Pictorial review of the pulmonary vasculature: from arteries to veins

Pathology of the pulmonary vasculature involves an impressive array of both congenital and acquired conditions. While some of these disorders are benign, disruption of the pulmonary vasculature is often incompatible with life, making these conditions critical to identify on imaging. Many reviews of pulmonary vascular pathology approach the pulmonary arteries, pulmonary veins and bronchial arteries as individual topics. The goal of this review is to provide an integrated overview of the high-yield features of all major disorders of the pulmonary vasculature. This approach provides a more cohesive and comprehensive conceptualisation of respiratory pathology. In this review, we present both the salient clinical and imaging features of congenital and acquired disorders of the pulmonary vasculature, to assist the radiologist in identifying pathology and forming a robust differential diagnosis tailored to the presenting patient. TEACHING POINTS: • Abnormalities of the pulmonary vasculature are both congenital and acquired. • Pathology of a single pulmonary vascular territory often affects the entire pulmonary vasculature. • Anomalous pulmonary venous flow is named as a function of its location and severity. • Bronchial arteries often undergo dilatation secondary to cardio-respiratory pathology.

Postoperative Obstruction of the Pulmonary Veins in Mixed Total Anomalous Pulmonary Venous Connection

Total anomalous pulmonary venous connection (TAPVC) is a rare form of congenital heart disease in which the pulmonary veins drain by various pathways to the right atrium instead of the left atrium. Postoperative obstruction of the pulmonary veins is a known complication. Identifying risk factors for morbidity and mortality is important for counseling and monitoring. We describe a pattern of postoperative obstruction in a specific arrangement of mixed TAPVC. Five patients with a type of mixed TAPVC, namely, three pulmonary veins connecting to the coronary sinus and the left upper pulmonary vein (LUPV) connecting to the innominate vein, were identified over an 11-year period at our institution. Two additional patients with this TAPVC arrangement were cared for at our institution after having surgery at other institutions. Of these, one patient received only comfort care at birth due to other clinical issues. The six other patients underwent surgical unroofing of the coronary sinus. The anomalous LUPV was not addressed during the initial surgery in any of these cases. Following repair, one patient died from non-cardiac reasons. The remaining five patients all developed obstruction of the repaired pulmonary veins with decompression through the unrepaired LUPV, requiring surgical revision. Three patients underwent a second reoperation as well. Three of the six repaired patients also developed refractory atrial arrhythmias. This cohort suggests that this mixed TAPVC pattern predisposes patients to obstruction after surgical repair. Further investigation may aid pediatric cardiologists in risk-stratifying and counseling these patients. Alternative surgical approaches may need to be considered.

Pulmonary vein thrombosis after lobectomy with vein stump closure by ligation

Objectives Thrombosis in the pulmonary vein stump after a left upper lobectomy is a rare but potentially life-threatening complication, and the pulmonary vein stump length plays an important role here. We assessed the frequency and risk factors for thrombosis in patients undergoing lobectomy with division of the superior pulmonary vein using ligation. Methods We retrospectively reviewed 425 patients with primary lung cancer who underwent lobectomy or bilobectomy in our institution from 2008 to 2016, with contrast-enhanced chest computed tomography within a year after lobectomy. The superior pulmonary vein was divided by thread ligation, while the inferior pulmonary vein was divided using a linear stapler. The pulmonary vein stump length was measured using contrast-enhanced chest computed tomography. Results Four (0.9%) of the 425 patients experienced thrombosis in the pulmonary vein stump within 6 months after lobectomy. All 4 patients had undergone a left upper lobectomy, and 4.1% of this subset developed thrombus. One patient with a thrombus in the pulmonary vein stump experienced renal and cerebral infarction after a left upper lobectomy. The left superior pulmonary vein stump was significantly longer than the other pulmonary vein stumps. Conclusions Thrombosis in the pulmonary vein stump occurred in 4.1% of patients undergoing a left upper lobectomy with pulmonary vein stump closure by thread ligation, which is a relatively low frequency. Superior pulmonary vein stump closure using thread ligation might help prevent pulmonary vein stump thrombus after a left upper lobectomy.

Key technical steps in dual-pathway repair of congenital pulmonary vein stenosis

We present the case of a 2-year-old girl with congenital stenosis of the left inferior pulmonary vein associated with a large perimembranous ventricular septal defect. The child underwent repair of the left inferior pulmonary vein with autologous left atrial appendage as a pedicled tube, followed by closure of the ventricular septal defect. Important technical steps to minimize the restenosis rate are highlighted.

How many versus how much: comprehensive haemodynamic evaluation of partial anomalous pulmonary venous connection by cardiac MRI

OBJECTIVES

The objective of this study was to investigate the effect of location and number of anomalously connected pulmonary veins and any associated atrial septal defect (ASD) on the magnitude of left-to-right shunting in patients with partial anomalous pulmonary venous connection (PAPVC), and how that influences right ventricular volume loading.

METHODS AND RESULTS

The cardiac magnetic resonance (CMR) and echocardiography examinations of 26 paediatric patients (mean age, 11.2 ± 5.1 years) with unrepaired PAPVC were analysed. Fourteen patients had right-sided, 11 left-sided and 1 patient bilateral PAPVC. An ASD was present in 11 patients, of which none had a Qp/Qs < 1.5 and 8 had a Qp/Qs≥ 2.0. No patient with isolated left upper PAPVC experienced a Qp/Qs ≥ 2.0 compared to 9/12 patients with right upper PAPVC. Qp/Qs correlated with indexed right ventricle (RV) end-diastolic volume (RVEDVi, r = 0.59, p = 0.002) by CMR and with echocardiographic right ventricular end-diastolic dimension (RVED) z-score (r = 0.68, p = 0.003). A RVEDVi >124 ml/m² by CMR and a RVED z-score >2.2 by echocardiography identified patients with a Qp/Qs ≥1.5 with good sensitivity and specificity.

CONCLUSIONS

An asymptomatic patient with a single anomalously connected left upper pulmonary vein and without an ASD is unlikely to have a significant left-to-right shunt. On the other hand, right-sided PAPVC is frequently associated with a significant left-to-right shunt, especially when an ASD is present.

KEY POINTS

• Patients with PAPVC and ASD routinely have a significant left-to-right shunt. • Patients with right PAPVC are likely to have a significant left-to-right shunt. • Patients with left PAPVC are unlikely to have a significant left-to-right shunt. • CMR is helpful in decision-making for patients with PAPVC.

Early Pulmonary Vein Conduction Recovery after Catheter Ablation of Atrial Fibrillation

Background

Pulmonary vein electrical isolation (PVI) is an effective treatment for atrial fibrillation (AF). However, recurrence of pulmonary vein (PV) conduction after ablation may limit long-term success. Early identification and treatment of acute PV conduction recovery during initial ablation may have an impact on subsequent clinical results.

Objective

To assess the prevalence of acute PV conduction recovery during the observation time after PV isolation for paroxysmal AF, and to evaluate the impact of re-isolation treatment on long-term clinical results.

Methods

76 patients with paroxysmal AF were randomized to 2 groups to undergo PVI. Group A (Study Group: 38 patients): 30 minutes of observation were given following PV isolation for detection of acute PV-reconnection, with re-ablation of reconnected PVs. Group B (Control Group: 38 patients). Ablation procedure was done either by conventional method or using 3D electro-anatomical mapping. Symptoms, ECG and Holter monitoring were used to evaluate the clinical effectiveness of ablation. Any episode of symptomatic or asymptomatic atrial tachyarrhythmia that lasted more than 30 seconds documented with ECG or Holter monitoring was considered a recurrence.

Results

There was no statistically significant difference in age, sex, AF history, previous AF ablation, structural heart diseases & antiarrhythmic drug history among both groups. In the study group, 14 patients (36.8%) showed no PV reconnection, while 24 patients (63.2%) showed acute PV reconnection within 30 minutes. The LSPV showed the highest rate of acute PV reconnection during the observation period (66.6% of patients showing PV reconnection). AF recurred in only 6 patients (15.8%) in the study group in comparison to 20 patients (52.6%) having AF recurrence post-ablation in the control group. Among 24 patients of the study group, who showed PV reconnection which was re-isolated, only 4 patients (16.7%) had AF recurrence on follow up. In patients who did not show PV reconnection (14 patients), only 2 patients (14.3%) had AF recurrence on follow up.

Conclusion

Re-isolation of recovered PV conduction contributed to the improvement in the success rate of ablation for paroxysmal AF.

Clinical and anatomic predictors of need for repeat atrial fibrillation ablation

AIM

To identify predictors of need for repeat procedures after initial atrial fibrillation (AF) ablation.

METHODS

We identified a cohort undergoing first time AF ablation at our institution from January 2004 to February 2014 who had cardiac magnetic resonance (CMR) imaging performed prior to ablation. Clinical variables and anatomic characteristics (determined from CMR) were assessed as predictors of need for repeat ablation. The decision regarding need for and timing of repeat ablation was at the discretion of the treating physician.

RESULTS

From a cohort of 331 patients, 142 patients (43%) underwent repeat ablation at a mean of 13.6 ± 18.4 mo after the index procedure. Both male gender (81% vs 71%, P = 0.05) and lower ejection fraction (57.4% ± 10.3% vs 59.8% ± 9.4%, P = 0.04) were associated with need for repeat ablation. On pre-ablation CMR, mean pulmonary vein (PV) diameters were significantly larger in all four PVs among patients requiring repeat procedures. In multivariate analysis, increased right superior PV diameter significantly predicted need for repeat ablation (odds ratio 1.08 per millimeter increase in diameter, 95%CI: 1.00-1.16, P = 0.05). There were also trends toward significance for increased left and right inferior PV sizes among those requiring repeat procedures.

CONCLUSION

Increased PV size predicts the need for repeat AF ablation, with each millimeter increase in PV diameter associated with an approximately 5%-10% increased risk of requiring repeat procedures.

Aging Modulates the Substrate and Triggers Remodeling in Atrial Fibrillation

Aging plays a critical role in the genesis of atrial fibrillation (AF) and also increases the risks of cardiac dysfunction and stroke in AF patients. AF is caused by increased AF triggering from abnormalities of the thoracic vein and/or modulated substrate (atrial) with enhancement of AF maintenance. Clinical and laboratory evidence indicates that aging is significant in the creation of atrial electrical and structural remodeling that leads to increased susceptibility to AF occurrence. Aging is commonly associated with cardiovascular comorbidities, oxidative stress, calcium dysregulation, atrial myopathy with apoptosis, and fibrosis, which all contribute to the genesis of AF. This review updates the current understanding of the effects of aging on the pathophysiology of AF.

Conduction recovery following catheter ablation in patients with recurrent atrial fibrillation and heart failure

BACKGROUND

Atrial fibrillation (AF) catheter ablation is increasingly proposed for patients suffering from AF and concomitant heart failure (HF). However, the optimal ablation strategy remains controversial. We performed this study to assess the prevalence of pulmonary vein (PV) or linear lesion reconnection in HF patients undergoing repeated procedures.

METHODS AND RESULTS

At seven high-volume centres, 165 patients with HF underwent a repeat procedure after a first AF ablation including PV isolation alone (47 patients, group A) or PV isolation plus left atrial lines (118 patients, group B). Group A patients presented more often paroxysmal AF (p<0.001), less enlarged left atrium (p<0.001) and less left ventricular systolic dysfunction (p=0.031) compared to Group B, that more commonly had atypical atrial flutter (p<0.001). Forty-one (87%) patients in Group A and 69 (58%) in Group B presented at least one reconnected PV (p<0.001). Sixty-one (52%) patients in Group B presented at least one reconnected atrial line (left isthmus or roof). Patients without any reconnected PV (n=54, 33%) more frequently experienced persistent AF (p<0.001), had longer AF duration (p=0.047) and larger left atrial volume (p<0.001). Twenty-five patients (15%) with no PV and/or line reconnection did not significantly differ, concerning baseline characteristics, compared to those with at least one reconnected ablation site.

CONCLUSION

As in the general AF population undergoing catheter ablation, PV reconnection is frequent in patients with HF and symptomatic recurrence. However, one third of patients presented arrhythmic recurrences even in the absence of PV reconnection, highlighting the importance of the underlying atrial substrate.

Catheter ablation of persistent atrial fibrillation : Circumferential pulmonary vein ablation: beneficial effect of an additional linear lesion at the roof of the left atrium on the long-term outcome

BACKGROUND

Circumferential pulmonary vein ablation is still the standard approach in patients with persistent atrial fibrillation. However, the results are not very favourable and more complex ablation strategies are the subject of current controversy. Therefore, we have evaluated the effect of an additional linear lesion at the roof of the left atrium on the long-term outcome.

METHODS

A total of 125 patients with symptomatic persistent atrial fibrillation underwent a circumferential pulmonary vein ablation procedure in combination with an additional linear lesion at the roof of the left atrium (group A). The long-term follow-up data was compared to 125 patients with similar clinical characteristics who underwent circumferential pulmonary vein ablation without an additional linear lesion at the roof of the left atrium (group B).

RESULTS

The ablation procedure could be performed as planned in all 250 patients. Three years after catheter ablation, the success rate was 72.0% (no arrhythmia recurrence in 90 out of 125 patients) in group A and 63.2% in group B (no arrhythmia recurrence in 79 out of 125 patients; P = 0.04). There were no major complications.

CONCLUSIONS

Catheter ablation of persistent atrial fibrillation comprising a circumferential pulmonary vein ablation and an additional linear lesion at the roof of the left atrium provides more favourable long-term results than circumferential pulmonary vein ablation alone.

Different dissecting orders of the pulmonary bronchus and vessels during right upper lobectomy are associated with surgical feasibility and postoperative recovery for lung cancer patients

Background

Right upper lobectomy (RUL) for lung cancer with different dissecting orders involves the most variable anatomical structures, but no studies have analyzed its effects on postoperative recovery. This study compared the conventional surgical approach, VAB (dissecting pulmonary vessels first, followed by the bronchus), and the alternative surgical approach, aBVA (dissecting the posterior ascending arterial branch first, followed by the bronchus and vessels) on improving surgical feasibility and postoperative recovery for lung cancer patients.

Methods

According to the surgical approach, consecutive lung cancer patients undergoing RUL were grouped into aBVA and VAB cohorts. Their clinical, pathologic, and perioperative characteristics were collected to compare perioperative outcomes.

Results

Three hundred one patients were selected (109 in the aBVA cohort and 192 in the VAB cohort). The mean operation time was shorter in the aBVA cohort than in the VAB cohort (164 vs. 221 min, P < 0.001), and less blood loss occurred in the aBVA cohort (92 vs. 141 mL, P < 0.001). The rate of conversion to thoracotomy was lower in the aBVA cohort than in the VAB cohort (0% vs. 11.5%, P < 0.001). The mean duration of postoperative chest drainage was shorter in the aBVA cohort than in the VAB cohort (3.6 vs. 4.5 days, P = 0.001). The rates of postoperative complications were comparable (P = 0.629). The median overall survival was not arrived in both cohorts (P > 0.05). The median disease-free survival was comparable for all patients in the two cohorts (not arrived vs. 41.97 months) and for patients with disease recurrences (13.25 vs. 9.44 months) (both P > 0.05). The recurrence models in two cohorts were also comparable for patients with local recurrences (6.4% vs. 7.8%), distant metastases (10.1% vs. 8.3%), and both (1.8% vs. 1.6%) (all P > 0.05).

Conclusions

Dissecting the right upper bronchus before turning over the lobe repeatedly and dissecting veins via the aBVA approach during RUL would promote surgical feasibility and achieve comparable postoperative recovery for lung cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40880-017-0220-9) contains supplementary material, which is available to authorized users.

Catheter ablation of atrial fibrillation facilitated by preprocedural three-dimensional transesophageal echocardiography: Long-term outcome

AIM

To evaluate the long-term outcome of catheter ablation of atrial fibrillation (AF) facilitated by preprocedural three-dimensional (3-D) transesophageal echocardiography.

METHODS

In 50 patients, 3D transesophageal echocardiography (3D TEE) was performed immediately prior to an ablation procedure (paroxysmal AF: 30 patients, persistent AF: 20 patients). The images were available throughout the ablation procedure. Two different ablation strategies were used. In most of the patients with paroxysmal AF, the cryoablation technique was used (Arctic Front Balloon, CryoCath Technologies/Medtronic; group A2). In the other patients, a circumferential pulmonary vein ablation was performed using the CARTO system [Biosense Webster; group A1 (paroxysmal AF), group B (persistent AF)]. Success rates and complication rates were analysed at 4-year follow-up.

RESULTS

A 3D TEE could be performed successfully in all patients prior to the ablation procedure and all four pulmonary vein ostia could be evaluated in 84% of patients. The image quality was excellent in the majority of patients and several variations of the pulmonary vein anatomy could be visualized precisely (e.g., common pulmonary vein ostia, accessory pulmonary veins, varying diameter of the left atrial appendage and its distance to the left superior pulmonary vein). All ablation procedures could be performed as planned and almost all pulmonary veins could be isolated successfully. At 48-mo follow-up, 68.0% of all patients were free from an arrhythmia recurrence (group A1: 72.7%, group A2: 73.7%, group B: 60.0%). There were no major complications.

CONCLUSION

3D TEE provides an excellent overview over the left atrial anatomy prior to AF ablation procedures and these procedures are associated with a favourable long-term outcome.

Right atrium positioning for exposure of right pulmonary veins during off-pump atrial fibrillation ablation

OBJECTIVES

Concomitant surgical ablation of atrial fibrillation (AF) is recommended for patients undergoing off-pump coronary revascularization in the presence of this arrhythmia. Achievement of optimal visualization of pulmonary veins while maintaining stable haemodynamic conditions is crucial for proper completion of the ablation procedure. This study evaluates the safety and feasibility of right atrial positioning using a suction-based cardiac positioner as opposed to compressive manoeuvres for exposure during off-pump surgical ablation for AF.

METHODS

Thirty-four consecutive patients underwent pulmonary vein isolation, ganglionated plexi ablation and left atrial appendage occlusion during off-pump coronary artery bypass grafting. Right atrial suction positioning was used to visualize right pulmonary veins. Safety and feasibility end points were analysed intraoperatively and in the early postoperative course.

RESULTS

In all patients, right atrial positioning created optimal conditions to complete transverse and oblique sinus blunt dissection, correct placement of a bipolar ablation probe, detection and ablation of ganglionated plexi and conduction block assessment. In all patients, this entire right-sided ablation procedure was completed with a single exposure manoeuvre. Feasibility end points were achieved in all study patients.

CONCLUSIONS

This report documents the safety and feasibility of right atrial exposure using a suction-based cardiac positioner to complete ablation for AF concomitant with off-pump coronary revascularization. This technique may be widely adopted to create stable haemodynamic conditions and optimal visualization of the right pulmonary veins.

Amplatzer vascular plug in occlusion of a pulmonary arteriovenous malformation

Pulmonary arteriovenous malformation is a rare condition with abnormal communication of the pulmonary artery with the pulmonary vein. It is associated with significant morbidity and mortality when patients develop complications. Patients with symptomatic pulmonary arteriovenous malformation should be considered for intervention. We describe the case of a 54-year-old woman with a large right pulmonary arteriovenous malformation who presented with right chest pain due to hemothorax. She underwent successful embolotherapy with an Amplatzer plug.

Catheter ablation of paroxysmal atrial fibrillation: circumferential pulmonary vein ablation: success rates with and without exclusion of areas adjacent to the esophagus

BACKGROUND

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory paroxysmal atrial fibrillation. Circumferential pulmonary vein ablation is still the standard approach in these patients. The occurrence of an atrioesophageal fistula is a rare but life-threatening complication after such ablation procedures. This is due to the fact that the esophagus does frequently have a very close anatomical relationship to the left or right pulmonary vein ostia. The aim of our study was to evaluate whether the exclusion of areas adjacent to the esophagus does have a significant effect on the success rate after circumferential pulmonary vein ablation.

METHODS

Two hundred consecutive patients [121 men, 69 women; mean age 59.1 years (SD ± 11.3 years)] with symptomatic paroxysmal atrial fibrillation underwent a circumferential pulmonary vein ablation procedure (using the CARTO- or the NAVX-system). In 100 patients, a complete circumferential pulmonary vein ablation was attempted regardless of the anatomical relationship between the ablation sites and the esophagus (group A). In the remaining 100 patients, the esophagus was marked by a special EP catheter and areas adjacent to the esophagus were excluded from the ablation procedure. After discharge, patients were scheduled for repeated visits at the arrhythmia clinic at 1, 3, 6, 9, 12, 24 and 36 months after the ablation procedure.

RESULTS

The ablation procedure could be performed as planned in all 200 patients. In group A, all pulmonary veins could be isolated successfully in 88 out of 100 patients (88%). A mean number of 3.9 pulmonary veins (SD ± 0.37 PVs) were isolated per patient. The 12 cases of an incomplete pulmonary vein isolation were due to poorly accessible pulmonary vein ostia. In group B, all pulmonary veins could be isolated successfully in only 58 out of 100 patients (58%; P < 0.01). A mean number of 3.5 PVs (SD ± 0.6 PVs) were isolated per patient (P < 0.01). This was mostly due to a close anatomical relationship to the esophagus. The ablation strategy had to be modified in 46/100 patients in group B because of a close anatomical relationship between the right (n = 25) or left (n = 21) pulmonary vein ostia and the esophagus. One year after the ablation procedure, 87% of patients in group A (87/100) and 79% of patients in group B (79/100) were free from an arrhythmia recurrence (P = 0.19). Three years after catheter ablation, the success rate was 80% (no arrhythmia recurrence in 80 out of 100 patients) in group A and 66% in group B (no arrhythmia recurrence in 66 out of 100 patients; P = 0.04). There were no major complications during long-term follow-up.

CONCLUSIONS

The exclusion of areas adjacent to the esophagus results in a markedly higher percentage of incompletely isolated pulmonary veins after circumferential pulmonary vein ablation procedures. This results in a significantly higher arrhythmia recurrence rate during long-term follow-up.

Catheter ablation of persistent atrial fibrillation : Beneficial effect of a short-term adjunctive amiodarone therapy on the long-term outcome

BACKGROUND

Catheter ablation has become the first line therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Circumferential pulmonary vein ablation is still the standard approach in these patients. However, the results are not very favorable (especially in patients with persistent atrial fibrillation). Therefore, more complex ablation strategies and the usefulness of (short-term) adjunctive antiarrhythmic drug therapy are a matter of discussion. The aim of this study was to analyze whether short-term amiodarone therapy after catheter ablation (3 months) has a positive effect on the success rates after circumferential pulmonary vein ablation in patients with persistent atrial fibrillation.

METHODS

A total of 230 consecutive patients with symptomatic persistent atrial fibrillation underwent a circumferential pulmonary vein ablation procedure (using the NAVX or CARTO system). Catheter ablation of the right or left atrial isthmus and a linear lesion in the roof of the left atrium were only performed in selected patients with documented episodes of atrial fibrillation. In 115 patients, a short-term adjunctive antiarrhythmic drug therapy with amiodarone was initiated immediately prior to the ablation procedure (for the first 3 months group A). In the remaining 115 patients, no antiarrhythmic drug therapy was administered except for beta blockers (group B).

RESULTS

Out of 115 patients 19 (16.5%) in group A and 34 (29.6%) in group B experienced an arrhythmia recurrence within the first 3 months after ablation requiring electrical cardioversion (P = 0.03; blanking period). One year after the ablation procedure 81.7% of patients in group A (94/115) and 73.0% of patients in group B (84/115) were free from further arrhythmia recurrences (P = 0.16). The success rate 2 years after catheter ablation was 76.5% (no arrhythmia recurrence in 88/115 patients) in group A and 63.5% in group B (no arrhythmia recurrence in 73/115 patients; P = 0.04). There were no major complications during long-term follow-up.

CONCLUSION

Adjunctive short-term amiodarone therapy improves the success rate after catheter ablation of persistent atrial fibrillation during long-term follow-up. This might be due to a decreased incidence of early arrhythmia recurrences after catheter ablation of atrial fibrillation and an improved reverse remodelling process.

Catheter ablation of persistent atrial fibrillation : Long-term results of circumferential pulmonary vein ablation in combination with a linear lesion at the roof of the left atrium

BACKGROUND

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. However, catheter ablation of persistent atrial fibrillation is still a challenge. Various relatively complex ablation strategies exist and their results are not very favorable. Therefore, the aim of our study was to evaluate a well-defined reasonable approach to catheter ablation of persistent atrial fibrillation. The strategy consisted of a circumferential pulmonary vein ablation in combination with a linear lesion at the roof of the left atrium.

METHODS

A total of 150 patients with symptomatic persistent atrial fibrillation were enrolled in this study. All patients underwent catheter ablation of persistent atrial fibrillation using the abovementioned approach.

RESULTS

The ablation procedure could be performed as planned in all 150 patients. Five years after catheter ablation, the success rate was 71.3% (no arrhythmia recurrence in 107 out of 150 patients). There were no major complications during long-term follow-up.

CONCLUSION

Catheter ablation of persistent atrial fibrillation can be performed safely and effectively using this ablation strategy providing favorable long-term follow-up results.

Biatrial connection of partial anomalous pulmonary venous return

We describe an extremely rare case of partial anomalous pulmonary venous return in a 3-year-old boy with an abnormal connection between the right upper pulmonary vein and the right middle pulmonary vein, which created biatrial communication hemodynamically. Patch closure on the orifice of the right upper pulmonary vein was performed to avoid distortion or kinking of the right pulmonary veins and the connection.

Adenosine-guided radiofrequency catheter ablation of atrial fibrillation: A meta-analysis of randomized control trials

BACKGROUND

The prognostic significance of adenosine-mediated dormant pulmonary vein conduction, and whether such dormant conduction should be eliminated, remains controversial. We sought to perform a meta-analysis of data from eligible studies to delineate the prognostic impact of adenosine-guided radiofrequency catheter ablation of atrial fibrillation.

METHODS

A systematic literature search was performed using online databases in order to identify relevant studies from January 2004 to September 2016. Ten studies [six observational and four randomized control trials (RCTs)] were included in the analysis.

RESULTS

Five studies (two observational and three RCTs) compared the efficacy of adenosine-mediated elimination of dormant conduction versus no adenosine test. Overall, the adenosine-guided ablation strategy displayed better long-term outcomes as compared with no adenosine testing (RR 1.08, 95% CI 1.01-1.14, p=0.02; Heterogeneity: I²=42%, p: 0.14). The meta-analysis of only RCTs failed to show any differences between the two strategies (RR 1.03, 95% CI 0.96-1.11, p=0.37; Heterogeneity: I² 0%, p: 0.41). Eight studies (five observational and three RCTs) addressed the efficacy of adenosine-induced dormant conduction and additional ablation versus no dormant conduction during adenosine challenge. Overall, a trend towards a better outcome in those without dormant conduction during drug challenge was noted (RR 0.89, 95% CI 0.77-1.03, p=0.11; Heterogeneity: I² 65% p: 0.006). The pooled analysis of RCTs failed to show any differences between the two arms (RR 0.90, 95% CI 0.62-1.30, p= 0.57; Heterogeneity: I² 88%, p: 0.0002).

CONCLUSIONS

Adenosine-guided radiofrequency catheter ablation of atrial fibrillation does not provide additional benefit in terms of freedom of arrhythmia recurrence.

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique : Long-term outcome

BACKGROUND

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation (AF). Cryoablation has been shown to be a safe and effective technique for pulmonary vein (PV) isolation. However, the arrhythmia recurrence rate is high after cryoablation procedures. Radiofrequency catheter ablation has been shown to be an effective strategy for redo procedures in these patients and to provide a favourable outcome during midterm follow-up. The aim of this study was to analyse whether the strategy also provides favourable results during long-term follow-up (5 years).

METHODS

In this study 30 patients (paroxysmal AF: 22 patients, persistent AF: 8 patients) underwent a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (Arctic Front Balloon, Medtronic). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (CARTO; Biosense Webster, Diamond Bar, CA, USA) depending on the intraprocedural findings.

RESULTS

During the repeat procedure, a mean number of 2.9 reconnected PV (SD ± 1.0) were detected. In 20 patients, a segmental approach was sufficient to eliminate the residual PV conduction because only a few PV fibres were recovered (1-3 reconnected PV; group A). In the remaining 10 patients, a circumferential ablation strategy was used because of a complete recovery of the pulmonary vein - left atrial (PV-LA) conduction (group B). All reconnected PV were isolated successfully again. A third or fourth ablation procedure had to be performed in 4 (3 and 1, respectively) patients (13.3%). At 5‑year follow-up, 66.7% of all patients were free from an arrhythmia recurrence (20 out of 30). There were no major complications during long-term follow-up.

CONCLUSION

In patients with an initial circumferential PV isolation using the cryoballoon technique, a repeat ablation procedure can be safely and effectively performed using radiofrequency catheter ablation providing good long-term follow-up results.

Imatinib relaxes the pulmonary venous bed of guinea pigs

Background

Recently, the IMPRES study revealed that systemic imatinib improves exercise capacity in patients with advanced pulmonary arterial hypertension. Imatinib blocks the tyrosine kinase activity of the platelet-derived growth factor (PDGF)-receptor (PDGFR), acts antiproliferative and relaxes pulmonary arteries. However so far, the relaxant effects of imatinib on pulmonary veins (PVs) and on the postcapillary resistance are unknown, although pulmonary hypertension (PH) due to left heart disease (LHD) is most common and primarily affects PVs. Next, it is unknown whether activation of PDGFR alters the pulmonary venous tone. Due to the reported adverse effects of systemic imatinib, we evaluated the effects of nebulized imatinib on the postcapillary resistance.

Methods

Precision-cut lung slices (PCLS) were prepared from guinea pigs. PVs were pre-constricted with Endothelin-1 (ET-1) and the imatinib-induced relaxation was studied by videomicroscopy; PDGF-BB-related vascular properties were evaluated as well. The effects of perfused/nebulized imatinib on the postcapillary resistance were studied in cavine isolated perfused lungs (IPL). Intracellular cAMP/cGMP was measured by ELISA in PVs.

Results

In PCLS, imatinib (100 μM) relaxed pre-constricted PVs (126%). In PVs, imatinib increased cAMP, but not cGMP and inhibition of adenyl cyclase or protein kinase A reduced the imatinib-induced relaxation. Further, inhibition of K_ATP-channels, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathrm{BK}}_{\mathrm{Ca}}^{2+} $$\end{document}BKCa2+-channels or K_v-channels diminished the imatinib-induced relaxation, whereas inhibition of NO-signaling was without effect. In the IPL, perfusion or nebulization of imatinib reduced the ET-1-induced increase of the postcapillary resistance. In PCLS, PDGF-BB contracted PVs, which was blocked by imatinib and by the PDGFR-β kinase inhibitor SU6668, whereas inhibition of PDGFR-α (ponatinib) had no significant effect. Conversely, PDGFR-β kinase inhibitors (SU6668/DMPQ) relaxed PVs pre-constricted with ET-1 comparable to imatinib, whereas the PDGFR-α kinase inhibitor ponatinib did not.

Conclusions

Imatinib-induced relaxation depends on cAMP and on the activation of K⁺-channels. Perfused or nebulized imatinib significantly reduces the postcapillary resistance in the pre-constricted (ET-1) pulmonary venous bed. Hence, nebulization of imatinib is feasible and might reduce systemic side effects. Conversely, PDGF-BB contracts PVs by activation of PDGFR-β suggesting that imatinib-induced relaxation depends on PDGFR-β-antagonism. Imatinib combines short-term relaxant and long-term antiproliferative effects. Thus, imatinib might be a promising therapy for PH due to LHD.

Pulmonary vein thrombosis in a patient with polycythemia vera

Pulmonary vein thrombosis (PVT) is a rarely encountered disease entity with varied clinical presentations. It is usually associated with lung carcinoma, lung surgeries and as a complication of the radiofrequency catheter ablation procedure for atrial fibrillation. Its clinical manifestations can vary from mild hemoptysis to lung infarction with hemodynamic compromise. A 76-year-old male presented with a 2-d history of pleuritic left sided chest pain. His past medical history included polycythemia vera, atrial fibrillation, coronary artery disease, pulmonary embolism and pulmonary hypertension. Chest radiograph was normal, troponins were normal and the 12-lead electrocardiogram did not show any ischemic changes. A computerized tomography pulmonary angiogram revealed a filling defect in the left lower lobe pulmonary vein. He was treated with subcutaneous enoxaparin and his symptoms improved. This case highlights a rare etiology of chest pain and the first reported case of the association of polycythemia vera and pulmonary vein thrombosis. A high index of suspicion is required for appropriate diagnostic work up. PVT can mimic pulmonary embolism. The diagnostic work up and treatment strategies depend on acuity of presentation.

Complications associated with radiofrequency ablation of pulmonary veins

OBJECTIVE

Radiofrequency ablation is an efficacious alternative in patients with symptomatic atrial fibrillation who do not respond to or are intolerant to at least one class I or class III antiarrhythmic drug. Although radiofrequency ablation is a safe procedure, complications can occur. Depending on the location, these complications can be classified into those that affect the pulmonary veins themselves, cardiac complications, extracardiac intrathoracic complications, remote complications, and those that result from vascular access. The most common complications are hematomas, arteriovenous fistulas, and pseudoaneurysms at the puncture site. Some complications are benign and transient, such as gastroparesis or diaphragmatic elevation, whereas others are potentially fatal, such as cardiac tamponade.

CONCLUSION

Radiologists must be familiar with the complications that can occur secondary to pulmonary vein ablation to ensure early diagnosis and treatment.

Unusual meandering right upper lobe pulmonary vein draining into right middle lobe pulmonary vein: a case report

Meandering right pulmonary vein is a rare vascular anomaly that requires accurate diagnosis to avoid unnecessary procedures and unintended vascular injury during operation. We describe an unusual meandering right upper lobe pulmonary vein draining into the left atrium via the right middle lobe pulmonary vein.