Noninvasive Diagnosis Of Pulmonary Hypertension Research Articles

Echocardiographic Screening of Liver Transplant Candidates-Prevalence of Features of Portopulmonary Hypertension.

Background: The prevalence of portopulmonary hypertension (PoPH) is relatively low; however, its presence significantly worsens patients' prognosis. When diagnosed, PoPH can be effectively treated, and specific therapies can lead to a substantial reduction in pulmonary circulation pressure, facilitating the safe performance of liver transplantation. Echocardiography is recommended as a first-line method for the non-invasive diagnosis of pulmonary hypertension and serves as a valuable screening tool for patients being evaluated for liver transplantation (LT). The objective of this study was to thoroughly assess the occurrence of echocardiographic signs indicative of pulmonary hypertension and hepatopulmonary syndrome (HPS) in candidates for LT. We assumed that our analysis also made it possible to assess how frequently these candidates require further invasive diagnostics for pulmonary hypertension at specialized centers and how often they may need targeted treatment for pulmonary arterioles as a bridge to transplantation, which could improve patient outcomes. Additionally, this study included a comprehensive review of the current literature. Methods: All LT candidates underwent standardized transthoracic echocardiography and contrast evaluation to identify intrapulmonary vascular shunts. Results: A total of 152 liver transplantation candidates (67 women, mean age 50.6 years) were included in the analysis. The estimated echocardiographic probability of pulmonary hypertension was classified as high in only one patient. However, 63 patients exhibited the visualization of microbubbles in the left heart chambers after an average of six cardiac cycles (ranging from three to nine cycles) following their appearance in the right heart. Conclusions: Our analysis shows that the features of PoPH and a high probability of PH were very rare in the LT candidates, and echocardiographic signs suggestive of hepatopulmonary syndrome were more prevalent. Liver transplant candidates need screening for PoPH and HPS, as both PoPH and HPS significantly worsen their prognosis, but specific PH treatment as a bridge to transplantation improves PoPH patients' survival.

N-terminal pro-B-type-natriuretic peptide as a screening tool for pulmonary hypertension in the paediatric population.

Although cardiac catheterisation (cath) is the diagnostic test for pulmonary hypertension, it is an invasive procedure. Echocardiography (echo) is commonly used for the non-invasive diagnosis of pulmonary hypertension but maybe limited by lack of adequate signals. Therefore, emphasis has been placed on biomarkers as a potential diagnostic tool. No prior paediatric studies have simultaneously compared N-terminal pro-B-type-natriuretic peptide (NTproBNP) with cath/echo as a potential diagnostic tool. The aim of this study was to determine if NTproBNP was a reliable diagnostic tool for pulmonary hypertension in this population. Patients were divided into Study (echo evidence/established diagnosis of pulmonary hypertension undergoing cath) and Control (cath for small atrial septal defect/patent ductus arteriosus and endomyocardial biopsy post cardiac transplant) groups. NTproBNP, cath/echo data were obtained. Thirty-one patients met inclusion criteria (10 Study, 21 Control). Median NTproBNP was significantly higher in the Study group. Echo parameters including transannular plane systolic excursion z scores, pulmonary artery acceleration time and right ventricular fractional area change were lower in the Study group and correlated negatively with NTproBNP. Receiver operation characteristic curve analysis demonstrated NTproBNP > 389 pg/ml was 87% specific for the diagnosis of pulmonary hypertension with the addition of pulmonary artery acceleration time improving the specificity. NTproBNP may be a valuable adjunctive diagnostic tool for pulmonary hypertension in the paediatric population. Echo measures of transannular plane systolic excursion z score, pulmonary artery acceleration time and right ventricular fractional area change had negative correlations with NTproBNP. The utility of NTproBNP as a screening tool for pulmonary hypertension requires validation in a population with unknown pulmonary hypertension status.

Non-invasive Diagnosis of Pulmonary Hypertension Considering Vascular Oscillation

Non-invasive Diagnosis of Pulmonary Hypertension Considering Vascular Oscillation

Non-invasive Diagnosis of Pulmonary Hypertension by Impedance Cardiography

Non-invasive Diagnosis of Pulmonary Hypertension by Impedance Cardiography

Non-invasive diagnosis of pulmonary hypertension from lung Doppler signal: a proof of concept study.

Transthoracic Parametric Doppler (TPD) is a novel ultrasound technique recently developed for the investigation of pulmonary blood vessels. Lung Doppler Signals (LDS) recorded from TPD provide information regarding the functional mechanical characteristics of pulmonary blood vessels. We aimed to define the specific profile of LDS generated from TPD imaging in patients with pulmonary hypertension (PH), and to evaluate the diagnostic performance of LDS to detect PH using right heart catheterization (RHC) as gold standard reference. Seventy nine PH patients and 79 healthy controls matched for age, gender and BMI were recruited in a prospective case-control multicenter study. LDS recordings were performed by TPD consisting of a pulsed Doppler with a 2MHz single element transducer. LDS were recorded within 24h of RHC. Following LDS extraction, classification and performance evaluation were performed offline using a support vector machine (k-fold cross validation method). The best LDS parameters for PH detection were (1) peak velocity of the systolic (S) and diastolic (D) signals, (2) the rise slope of the S and D signals, and (3) time to peak of the S signal. Overall, the sensitivity and specificity of TPD for detection of PH were 82.7% (95% CI 81.3-84.1) and 87.4% (95% CI 86.3-88.5), respectively, with an area under the receiver operating curve of 0.95 (95% CI 0.94-0.96). Detection rate of PH increased progressively with the level of mean pulmonary artery pressure. LDS recorded by TPD display a specific profile in PH and appears to be a promising and reliable tool for PH diagnosis. Further studies are required to confirm the clinical usefulness of LDS.

Diagnostic Value of Right Pulmonary Artery Distensibility Index in Dogs with Pulmonary Hypertension: Comparison with Doppler Echocardiographic Estimates of Pulmonary Arterial Pressure.

BackgroundNoninvasive diagnosis of pulmonary hypertension (PH) primarily relies upon Doppler echocardiography of tricuspid regurgitation (TR). However, TR might be absent or difficult to measure.Hypothesis/ObjectivesTo determine the diagnostic value of right pulmonary artery distensibility (RPAD) index for prediction of Doppler‐derived estimates of pulmonary artery (PA) pressure compared to other indices of PH in dogs.AnimalsSixty‐nine client‐owned dogs with TR.MethodsProspective observational study. Dogs were allocated to groups according to TR pressure gradient (TRPG): TRPG <36 mmHg (control, n = 22), TRPG 36–50 (n = 16), TRPG 50–75 (n = 14) and TRPG >75 mmHg (n = 17). Right pulmonary artery distensibility index, acceleration time to peak PA flow (AT), AT: ejection time of PA flow (AT:ET) and main PA size: aorta size (MPA:Ao) were calculated in each dog.ResultsRight pulmonary artery distensibility index demonstrated the strongest correlation (r = −0.90; P < .0001) to TRPG followed by MPA:Ao (r = 0.78; P < .0001), AT (r = −0.69; P < .0001) and AT:ET (r = −0.68; P < .0001). RPAD index possessed the most accurate cutoff (<29.5%; Sensitivity [Sn] 0.84, Specificity [Sp] 0.95) to predict TRPG >50 mmHg compared to AT (<53.9 ms; Sn 0.74, Sp 0.87), AT:ET (<0.30; Sn 0.61, Sp 0.97) and MPA:Ao (>1.04; Sn 0.94, Sp 0.74). All intra‐ and interobserver measurement variabilities exhibited coefficients of variation ≤13%.Conclusions and Clinical ImportanceRight pulmonary artery distensibility index is an accurate predictor of TRPG and should be particularly useful if TR is absent or difficult to measure.

A syndrome of severe idiopathic pulmonary parenchymal disease with pulmonary hypertension in Pekingese.

This paper describes 35 Pekingese dogs with a syndrome characterized by dyspnea, cyanosis, episodic syncope, soft pulmonary “velcro” crackles, pulmonary hypertension (PH), and computed tomography and radiographic changes consistent with pulmonary parenchymal disease. The medical data base was searched with the criteria “Pekingese” and “syncope” or “dyspnea” or “tachypnea” or “pulmonary hypertension”, over a 36-month period. Inclusion criteria were echocardiographic changes consistent with noninvasive diagnosis of PH, either subjectively by B-mode or objectively by Doppler. Dogs were excluded (n=106) if there were insufficient or poor-quality radiographic or echocardiographic records or if diseases other than chronic pulmonary disease were found to be the etiology. The records of 35 dogs met these criteria and presented with a respiratory crises preceded by a history of chronic exercise intolerance and episodic syncope. The average age was 14.5 years (range: 7–19 years), with 21 males and 14 females. Most of the dogs had an interstitial lung pattern with radiographic evidence of right heart enlargement. There was a 77% (n=27) mortality and a median survival of 60 days (interquartile range: 9–210 days). This study highlights a cor pulmonale syndrome from PH due to chronic pulmonary parenchymal disease, with a grave prognosis, in middle-aged to geriatric population of Hong Kong Pekingese.

Blood flow vortices along the main pulmonary artery measured with MR imaging for diagnosis of pulmonary hypertension.

To approximate the functional relationship between invasively measured mean pulmonary arterial pressure (mPAP) and the phase-contrast magnetic resonance (MR) imaging-derived duration of vortical blood flow along the main pulmonary artery and to analyze its applicability for noninvasive diagnosis of pulmonary hypertension (PH) and borderline mPAP. The local ethics review board approved this prospective study of 145 patients suspected of having PH (69 patients with PH, 19 patients with borderline mPAP, and 57 patients with normal mPAP) who underwent right heart catheterization (RHC) and three-directional phase-contrast MR imaging of the main pulmonary artery. Velocity fields were viewed with dedicated software and evaluated for the duration of vortical blood flow in the main pulmonary artery (tvortex, the percentage of cardiac phases with vortex present). The relationship between mPAP at RHC and tvortex was assessed by means of a segmented linear regression model, and by Bland-Altman and receiver operating characteristic curve analyses. The relationship between mPAP and tvortex was described adequately (R(2) = 0.95) as linearly increasing, from tvortex of 0% (mPAP ≤ 16.0 mm Hg) with a slope of 1.59% per millimeter of mercury. The standard deviation between mPAP values derived from RHC and those estimated by using tvortex was 3.9 mm Hg. The area under the curve for tvortex-based diagnosis of PH was 0.994 (95% confidence interval [CI]: 0.982, 0.998), and the calculated PH cut-off value (tvortex ≥ 14.3%) resulted in sensitivity of 0.97 (95% CI: 0.90, 0.99) and specificity of 0.96 (95% CI: 0.89, 0.99). Vortical blood flow with tvortex less than 14.3% was specific for borderline mPAP. Duration of vortical blood flow in the main pulmonary artery that is determined by using phase-contrast MR imaging allows accurate estimation of elevated mPAP and diagnosis of PH. Clinical trial registration no. NCT00575692.

Reliability of noninvasive assessment of systolic pulmonary artery pressure by Doppler echocardiography compared to right heart catheterization: analysis in a large patient population.

BackgroundPulmonary artery pressure (PAP) is an important marker in cardiovascular disorders, being closely associated with morbidity and mortality. Noninvasive assessment by Doppler echocardiography is recommended by current guidelines. So far, the reliability of this method has been assessed only in small studies with contradictory results. Therefore, the aim of this study was to analyze the reliability of noninvasive PAP assessment by Doppler echocardiography compared to invasive measurements in a large patient population.Methods and ResultsWe retrospectively analyzed data from a large tertiary cardiology department over 6 years in order to compare invasively measured PAP to estimated PAP from echocardiography examinations. N=15 516 patients fulfilled inclusion criteria and n=1695 patients with timely matched examinations (within 5 days) were analyzed. In n=1221 (72%) patients, pulmonary hypertension (PH) was diagnosed invasively (postcapillary PH: n=1122 [66%]; precapillary PH: n=99 [6%]). Systolic pulmonary artery pressure (sPAP) was 45.3±15.5 mm Hg by Doppler echocardiography and 47.4±16.4 mm Hg by right heart catheterization. Pearson's correlation coefficient was r=0.87 (P<0.0001). Mean right atrial pressure (RAP) was 12.0±5.7 mm Hg by right heart catheterization and was estimated to be 12.1±6.6 mm Hg by echocardiography (r=0.82, P<0.0001). Bland–Altman analysis showed a bias of −2.0 mm Hg for sPAP (95% limits of agreement −18.1 to +14.1 mm Hg) and +1.0 mm Hg for RAP (95% limits of agreement +0.1 to +1.9 mm Hg). Noninvasive diagnosis of pulmonary hypertension with Doppler echocardiography had a good sensitivity (87%) and specificity (79%), positive and negative predictive values (91% and 70%), as well as accuracy (85%) for a sPAP cut‐off value of 36 mm Hg (AUC 0.91, P<0.001, CI 0.90 to 0.93).ConclusionsIn this study, Doppler echocardiography proved to be a reliable method for the assessment of sPAP, being well suited to establish the noninvasive diagnosis of pulmonary hypertension in patients with cardiac diseases.

Evaluation of Elevated Mean Pulmonary Arterial Pressure Based on Magnetic Resonance 4D Velocity Mapping: Comparison of Visualization Techniques

PurposeThree-dimensional (3D) magnetic resonance phase contrast imaging (PC-MRI) allows non-invasive diagnosis of pulmonary hypertension (PH) and estimation of elevated mean pulmonary arterial pressure (mPAP) based on vortical motion of blood in the main pulmonary artery. The purpose of the present study was to compare the presence and duration of PH-associated vortices derived from different flow visualization techniques with special respect to their performance for non-invasive assessment of elevated mPAP and diagnosis of PH.MethodsFifty patients with suspected PH (23 patients with and 27 without PH) were investigated by right heart catheterization and time-resolved PC-MRI of the main pulmonary artery. PC-MRI data were visualized with dedicated prototype software, providing 3D vector, multi-planar reformatted (MPR) 2D vector, streamline, and particle trace representation of flow patterns. Persistence of PH-associated vortical blood flow (tvortex) was evaluated with all visualization techniques. Dependencies of tvortex on visualization techniques were analyzed by means of correlation and receiver operating characteristic (ROC) curve analysis.Resultstvortex values from 3D vector visualization correlated strongly with those from other visualization techniques (r = 0.98, 0.98 and 0.97 for MPR, streamline and particle trace visualization, respectively). Areas under ROC curves for diagnosis of PH based on tvortex did not differ significantly and were 0.998 for 3D vector, MPR vector and particle trace visualization and 0.999 for streamline visualization. Correlations between elevated mPAP and tvortex in patients with PH were r = 0.96, 0.93, 0.95 and 0.92 for 3D vector, MPR vector, streamline and particle trace visualization, respectively. Corresponding standard deviations from the linear regression lines ranged between 3 and 4 mmHg.Conclusion3D vector, MPR vector, streamline as well as particle trace visualization of time-resolved 3D PC-MRI data of the main pulmonary artery can be employed for accurate vortex-based diagnosis of PH and estimation of elevated mPAP.

Non-invasive diagnosis of pulmonary hypertension: ESC/ERS Guidelines with Updated Commentary of the Cologne Consensus Conference 2011

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension have been adopted for Germany. The guidelines contain detailed recommendations for the diagnosis of pulmonary hypertension. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the non-invasive diagnosis of pulmonary hypertension. This manuscript describes in detail the results and recommendations of the working group which were last updated in October 2011.

Idiopathic pulmonary fibrosis‐related pulmonary hypertension; an exercising diagnosis?

Idiopathic pulmonary fibrosis‐related pulmonary hypertension; an exercising diagnosis?

Noninvasive diagnosis of pulmonary hypertension using heart sound analysis

Right-heart catheterization is the most accurate method for measuring pulmonary artery pressure (PAP). It is an expensive, invasive procedure, exposes patients to the risk of infection, and is not suited for long-term monitoring situations. Medical researchers have shown that PAP influences the characteristics of heart sounds. This suggests that heart sound analysis is a potential method for the noninvasive diagnosis of pulmonary hypertension. We describe the development of a prototype system, called PHD (pulmonary hypertension diagnoser), that implements this method. PHD uses patient data with machine learning algorithms to build models of how pulmonary hypertension affects heart sounds. Data from 20 patients were used to build the models and data from another 31 patients were used as a validation set. PHD diagnosed pulmonary hypertension in the validation set with 77% accuracy and 0.78 area under the receiver-operating-characteristic curve.

Exercise stress tests for detection and evaluation of pulmonary hypertension

The use of an exercise stress test in the diagnosis or evaluation of pulmonary hypertension rests on the assumption that multipoint mean pulmonary artery pressure (mPpa)–flow (Q) plots are superior to isolated pulmonary vascular resistance determinations for the evaluation of the functional state of the pulmonary circulation. A multipoint mPpa–Q relationship is best described by a linear approximation and, as such, characterized by an extrapolated pressure intercept and by a slope. Both are dependent on the method used to increase flow. The slope is higher and the pressure intercept lower when exercise is used to increase flow, rather than unilateral pulmonary artery balloon occlusion or low-dose dobutamine. This is because of exercise-induced pulmonary vasoconstriction. The steepest slopes, i.e. the highest pressures at a given flow, are obtained by resistive exercise (handgrip) when compared with dynamic exercise (cycling) because of systemic vascular resistance and intrathoracic pressure changes. Since systolic, diastolic, and mean pulmonary artery pressures are tightly correlated and since in experienced hands, systolic pulmonary artery pressures and cardiac output are reliably measured using Doppler echocardiography, mPpa–Q lines can be obtained non-invasively. The exercise stress test for non-invasive diagnosis of pulmonary hypertension may be particularly useful for the detection of early disease and for more accurate quantification of pulmonary vascular changes induced by disease progression and/or therapeutic interventions.

More on the noninvasive diagnosis of pulmonary hypertension: Doppler echocardiography revisited

More on the noninvasive diagnosis of pulmonary hypertension: Doppler echocardiography revisited

Should patients have right heart catheterization prior to long-term oxygen treatment?

The presence of pulmonary hypertension (PH) is not an obligatory prerequisite for prescribing long-term oxygen therapy (LTO) in patients with chronic obstructive pulmonary disease (COPD), at least when PaO2 is repeatedly less than 55 mmHg in a stable state of the disease. It is generally accepted that LTO is indicated in patients whose PaO2 is in the range 55-59 mmHg, but exhibiting polycythaemia, "cor pulmonale", and (or) PH. The clinical signs of "cor pulmonale" occur late and the noninvasive diagnosis of PH is not yet satisfactory; it ensues that right heart catheterization is useful in these patients, before prescribing LTO. Pulmonary hypertension is probably the most important consequence of long-standing hypoxaemia and, in our opinion, the presence and the degree of PH should be assessed in every patient before starting such a heavy therapy as LTO.