Pulmonary Arterial Hypertension with Features of Venous Involvement: A Detective's Task

Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis are rare types of histopathological substrates within the spectrum of pulmonary arterial hypertension (PAH) with a very poor prognosis. They are characterized by a widespread fibroproliferative process of the small caliber veins and/or capillaries with sparing of the larger veins, resulting in a pre-capillary pulmonary hypertension phenotype. Clinical presentation is unspecific and similar to other PAH etiologies. Definitive diagnosis is obtained through histological analysis, although lung biopsy is not advised due to a higher risk of complications. However, some additional findings may allow a presumptive clinical diagnosis of PVOD, particularly a history of smoking, chemotherapy drug use, exposure to organic solvents (particularly trichloroethylene), low diffusing capacity for carbon monoxide (DLCO), exercise induced desaturation, and evidence of venous congestion without left heart disease on imaging, manifested by a classical triad of ground glass opacities, septal lines, and lymphadenopathies. Lung transplant is the only effective treatment, and patients should be referred at the time of diagnosis due to the rapid progression of the disease and associated poor prognosis. We present a case of a 58-year-old man with PAH with features of venous/capillary involvement in which clinical suspicion, prompt diagnosis, and early referral for lung transplantation were determinant factors for the successful outcome.

Recanalization of a Chronic Total Pulmonary Vein Occlusion Occurring after Transcatheter Atrial Fibrillation Ablation

Pulmonary vein occlusion (PVO) is a known complication of radiofrequency ablation for atrial fibrillation. We present a case with delayed presentation leading to chronic total PVO. Computed Tomography (CT) imaging did not predict the presence of residual flow. Despite this, the occlusion was successfully stented using wire escalation techniques adapted from chronic total occlusion coronary angioplasty, with resolution of symptoms. This emphasises the importance of combining CT with invasive angiography for patient selection and interventional strategy. Innovative angioplasty techniques used to overcome PVO need to be balanced against additional risk of perforation when dealing with extra-cardiac structures.

Pulmonary Veno-occlusive Disease that Developed Following Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia

We herein report a case of pulmonary veno-occlusive disease (PVOD) induced by allo-hematopoietic stem cell transplantation (HSCT) in a 48-year-old man who was diagnosed with acute myeloid leukemia. Five months after transplantation, he developed dyspnea and was diagnosed with pulmonary hypertension based on right heart catheterization. Although he received treatment with pulmonary vasodilators, diuretics, and corticosteroids, his pulmonary artery pressure did not decrease, and his pulmonary edema worsened. Based on the clinical course, hypoxemia, diffusion impairment, and computed tomography findings, the patient was diagnosed with HSCT-related PVOD. Critical attention should be paid to dyspnea after HSCT for the early diagnosis of PVOD.

Dual-energy CT lung perfusion characteristics in pulmonary arterial hypertension (PAH) and pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis (PVOD/PCH): preliminary experience in 63 patients

BACKGROUND

In the stratification of potential causes of PH, current guidelines recommend performing V/Q lung scintigraphy to screen for CTEPH. The recognition of CTEPH is based on the identification of lung segments or sub-segments without perfusion but preserved ventilation. The presence of mismatched perfusion defects has also been described in a small proportion of idiopathic pulmonary arterial hypertension (PAH) and pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis (PVOD/PCH). Dual-energy CT lung perfusion changes have not been specifically investigated in these two entities.

PURPOSE

To compare dual-energy CT (DECT) perfusion characteristics in PAH and PVOD/PCH, with specific interest in PE-type perfusion defects.

MATERIALS AND METHODS

Sixty-three patients with idiopathic or heritable PAH (group A; n = 51) and PVOD/PCH (group B; n = 12) were investigated with DECT angiography with reconstruction of morphologic and perfusion images.

RESULTS

The number of patients with abnormal perfusion did not differ between group A (35/51; 68.6%) and group B (6/12; 50%) (p = 0.31) nor did the mean number of segments with abnormal perfusion per patient (group A: 17.9 ± 4.9; group B: 18.3 ± 4.1; p = 0.91). The most frequent finding was the presence of patchy defects in group A (15/35; 42.9%) and a variable association of perfusion abnormalities in group B (4/6; 66.7%). The median percentage of segments with PE-type defects per patient was significantly higher in group B than in group A (p = 0.041). Two types of PE-type defects were depicted in 8 patients (group A: 5/51; 9.8%; group B: 3/12; 25%), superimposed on PH-related lung abnormalities (7/8) or normal lung (1/8). The iodine concentration was significantly lower in patients with abnormal perfusion (p < 0.001) but did not differ between groups.

CONCLUSION

Perfusion abnormalities did not differ between the two groups at the exception of a higher median percentage of segments with PE-type defects in patients with PVOD/PCH.

KEY POINTS

• Patchy perfusion defect was the most frequent pattern in PAH. • A variable association of perfusion abnormalities was seen in PVOD/PCH. • Lobular and PE-type perfusion defects larger than a sub-segment were depicted in both PAH and PVOD/PCH patients.

Sudden Death in a Patient with Pulmonary Veno-occlusive Disease (PVOD) and Severe Pulmonary Hypertension

A 58-year-old woman was referred to our hospital with a chief complaint of exertional dyspnea. Bronchoscopy failed to establish a diagnosis, and the patient subsequently died suddenly due to respiratory insufficiency because of advanced pulmonary hypertension (PH). The pathological diagnosis at autopsy was pulmonary veno-occlusive disease (PVOD). PVOD is difficult to diagnose antemortem and has a poor prognosis. Lung transplantation is the only curative treatment for PVOD.

Early-onset Atrial Fibrillation in Brothers with a Huge Left Atrial Appendage

Having a relative with atrial fibrillation (AF) is one of the risk factors for AF development, especially in young patients, which is known as familial AF. Although familial AF is considered to be associated with inherited factors, its genetic and pathophysiological backgrounds have not been fully identified. We report two young brothers undergoing radiofrequency catheter ablation for AF, who had a huge left atrial appendage (LAA). In both cases, the origins of the main triggers of the AF were not the huge LAA itself, but left pulmonary veins compressed by the LAA. Since catheter ablation including pulmonary vein isolation, the sinus rhythm has been maintained in both patients.

[Echocardiography and Respiratory Function Testing for Pulmonary Arterial Hypertension]

Pulmonary hypertension (PH) is a hemodynamic and pathophysiologic condition characterized by elevated pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), defined as an increase in the mean PAP of more than 20 mmHg at rest. PH can be a progressive and fatal disease if not treated appropriately. In the advanced stage of PH, the right ventricular (RV) function may be impaired, and it is associated with poor outcomes in PH. PH, however, can be easily misdiagnosed until the disease is at an advanced stage, because of its nonspecific and subtle symptoms in the early stages. PH is also a multi-factorial disease, it can be due to a primary elevation of pressure in the pulmonary arterial system alone (pulmonary arterial hypertension), or secondary to elevations of pressure in the pulmonary venous and pulmonary capillary systems (pulmonary venous hypertension). Establishing its etiology is also important for the early diagnosis of PH. Echocardiography is an important modality to assess the presence or absence of PH and its etiology, and it has been used to screen for this disease, determine the left and right heart structure and function, and assess the response to therapy in persons with PH. The pulmonary function test is also useful in PH, especially PH in chronic lung disorders. PH patients may also display mild to moderate ventilatory impairment in the absence of any evidence of lung airway or parenchymal disease, mainly in the form of airway obstruction. In this review, we discuss the diagnostic and prognostic role of clinical echocardiography and pulmonary function testing in clinical practice for pulmonary hypertension in this modern era.

Evaluation of pulmonary hypertension in a child: role of computed tomography

Unexplained pulmonary hypertension in pediatric patient is a diagnostic challenge. The natural history as well as management depends upon etiology of pulmonary hypertension. Despite newer insights in pathophysiology and management strategies, the outcome of pulmonary veno-occlusive disease remains dismal. The author's report a case of 12-year-old girl who presented with severe pulmonary hypertension. Stepwise evaluation and CT angiographic assessment in the index case led to definitive diagnosis of pulmonary veno-occlusive disease. This case highlights the role of cardiac imaging in localising site of pulmonary hypertension. It is important for health care professionals involved in care of patients with pulmonary hypertension to make correct diagnosis of pulmonary veno-occlusive disease for better prognostication as well as to avoid therapeutic mishaps.

Long-term remission of pulmonary veno-occlusive disease associated with primary Sjögren's syndrome following immunosuppressive therapy

The patient described here is a 21-year-old Japanese woman with primary Sjögren's syndrome (pSS) presenting with worsening of dyspnea, palpitation, recurrent parotitis, and arthritis. Chest computed tomography showed diffuse interlobular septal thickening and ground-glass opacities. Right heart catheterization demonstrated pulmonary hypertension, right-sided heart failure, normal pulmonary capillary wedge pressure, and no evidence of arterio-venous shunt. Transbronchial lung biopsy showed luminal obliteration of pulmonary venules by intimal cellular proliferations, without abnormalities in the small pulmonary arteries. These findings were consistent with pulmonary veno-occlusive disease (PVOD). Immunosuppressive therapy, starting with prednisolone 20 mg/day and subsequently combined with azathioprine, resulted in the disappearance of the signs and symptoms, including exertional dyspnea and abnormal pulmonary parenchymal shadows on computed tomography, and the normalization of pulmonary artery pressure. So far, there have been no reported cases of PVOD associated with pSS. Of interest, immunosuppressive therapy without vasodilator therapy almost completely resolved the pulmonary hypertension in this patient.

[Pulmonary vein stenosis after radio frequency ablation]

Physicians should be alert to the occurrence of respiratory symptoms after radio frequency ablation for the treatment of atrial fibrillation. Pulmonary veins stenosis could appear with an incidence of between 1 and 3% during the two years following the procedure. We present the case of a 41 year-old-male patient admitted with a three weeks old hemoptysis and thoracodinia and a prior history of a radiofrequency ablation procedure performed six months earlier. The angiotomography was not compatible with the diagnosis of pulmonary embolism and the angio-MRI detected hypoperfusion of the left upper pulmonary lobe. Consequently pulmonary veins angiotomography was requested, showing upper pulmonary lobe vein stenosis. An hemodynamic study with vein expansion and stent placement was successfully performed.

Acquired pulmonary vein stenosis: one problem, two mechanisms

Until the last decade, acquired pulmonary vein (PV) stenosis in the adult population was a rare finding, caused by neoplasm or inflammatory conditions such as sarcoidosis or fibrosing mediastinitis. With the increased use of catheter-based ablation for the treatment of atrial fibrillation, PV stenosis is increasingly recognized as a complication of this procedure. Additionally, PV stenosis has been described as a rare complication of cardiac surgery. This report describes two cases of PV stenosis, one acquired as a result of multiple left atrial ablation procedures and the other after surgical cannulation of the right upper PV.

Idiopathic pulmonary veno-occlusive disease

We report a case of idiopathic pulmonary veno-occlusive disease (PVOD). The patient experienced progressively worsening dyspnea. Heart catheterization revealed severe pulmonary hypertension. High-resolution computed tomography (HRCT) showed diffuse, poorly identified centrilobular ground-glass opacities. Surgical lung biopsy led to the diagnosis of PVOD. A microscopic examination revealed occlusions of pulmonary veins and venules over a wide area with prominent loop-like capillary dilatations. These pathological findings may be correlated with the radiological characteristics of HRCT in this case.

Pulmonary veno-occlusive disease: clinical, functional, radiologic, and hemodynamic characteristics and outcome of 24 cases confirmed by histology

Pulmonary veno-occlusive disease (PVOD) is defined by specific pathologic changes of the pulmonary veins. A definite diagnosis of PVOD thus requires a lung biopsy or pathologic examination of pulmonary explants or postmortem lung samples. However, lung biopsy is hazardous in patients with severe pulmonary hypertension, and there is a need for noninvasive diagnostic tools in this patient population. Patients with PVOD may be refractory to pulmonary arterial hypertension (PAH)-specific therapy and may even deteriorate with it. It is important to identify such patients as soon as possible, because they should be treated cautiously and considered for lung transplantation if eligible. High-resolution computed tomography of the chest can suggest PVOD in the setting of pulmonary hypertension when it shows nodular ground-glass opacities, septal lines, lymph node enlargement, and pleural effusion. Similarly, occult alveolar hemorrhage found on bronchoalveolar lavage in patients with pulmonary hypertension is associated with PVOD. We conducted the current study to identify additional clinical, functional, and hemodynamic characteristics of PVOD. We retrospectively reviewed 48 cases of severe pulmonary hypertension: 24 patients with histologic evidence of PVOD and 24 randomly selected patients with idiopathic, familial, or anorexigen-associated PAH and no evidence of PVOD after meticulous lung pathologic evaluation. We compared clinical and radiologic findings, pulmonary function, and hemodynamics at presentation, as well as outcomes after the initiation of PAH therapy in both groups. Compared to PAH, PVOD was characterized by a higher male:female ratio and higher tobacco exposure (p < 0.01). Clinical presentation was similar except for a lower body mass index (p < 0.02) in patients with PVOD. At baseline, PVOD patients had significantly lower partial pressure of arterial oxygen (PaO2), diffusing lung capacity of carbon monoxide/alveolar volume (DLCO/VA), and oxygen saturation nadir during the 6-minute walk test (all p < 0.01). Hemodynamic parameters showed a lower mean systemic arterial pressure (p < 0.01) and right atrial pressure (p < 0.05), but no difference in pulmonary capillary wedge pressure. Four bone morphogenetic protein receptor II (BMPR2) mutations have been previously described in PVOD patients; in the current study we describe 2 additional cases of BMPR2 mutation in PVOD. Computed tomography of the chest revealed nodular and ground-glass opacities, septal lines, and lymph node enlargement more frequently in patients with PVOD compared with patients with PAH (all p < 0.05). Among the 16 PVOD patients who received PAH-specific therapy, 7 (43.8%) developed pulmonary edema (mostly with continuous intravenous epoprostenol, but also with oral bosentan and oral calcium channel blockers) at a median of 9 days after treatment initiation. Acute vasodilator testing with nitric oxide and clinical, functional, or hemodynamic characteristics were not predictive of the subsequent occurrence of pulmonary edema on treatment. Clinical outcomes of PVOD patients were worse than those of PAH patients.

Intravascular sarcoidosis presenting as pulmonary vein occlusion: CT and pathologic findings

It is well known that destruction of the distal capillary bed from extensive fibrosis and honeycombing in the setting of sarcoidosis may lead to pulmonary hypertension. However, we report an unusual manifestation of sarcoidosis where pulmonary hypertension resulted from granulomatous involvement of the pulmonary veins and venules. This presented as venous occlusion and intraluminal filling defects that simulated thrombus on chest computed tomography. To our knowledge, this is the first reported imaging case of such a presentation.

Pulmonary venous flow assessed by Doppler echocardiography in the management of atrial fibrillation

Pulmonary venous blood flow (PVF) visualized by Doppler echocardiography exhibits a pulsatile behavior, which is related to left atrial pressure and function, mitral valve function, and left ventricular compliance. In atrial fibrillation (AF), the disappearance of atrial reverse flow, a decrease in systolic flow with a greater diastolic than systolic flow, a prolonged onset of systolic flow and the appearance of an early systolic reverse flow are characteristic findings. A reduction in systolic PVF expressed by reduced peak velocity, reduced velocity-time integral of systolic flow, and reduced systolic fraction of PVF has been found to be associated with reduced left atrial appendage flow, left atrial spontaneous echo contrast formation, frequency of AF paroxysms and propensity for AF recurrence following restoration of sinus rhythm. Ablation techniques targeting pulmonary vein ostia and adjacent left atrium are promising treatment options to cure AF. Monitoring the PVF response to and adjusting of ablation procedures has been suggested to optimize outcome and prevent complications such as pulmonary vein stenosis. In conclusion, assessment of PVF variables and patterns by Doppler echocardiography seems useful in the management of AF patients. Especially the reduction in systolic PVF may be used as marker for left atrial dysfunction which favors thrombus formation and AF reinitiation. Finally, PVF monitoring has the potential to an increasing role in AF ablation procedures.

PVOD suggested by MDCT and clinical findings in a pregnant woman

Pulmonary hypertension secondary to pulmonary venoocclusive disease (PVOD) is increasingly recognized (Wagenvoort, Chest 69:82-86, [20]; Scully et al., N Engl J Med 308:823-834, [21]). The clinical presentation is usually progressive pulmonary hypertension. It should be kept in mind when there is pulmonary arterial hypertension, pulmonary edema, and a normal pulmonary artery wedge pressure. Importance of diagnosing this condition is to protect patient from fatal pulmonary edema when using prostacyclins that are effective for treatment of primary pulmonary hypertension. Herein, we present multidetector computed tomography findings of PVOD in a pregnant woman that presented with pulmonary hypertension.

Severely obstructed totally anomalous pulmonary venous return with residual connection to the left atrium

Totally anomalous pulmonary venous return may present diagnostic difficulty to clinicians, as it often appears similar to severe neonatal pulmonary disease. We describe a neonate who presented with severely obstructed pulmonary venous return, but with a residual venous connection to the left atrium. The unusual anatomy confounded the diagnosis. To our knowledge, this particular permutation has not previously been described. Our experience indicates that echocardiographic interrogation should be repeated in cases where there is no response to conventional therapy, and all individual pulmonary veins should be observed carefully.

From the Archives of the AFIP: pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis

Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis (PCH) are two unusual idiopathic disorders that almost uniformly manifest to the clinician as pulmonary arterial hypertension (PAH). Impressive clinical signs and symptoms often obscure the true underlying capillary or postcapillary disorder, thus severely compromising timely and appropriately directed therapy. The hemodynamics of PVOD and PCH are the consequence of a widespread vascular obstructive process that originates in either the alveolar capillary bed (in cases of PCH) or the pulmonary venules and small veins (in PVOD). Since the earliest descriptions of PVOD and PCH, there has been a debate as to whether these are two distinct diseases or varied expressions of a single disorder. The cause of PVOD or PCH has not yet been identified, although there are several reported associations. Without curative lung or heart-lung transplantation, patients with these conditions face inexorable clinical deterioration and death within months to a few short years of initial presentation. Surgical lung biopsy is the definitive diagnostic test, but it is a risky undertaking in such critically ill patients. The imaging manifestations of PVOD and PCH often reflect the underlying hemodynamic derangements, and these findings may assist the clinician in discerning PAH from an underlying capillary or postcapillary process with findings of septal lines, characteristic ground-glass opacities, and occasionally pleural effusion.

Detection of pulmonary vein stenosis by transesophageal echocardiography: comparison with multidetector computed tomography

OBJECTIVE

The objective of this study is to compare the use of transesophageal echocardiography (TEE) vs multidetector computed tomography (MDCT) for detecting pulmonary vein stenosis.

BACKGROUND

Pulmonary vein isolation is increasingly used to treat atrial fibrillation. Pulmonary vein stenosis remains a potential complication of pulmonary vein isolation and ideal methods for detection of stenosis are still to be determined.

METHODS

Thirty-six subjects who underwent pulmonary vein isolation returned for follow-up MDCT and TEE. Percent diameter loss was reported for each pulmonary vein stenosis by MDCT. A 50% narrowing was considered as an indication of a stenosis. Pulsed-wave Doppler using TEE was used to measure peak velocities of all pulmonary veins.

RESULTS

Multidetector computed tomography and TEE were performed in all subjects (58 +/- 10 years) at 4 +/- 2 months after pulmonary vein isolation. Atrial fibrillation was present in 14% at time of follow-up. Multidetector computed tomography was able to evaluate all 4 (100%) pulmonary veins in 36 subjects, whereas full interrogation by TEE was possible in 138 (96%) of 144 veins. Pulmonary vein stenosis >50% by MDCT was present in 7 pulmonary veins. Analysis of the receiver operating curve for TEE showed that it had optimum detection of pulmonary vein stenosis at peak velocities approximately 100 cm/s with 86% sensitivity and 95% specificity. Area under the curve for TEE was 0.93. Clinically significant stenosis was observed in 2 subjects and was detected by both TEE and MDCT.

CONCLUSIONS

Transesophageal echocardiography was able to detect most pulmonary veins with good sensitivity and specificity in comparison to MDCT. Pulmonary veins may be visualized more frequently by MDCT; however, TEE provides additional data about the functional significance of a pulmonary vein stenosis.

Transesophageal echocardiography: A follow-up tool after catheter ablation of atrial fibrillation and interventional therapy of pulmonary vein stenosis and occlusion

BACKGROUND

Pulmonary vein stenosis (PVS) has been described as a complication after primary catheter ablation of atrial fibrillation (Afib). The purpose of this study was to evaluate the utility of transesophageal echocardiography (TEE) as follow-up tool after catheter ablation of Afib and interventional therapy of PVS and pulmonary vein occlusion (PVO).

METHODS

We report on 28 patients with stenosis (PVS) of 33 pulmonary veins (PVs) and total PVO of 4 veins complicating ablation of Afib assessed by angiography and/or magnetic resonance imaging (MRI). Subsequently, transseptal PV angiograms were performed, followed by recanalization of three totally occluded PVs and balloon dilatation of seven severe PVS (in four cases combined with PV stenting). PVs were analyzed by multiplane TEE in an intraindividual comparison of preablation/preintervention and follow-up measurements of mean and peak flow velocity, velocity time integrals, and diameters.

RESULTS

Of a total of 28 patients, 14 had mild PVS (n = 14), 9 had moderate PVS (n = 10), 6 had severe PVS (n = 8), and 4 patients showed totally occluded PVs (n = 4). In multivariate analysis flow velocities and vessel diameters showed significant differences (mild, moderate, and severe PVS and PVO; p = 0.001). Interventional benefits of balloon dilatation (n = 10) and stent implantation (n = 4), as well as in-stent restenosis could be detected (p = 0.014). In all recanalized vessels TEE showed reestablished flow. In occluded PVs no flow was detectable. The TEE vessel diameters correlated with angiography data (r = 0.87) and computed tomography/MRI (r = 0.90).

CONCLUSIONS

TEE can be used as a follow-up tool after interventional therapy in patients after catheter ablation and acquired PVS/PVO. Restenosis/in-stent restenosis can be identified by analyzing the vessel diameters and blood flow characteristics.

High-Resolution Computed Tomographic Imaging and Pathologic Features of Pulmonary Veno-Occlusive Disease: A Review of Three Patients

Pulmonary veno-occlusive disease (PVOD) is a rare and severe form of pulmonary hypertension that is often difficult to differentiate from primary pulmonary hypertension. Differentiating these two entities before medical treatment is critical, as therapy commonly indicated for patients with primary pulmonary hypertension can be harmful and even fatal in patients with PVOD. In the setting of known pulmonary hypertension, computed tomography findings that are highly suggestive of PVOD include extensive, patchy centrilobular ground-glass opacities, ill-defined nodular densities, and interlobular septal thickening. Definitive diagnosis requires lung biopsy, demonstrating fibrous obliteration of the pulmonary venules and small veins of the lobular septa, with secondary medial hypertrophy of the pulmonary arteries. The purpose of this article is to review reported radiographic clues to the diagnosis of PVOD, as well as to illustrate these high-resolution computed tomography findings along with pathologic correlation.

Successful release of recurrent pulmonary venous obstruction after repair of totally anomalous pulmonary venous connection by transcatheter implantation of stents

We report a 3-month-old female infant, in whom pulmonary venous obstruction occurred after repair of totally anomalous pulmonary venous connection, and which was successfully released by a transcatheter implantation of a stent using the transseptal approach. Close follow-up is required, since the long-term outcome is still unclear. Nevertheless, transcatheter implantation of stents is a promising option for treating this challenging lesion.

An unusual cause of pulmonary vein stenosis: a case report and review of the literature

We describe the case of a patient with the Carney syndrome and several resections for recurrent left atrial myxomas who underwent autotransplantation of the heart with resection of the left and right atria and reconstruction of both atria with bovine pericardium. She subsequently presented with severe shortness of breath, ascites, and peripheral edema. She was found to have stenosis of all four pulmonary veins and severe pulmonary hypertension. We describe the echocardiographic findings and review the literature on assessment of acquired pulmonary vein stenosis.

Atresia of the common pulmonary vein

A newborn girl with atresia of the common pulmonary vein, presented immediately after birth with severe cyanosis and acidosis. The diagnosis of totally obstructed total pulmonary venous return was made by cross-sectional echocardiography. Subsequent cardiac catheterization failed to demonstrate the site of pulmonary venous return. Necropsy showed the pulmonary veins to be connected bilaterally to an atretic common pulmonary vein. There was no obvious alternative pathway for pulmonary venous return.

Usefulness of cutting balloon angioplasty for pulmonary vein in-stent stenosis

After radiofrequency ablation for atrial fibrillation, patients may develop pulmonary vein stenoses requiring stent angioplasty. The treatment options for when such patients develop in-stent stenoses are poorly defined. The investigators retrospectively reviewed their initial experience with cutting balloon angioplasty for pulmonary vein in-stent stenosis. Ten patients with 21 previously stented pulmonary veins returned to the catheterization laboratory for in-stent stenoses. Angioplasty of individual in-stent stenotic vessels were grouped into standard angioplasty alone (n = 6) and a combination of cutting balloon followed by standard angioplasty (n = 15). Although final mean lesion diameter was increased significantly in the 2 groups, restenosis occurred in 4 of 6 vessels in the group with angioplasty alone and 2 of 15 vessels in the cutting balloon group. In conclusion, cutting balloon angioplasty for pulmonary vein in-stent stenosis appears to improve the intermediate results of repeat angioplasty.

Complete repair of concomitant interrupted aortic arch and partial anomalous pulmonary venous connection

We report a rare case of concomitant presentation of partial anomalous pulmonary venous connection and type A interrupted aortic arch in a 4-week-old, 2.1 kg newborn. She presented in extremis and was found to have a closed ductus arteriosus with the entire left pulmonary venous return obstructed at its connection with the innominate vein. Emergent operative repair was performed in one-stage, consisting of aortic arch reconstruction and anomalous vein translocation. Postoperative recovery was unremarkable and the patient was discharged from hospital 12 days after operation.

Asymptomatic partial anomalous pulmonary venous return masquerading as pulmonary vein occlusion following radiofrequency ablation

Recent advances in the field of cardiac electrophysiology have resulted in the rapid growth of radiofrequency ablation for treatment of arrhythmias. Pulmonary vein stenosis or occlusion is a rare, but well described adverse outcome. Fortunately, the concomitant evolution of multislice computed tomography (CT) scanners has provided an excellent non-invasive method of monitoring for this complication. We recently encountered a case on multislice CT that initially appeared to be a pulmonary vein occlusion related to the procedure, but on further evaluation was found to be an asymptomatic case of partial anomalous pulmonary venous return.

Temporary pulmonary vein stenosis during intraoperative transesophageal echocardiography in total cavopulmonary connection

Two patients operated on by one of the authors (MK) developed hemodynamic instability after otherwise uneventful completion of total cavopulmonary anastomosis with an extracardiac tube. In both, a stenosis of the right pulmonary veins was demonstrated during routine intraoperative transesophageal echocardiography. The transesophageal probe was found to be the underlying problem. Apparently, the pulmonary veins became compressed between the probe and the extracardiac conduit.

Visualization of pulmonary vein stenosis after radio frequency ablation using multi-slice computed tomography: initial clinical experience in 33 patients

PURPOSE

Radio frequency ablation (RFA) of the pulmonary veins (PV) is an established technique for treatment of atrial fibrillation (AF). However, stenoses within the treated areas are well known complications. Thus, a reliable non-invasive diagnosis of PV stenosis would be an important step forward in the care of these patients (pts). Aim of the present study was the diagnostic accuracy of new multi-slice detected computed tomography (MSCT) in visualization of PV and in detecting PV stenosis.

MATERIAL AND METHODS

A total of 33 pts (17 male, 16 female, mean age 57+/-10.2 years [40-71]) were included. Retrospectively ECG-gated CT angiography (CTA) was performed within 1 day to a maximum of 380 days after RFA with a MSCT scanner. Interpretation of the scan was performed on conventional contrast enhanced axial slices and on 3D volume rendering images (maximum intensity projection: MIP, multi-planar reconstruction: MPR). Lesion severity was determined on a semi-quantitative scale (mild: <20%, intermediate: 20-50%, severe >50%) and compared to conventional angiography which had been performed at the beginning and at the end of RFA.

RESULTS

MSCTA was applied without any complications, and all treated pulmonary veins (n=73) could be visualized. Diagnostic image quality was obtained in all examinations. A significant stenosis was detected by conventional angiography in 26/73 (36%) PV (2/73 (3%) severe, 14/73 (19%) intermediate, 10/73 (14%) mild). Using MSCTA, only 13 stenosis in 73 treated PV could be visualized (1/73 (1%) severe, 6/73 (8%) intermediate, 6/73 (8%) mild).

CONCLUSIONS

Multi-slice-detector CT is able to visualize PV and to detect PV stenoses. However, stenosis severity seems to be underestimated and not all lesions could be accurately detected. Larger studies have to be performed to further assess the diagnostic accuracy and clinical reliability of this new non-invasive method and to focus on the incidence of PV stenosis following RFA especially in long-time follow up.

CT imaging of peripheral pulmonary vessel disease

The diseases concerning the small pulmonary vessels are difficult to diagnose. Pathologic findings are rarely limited to the small vessels, and a continuum between the involvement of small and large vessels is frequent. Moreover, small vessels can be affected by various disease entities with overlapping radiologic features and a wide spectrum of clinical manifestations. Nevertheless, these various entities can be easily separated into two different groups by imaging techniques, particularly by computed tomography: obstructive and inflammatory diseases. Radiologic findings of obstructive diseases are relatively constant, dominated by the manifestation of pulmonary hypertension. In contrast, radiologic manifestations of inflammatory diseases are often florid and nonspecific. After a recall of the classification of small vessel diseases and the imaging techniques, we show the computed tomography features of the principal diseases involving the small pulmonary vessels by classifying them in these two principal groups.

[Pulmonary venous occlusive disease]

The present study deals with the radiation diagnosis of the rare disease--pulmonary venous occlusive disease. The follow-up covered three cases that ended with death. The clinical picture of the disease did not differ from the manifestations of primary pulmonary hypertension. All the patients underwent chest X-ray study in four standard projections. The morphological verification of its diagnosis was made on the basis of autopsy data. X-rat study promoted identification of such signs as peculiar changes in the lung pattern in form of its looping, reticulation, fine-focality along with reticular changes, the presence of Kerley lines, the diameter of root branches, enlargements of the pulmonary trunk without any symptoms of the enlarged left atrium.

Assessment of intra- and interobserver variability of pulmonary vein measurements from CT angiography

RATIONALE AND OBJECTIVES

Pulmonary vein (PV) stenosis is a common complication after radiofrequency ablation for atrial fibrillation. This study investigated the intra- and interobserver variability and precision of PV ostial measurements from three-dimensional computed tomography angiography.

MATERIALS AND METHODS

Four observers measured the maximum and minimum diameters, as well as area, of the four PVs of seven patients who underwent a three-dimensional computed tomography scan before radiofrequency ablation. Each observer performed two sets of measurements. The intra- and interobserver variability of the measurements was calculated using analysis of variance.

RESULTS

Intraobserver variability was approximately two times lower than interobserver variability in measurements of diameter and area. The standard error of the measurement (SEM), SEM(intra) and SEM(inter), were lower for the mean diameter than the maximum diameter. The minimum detectable changes in diameters, DeltaD(intra) and DeltaD(inter), and area, DeltaA(intra) and DeltaA(inter), demonstrated the same statistical trend as the corresponding SEM for each of the four veins. Both DeltaD(intra) and DeltaD(inter) and DeltaA(intra) and DeltaA(inter) were smaller than the corresponding lower bounds of the 95% confidence interval for 50% diameter reduction and 75% area reduction. The direct results of DeltaA(intra) and DeltaA(inter) for each of the four veins were consistently less than DeltaA's calculated from the corresponding DeltaD(intra) and DeltaD(inter).

CONCLUSION

PV ostial measurements are less variable when made by a single observer than by multiple observers, and mean diameter measurements are more precise than a single, maximum diameter measurement. Both diameter and area measurements are capable of quantifying the mild PV stenosis. Furthermore, area can be measured with greater precision than mean diameter and should be used in PV ostium caliber determination.

Pulmonary hypertension: CT of the chest in pulmonary venoocclusive disease

OBJECTIVE

Pulmonary venoocclusive disease is a rare cause of pulmonary hypertension that is often difficult to distinguish from severe primary pulmonary hypertension. Unfortunately, medical treatment of primary pulmonary hypertension with prostacyclin can be fatal in patients with venoocclusive disease, and an early pretreatment diagnosis of this uncommon condition is critical. The aim of our study was to evaluate this disease noninvasively using CT of the chest.

MATERIALS AND METHODS

We reviewed cross-referenced records from 1996 to 2001 in our departments of radiology and pathology and identified 15 patients with initial pretreatment CT scans who had pathologically confirmed pulmonary venoocclusive disease. Their CT scans were compared with the CT scans of 15 consecutive patients with pathologically confirmed primary pulmonary hypertension. All patients had undergone a postmortem or posttransplantation examination.

RESULTS

Ground-glass opacities were significantly more frequent in pulmonary venoocclusive disease (p = 0.003); the opacities were abundant with random zonal predominance and preferentially centrilobular distribution (p = 0.03). Subpleural septal lines and adenopathy were also significantly more frequent (p < 0.0001).

CONCLUSION

On the initial pretreatment chest CT scan, the presence of ground-glass opacities (particularly with a centrilobular distribution), septal lines, and adenopathy are indicative of pulmonary venoocclusive disease in patients displaying pulmonary hypertension. Caution should be exercised before vasodilator therapy is initiated in the patients whose scans show such radiologic abnormalities.

Detection of Inadvertent Catheter Movement into a Pulmonary Vein During Radiofrequency Catheter Ablation by Real-Time Impedance Monitoring

INTRODUCTION

During radiofrequency ablation to encircle or isolate the pulmonary veins (PVs), applications of radiofrequency energy within a PV may result in stenosis. The aim of this study was to determine whether monitoring of real-time impedance facilitates detection of inadvertent catheter movement into a PV.

METHODS AND RESULTS

In 30 consecutive patients (mean age 53 +/- 11 years) who underwent a left atrial ablation procedure, the three-dimensional geometry of the left atrium, the PVs, and their ostia were reconstructed using an electroanatomic mapping system. The PV ostia were identified based on venography, changes in electrogram morphology, and manual and fluoroscopic feedback as the catheter was withdrawn from the PV into the left atrium. Real-time impedance was measured at the ostium, inside the PV at approximately 1 and 3 cm from the ostium, in the left atrial appendage, and at the posterior left atrial wall. There was an impedance gradient from the distal PV (127 +/- 30 Omega) to the proximal PV (108 +/- 15 Omega) to the ostium (98 +/- 11 Omega) in each PV (P < 0.01). There was no significant impedance difference between the ostial and left atrial sites. During applications of radiofrequency energy, movement of the ablation catheter into a PV was accurately detected in 80% of the cases (20) when there was an abrupt increase of >/=4 Omega in real-time impedance.

CONCLUSION

There is a significant impedance gradient from the distal PV to the left atrium. Continuous monitoring of the real-time impedance facilitates detection of inadvertent catheter movement into a PV during applications of radiofrequency energy.

Variations in pulmonary venous drainage to the left atrium: implications for radiofrequency ablation

PURPOSE

To evaluate and classify the various drainage patterns of the pulmonary veins as depicted with thin-section chest computed tomography (CT).

MATERIALS AND METHODS

Thin-section (2.5-mm collimation) contrast material-enhanced CT scans of 201 consecutive patients obtained over a 3-month period for diagnosis of pulmonary embolism (n = 197), pulmonary vein stenosis (n = 2), or aortic injury (n = 2) were routinely reviewed in transverse and (if necessary) coronal and coronal-oblique imaging planes. A classification was formulated based on both the number of venous ostia on each side and the drainage patterns of pulmonary veins. The frequency of each pattern was determined, and association with atrial arrhythmia was assessed with the chi(2) and Fisher exact tests.

RESULTS

Most patients (n = 142, 71%) had two ostia on the right side for upper and lower lobe veins. Fifty-six patients (28%) had three to five ostia on the right side, which were due to one or two separate middle lobe vein ostia in 52 (26%) patients. Three patients (2%) had a single venous ostium on the right side. Most patients (n = 173, 86%) had two ostia on the left side for upper and lower lobe veins. The remainder (n = 28, 14%) had a single ostium. There was no significant association between any particular venous drainage pattern and atrial arrhythmia; however, patients with a separate ostia for the right middle lobe pulmonary vein(s) tended to have a higher frequency of atrial arrhythmia than those with other patterns (P =.053).

CONCLUSION

A classification system to succinctly describe pulmonary venous drainage patterns was developed. Right-sided venous drainage was more variable than left-sided venous drainage. One-quarter of patients had more than two venous ostia on the right side.