Left Superior Vein Research Articles

Comparing cerebral microembolisation patterns between high power short duration and pulsed field ablation techniques using artificial intelligence based robotic transcranial doppler monitoring

Abstract Thromboembolism is a rare (<1%) complication of atrial fibrillation (AF) ablation , but the incidence of silent ischaemic lesions (SIL) is 5-15% (1). Artificial intelligence (AI)-based robotic transcranial Doppler (r-TCD) enables real-time cerebral embolisation detection. We aimed to investigate the cerebral microembolization signal (MES) load with r-TCD of patients undergoing PF ablation, comparing the number of detected MES-s between 90 W radiofrequency (RFA) "very high power short duration (vHPSD) ablation" and "pulsed field ablation (PFA)" techniques. Our interim analysis included r-TCD registratums of 26 patients. 16 interventions were performed with VHPSD, 10 with PFA, during which we recorded the flow curve of the arteria cerebri media (ACM) bilaterally with r-TCD and analyzed the MES-s quantitatively and qualitatively with AI-based embolisation detection software. Postoperative cranial MRI exams were performed. Continuous variables were compared between the groups using a two-sample t-test, and categorical variables were compared using a Fisher exact test. The MES load by the different pulmonary veins was compared using Wilcoxon test and Bonferroni correction. A p-value below 0,05 was considered significant. The two groups were comparable regarding baseline parameters (mean age: 63 vs.58 p=0,253; EF:59% vs.62 .2% p=0,33). Ablations with vHPSD were significantly longer compared to PFA (88,7 min vs. 54,7 min p<0,001), left atrial time was significantly shorter with PFA (52,1 min vs. 29 min p<0 001), but the fluoroscopic time was significantly longer (5,4 min vs. 9,3 min p=0,009) during ablation with PFA. Neither solid emboli, nor ischaemic lesion or neurological deficit was detected. During the ablations, we saw an average of 246 gas MES-s with PFA and 138 with RFA (p=0,216). During PFA we analyzed the MES load per pulmonary vein: by the left superior vein we detected a median of 56,5 (IQR: 21,5-116,5), by the left inferior there were a median of 23 MES-s (IQR: 4,5 115,5), by the right inferior a median of 32 (IQR: 12-84,5), and by the right superior a median of 22,5(IQR: 8,5-70) respectively, p=0,03. While comparing each veins to each other, by the right vs. left superior vein, the p value resulted 0,01. On an initial sample,we detected known differences in the procedural parameters of the two interventions. There tended to be more MES-s during PFA, but this difference was not significant. Regarding the MES load by the ablation of different pulmonary veins, we found a significant overall difference between the MES load by the four veins, especially between the left and right superior vein. A larger number of interventions and r-TCD registratums is needed to determine the cerebral safety of PFA compared to RFA.

Impact of wall thickness on tissue cooling effect of cryoballoon ablation: Investigation using an experimental heart model

Abstract Background Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein isolation is lacking. Purpose To delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. Methods A left atrial-pulmonary vein model, produced by a 3-dimensional printer using CT data from a patient, was constructed so that porcine thigh muscles of various thicknesses could be fixed and thermocouples could be fixed at locations corresponding to the epicardial side of the pulmonary vein ostium. The model was placed in a 37-degree water bath with a pulmonary vein water flow at a rate that mimicked biological blood flow, and the cryoballoon was advanced into the left superior vein until the vein was completely occluded. Cryofreezing was performed 5 times each for a porcine thigh muscle of 2-, 4-, and 6-mm thickness, and epicardial tissue cooling was monitored as assessed by the mean temperature of 12 evenly distributed thermocouples covering the roof region of the left superior vein. Results Epicardial tissue cooling effects were more in the order of 2-mm, 4-mm, and 6-mm thickness (Figure) with a mean temperature of -41.4 ± 4.2 for 2 mm, -33.0 ± 4.0 for 4 mm, and 8.0 ± 8.7 °C for 6 mm at 180 sec (p for trend < 0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9, 3.9 ± 0.7, 1.3 ± 0.7 °C, p for trend < 0.0001). Conclusion The cooling effect is weaker in the deeper layers during cryobaloon freezing, and longer freezing duration would be recommended in case of thick myocardium.

P231 Cardiac metastasis mimicking a myocardial infarction

Abstract We present the case of a 79 years old male patient affected by a lung squamous cell carcinoma (T4 N0 M1a) diagnosed in december 2018 with a 5x5 cm mass in the inferior lobe of the left lung close to the pericardium and a second 5 cm mass in the apical lobe of the right lung. TT echocardiography at that time was normal. Treatment with gemcitabine was scheduled with slight progression of the disease at the CT scan control in april 2019 when initial invasion of the left inferior pulmonary vein was detected. An ECG performed during routine control revealed the presence of q waves and ST segment elevation in the inferior leads. The patient was asymptomatic about the heart but the blood tests revealed a slight increase of HS Troponin I. We decided to repeat the TT echo, which showed the presence of a rounded mobile mass of about 3x2.5 cm in the left atrium close to the upper left pulmonary vein and another formation of about 5x2 cm infiltrating the inferior wall of the left ventricle that appeared akynetic. Both metastatic and thrombotic origins were debated and anticoagulant therapy with LMWH was started. We chose to perform a TE echocardiography, which confirmed the presence of the rounded mass in the left atrium, enlarged as compared to the TT evaluation. At the 3D reconstruction, it appeared to come from the left inferior pulmonary vein, completely occluding it, and expanding to the left superior vein, narrowing but not closing its orifice. The mass was well delimitated, disomogenous and vacuolated, thus confirming its likely neoplastic origin. From the trans-gastric view, we confirmed the large infiltration of the inferior wall of the left ventricle. General conditions of the patients quickly deteriorated and he experienced an ischemic stroke. At the TT echo re-evaluation the mass in the left atrium was greatly reduced as compared to the previous control. Cardiac metastases are a rare and frequently clinically silent occurrence; However, in a minority of cases they may present with ECG alterations such as ST-T segment modifications. In neoplastic patients an ischaemic ECG pattern not following its typical progression, without typical symptoms of ischaemia should rise the suspicion of a cardiac metastasis. In our case the abnormalities could be caused by a loss of viable myocardium secondary to the infiltrating mass or by a compression of the right coronary artery. In this context the echocardiography, both TT and especially TE, is a valuable tool that allow to recognize the real cause of these abnormalities and provides useful informations that enable to distinguish neoplastic mass from a thrombus. The ischaemic stroke was probably due to an embolization of the mass from the left atrium, as confirmed by its important reduction at the last echo control. Abstract P231 Figure. ECG abnormalities and TE echo alteration

P2849Prevalence and significance of sustained pulmonary vein isolation in repeat AF ablation procedures

Abstract Introduction Pulmonary vein (PV) reconnection is a common cause of relapse after catheter ablation of atrial fibrillation (AF). However, some patients have AF recurrence despite durable PV isolation. The aim of this study was to assess the PV isolation status at the time of a second catheter ablation (redo) procedure, and its relationship with subsequent AF relapse. Methods Consecutive patients with symptomatic drug-resistant AF who underwent redo procedures from January 2006 to December 2017 were identified in a single-center observational registry. Pulmonary vein isolation status was assessed during the electrophysiologic study with a circular mapping catheter. Additional radiofrequency (RF) energy applications were also recorded. AF relapse was defined as symptomatic or documented AF/atrial tachycardia/atrial flutter after a 3-month blanking period. Results We identified 240 patients (77 [32%] females, median age 61 [IQR 53–67] years, 85 [35%] with non-paroxysmal AF) undergoing redo procedures during the study period. At the time of redo, 17 (7%) of the patients presented bidirectional conduction block of all PVs. PV reconnection occurred in 157 (65%) of cases in the left superior vein, 142 (59%) in the left inferior vein, 177 (73%) in the right superior vein, and 163 (68%) in the right inferior vein (table). All of the PVs were reconducted in 91 (38%) patients. Additional RF applications were performed in the left atrium (LA) roof, LA posterior wall, cavotricuspid isthmus, mitral isthmus, superior vena cava, coronary sinus, and left atrial appendage ostium, at the operator's discretion (table 1). Over a median follow-up of 2-years (IQR 1–5), 126 patients (53%) suffered AF recurrence, yielding a mean relapse rate of 17%/year. In multivariate Cox regression analysis, the lack of PV reconnection at the time of redo emerged as an independent predictor of subsequent relapse (HR 1.97, 95% CI 1.12–3.49, p=0.019) even after adjustment for univariate predictors including non-paroxysmal AF, body mass index, female sex, and active smoking. Conclusion In patients undergoing redo AF ablation procedures, less than 10% present with complete PV isolation. Despite being relatively infrequent, this finding is independently associated with greater likelihood of subsequent recurrence, suggesting that other mechanisms, not fully addressed by additional RF applications, are at play.

Pulmonary venous abnormalities encountered on pre-radiofrequency ablation mapping multidetector computed tomography

Multidetector computed tomography (MDCT) elegantly renders pulmonary venous anatomy. With increasing numbers of radiofrequency ablation procedures being performed, there is now a greater emphasis on pre-procedure imaging to delineate this anatomy. Pulmonary venous mapping studies can be performed with or without ECG-gating. However, ECG-gating improves both the quality of 3D images and the accuracy of pulmonary vein (PV) ostial diameter measurements. Including the superior thorax, and not just the left atrium and central PVs, allows visualization of aberrant pulmonary venous drainage to the brachiocephalic veins or superior vena cava. Normally, there are two superior PVs, one right and one left, and two inferior PVs, one right and one left. The right superior vein usually drains the right upper and middle lobe. The left superior vein drains the left upper lobe including the lingula. The inferior veins drain their respective lower lobe. PV anatomy is more variable than pulmonary arterial anatomy, and developmental anomalies are common. This article describes, illustrates and reviews the common anomalies of the PVs in our experience performing over 1000-pre-radiofrequency ablation cardiac MDCT studies. The commonest anomalies are supernumerary or accessory veins (on the right) and a (left) common trunk. More rarely, partial anomalous pulmonary venous return and Cor triatriatum are seen, and rarest of all is total anomalous pulmonary venous return, PV varix and single or multiple vein stenosis or atresia.

Blood stasis may cause thrombosis in the left superior pulmonary vein stump after left upper lobectomy.

BackgroundWe previously reported that arterial infarction of vital organs after lobectomy might occur only after left upper lobectomy and be caused by thrombosis in the left superior pulmonary vein stump. We hypothesized that changes in blood flow, such as blood stasis and disturbed stagnant flow, in the left superior pulmonary vein stump cause thrombosis, and this was evaluated by intraoperative ultrasonography.MethodsFrom July 2013 to April 2014, 24 patients underwent lobectomy in the Steel Memorial Muroran Hospital. During the procedure, an ultrasound probe was placed at the pulmonary vein stump and the velocity in the stump was recorded with pulse Doppler mode. The peak velocity and the presence of spontaneous echo contrast in the stump were evaluated. After the operation, the patients underwent contrast-enhanced CT within 3 months.ResultsThe operative procedures were seven left upper lobectomies, four left lower lobectomies, seven right upper lobectomies, and six right lower lobectomies. Blood flow was significantly slower in the left superior pulmonary vein stump than in the right pulmonary vein stumps. However, that was not significantly slower than that in the left inferior pulmonary vein stump. Spontaneous echo contrast in the pulmonary vein stump was seen in three patients who underwent left upper lobectomy. Of the three patients with spontaneous echo contrast, two patients developed thrombosis in the left superior vein stump within 3 months after the operation. There was no patient who developed arterial infarction.ConclusionsIn patients who underwent left upper lobectomy, intraoperative ultrasonography to evaluate blood flow and the presence of spontaneous echo contrast in the left superior pulmonary vein stump may be useful to predict thrombosis that may cause arterial infarction.Electronic supplementary materialThe online version of this article (doi:10.1186/s13019-014-0159-8) contains supplementary material, which is available to authorized users.

Transesophageal and Contact Ultrasound Echographic Assessments of Pulmonary Vessels in Bilateral Lung Transplantation

Intraoperative transesophageal echocardiographic visualization of the vascular anastomosis of lung grafts can be difficult. The goal of this prospective study was to compare intraoperative transesophageal echocardiography and contact ultrasound. Vessel imaging and Doppler analysis obtained before chest closure by both techniques were compared in 18 bilateral lung transplant recipients. Twenty-four arteries in 36 and 45 pulmonary veins in 72 were recorded using transesophageal echocardiography versus 34 and 60 by contact ultrasound (p = 0.05). Views of the left pulmonary artery (p = 0.04) and of the left superior and inferior pulmonary veins (p = 0.04 and p = 0.02, respectively) were more often obtained with contact ultrasound. Measurements of vessel diameters were similar by both methods except for the left superior vein, which was smaller by the transesophageal approach (p = 0.002). In 1 patient, inferior venous diameters could not be obtained by either method. Nine arterial and 47 venous velocities were recorded by transesophageal echocardiography versus 21 and 33 by contact ultrasound (p = 0.001). Contact ultrasound produced better left pulmonary artery recordings (p = 0.02), whereas transesophageal echocardiography was more effective on venous velocities. Left inferior vein velocity was twofold higher using transesophageal echocardiography (p < 0.001). These results suggest clinicians should exercise caution when making treatment decisions when using transesophageal echocardiography alone.

A 50-Year-Old Woman With a History of Atrial Fibrillation Presents With Acute Dyspnea and Pleuritic Chest Pain

A 50-Year-Old Woman With a History of Atrial Fibrillation Presents With Acute Dyspnea and Pleuritic Chest Pain

How many leads through persistent left superior vein cava and coronary sinus?

In the modern implanting era with progressive expanding indications to resynchronization therapy, upgrading procedure is a relatively common event. Persistent left superior vena cava (PLSVC), the most common venous abnormality, may exacerbate technical difficulties. We describe the procedure of upgrading from a dual chamber pacemaker to resynchronization/defibrillation system with a total of 4 leads through a PLSVC entering a dilated coronary sinus (CS) never described before. The case report, in addition to the description of a unique technical approach, raises a lot of clinical questions about how many leads we can introduce in such a venous structure and inside CS without hemodynamic impact on venous drainage potentially leading to life-threatening situations.

Donor graft outflow venoplasty in living donor liver transplantation

Hepatic venous outflow reconstruction is a key to successful living donor liver transplantation (LDLT) because its obstruction leads to graft dysfunction and eventual loss. Inclusion or reconstruction of most draining veins is ideal to ensure graft venous drainage and avoids acute congestion in the donor graft. We developed donor graft hepatic venoplasty techniques for multiple hepatic veins that can be used in either right- or left-lobe liver transplantation. In left-lobe grafts, venoplasty consisting of the left hepatic vein and adjacent veins such as the left superior vein, middle hepatic vein, or segment 3 vein is performed to create a single, wide orifice without compromising outflow for anastomosis with the recipient's vena cava. In right lobe graft where a right hepatic vein (RHV) is adjacent with a significantly-sized segment 8 vein, accessory RHV, and/or inferior RHV, venoplasty of the RHV with the accessory RHV, inferior RHV, and/or segment 8 vein is performed to create a single orifice for single outflow reconstruction with the recipient's RHV or vena cava. Of 35 venoplasties, 2 developed hepatic venous stenoses which were promptly managed with percutaneous interventional radiologic procedures. No graft was lost due to hepatic venous stenosis. In conclusion, these techniques avoid interposition grafts, are easily performed at the back table, simplify graft-to-recipient cava anastomosis, and avoid venous outflow narrowing.

Quantitative study of nerves of the human left atrium

To quantify and study the distribution of innervation of the left atrium and the pulmonary veins in humans. Damage to cardiac nerves has been hypothesized as the explanation for successful radiofrequency ablation of atrial fibrillation. From January 2003 to September 2003, histologic and quantitative studies of innervation of the left atrium and the pulmonary veins was performed in 43 consecutive necropsied adult hearts (30 men and 3 women; mean age 45.5 +/- 12.4 years). The left atrium was sectioned in 1-cm slices from left to right, with the plane of section perpendicular to the long axis of the heart. Sections of the pulmonary veins at their ostia and sections 1 cm away of this structure also were obtained. Nerve fiber density was counted manually for each case and expressed as the mean number per slice. Numerous epicardial nerve fibers and ganglia having distinct patterns of distribution in the left atrium were found. Nerve density was significantly higher at the ostia of the four pulmonary veins than in their distal part (7.1 +/- 2.1 vs 5.2 +/- 1.3 for left upper pulmonary vein; 6.3 +/- 1.5 vs 5.2 +/- 1.7 for right upper pulmonary vein; 7.4 +/- 2 vs 5.9 +/- 2 for left lower pulmonary vein; 6.7 +/- 1.8 vs 3.9 +/- 1.3 for right lower pulmonary vein). The left superior vein was significantly more innervated than the right inferior vein (12.3 +/- 3 vs 10.6 +/- 1.4). Gradients of innervation were found from right to left (9.8 +/- 4.6 vs 18.5 +/- 6.6, P < .05) and from the front to the rear of the atrium (17.2 +/- 6.4 vs 20.7 +/- 6.5, P < .05). The same heterogeneous distribution was observed at the myocardial level but with thinner nerve fibers, making quantification difficult. Only very thin nerve fibers were present in the endocardium. The human left atrium exhibits several gradients of innervation at discrete sites. These findings may have clinical implications for radiofrequency ablation of atrial fibrillation.

Ultrasonographic Anatomy of Veins Draining the Left Lobe of the Liver

The anatomic variations of the left hepatic vein (LHV) in 182 patients with normal liver functions were analyzed using ultrasonography in order to clarify the feasibility of live related hepatic transplantation (LRHT). LHV was demonstrated in 151 patients (83%). Based on the location of the confluence of the middle hepatic vein (MHV) and LHV and the ramifications of the left medial vein (LMV) and the left superior vein (LSV), the livers were classified into 3 types: a) intrahepatic confluence (42/151 livers, 27.8%); b) extrahepatic confluence (69/151 livers, 45.7%); c) separate insertion (40/151 livers, 26.5%); and 23 subtypes. The length of the common trunk and the intrahepatic common trunk of MHV and LHV and the distance from LMV or LSV to the confluence of MHV and LHV were measured. Overall, the control of LHV in situ for LRHT appeared easy in 34/151 patients (22.5%), while in 44/151 patients (29.1%), the length of free LHV and the common trunk was less than optimal for procurement of a left hepatic lobe graft with complete venous outflow and sufficient extraparenchymal length of LHV.