantly affects the lungs and heart, and pulmonary hypertension (PH) is a severe manifestation that leads to considerable morbidity and mortality.

OBJECTIVES

We aimed to determine the prevalence and risk factors of probable SLE-PH, assess the main echocardiographic predictors and develop a potential screening strategy.

METHODS

A prospective single-centre study was conducted on 201 patients with SLE who underwent transthoracic echocardiography. Patients meeting PH criteria were referred for right heart catheterisation (RHC).

RESULTS

Among patients, 88.56% were women, 85.57% were of Spanish origin and 43.78% had structural heart disease. Out of these, 16 (7.96%) had intermediate or high probability criteria for PH according to European Society of Cardiology (ESC) 2022. Six RHCs confirmed PH with a prevalence of 2.99% for SLE-PH and 1.99% for SLE-pulmonary arterial hypertension (PAH).

KEY RISK FACTORS

Key risk factors included age, cardiorespiratory symptoms, serositis, anti-Ro, cardiac biomarkers and altered pulmonary function tests (PFTs). PH was linked to a higher Systemic Lupus International Collaborative Clinics/American College of Rheumatology Damage Index (SDI) (mean SDI 4.75 vs 2.05, p<0.001) and increased mortality risk in a 2-year follow-up (12.50% vs 1.08%, p=0.002).

CONCLUSION

In our cohort, 7.96% of patients with SLE had an intermediate or high PH probability. By RHC, six patients (2.99%) met the ESC/European Respiratory Society criteria for PH and four (1.99%) for PAH. The main risk factors were older age, cardiorespiratory symptoms, serositis, anti-Ro, cardiac biomarkers and altered PFTs. PH was a severe SLE complication, suggesting the need for earlier diagnosis through data-driven screening to reduce associated morbidity and mortality.

The PH-ILD Detection tool: External validation and use in patients with ILD

Pulmonary hypertension (PH) results in increased morbidity and mortality in patients with interstitial lung disease (ILD). Early recognition of PH in this population is essential for planning diagnostic testing, initiating therapy, and evaluating for lung transplantation. The previously developed PH-ILD Detection tool has significant potential in the evaluation and treatment of ILD patients; the aim of this study was to validate the tool in an independent, multicenter cohort of patients. We conducted a retrospective review of prospectively collected data from 161 ILD patients. Patients were stratified into low- (n = 78, 48.4%), intermediate- (n = 54, 33.5%), and high-risk (n = 29, 18.0%) groups based on the score obtained with the tool. Intermediate- and high-risk patients underwent follow-up echocardiogram (TTE); 49.4% (n = 41) had an abnormal TTE suggestive of underlying PH. These patients underwent right heart catheterization; PH-ILD was diagnosed in 73.2% (n = 30) of these cases. The PH-ILD Detection tool has a sensitivity of 93.3%, specificity of 90.9%, and area-under-the-curve of 0.921 for diagnosing PH in ILD patients, validating the findings from the original study and establishing the tool as a fundamental resource for early recognition of PH in ILD patients.

Operability of atrial septal defect with borderline pulmonary vascular resistance index: A study in developing country

Background

Pulmonary arterial hypertension secondary to atrial septal defect (ASD) is an important determinant of morbidity and mortality in defect closure. We aimed to compare perioperative outcome between preoperative borderline and low pulmonary vascular resistance index (≥4 WU.m2 and &lt;4 WU.m2, respectively) in surgical closure of secundum atrial septal defect with concomitant pulmonary arterial hypertension.

Methods and results

This was a single-center retrospective cohort study between January 2015 and January 2020. We classified patients with low and borderline PVRI who underwent ASD closure and recorded the perioperative outcomes.

Results

We analyzed a total of 183 patients with atrial septal defect and pulmonary arterial hypertension; 92 patients with borderline PVRI and 91 patients with low PVRI. Borderline pulmonary vascular resistance index was not associated with increased risk of postoperative mortality (p = 0.621; OR0.48, 95% CI 0.04–5.48), but associated with higher risk of overall morbidity in bivariate analysis (p = 0.002; OR3.28, 95% CI 1.5–6.72). Multivariate analysis showed positive association of borderline pulmonary vascular resistance index (p = 0.045; OR2.63, 95% CI 1.02–6.77) and preoperative tricuspid valve gradient ≥64 mmHg (p = 0.034; OR2.77, 95% CI 1.08–7.13) with overall morbidity.

Conclusion

There is no difference in incidence of in-hospital mortality between preoperative borderline and low pulmonary vascular resistance index patients. However, preoperative borderline pulmonary vascular resistance index and tricuspid valve gradient ≥64 mmHg are associated with increased overall morbidity after surgical closure in secundum atrial septal defect patients with pulmonary arterial hypertension.

IMproving PULmonary hypertension Screening by Echocardiography: IMPULSE

BACKGROUND

The world symposium on pulmonary hypertension (PH) has proposed that PH be defined as a mean pulmonary artery pressure (mPAP) > 20 mmHg as assessed by right heart catheterisation (RHC). Transthoracic echocardiography (TTE) is an established screening tool used for suspected PH. International guidelines recommend a multi-parameter assessment of the TTE PH probability although effectiveness has not been established using real world data.

STUDY AIMS

To determine accuracy of the European Society of Cardiology (ESC) and British Society of Echocardiography (BSE) TTE probability algorithm in detecting PH in patients attending a UK PH centre. To identify echocardiographic markers and revised algorithms to improve the detection of PH in those with low/intermediate BSE/ESC TTE PH probability.

METHODS

TTE followed by RHC (within 4 months after) was undertaken in patients for suspected but previously unconfirmed PH. BSE/ESC PH TTE probabilities were calculated alongside additional markers of right ventricular (RV) longitudinal and radial function, and RV diastolic function. A refined IMPULSE algorithm was devised and evaluated in patients with low and/or intermediate ESC/BSE TTE PH probability.

RESULTS

Of 310 patients assessed, 236 (76%) had RHC-confirmed PH (average mPAP 42.8 ± 11.7). Sensitivity and specificity for detecting PH using the BSE/ESC recommendations was 89% and 68%, respectively. 36% of those with low BSE/ESC TTE probability had RHC-confirmed PH and BSE/ESC PH probability parameters did not differ amongst those with and without PH in the low probability group. Conversely, RV free wall longitudinal strain (RVFWLS) was lower in patients with vs. without PH in low BSE/ESC probability group (- 20.6 ± 4.1% vs - 23.8 ± 3.9%) (P < 0.02). Incorporating RVFWLS and TTE features of RV radial and diastolic function (RVFAC and IVRT) within the IMPULSE algorithm reduced false negatives in patients with low BSE/ESC PH probability by 29%. The IMPULSE algorithm had excellent specificity and positive predictive value in those with low (93%/80%, respectively) or intermediate (82%/86%, respectively) PH probability.

CONCLUSION

Existing TTE PH probability guidelines lack sensitivity to detect patients with milder haemodynamic forms of PH. Combining additional TTE makers assessing RV radial, longitudinal and diastolic function enhance identification of milder forms of PH, particularly in those who have a low BSE/ESC TTE PH probability.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

Notching into a Diagnosis—Incorporating Doppler Interrogation into Point-of-Care Ultrasonography to Diagnose a Submassive Pulmonary Embolism

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Doppler interrogation in bedside POCUS practice is an essential tool.

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Various echocardiographic findings exist in the face of pulmonary hypertension.

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McConnel’s sign, MSN, and 60/60 sign are linked to PE.

Elastin Insufficiency Confers Proximal and Distal Pulmonary Vasculopathy in Mice, Partially Remedied by the KATP Channel Opener Minoxidil: Considerations and Cautions for the Treatment of People With Williams-Beuren Syndrome

Background

Williams Beuren syndrome (WBS) is a recurrent microdeletion disorder that removes one copy of elastin (ELN), resulting in large artery vasculopathy. Early stenosis of the pulmonary vascular tree is common, but few data are available on longer-term implications of the condition.

Methods

Computed tomography (CT) angiogram (n = 11) and echocardiogram (n = 20) were performed in children with WBS aged 3.4–17.8 years. Controls (n = 11, aged 4.4–16.8 years) also underwent echocardiogram. Eln^+/− mice were analyzed by invasive catheter, echocardiogram, micro-CT (μCT), histology, and pressure myography. We subsequently tested whether minoxidil resulted in improved pulmonary vascular endpoints.

Results

WBS participants with a history of main or branch pulmonary artery (PA) stenosis requiring intervention continued to exhibit increased right ventricular systolic pressure (RVSP, echocardiogram) relative to their peers without intervention (p < 0.01), with no clear difference in PA size. Untreated Eln^+/− mice also show elevated RVSP by invasive catheterization (p < 0.0001), increased normalized right heart mass (p < 0.01) and reduced caliber branch PAs by pressure myography (p < 0.0001). Eln^+/− main PA medias are thickened histologically relative to Eln^+/+ (p < 0.0001). Most Eln^+/− phenotypes are shared by both sexes, but PA medial thickness is substantially greater in Eln^+/− males (p < 0.001). Eln^+/− mice showed more acute proximal branching angles (p < 0.0001) and longer vascular segment lengths (p < 0.0001) (μCT), with genotype differences emerging by P7. Diminished PA acceleration time (p < 0.001) and systolic notching (p < 0.0001) were also observed in Eln^+/− echocardiography. Vascular casting plus μCT revealed longer generation-specific PA arcade length (p < 0.0001), with increased PA branching detectable by P90 (p < 0.0001). Post-weaning minoxidil decreased RVSP (p < 0.01) and normalized PA caliber (p < 0.0001) but not early-onset proximal branching angle or segment length, nor later-developing peripheral branch number.

Conclusions

Vascular deficiencies beyond arterial caliber persist in individuals with WBS who have undergone PA stenosis intervention. Evaluation of Eln^+/− mice reveals complex vascular changes that affect the proximal and distal vasculatures. Minoxidil, given post-weaning, decreases RVSP and improves lumen diameter, but does not alter other earlier-onset vascular patterns. Our data suggest additional therapies including minoxidil could be a useful adjunct to surgical therapy, and future trials should be considered.

Recognizing pulmonary hypertension following pulmonary thromboendarterectomy: A practical guide for clinicians

Chronic thromboembolic pulmonary hypertension (CTEPH) is a form of pulmonary hypertension (PH) arising from pulmonary vascular obstruction at varying levels within the pulmonary vascular bed, due to chronic pulmonary emboli. The cornerstone of treatment for CTEPH is pulmonary thromboendarterectomy (PTE), a specialized surgery to remove the chronic vascular obstruction. At experienced centers, PTE leads to marked hemodynamic improvement and, in many cases, normalization of cardiopulmonary hemodynamics. However, increasing evidence supports the fact that a significant percentage of patients will have persistent PH after PTE. No consensus exists on the optimal approach to post-PTE patient assessment, and often the most experienced CTEPH centers have little experience in the direct follow-up care of the CTEPH patient post PTE. In this article, we will discuss a practical approach to patient assessment after PTE to help guide clinicians on how to recognize significant PH following PTE. In doing so, we identify the true phenotype of persistent PH post PTE so that appropriate patients can be further helped with the evolving therapies for the management of CTEPH.

Echocardiographic Ventricular Septal Motion Abnormalities are Associated With Pre-Capillary Pulmonary Hypertension in Patients With Preserved Left Ventricular Function

BACKGROUND

Ventricular septal motion abnormalities (VSMA) are common echocardiographic finding in patients with pulmonary hypertension (PHTN). This study sought to evaluate the relationship between echocardiographic findings and the classification of PHTN.

METHODS

This study retrospectively studied 146 consecutive patients referred for right heart catheterisation for clinically suspected PHTN. VSMA were defined as any echocardiographic description of leftward abnormal septal motion or position.

RESULTS

VSMA were present in 42 patients (29%). Patients with VSMA were younger and more likely to have prior pulmonary embolism. They also had less obstructive sleep apnoea, hypertension and dyslipidaemia. By echocardiography, patients with VSMA had lower left ventricular mass, left atrial size and lateral wall E/e' ratio. At cardiac catheterisation, PHTN was confirmed in all (100%) patients with VSMA (compared with 75% in patients without VSMA); 98% with VSMA had elevated pulmonary vascular resistance (compared with 55% without VSMA; p<0.005 for all). VSMA were found to have 91% sensitivity and 51% specificity for the diagnosis of pre-capillary PHTN. On multivariate analysis, VSMA were found to be strong independent predictors for the diagnosis of pre-capillary PHTN (HR, 9.15; 95% CI, 3.0-28.2; p<0.001). Left atrial enlargement was also a strong negative predictor for pre-capillary PHTN (HR, 0.14; 95% CI, 0.05-0.36; p<0.001).

CONCLUSION

Ventricular septal motion abnormalities were strongly associated with pre-capillary PHTN in patients with suspected PHTN. The findings suggest that patients with VSMA should be further evaluated by right heart catheterisation.

Assessment of Right Heart Functions in Children with Mild Cystic Fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multisystemic disease that prevalently involves the lungs. Hypoxemia occurs due to the existing of progressive damage to the pulmonary parenchyma and pulmonary vessels. The condition may cause systolic and diastolic dysfunction to the right ventricle due to the effects of high pulmonary artery systolic pressure (PASP). The study aimed to determine echocardiographic alterations in PASP, right ventricle (RV) anatomy, and functions in mild CF children.

MATERIALS AND METHODS

RV anatomy, systolic, and diastolic functions were evaluated with conventional echocardiographic measurements. Estimated PASP was used measured with new echocardiographic modalities, including pulmonary artery acceleration time (PAAT), right ventricular ejection time (RVET), and their ratio (PAAT/RVET). The obtained echocardiographic data were statistically compared between the patient group and the control group.

RESULTS

The study consisted of 30 pediatric patients with mild CF and 30 healthy children with similar demographics. In patient group, conventional parameters disclosed differences in RV anatomy, both systolic and diastolic functions of RV compared with the healthy group. We did not compare the patient group with published standard data because of the wide range variability. However, new echocardiographic parameters showed notable increase in pulmonary artery pressure compared with values of control group and published standard data (p<0.001).

CONCLUSION

Elevated PASP, RV failure, and Cor pulmonale usually begin early in children with mild CF. In addition to routine echocardiographic measurements to evaluate RV, we recommend the use of new echocardiographic modalities for routine examinations and in the follow up of children with mild CF.

Assessment of Pulmonary Artery Pressures by Various Doppler Echocardiographic Parameters and its Correlation with Cardiac Catheterization in Patients with Pulmonary Hypertension

Background:

Measuring pulmonary artery pressures is a routine index in Doppler echocardiography to diagnose, risk stratify, and prognosticate patients with pulmonary hypertension (PH). There are numerous methods in use to measure it in routine clinical practice.

Objective:

The objective of this study was to assess the correlation between the commonly used Doppler-derived parameters such as tricuspid regurgitation (TR)-derived systolic pulmonary artery pressure (SPAP), pulmonary regurgitation (PR)-derived mean pulmonary artery pressure (MPAP), and right ventricular outflow tract acceleration time (RVOT AcT) with right heart catheterization (RHC) data which are the gold standard.

Materials and Methods:

In this analytical study, we prospectively measured echo and angiogram parameters such as TR-derived SPAP, PR-derived MPAP, and RVOT AcT and studied its association with RHC data of thirty patients for a span of 2 years. Right ventricular AcT was also included in the study. Their relationship was displayed using Bland–Altman scatter plots. P < 0.05 was considered as statistically significant.

Results:

Although both TR-derived SPAP and PR-derived MPAP had a moderate correlation with RHC-acquired data, the agreement between them was poor. RVOT AcT showed a strong inverse correlation with invasive MPAP.

Conclusion:

Among the three Doppler methods that were assessed to measure pulmonary pressures, RVOT AcT had a strong correlation with MPAP. RVOT AcT of <80 ms had a high sensitivity to detect severe PH (defined as MPAP >45 mmHg). Hence, it is recommended to include AcT as a routine measure in the armamentarium of echocardiographic parameters used in patients with PH.

Virtual echocardiography screening tool to differentiate hemodynamic profiles in pulmonary hypertension

This study validated a novel virtual echocardiography screening tool (VEST), which utilized routinely reported echocardiography parameters to predict hemodynamic profiles in pulmonary hypertension (PH) and identify PH due to pulmonary vascular disease (PHPVD). Direct echocardiography imaging review has been shown to predict hemodynamic profiles in PH; however, routine use often overemphasizes Doppler-estimated pulmonary artery systolic pressure (PASPDE), which lacks discriminatory power among hemodynamically varied PH subgroups. In patients with PH of varying subtypes at a tertiary referral center, reported echocardiographic findings needed for VEST, including left atrial size, E:e' and systolic interventricular septal flattening, were obtained. Receiver operating characteristic analyses assessed the predictive performance of VEST vs. PASPDE in identifying PHPVD, which was later confirmed by right heart catheterization. VEST demonstrated far superior discriminatory power than PASPDE in identifying PHPVD. A positive score was 80.0% sensitive and 75.6% specific for PHPVD with an area under the curve of 0.81. PASPDE exhibited poorer discriminatory power with an area under the curve of 0.56. VEST's strong discriminatory ability remained unchanged when validated in a second cohort from another tertiary center. We demonstrated that this novel VEST using three routine parameters that can be easily extracted from standard echocardiographic reports can successfully capture PH patients with a high likelihood of PHPVD. During the Covid-19 pandemic, when right heart catheterization and timely access to experts at accredited PH centers may have limited widespread availability, this may assist physicians to rapidly and remotely evaluate PH patients to ensure timely and appropriate care.

Echocardiographic Screening Methods for Pulmonary Hypertension: A Practical Review

Pulmonary hypertension (PH) is a debilitating condition defined as mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. The importance of impaired right ventricular (RV) hemodynamics is increasingly being recognized in treatment of patients with PH. In World Health Organization Group 1 patients with pulmonary arterial hypertension, upfront combination therapy has recently been proposed to improve long-term survival. Also, the mPAP in Group 2 and 3 PH patients has been shown to be strongly associated with clinical outcomes. Thus, screening and monitoring of RV hemodynamics are becoming increasingly important. The gold standard for measuring RV hemodynamics is right heart catheterization (RHC). Although RHC can obtain the most accurate results, it is invasive, cumbersome to patients, and often associated with complications, making it unsuitable for a screening or monitoring modality. Echocardiography is useful in estimating hemodynamic parameters that can be obtained from RHC. Accordingly, the role of echocardiography in evaluating such patients with PH is becoming more important. In this article, we review practical echocardiographic methods in approximating RV hemodynamics for PH.

Multimodality cardiovascular imaging in pulmonary embolism

Acute pulmonary embolism (APE) is one of the leading causes of cardiovascular (CV) morbidity and mortality. To select appropriate therapeutic strategy and/or to minimize the mortality and morbidity, rapid and correct identification of life-threatening APE is very important. Also, right ventricular (RV) failure usually precedes acute hemodynamic compromise or death, and thus the identification of RV failure is another important step in risk stratification or treatment of APE. With advances in diagnosis and treatment, the prognosis of APE has been dramatically improving in most cases, but inadequate therapy or recurrent episodes of pulmonary embolism (PE) may result in negative outcomes or, so called, chronic thromboembolic pulmonary hypertension (CTEPH). CTEPH is a condition characterized by remaining chronic thromboembolic material in the pulmonary vasculature and subsequent chronic pulmonary hypertension. Various imaging modalities include chest computed tomography pulmonary angiography (CTPA), echocardiography, magnetic resonance imaging, and nuclear imaging and each are used for the assessment of varying status of PE. Assessment of thromboembolic burden by chest CTPA is the first step in the diagnosis of PE. Hemodynamic assessment can be achieved by echocardiography and also by chest CTPA. Nuclear imaging is useful in discriminating CTEPH from APE. Better perspectives on diagnosis, risk stratification and decision making in PE can be provided by combining multimodality CV imaging. Here, the advantages or pitfalls of each imaging modality in diagnosis, risk stratification, or management of PE will be discussed.

Risk Factors for Pulmonary Hypertension in Adults After Atrial Septal Defect Closure

Atrial septal defect (ASD) closure is performed to prevent pulmonary hypertension (PH), which is associated with poor outcome. This study investigated the prevalence of PH in adults before and after ASD closure and explored associations between patient characteristics and PH after ASD closure. Consecutive adult patients who underwent surgical or percutaneous ASD closure in the Erasmus MC, the Netherlands, were included (2000 to 2014). Echocardiograms before and after ASD closure were retrospectively assessed. Patients were categorized into 3 groups (no PH, possible PH, and PH) based on tricuspid regurgitation velocity (<2.9, 2.9 to 3.4, and ≥3.4 m/s) or mean pulmonary arterial pressure (<20, 20 to 24, and ≥25 mm Hg). Cox regression was performed to identify associations between patient characteristics and PH after ASD closure. Of the 244 eligible patients who underwent ASD closure, 198 (81%) had echocardiograms both before and median 15 (interquartile range 12 to 35) months after ASD closure (median age at closure 45 [interquartile range 30 to 57] years, 75% woman). The prevalence of PH was 13.1% (n = 26) before ASD closure and 5.0% (n = 10) after closure. New York Heart Association III to IV (hazard ratio [HR] 11.07, 95% confidence interval [CI] 3.12 to 39.29, p <0.001), pulmonary disease (HR 10.43, 95% CI 2.12 to 51.21, p = 0.004), cardiac medication use (HR 3.96, 95% CI 1.02 to 15.34, p = 0.047), right ventricular fractional area change (HR 0.87, 95% CI 0.81 to 0.93, p <0.001), and tricuspid annular plane systolic excursion (HR 0.75, 95% CI 0.59 to 0.95, p = 0.018) were significantly associated with PH. In conclusion, adult patients with low pulmonary pressures before ASD closure are not at risk of PH after closure. Nevertheless, PH remained prevalent in approximately 5% of patients. Especially those patients with high New York Heart Association functional class, presence of pulmonary disease, cardiac medication use and impaired RV function at baseline are at risk.

Alterations in cardiovascular function in an experimental model of lung fibrosis and pulmonary hypertension

NEW FINDINGS

What is the central question of this study? We have evaluated changes in cardiovascular physiology using echocardiography in an experimental model of lung fibrosis. What is the main finding and its importance? Remarkably, we report changes in cardiovascular function as early as day 7, concomitant with evidence of vascular remodelling. We also report that isolated pulmonary arteries were hypercontractile in response to a thromboxane A2 agonist. These findings are significant because the development of pulmonary hypertension is one of the most significant predictors of mortality in patients with lung fibrosis, where there are no available therapies and a lack of animal models.

ABSTRACT

Group III pulmonary hypertension is observed in patients with chronic lung diseases such as chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. Pulmonary hypertension (PH) develops as a result of extensive pulmonary vascular remodelling and resultant changes in vascular tone that can lead to right ventricle hypertrophy. This eventually leads to right heart failure, which is the leading indicator of mortality in patients with idiopathic pulmonary fibrosis. Treatments for group III PH are not available, in part owing to a lack of viable animal models. Here, we have evaluated the cardiovascular changes in a model of lung fibrosis and PH. Data obtained from this study indicated that structural alterations in the right heart, such as right ventricular wall hypertrophy, occurred as early as day 14, and similar increases in right ventricle chamber size were seen between days 21 and 28. These structural changes were correlated with decreases in the systolic function of the right ventricle and right ventricular cardiac output, which also occurred between the same time points. Characterization of pulmonary artery dynamics also highlighted that PH might be occurring as early as day 21, indicated by reductions in the velocity-time integral; however, evidence for PH is apparent as early as day 7, indicated by the significant reduction in pulmonary acceleration time values. These changes are consistent with evidence of vascular remodelling observed histologically starting on day 7. In addition, we report hyperactivity of bleomycin-exposed pulmonary arteries to a thromboxane A2 receptor (Tbxa2r) agonist.

Normal values of the pulmonary artery acceleration time (PAAT) and the right ventricular ejection time (RVET) in children and adolescents and the impact of the PAAT/RVET-index in the assessment of pulmonary hypertension

New echocardiographic modalities including pulmonary artery acceleration time (PAAT) and right ventricular ejection time (RVET) are evolving to facilitate an early non-invasive diagnosis for pulmonary hypertension (PH) in adults. In children, PAAT depends on age, body surface area (BSA) and heart rate (HR) and is used to predict PH. Normal values of RVET and their role to predict PH in children are still missing. PAAT/RVET-index correlates negatively with PH. We hypothesized that this index is a good predictor for PH in children and adolescents independent of age, BSA and HR and RVET is significantly reduced in PH. PAAT and RVET of 401 healthy children and 30 PH-patients were measured using pulsed-wave-Doppler. PH was diagnosed in PH-group invasively. PAAT/RVET-index for both groups was calculated. Sensitivity and specificity in prediction of PH of PAAT, PAAT z-score and PAAT/RVET-index were compared. We demonstrated normal values of RVET in children. In the healthy group, PAAT and RVET correlated significant positive to age (p < 0.001), and BSA (p < 0.001) and negative to HR (p < 0.001). PAAT/RVET-index correlated weakly to age, BSA and HR (p < 0.001). Mean pulmonary artery pressure (PAPM) ranged in the PH-group from 27 to 82 mmHg (mean 44 mmHg). In predicting PH, RVET is significantly reduced (p < 0.001). Comparing area under the curve (AUC), the difference between sensitivity and specificity of PAAT/RVET-index < 0.29 and calculated PAAT cut-off-point (87 ms) was significant (p < 0.001). Equally, AUC comparison between PAAT/RVET-index < 0.29 and PAAT z-score of - 1.33 was significant (p = 0.008). PAAT/RVET-index < 0.29 represents a good predictor of PH with a 100% sensitivity and a 95.8% specificity. PAAT/RVET-index is a simple tool and facilitates prediction of PH independent from z-scores.

When appearances deceive: Echocardiographic changes due to common chest pathology

Most indications for performing echocardiography focus on the evaluation of properties intrinsic to the heart. However, numerous extra-cardiac conditions indirectly convey changes to the echocardiographic appearance through alterations in the governing physiology. Pulmonary embolism increases pulmonary arterial pressure if a sufficient cross-sectional area of the pulmonary vascular bed is occluded. This may result in dilatation of the right ventricle and, in severe cases, concomitant early diastolic septal collapse into the left ventricle. Acute respiratory failure has been shown to yield a similar echocardiographic appearance in experimental conditions due to the resultant pulmonary vasoconstriction. Echocardiography in the presence of pulmonary disease can reveal underlying cardiac pathologies such as pulmonary hypertension that contribute to the clinical severity of respiratory distress. Positive pressure ventilation affects preload, afterload, and compliance of both ventricles. The echocardiographic net result cannot be uniformly anticipated, but provides information on the deciding physiology or pathophysiology. Mediastinal pathology including tumors, herniation of abdominal content, and pleural effusion can often be visualized directly with echocardiography. Mediastinal pathologies adjacent to the heart may compress the myocardium directly, thus facilitating echocardiographic and clinical signs of tamponade in the absence of pericardial effusion. In conclusion, many pathologies of extra-cardiac origin influence the echocardiographic appearance of the heart. These changes do not reflect properties of the myocardium but may well be mistaken for it. Hence, these conditions are essential knowledge to all physicians performing echocardiography across the spectrum from advanced cardiological diagnostics to rapid point-of-care focused cardiac ultrasonography.

Echocardiographic assessment of pulmonary hypertension: a guideline protocol from the British Society of Echocardiography

Pulmonary hypertension is defined as a mean arterial pressure of ≥25 mmHg as confirmed on right heart catheterisation. Traditionally, the pulmonary arterial systolic pressure has been estimated on echo by utilising the simplified Bernoulli equation from the peak tricuspid regurgitant velocity and adding this to an estimate of right atrial pressure. Previous studies have demonstrated a correlation between this estimate of pulmonary arterial systolic pressure and that obtained from invasive measurement across a cohort of patients. However, for an individual patient significant overestimation and underestimation can occur and the levels of agreement between the two is poor. Recent guidance has suggested that echocardiographic assessment of pulmonary hypertension should be limited to determining the probability of pulmonary hypertension being present rather than estimating the pulmonary artery pressure. In those patients in whom the presence of pulmonary hypertension requires confirmation, this should be done with right heart catheterisation when indicated. This guideline protocol from the British Society of Echocardiography aims to outline a practical approach to assessing the probability of pulmonary hypertension using echocardiography and should be used in conjunction with the previously published minimum dataset for a standard transthoracic echocardiogram.

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right-sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra-operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno-venous bypass placement; (3) intra-operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra-operative investigation of "acute hypoxemia" due to pulmonary and cardiac issues using trans-esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.

Prognostic Value of Serial N-Terminal Pro-B-Type Natriuretic Peptide Measurements in Adults With Congenital Heart Disease

BACKGROUND

A single NT-proBNP (N-terminal pro-B-type natriuretic peptide) measurement is a strong prognostic factor in adult congenital heart disease. This study investigates NT-proBNP profiles within patients with adult congenital heart disease and relates these to cardiovascular events.

METHODS AND RESULTS

In this prospective cohort, 602 patients with adult congenital heart disease were enrolled at the outpatient clinic (years 2011-2013). NT-proBNP was measured at study inclusion in 595 patients (median age 33 [IQR 25-41] years, 58% male, 90% NYHA I) and at subsequent annual visits. The primary end point was defined as death, heart failure, hospitalization, arrhythmia, thromboembolic event, or cardiac intervention; the secondary end point as death or heart failure. Repeated measurements were analyzed using linear mixed models and joint models. During a median follow-up of 4.4 [IQR 3.8-4.8] years, a total of 2424 repeated measurements were collected. Average NT-proBNP increase was 2.9 pmol/L the year before the primary end point (n=199, 34%) and 18.2 pmol/L before the secondary end point (n=58, 10%), compared with 0.3 pmol/L in patients who remained end point-free (P-value for difference in slope 0.006 and <0.001, respectively). In patients with elevated baseline NT-proBNP (>14 pmol/L, n=315, 53%), repeated measurements were associated with the primary end point (HR per 2-fold higher value 2.08; 95% CI 1.31-3.87; P<0.001) and secondary end point (HR 2.47; 95% CI 1.13-5.70; P=0.017), when adjusted for the baseline measurement.

CONCLUSIONS

NT-proBNP increased before the occurrence of events, especially in patients who died or developed heart failure. Serial NT-proBNP measurements could be of additional prognostic value in the annual follow-up of patients with adult congenitive heart disease with an elevated NT-proBNP.

Right Ventricular Structure and Function in the Veteran Ultramarathon Runner: Is There Evidence for Chronic Maladaptation?

BACKGROUND

It has been proposed that chronic exposure to prolonged strenuous exercise may result in maladaptation of the right ventricle (RV). The aim of this study was to establish RV structure and function, including septal insertion points, using conventional echocardiography and myocardial strain (ε) imaging in a veteran population of ultramarathon runners (UR) and age- and sex-matched controls.

METHODS

A retrospective study design provided 40 UR (>35 years old; mean ± SD training experience, 18 ± 12 years) and 24 sedentary controls who had previously undergone conventional two-dimensional, tissue Doppler and speckle-tracking echocardiography to measure RV size and function. Peak RV ε and strain rate (SR) were assessed from the base, mid, and apical lateral wall. SR were assessed during systole (SRs'), early diastole (SRe') and late diastole (SRa'). Regional assessment of RV insertion points was made at the basal inferoseptum and apical septum using left ventricular (LV) longitudinal ε and at the anteroseptum and inferoseptum using LV circumferential and radial ε.

RESULTS

All structural indices of RV size were significantly larger in UR. RV regional and global peak ε were not different between groups, whereas basal RV SR was significantly lower in UR. UR had significantly higher peak LV circumferential ε (anteroseptum, -26% ± 8% vs -21% ± 6%; inferoseptum, -25% ± 6% vs -16% ± 9%) and higher peak LV longitudinal ε (apical septum, -28% ± 7% vs -22% ± 4%) compared with controls. There was regional heterogeneity in UR that was not observed in controls with significantly lower longitudinal ε at the basal inferoseptal insertion point when compared with the global ε (-19% ± 2% vs -22% ± 4%).

CONCLUSIONS

Myocardial ε imaging highlights no overt maladaptation in this cohort of veteran UR, although lower insertion point ε, compared with global ε, in UR may warrant further investigation.

Non-invasive imaging of global and regional cardiac function in pulmonary hypertension

Pulmonary hypertension (PH) is a progressive illness characterized by elevated pulmonary artery pressure; however, the main cause of mortality in PH patients is right ventricular (RV) failure. Historically, improving the hemodynamics of pulmonary circulation was the focus of treatment; however, it is now evident that cardiac response to a given level of pulmonary hemodynamic overload is variable but plays an important role in the subsequent prognosis. Non-invasive tests of RV function to determine prognosis and response to treatment in patients with PH is essential. Although the right ventricle is the focus of attention, it is clear that cardiac interaction can cause left ventricular dysfunction, thus biventricular assessment is paramount. There is also focus on the atrial chambers in their contribution to cardiac function in PH. Furthermore, there is evidence of regional dysfunction of the two ventricles in PH, so it would be useful to understand both global and regional components of dysfunction. In order to understand global and regional cardiac function in PH, the most obvious non-invasive imaging techniques are echocardiography and cardiac magnetic resonance imaging (CMRI). Both techniques have their advantages and disadvantages. Echocardiography is widely available, relatively inexpensive, provides information regarding RV function, and can be used to estimate RV pressures. CMRI, although expensive and less accessible, is the gold standard of biventricular functional measurements. The advent of 3D echocardiography and techniques including strain analysis and stress echocardiography have improved the usefulness of echocardiography while new CMRI technology allows the measurement of strain and measuring cardiac function during stress including exercise. In this review, we have analyzed the advantages and disadvantages of the two techniques and discuss pre-existing and novel forms of analysis where echocardiography and CMRI can be used to examine atrial, ventricular, and interventricular function in patients with PH at rest and under stress.

Right ventricular functional analysis utilizing first pass radionuclide angiography for pre-operative ventricular assist device planning: a multi-modality comparison

BACKGROUND

Advanced heart failure treated with a left ventricular assist device is associated with a higher risk of right heart failure. Many advanced heart failures patients are treated with an ICD, a relative contraindication to MRI, prior to assist device placement. Given this limitation, left and right ventricular function for patients with an ICD is calculated using radionuclide angiography utilizing planar multigated acquisition (MUGA) and first pass radionuclide angiography (FPRNA), respectively. Given the availability of MRI protocols that can accommodate patients with ICDs, we have correlated the findings of ventricular functional analysis using radionuclide angiography to cardiac MRI, the reference standard for ventricle function calculation, to directly correlate calculated ejection fractions between these modalities, and to also assess agreement between available echocardiographic and hemodynamic parameters of right ventricular function.

METHODS

A retrospective review from January 2012 through May 2014 was performed to identify advanced heart failure patients who underwent both cardiac MRI and radionuclide angiography for ventricular functional analysis. Nine heart failure patients (8 men, 1 woman; mean age of 57.0 years) were identified. The average time between the cardiac MRI and radionuclide angiography exams was 38.9 days (range: 1 - 119 days). All patients undergoing cardiac MRI were scanned using an institutionally approved protocol for ICD with no device-related complications identified. A retrospective chart review of each patient for cardiomyopathy diagnosis, clinical follow-up, and echocardiogram and right heart catheterization performed during evaluation was also performed.

RESULTS

The 9 patients demonstrated a mean left ventricular ejection fraction (LVEF) using cardiac MRI of 20.7% (12 - 40%). Mean LVEF using MUGA was 22.6% (12 - 49%). The mean right ventricular ejection fraction (RVEF) utilizing cardiac MRI was 28.3% (16 - 43%), and the mean RVEF calculated by FPRNA was 32.6% (9 - 56%). The mean discrepancy for LVEF between cardiac MRI and MUGA was 4.1% (0 - 9%), and correlation of calculated LVEF using cardiac MRI and MUGA demonstrated an R of 0.9. The mean discrepancy for RVEF between cardiac MRI and FPRNA was 12.0% (range: 2 - 24%) with a moderate correlation (R = 0.5). The increased discrepancies for RV analysis were statistically significant using an unpaired t-test (t = 3.19, p = 0.0061). Echocardiogram parameters of RV function, including TAPSE and FAC, were for available for all 9 patients and agreement with cardiac MRI demonstrated a kappa statistic for TAPSE of 0.39 (95% CI of 0.06 - 0.72) and for FAC of 0.64 (95% of 0.21 - 1.00).

CONCLUSION

Heart failure patients are increasingly requiring left ventricular assist device placement; however, definitive evaluation of biventricular function is required due to the increased mortality rate associated with right heart failure after assist device placement. Our results suggest that FPRNA only has a moderate correlation with reference standard RVEFs calculated using cardiac MRI, which was similar to calculated agreements between cardiac MRI and echocardiographic parameters of right ventricular function. Given the need for identification of patients at risk for right heart failure, further studies are warranted to determine a more accurate estimate of RVEF for heart failure patients during pre-operative ventricular assist device planning.

Echocardiographic assessment of the right ventricle in the current era: Application in clinical practice

The right ventricle has unique structural and functional characteristics. It is now well recognized that the so-called forgotten ventricle is a key player in cardiovascular physiology. Furthermore, there is accumulating evidence that demonstrates right ventricular dysfunction as an important marker of morbidity and mortality in several commonly encountered clinical situations such as heart failure, pulmonary hypertension, pulmonary embolism, right ventricular myocardial infarction, and adult congenital heart disease. In contrast to the left ventricle, echocardiographic assessment of right ventricular function is more challenging as volume estimations are not possible without the use of three-dimensional (3D) echocardiography. Guidelines on chamber quantification provide a standardized approach to assessment of the right ventricle. The technique and limitations of each of the parameters for RV size and function need to be fully understood. In this era of multimodality imaging, echocardiography continues to remain a useful tool for the initial assessment and follow-up of patients with right heart pathology. Several novel approaches such as 3D and strain imaging of the right ventricle have expanded the usefulness of this indispensable modality.

Evidence on Exercise Training in Pulmonary Hypertension

Pulmonary hypertension (PH) is a chronic, debilitating condition which gravely affects exercise tolerance and quality of life. Though most therapies focus purely on medical intervention, there is a growing body of evidence to suggest the role and benefits of exercise training. This chapter discusses the various physiological basis for exercise intolerance observed in PH and highlights the rationale for exercise training. Recent evidence related to exercise training is summarized and potential pathways to suggest adaptations to exercise training are put forward. While keeping the paper applicable to clinicians, details on evaluating exercise intolerance, prescribing exercise and setting up rehabilitation centers for PH are discussed.

Exercise intolerance in pulmonary hypertension: mechanism, evaluation and clinical implications

INTRODUCTION

Exercise intolerance in pulmonary hypertension (PH) is a major factor affecting activities of daily living and quality of life. Evaluation strategies (i.e., non-invasive and invasive tests) are integral to providing a comprehensive assessment of clinical and functional status. Despite a growing body of literature on the clinical consequences of PH, there are limited studies discussing the contribution of various physiological systems to exercise intolerance in this patient population.

AREAS COVERED

This review, through a search of various databases, describes the physiological basis for exercise intolerance across the various PH etiologies, highlights the various exercise evaluation methods and discusses the rationale for exercise training amongst those diagnosed with PH. Expert commentary: With the growing importance of evaluating exercise capacity in PH (class 1, Level C recommendation), understanding why exercise performance is altered in PH is crucial. Thus, the further study is required for better quality evidence in this area.

The Pulmonary Hypertension Consult: Clinical and Coding Considerations

Pulmonary hypertension (PH) is an increasingly recognized cause of morbidity and mortality, and in the past 20 years, there has been a rapid expansion in research and available therapies. Although it is defined quite simply as a mean pulmonary arterial pressure of ≥ 25 mm Hg, PH encompasses a heterogeneous group of disease processes. In the past, PH was classified as primary or secondary, but as understanding of the various contributing diseases has increased, classification systems have attempted to group these diseases by clinical features and disease mechanism. The evaluation of patients with suspected PH can be cumbersome, and a careful and methodical approach is needed to ensure timely and accurate diagnosis, correct physiological classification, and appropriate treatment. In this review, we discuss the classification and diagnostic evaluation of PH in adults as well as some of the billing and coding considerations involved in this evaluation.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Effects of the Pulmonary Hypertension Manual (PulHMan) on Awareness of Exercise in Patients with Pulmonary Hypertension

BACKGROUND

Patient education is an important part of holistic care for patients with chronic diseases. With the success of the Heart Manual, it was felt there is a strong need to develop such a manual for those with pulmonary hypertension (PH) - the Pulmonary Hypertension Manual (PulHMan). This was developed through a qualitative methodology in order to ensure the needs of the patients were being met. The impact of the PulHMan on awareness about exercise-related benefits and PH are not known. Therefore the aim of this study was to assess the effects of the PulHMan on improving awareness among individuals with PH.

METHODS

A repeat cross sectional study was carried out on 30 patients with PH to assess the effects of using the PulHMan on awareness of exercise-related benefits in PH. Awareness was assessed from a self-developed and validated questionnaire that included components of PH and exercise related components.

RESULTS

Thirty patients with PH (mean right ventricular systolic pressure and six minute walk distance of 89.2±4.1mm Hg and 322.8±102m respectively) were included in the study. At baseline, it was seen that there was a low awareness regarding the benefits of exercise for PH. However, they were aware of the general health benefits of walking. After three months, it was seen that the PulHMan improved awareness on the benefits of exercising. Despite a low number willing to exercise (2/30) and participate in a home-based program (2/30), after using the PulHMan for three months, there was an improvement in those willing to exercise and participate in a home-based program (22/30 and 25/30 respectively).

CONCLUSIONS

The PulHMan was seen to improve awareness regarding the exercise-related benefits among patients with PH. More studies are needed to determine if this change in awareness translates into a behavioural change for those with PH.

Reversal of echocardiographic right-sided heart pathology in a dog with severe pulmonary hypertension: a case report

Pathologic right-sided heart changes are a common echocardiographic finding in patients with pulmonary hypertension (PH). Canines with PH may have right heart pathology documented via echocardiographic color Doppler interrogation including tricuspid valve regurgitation, pulmonic valve insufficiency, elevated pulmonary arterial systolic pressure, elevated pulmonary arterial diastolic pressure, and alterations in ejection profiles. Two-dimensional echocardiographic findings may include right ventricular hypertrophy, interventricular septal flattening, paradoxical interventricular septal motion, pulmonary artery dilation, and potentially abnormal left heart dimensions. In veterinary medicine, much confidence is given to the measurement of pulmonary arterial systolic pressure estimated from tricuspid valve regurgitation to grade the severity of PH and monitor its improvement with little emphasis placed on the integration of two-dimensional echocardiographic right and left heart pathology in conjunction with Doppler findings. To the authors' knowledge, marked improvement and/or resolution of echocardiographic-documented right heart pathology have not been previously reported in the veterinary literature. This case report documents profound echocardiographic improvement of right-sided heart disease in a dog with severe PH.

Biomechanics of the right ventricle in health and disease (2013 Grover Conference series)

Right ventricular (RV) function is a major determinant of the symptomatology and outcome in pulmonary hypertension. The normal RV is a thin-walled flow generator able to accommodate large changes in venous return but unable to maintain flow output in the presence of a brisk increase in pulmonary artery pressure. The RV chronically exposed to pulmonary hypertension undergoes hypertrophic changes and an increase in contractility, allowing for preserved flow output in response to peripheral demand. Failure of systolic function adaptation (homeometric adaptation, described by Anrep's law of the heart) results in increased dimensions (heterometric adaptation; Starling's law of the heart), with a negative effect on diastolic ventricular interactions, limitation of exercise capacity, and vascular congestion. Ventricular function is described by pressure-volume relationships. The gold standard of systolic function is maximum elastance (E max), or the maximal value of the ratio of pressure to volume. This value is not immediately sensitive to changes in loading conditions. The gold standard of afterload is arterial elastance (E a), defined by the ratio of pressure at E max to stroke volume. The optimal coupling of ventricular function to the arterial circulation occurs at an E max/E a ratio between 1.5 and 2. Patients with severe pulmonary hypertension present with an increased E max, a trend toward decreased E max/E a, and increased RV dimensions, along with progression of the pulmonary vascular disease, systemic factors, and left ventricular function. The molecular mechanisms of RV systolic failure are currently being investigated. It is important to refer biological findings to sound measurements of function. Surrogates for E max and E a are being developed through bedside imaging techniques.

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.

The right ventricle in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a right heart failure syndrome. In early-stage PAH, the right ventricle tends to remain adapted to afterload with increased contractility and little or no increase in right heart chamber dimensions. However, less than optimal right ventricular (RV)-arterial coupling may already cause a decreased aerobic exercise capacity by limiting maximum cardiac output. In more advanced stages, RV systolic function cannot remain matched to afterload and dilatation of the right heart chamber progressively develops. In addition, diastolic dysfunction occurs due to myocardial fibrosis and sarcomeric stiffening. All these changes lead to limitation of RV flow output, increased right-sided filling pressures and under-filling of the left ventricle, with eventual decrease in systemic blood pressure and altered systolic ventricular interaction. These pathophysiological changes account for exertional dyspnoea and systemic venous congestion typical of PAH. Complete evaluation of RV failure requires echocardiographic or magnetic resonance imaging, and right heart catheterisation measurements. Treatment of RV failure in PAH relies on: decreasing afterload with drugs targeting pulmonary circulation; fluid management to optimise ventricular diastolic interactions; and inotropic interventions to reverse cardiogenic shock. To date, there has been no report of the efficacy of drug treatments that specifically target the right ventricle.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Pulmonary arterial hypertension: the key role of echocardiography

Echocardiography is a key screening tool in the diagnostic algorithm of pulmonary arterial hypertension (PAH). It provides an estimate of right ventricular function and pulmonary artery pressure, either at rest or during exercise, and is useful in ruling out secondary causes of pulmonary hypertension (PH) such as left heart disease or congenital heart disease. Several studies have showed that echocardiography is insufficiently precise as single tool for the ultimate diagnosis of PH respect to the right heart catheterization, considered the gold standard technique. Echocardiography is valuable in assessing prognosis and treatment options, monitoring the efficacy of specific therapeutic interventions, and detecting the preclinical stages of disease. The ideal imaging modality for accurate noninvasive assessment of the right heart should be accurate and precise, not influenced by loading conditions, routinely practicable and easily repeatable. For all such reasons and considering that PAH is a rare and severe condition, a complete noninvasive assessment of right heart function requires a deep knowledge of the disease and a multimodality approach.

Impairment of pulmonary vascular reserve and right ventricular systolic reserve in pulmonary arterial hypertension

Background

Exercise capacity is impaired in pulmonary arterial hypertension (PAH). We hypothesized that cardiovascular reserve abnormalities would be associated with impaired hemodynamic response to pharmacological stress and worse outcome in PAH.

Methods

Eighteen PAH patients (p) group 1 NYHA class II/III and ten controls underwent simultaneous right cardiac catheterization and intravascular ultrasound at rest and during low dose-dobutamine (10 mcg/kg/min) with trendelenburg (DST). We estimated cardiac output (CO), pulmonary vascular resistance (PVR) and capacitance (PC), and PA elastic modulus (EM). We concomitantly measured tricuspid annular plane systolic excursion (TAPSE), RV myocardial peak systolic velocity (Sm) and isovolumic myocardial acceleration (IVA) in PAH patients. Based on the rounded mean + 2 SD of the increase in mPAP in our healthy control group during DST (2.8 + 1.8 mm Hg), PAH p were divided into two groups according to mean PA pressure (mPAP) response during DST, 1: ΔmPAP > 5 mm Hg and 2: ΔmPAP ≤ 5 mm Hg. Cardiovascular reserve was estimated as the change (delta, Δ) during DST compared with rest, including ΔmPAP with respect to ΔCO (ΔmPAP/ΔCO). All patients were prospectively followed up for 2 years.

Results

PAH p showed significant lower heart rate and CO increase than controls during DST, with a significant mPAP and pulse PAP increase and higher ΔmPAP/ΔCO (p < 0.05). Neither hemodynamic, IVUS and echocardiographic data were different between both PAH groups at rest. In group 1, DST caused a higher ΔEM, ΔmPAP/ΔCO, ΔPVR, and ΔTAPSE than group 2, with a lower IVA increase and a negative ΔSV (p < 0.05). TAPSE correlated with mPAP and RVP (p < 0.05) and, IVA and Sm correlated with CO (p < 0.05). ΔEM correlated with ΔmPAP and ΔIVA with ΔCO (p < 0.05). There were two deaths/pulmonary transplantations in group 1 and one death in group 2 during the follow-up (p > 0.05).

Conclusions

Pulmonary vascular reserve and RV systolic reserve are significantly impaired in patients with PAH. The lower recruitable cardiovascular reserve is significantly related to a worse hemodynamic response to DST and it could be associated with a poor clinical outcome.

Relationship between echocardiographic and magnetic resonance derived measures of right ventricular size and function in patients with pulmonary hypertension

BACKGROUND

Transthoracic echocardiographic (TTE) imaging is the mainstay of clinical practice for evaluating right ventricular (RV) size and function, but its accuracy in patients with pulmonary hypertension has not been well validated.

METHODS

Magnetic resonance imaging (MRI) and TTE images were retrospectively reviewed in 40 consecutive patients with pulmonary hypertension. RV and left ventricular volumes and ejection fractions were calculated using MRI. TTE areas and indices of RV ejection fraction (RVEF) were compared.

RESULTS

The average age was 42 ± 12 years, with a majority of women (85%). There was a wide range of mean pulmonary arterial pressures (27-81 mm Hg) and RV end-diastolic volumes (111-576 mL), RVEFs (8%-67 %), and left ventricular ejection fractions (26%-72%) by MRI. There was a strong association between TTE and MRI-derived parameters: RV end-diastolic area (by TTE imaging) and RV end-diastolic volume (by MRI), R(2) = 0.78 (P < .001); RV fractional area change by TTE imaging and RVEF by MRI, R(2) = 0.76 (P < .001); and tricuspid annular plane systolic excursion by TTE imaging and RVEF by MRI, R(2) = 0.64 (P < .001). By receiver operating characteristic curve analysis, an RV fractional area change < 25% provided excellent discrimination of moderate systolic dysfunction (RVEF < 35%), with an area under the curve of 0.97 (P < .001). An RV end-diastolic area index of 18 cm(2)/m(2) provided excellent discrimination for moderate RV enlargement (area under the curve, 0.89; P < .001).

CONCLUSIONS

Echocardiographic estimates of RV volume (by RV end-diastolic area) and function (by RV fractional area change and tricuspid annular plane systolic excursion) offer good approximations of RV size and function in patients with pulmonary hypertension and allow the accurate discrimination of normal from abnormal.