Noninvasive Estimation of Pulmonary Vascular Resistance in Pulmonary Hypertension

Background: Determination of pulmonary vascular resistance (PVR) in patients with suspected or known pulmonary hypertension (PH) requires right heart catheterization. Our purpose was to use Doppler echocardiography to estimate PVR in patients with PH. Methods: Patient population consisted of 52 patients (53 ± 12 years; 35 females) who underwent Doppler echocardiography and right heart catheterization within 24 hours of each other. The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time-velocity integral (VTI_RVOT) was measured via transthoracic echocardiography and correlated to invasively determined PVR. A linear regression equation was generated to determine PVR by echocardiography based upon the TRV/VTI_RVOT ratio. PVR by echocardiography was compared to invasive PVR using Bland-Altman analysis. Results: Significant correlation was demonstrated between TRV/VTI_RVOT and PVR by catheterization (r = 0.73; P < 0.001). However, Bland-Altman analysis showed that agreement between PVR determined by echocardiography and invasive PVR was poor (bias = 0; standard deviation = 4.3 Wood units). In a subset of patients with invasive PVR < 8 Wood units (26 patients), correlation between TRV/VTI_RVOT and invasive PVR was strong (r = 0.94; P < 0.001). In these patients, agreement between PVR by echocardiography and invasive PVR was satisfactory (bias = 0; standard deviation = 0.5 Wood units). There was no correlation between TRV/VTI_RVOT and invasive PVR in patients with PVR > 8 Wood units (n = 26; r = 0.17). Conclusion: While TRV/VTI_RVOT correlates significantly with PVR, using it to estimate PVR in a PH patient population cannot be recommended.     

Balloon Pulmonary Angioplasty in Patients With Thromboembolic Pulmonary Hypertension

Purpose of review

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only potentially curable form of precapillary pulmonary hypertension. Although pulmonary endarterectomy (PEA) is the preferred management strategy, a significant number of CTEPH patients will have an inoperable disease. As drug therapy is not expected to offer relief from the mechanical component of the disease, the novel technique of balloon pulmonary angioplasty (BPA) has provided a new therapeutic option for patients with inoperable CTEPH. This review will discuss the contemporary use of BPA technique in inoperable CTEPH patients highlighting the effectiveness and safety of this therapeutic option.

Recent findings

Data supporting the role of BPA in inoperable CTEPH are limited to observational studies. However, these observational studies report consistent findings that BPA results in marked improvements in pulmonary hemodynamics and exercise capacity indicating its efficacy and safety as a treatment strategy in inoperable CTEPH patients.

Summary

Summarizing, BPA is an emerging treatment option providing marked improvements in parameters affecting the outcome of CTEPH patients, but multicenter studies are needed to confirm the safety and the long-term efficacy of the procedure, before BPA can be recommended as an established treatment for CTEPH.

     

Partitioning of Pulmonary Vascular Resistance in Primary Pulmonary Hypertension

Objectives. This study sought to determine the site of increased pulmonary vascular resistance (PVR) in primary pulmonary hypertension by standard bedside hemodynamic evaluation.Background. The measurement of pulmonary vascular pressures at several levels of flow (Q) allows the discrimination between active and passive, flow-dependent changes in mean pulmonary artery pressure (Ppa), and may detect the presence of an increased pulmonary vascular closing pressure. The determination of a capillary pressure (Pc′) from the analysis of a Ppa decay curve after balloon occlusion allows the partitioning of PVR in an arterial and a (capillary + venous) segment. These approaches have not been reported in primary pulmonary hypertension.Methods. Ppa and Pc′ were measured at baseline and after an increase in Q induced either by exercise or by an infusion of dobutamine, at a dosage up to 8 μg/kg body weight per min, in 11 patients with primary pulmonary hypertension. Reversibility of pulmonary hypertension was assessed by the inhalation of 20 ppm nitric oxide (NO), and, in 6 patients, by an infusion of prostacyclin.Results. At baseline, Ppa was 52 ± 3 mm Hg (mean value ± SE), Q 2.2 ± 0.2 liters/min per m², and Pc′ 29 ± 3 mm Hg. Dobutamine did not affect Pc′ and allowed the calculation of an averaged extrapolated pressure intercept of Ppa/Q plots of 34 mm Hg. Inhaled NO had no effect. Prostacyclin decreased Pc′ and PVR. Exercise increased Pc′ to 40 ± 3 mm Hg but did not affect PVR.Conclusions. These findings are compatible with a major increase of resistance and reactivity at the periphery of the pulmonary arterial tree.     

Unfavourable Effect of Pulmonary Arterial Dilatation in Pulmonary Hypertension

No abstract available.     

Chymase在肺动脉高压疾病的肺动脉重构中的表达

目的探讨了慢性香烟暴露诱导的PAH病变过程中仓鼠肺组织chymase的表达变化。方法将12只雄性仓鼠随机分为：对照组、香烟暴露组;仓鼠暴露于香烟烟雾中4个月建立肺动脉高压模型;免疫组织化学染色法检测肺小动脉中chymase的蛋白表达。结果Chymase在香烟暴露组仓鼠的肺小动脉中的表达增加,尤其在肺小动脉外膜及增生的内皮细胞中,染色呈强阳性。结论随着肺结构的改变,香烟暴露可刺激chymase的表达增加,表明chymase在PAH中肺小动脉的重构病变中起作用,因此,抑制chymase的形成将有助于阻止香烟诱导的肺动脉高压疾病的发生、发展。     

Pulmonary Artery Pulse Wave Velocity in Idiopathic Pulmonary Arterial Hypertension

Background

Idiopathic pulmonary artery (PA) hypertension (IPAH) is associated with severe PA remodelling. Although the resulting increase in pulse wave velocity (PWV) might be of major pathophysiological relevance, little is known about PA-PWV in IPAH. The aim of this study was to characterize PA-PWV and its predictors in patients with IPAH.

Methods

We studied 26 consecutive patients with incident IPAH aged 55.0 (45.0-66.0) years (62% female) and 10 control subjects without pulmonary hypertension. PA-PWV was measured invasively; PA wall thickness and diameter were assessed using intravascular and transthoracic ultrasonography.

Results

PA-PWV was higher in IPAH than in control subjects (10.0 [7.5-14.0] m/s vs 3.5 [1.9-4.0] m/s; P < 0.001) as was also PA diameter and PA wall thickness. In IPAH patients, in univariate analysis PA-PWV was greater in men than in women and in patients with body mass index (BMI) < 25 kg/m² than with BMI ≥ 25 kg/m² and correlated positively with symptomatic disease duration, mean PA pressure, pulmonary vascular resistance, creatinine level, and negatively with low-density lipoprotein (LDL) cholesterol and triglyceride level but not with PA diameter or PA wall thickness. In multiple regression analysis mean PA pressure, LDL cholesterol level and BMI < 25 kg/m² were the main predictors of PA-PWV in IPAH patients (R² = 77%; P < 0.001).

Conclusions

PA-PWV is increased in IPAH patients. High PA pressure, low LDL cholesterol level, and BMI < 25 kg/m² explain most of its variability in this group.     

Pulmonary Artery Elastic Properties After Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background

A significant proportion of the right ventricular afterload is determined by the elastic properties of the pulmonary artery (PA). We aimed to assess the effect of balloon pulmonary angioplasty (BPA) on PA elastic properties in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

Pulmonary Artery Sarcoma Mimicking Pulmonary Embolism

Primary sarcomas that arise from major blood vessels are exceedingly rare, and some of the published cases have been autopsy reports. Most patients are adults. We report a case of pulmonary artery sarcoma in a 77-year-old man who presented with acute onset of dyspnea. Magnetic resonance imaging of the chest revealed a large mass within the pulmonary trunk and its main branches. Because massive pulmonary embolism was suspected, both anticoagulant and thrombolytic therapies were initiated. The patient responded poorly to these therapies, which then necessitated resection of both the mass and the pulmonary valve. A bioprosthetic porcine valve replaced the native valve, and we reconstructed the right ventricular outflow tract with a Dacron patch. Histopathologic examination revealed a high-grade sarcoma with focal myogenic and chondrogenic differentiation. The patient tolerated the procedure well and was discharged from the hospital on postoperative day 7. He was subsequently treated with chemotherapy and radiation and continued to show no evidence of disease.The diagnosis of pulmonary artery sarcoma should be suspected in patients who present with manifestations of pulmonary embolism, especially when there is no evidence of deep venous thrombosis and poor response to anticoagulant therapy. Multimodal therapy can provide prolonged survival.     

Pulmonary actinomycosis in Korea

Pulmonary actinomycosis is a chronic pulmonary infection caused by Actinomyces, a Gram-positive, microaerophilic bacterium. Pulmonary involvement, other than cervicofacially or abdominopelvically, is uncommon and often leads to a misdiagnosis of pulmonary tuberculosis or lung cancer. In order to investigate the clinical, radiological, diagnostic and therapeutic characteristics of pulmonary actinomycosis, we reviewed a total of 25 cases reported in Korea. Thirteen were diagnosed at our hospital between 1985 and 1997 and 12 were reported in Korean publications. The condition occurred most frequently in middle-aged males, the most common symptom being haemoptysis, followed by cough and sputum. The main radiological features were peripherally located mass or nodule and consolidation, with central low attenuation. Complications such as empyema, sinus fistula or mediastinitis did not occur. Diagnosis was confirmed by percutaneous needle aspiration (n = 8), bronchoscopic biopsy (n = 3) or thoracotomy (n = 13). Eleven of 25 cases were treated medically and in nine others, surgical resection was followed by treatment with antibiotics. In conclusion, when a middle-aged male patient presents with haemoptysis and cough, together with radiologic findings of a peripheral mass or nodule with/without central low attenuation, pulmonary actinomycosis should be suspected.     

Pulmonary pneumatoceles in neonates

Pulmonary pneumatoceles were relatively common in neonates in the pre‐surfactant era. In the current era of surfactant, noninvasive and gentle invasive ventilation there is a paucity of data on clinical characteristics and outcomes of pneumatoceles in neonates. The lesion generally resolves spontaneously, but a few cases follow a complicated course with formation of extensive and expanding lesions. To better understand the pathophysiology, clinical significance, natural history, complications, treatment options and prognosis of pulmonary pneumatoceles in neonates, an extensive research was performed on the databases of medical literature. The information collected in this review is important for the clinicians in decision‐making, especially in the most difficult cases.     

Pulmonary function in alcoholics

Twenty-three chronic alcoholics were investigated by means of pulmonary function studies. All 23 patients had respiratory symptoms. Clinically, 21 (91 per cent) of 23 patients were diagnosed as having chronic bronchitis, and 14 patients (60 per cent) had dyspnea. The maximal mid-expiratory flow and single breath diffusing capacity for carbon monoxide (SBDCO) were abnormal in 16 (70 per cent) and 14 (61 per cent) patients, respectively. Twenty-two of 23 patients had one or more abnormal function. The total lung capacity, residual volume, vital capacity, 1 second forced expiratory volume and SBDCO progressively declined with increasing alcohol consumption. An attempt was made to separate the pulmonary effects of alcohol from (1) the effects of previous pulmonary infections, (2) the effects of cigarette smoking, and (3) the effects of cirrhosis of the liver. The data suggest that either alcohol itself through some unknown mechanism may be a causative agent in producing lung disease or that alcohol makes a higher percentage of the population susceptible to the harmful effects of cigarette smoking.     

Pulmonary hemorrhage in cryoglobulinemia

Pulmonary manifestations of cryoglobulinemia are uncommon and their clinical behaviour is unpredictable, ranging from mild dyspnea to life-threatening presentations. A patient with cryoglobulinemia who presented with hypoxic respiratory failure attributed to pulmonary hemorrhage is reported.