Vein Connection Research Articles

Circulation: Arrhythmia and Electrophysiology Editors’ Picks

<i>Circulation: Arrhythmia and Electrophysiology</i> Editors’ Picks

Oclusión percutánea de la vena vertical con un Amplatzer® Vascular Plug. Informe de un caso

The use of the Amplatzer®Vascular Plug has diversified and has been described successfully in different clinical settings. We describe another application for this device, presenting the case of a patient with a history of correction of total anomalous connection of pulmonary veins, who underwent occlusion of the unligated vertical vein with the Amplatzer®Vascular Plug.

Cine acquisition strategies for visualizing atrial septal defects by CMR

Background Atrial septal defects (ASDs) may escape detection before adulthood, particularly those in unusual locations, which may elude echocardiographic visualisation. CMR is established for the quantification of shunt flow and, if appropriately acquired, can provide clear visualisation of ASDs and adjacent structures to inform decisions regarding intervention. Our objective is to recommend cardiovascular magnetic resonance (CMR) cine acquisition strategies suitable for the visualisation of the less common as well as the common types of ASD. Methods In the CMR Unit of a tertiary referral centre for adults with congenital heart disease we retrospectively reviewed the CMRs of patients with unoperated ASDs over a 3 year period to assess the suitability of cine acquisition strategies for the visualisation of different types of ASD and any associated anomalies of pulmonary venous connection. Results 157 patients with unoperated ASDs had CMR studies in 3 years. If already suspected, we had routinely acquired an ‘atrial stack’ of cines, meaning a contiguous stack, 5mm thick, parallel to the routine ventricular short axis (SA) stack, stepping backward from the basal ventricular plane until the superior vena cava was identifiable. This orientation visualized ostium secundum ASDs well (n=117), and was also good for inferior sinus venosus defects (n=2) and unroofed coronary sinus (n=3). In superior sinus venosus defects (n=21), a transaxial cine stack was found to give clearer visualisation of both the defect and any associated anomalous pulmonary vein connection(s) (n=20, plus 4 anomalous connections identified with secundum ASDs). The transaxial cine orientation was also the more suitable one for atrio-ventricular septal defects (AVSD, n=15) as it depicted insertions of the A-V valve leaflets adjacent to the defect(s). Conclusions In patients with suspected ASDs, we recommend the acquisition of an atrial SA cine stack and a transaxial cine stack that covers atrial to aortic arch levels. Additional oblique cines aligned with the defect can supplement these, as indicated in the table. Funding None.

Neonatal screening to detect critical congenital cardiac disease. A revolution in pediatrics

There is solid evidence that demonstrate the usefulness of routine oxygen saturation testing in every apparently healthy newborn after 24 hours of life and before 48 hours. This procedure is known as “newborn screening for critical congenital heart disease” and serves to detect timely those congenital structural cardiac malformations with hypoxema, such as heart syndrome, pulmonary valve atresia, truncus arteriosus, total anomalous pulmonary vein connection, complete transposition of the great arteries, tetralogy of Fallot and tricuspid valve atresia. This test has been included in the mandatory neonatal screening panel of many countries and its generalization all over the world, seems imminent.

Ultrasound Mapping of Arterial and Venous Patterns of the Upper Extremities in Patients with End-Stage Renal Disease

Objectives We sought to (1) to determine prevalence of high brachial artery bifurcation, forearm cephalic-arm cephalic connection, forearm cephalic-arm basilic vein alternate connection, and levels of basilic-brachial vein junction; and (2) to compare average diameters of forearm and arm cephalic and basilic venous segments according to the results of ultrasound mapping of the upper extremities (UE). Methods Consecutive ultrasound mappings were performed in 100 UE of 23 women, 69 ± 12 (47–84), and 27 men, 62 ± 12 (34–79) years of age. Brachial, radial and ulnar arteries and cephalic and basilic veins were scanned from wrist to axilla. Results Brachial artery bifurcation at the proximal/mid arm was noted in 25 UE of 18 subjects. Arm (a) or forearm (f) cephalic (ce) or basilica (ba) veins were absent in 18 (ace), 15 (fce), 10 (aba), and 14 (fba) UE, respectively. A forearm cephalic-arm cephalic vein connection was noted in 67 UE; of these, 9 (13.6%) also had a significant forearm cephalic-arm basilic connection. A primary forearm cephalic-arm basilic connection was noted in 5 UE, one with a secondary connection to the arm cephalic vein. The basilic joined the brachial vein at the proximal, proximal-mid, mid, mid-distal and distal arm in 29, 17, 26, 4, and 2 UE; a complex connection to radial/ulnar veins was noted in 14 UE. Average diameters were 4.2 ± 1.4 (1.2–7.8), 3.1 ± 1.1 (0.6–6.3), 2.9 ± 0.9 (1.4–4.9), and 2.2 ± 0.9 (0.7–4.5) mm for the arm basilic, arm cephalic, forearm cephalic and forearm basilic veins. Conclusions A significant prevalence of anatomical anomalies was noted, justifying mapping of the upper extremity vasculature prior to planning an arteriovenous fistula or prosthetic graft in patients with end-stage renal disease.

Contrast study of cardiac output and oxygen metabolism in infants with congenital heart disease after cardiopulmonary bypass

To conduct a contrast study of postoperative cardiac output and oxygen metabolism in infants with congenital heart disease undergoing cardiopulmonary bypass. Retrospective analysis was conducted for 55 case of congenital heart disease from January 2006 to January 2009 at our hospital. There were 34 males and 21 females. And they were divided into simple group (n = 30) and complex group (n = 25). In the simple group, all had pulmonary arterial hypertension and there were simple ventricular septal defect (VSD) (n = 15), atrial septal defect (ASD) + VSD (n = 9) and ASD + VSD + patent ductus arteriosus (PDA) (n = 6); in the complex group, there were tetralogy of Fallot (TOF) (n = 12), double outlet of right ventricular with pulmonary stenosis (DORV) (n = 8) and total anomalous pulmonary vein connection (TAPVC) (n = 5). All completed cardiopulmonary bypass procedures under venous injection and inhalation anesthesia. Cardiac outputs were measured by the thermodilution method with a 4 F Swan-Ganz floating catheter at operation completion and postoperative 4, 8, 12, 24, 48, 72 h. Arterial and mixed venous blood specimens were collected through radial artery and floating catheter for blood gas analysis. The parameters of cardiac index (CI), oxygen supply index (DO₂I), oxygen consumption index (VO₂I) and oxygen intake rate (O₂ER) were calculated with PHLIPS M: 8007 A. (1) At postoperative 8 h, ScVO₂ was minimal (simple group 68% ± 14%; complex group 65% ± 9%); and postoperative 12 h CI (L×min⁻¹×m⁻²) bottomed out (simple group 3.29 ± 0.65; complex group 2.88 ± 0.54); DO₂I (492 ± 153) ml×min⁻¹×m⁻² and VO₂I(138 ± 45) ml×min⁻¹×m⁻² were minimal in complex group. (2) DO₂I, VO₂I, O₂ER and ScVO₂ changed with CI and simple group was higher than complex group. (3) Postoperative CI showed a positive correlation with DO₂I, VO₂I, ScVO₂ and a negative correlation with O₂ER. The postoperative cardiac output decreases and oxygen metabolism becomes disordered in congenital heart disease. It is most obvious at postoperative 12 h. And complex CHD is more serious. Cardiac output should be actively boosted to improve tissue oxygen metabolism during an early postoperative period.

Partial Anomalous Connection of Both Superior Pulmonary Veins

Several patterns of anomalous pulmonary venous drainage have been described in the literature, and bilateral partial pulmonary anomalous vein connection (PAPVC) has been described as a rare congenital cardiac anomaly. We report an unusual type of bilateral PAPVC, involving both the superior right and left pulmonary veins draining into the left brachiocephalic vein in a young adult who was symptomatic with dyspnea and a dry cough.

Frequency and Outcomes of Cardiac Operations and Catheter Interventions in Turner Syndrome

Cardiac malformations occur commonly in Turner syndrome (TS), but the outcomes of cardiac operations and catheter-based procedures are unknown. The Pediatric Cardiac Care Consortium database was queried for individuals with TS and other female subjects without genetic abnormalities or syndromes (non-TS [NTS]). Procedures for left-sided heart lesions represented most TS procedures (95.2%). Three hundred ninety-eight patients with TS who underwent 637 of these procedures of interest were compared with 25,913 female NTS subjects who underwent 56,625 procedures. The numbers of procedures per admission (1.47 vs 1.61, p = 0.01) and per patient (1.85 vs 2.16, p <0.0001) were significantly lower in patients with TS. Procedures for cyanotic heart disease other than hypoplastic left heart (HLH) were performed 4.5-fold less frequently in patients with TS. Patients with TS and NTS subjects had equivalent hospital lengths of stay, except for patients with TS who underwent hypoplastic aortic arch operations, patent ductus arteriosus ligation, pulmonary artery balloon dilation, balloon atrial septostomy, and catheter closure of atrial septal defects. There were 34 deaths among patients with TS and 1,795 among NTS subjects (8.6% vs 7.2%, p = 0.30). When HLH was excluded, mortality was lower in the TS group (3.9% vs 6.5%, p = 0.05). Operations for partial anomalous pulmonary venous connection (14.3% vs 1.9%, p = 0.03) and HLH (90.4% vs 70.5%, p = 0.08) were more likely to result in death in patients with TS. In conclusion, given generally comparable lengths of stay and numbers of procedures as well as uniformly excellent results, these data suggest that the diagnosis of TS does not increase the utilization of limited health care resources. Operations for HLH and partial anomalous pulmonary vein connection carry additional risk for those with TS. These results will permit risk stratification, prognostication, and counseling of individuals with TS and their families.

Prenatal diagnosis of abnormal course of umbilical vein and ductus venosus agenesis: Report of three cases

Ductus venosus connecting the portal and embryonic venous circulation into the inferior vena cava has a crucial role in fetal circulation. The absence of ductus venosus is a rare anomaly, in which the umbilical vein connection to the venous system may be extrahepatic, bypassing the liver or intrahepatic via the portal venous system. We report three cases of ductus venosus agenesis with associated anomalies. In two of them the connection was directly to the right atrium, whereas the umbilical vein drained to the left internal iliac artery in the third case.

Arterio-venous fistula with pseudoaneurysm of renal artery

The authors describe a rare but potentially severe, sometimes even life-threatening complication occurring after various invasive renal interventions. The cause that gives rise to a fistula formation between close branches of renal artery and vein is an injury of these vessels during resection of a localised renal tumour, renal biopsy, percutaneous nephrostomy, and even blunt injury of the kidney. Blood flows under pressure from renal artery, pushes the surrounding renal parenchyma open, and creates a cavity varying in size and shape. This pseudoaneurysm may communicate with the collecting system of the kidney, in which case it may lead to haematuria, one of the typical symptoms of arteriovenous fistula. The authors observed this complication in 8 patients (6 males aged from 56 to 70, average 61.7, and two females aged 28 and 54). In 7 patients, the fistula developed after resection of a localised renal tumour, in one patient after percutaneous nephrolitholapaxy of a stone in the kidney. The fistulae manifested themselves between 7 an 21 days after surgery by massive haematuria in 4 patients and by intermittent macroscopic haematuria in 3 patients. In one patient the fistula was asymptomatic while the pseudoaneurysm at the place of pathological connection of renal veins was found during ultrasonographic examination after renal resection. In all patients, the diagnosis of arteriovenous fistula and pseudoaneurysm of renal artery was achieved by ultrasonographic and/or CT examinations. The highest diagnostic value can be ascribed to digital subtraction renoangiography by Seldinger method that subsequently allowed active treatment by introducing an endovascular coil. By this method we cured 5 fistulae. In two patients, urgent nephrectomies were needed because of massive life-threatening haematuria. One of arteriovenous fistulae underwent spontaneous thrombosis. The symptomatic arteriovenous fistula requires fast and precise diagnosis subsequently enabling efficient treatment. Endovascular manipulation is a method allowing the preservation of kidney affected by arteriovenous fistula with renal artery pseudoaneurysm (Fig. 7, Ref. 21).

Partial anomalous pulmonary venous connection with intact atrial septum in a child with ventricular septal defect: a case report.

Partial anomalous pulmonary vein connection (PAPVC) is a rare congenital abnormal cardiac defect involving the pulmonary veins draining into the right atrium (RA) directly or indirectly by venous connection. Ninety percent of PAPVCs are accompanied by atrial septal defect (ASD). To our knowledge, there is no previous report of PAPVC with ventricular septal defect (VSD) without ASD in Korea, and in this paper, we report the first such case. A 2-day-old girl was admitted into the Chonnam National University Hospital for evaluation of a cardiac murmur. An echocardiogram revealed perimembranous VSD without ASD. She underwent patch closure of the VSD at 5 months of age. Although the VSD was completely closed, she had persistent cardiomegaly with right ventricular volume overload, as revealed by echocardiography. Three years later, cardiac catheterization and chest computed tomography revealed a PAPVC, with the right upper pulmonary vein draining into the right SVC. Therefore, correction of the PAPVC was surgically performed at 3 years of age. We conclude that it is important to suspect PAPVC in patients with right ventricular volume overload, but without ASD.

Impact of the Evolution of the Fontan Operation on Early and Late Mortality: A Single-Center Experience of 405 Patients Over 3 Decades

Postoperative mortality has decreased in patients undergoing the Fontan operation, and the determinants of such mortality may also have changed significantly. We conducted a study intended to focus on clarifying the determinants of mortality in 405 consecutive patients who had undergone a Fontan operation (62 patients after an atriopulmonary connection, 105 after an intra-atrial rerouting, and 238 patients after an extracardiac rerouting) between 1979 and 2010. The overall 1-year, 5-year, 10-year, and 15-year rates of survival were 87.1%, 84.6%, 83.4%, and 81.6%, respectively, and the type of procedure as well as heterotaxy syndrome, ventricular ejection fraction, and atrioventricular valve repair at the time of the Fontan operation were independent predictors of overall mortality (p < 0.05 for all). Heterotaxy syndrome and atrioventricular (AV) valve repair were independent predictors of early (less than 6 months postoperative) mortality and the type of procedure was an independent predictor of late (6 or more months postoperative) mortality (p < 0.05 to 0.01). In the era of intra-atrial rerouting, heterotaxy syndrome was the only independent predictor of total, early, and late mortality (p < 0.05 for all), whereas a low ejection fraction, AV valve repair, and repair of a total anomalous pulmonary vein connection, rather than heterotaxy syndrome, were independent predictors of total or early mortality or both (p < 0.05 for all) in the era of extracardiac rerouting. Even in the modern era of extracardiac rerouting in the Fontan operation, a low ventricular ejection fraction, AV valve dysfunction, or a total anomalous pulmonary vein connection remain significant risk factors for mortality in patients with a single-ventricle physiology.

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

Monochorionic (MC) twin pregnancies are associated with significantly higher morbidity and mortality rates than dichorionic twins. Approximately 50% of MC twin pregnancies develop complications arising from the shared placenta and associated vascular connections. Severe twin-to-twin syndrome (TTTS) is reported to account for approximately 20% of these complications. Inter-twin vascular connections occur in almost all MC placentas and are related to the prognosis and outcome of these high-risk twin pregnancies. The number, size and type of connections have been implicated in the development of TTTS and other MC twin conditions. Three types of inter-twin vascular connections occur: 1) artery to vein connections (AVs) in which a branch artery carrying deoxygenated blood from one twin courses along the fetal surface of the placenta and dives into a placental cotyledon. Blood flows via a deep intraparenchymal capillary network into a draining vein that emerges at the fetal surface of the placenta and brings oxygenated blood toward the other twin. There is unidirectional flow from the twin supplying the afferent artery toward the twin receiving the efferent vein; 2) artery to artery connections (AAs) in which a branch artery from each twin meets directly on the superficial placental surface resulting in a vessel with pulsatile bidirectional flow, and 3) vein to vein connections (VVs) in which a branch vein from each twin meets directly on the superficial placental surface allowing low pressure bidirectional flow. In utero obstetric sonography with targeted Doppler interrogation has been used to identify the presence of AV and AA connections. Prenatally detected AAs that have been confirmed by postnatal placental injection studies have been shown to be associated with an improved prognosis for both twins. Furthermore, fetoscopic laser ablation of inter-twin vascular connections on the fetal surface of the shared placenta is now the preferred treatment for early, severe TTTS. Postnatal placental injection studies provide a valuable method to confirm the accuracy of prenatal Doppler ultrasound findings and the efficacy of fetal laser therapy. Using colored dyes separately hand-injected into the arterial and venous circulations of each twin, the technique highlights and delineates AVs, AAs, and VVs. This definitive demonstration of MC placental vascular anatomy may then be correlated with Doppler ultrasound findings and neonatal outcome to enhance our understanding of the pathophysiology of MC twinning and its sequelae. Here we demonstrate our placental injection technique.

Correlation of Mortality and Location of Arteriovenous Fistula in Hemodialysis Patients

Since the type of vascular access is very important and a significant risk factor for mortality in patients on hemodialysis, the aim of our study was to determine the impact of AVF positioning on the mortality of our patients. The survey was organized as a prospective, clinical and non-randomized study of 538 surgical interventions on 323 patients, which indicates that a large number of patients had more than one fistula. Among these patients, 120 subjects (81 (67.5%) men and 39 (32.5%) women) died during the study period. We analyzed the demographic structure, the site location and type of anastomosis for the arteriovenous fistula, artery and vein lumen and presence of instillation catheters, as well as measuring flow through the fistula and arterial blood pressure. Biochemical parameters thought to have a significant impact on survival were obtained from routine monthly analyses. In patients in whom infection was the cause of death, termino-terminal anastomosis was more frequently present (p=0.035). Variables that were statistically significant predictors of death were elderly individuals (Beta 0.033, p<0.001); patients whose diastolic blood pressure was low (Beta -0.028, p<0.001); and the position of the arteriovenous fistula (distal Beta -0.737, p=0.001; proximal Beta -0.581, p=0.008). Patients with a cubital fistula (p=0.001) had a significantly shorter Kaplan-Meier survival curve. End-to-end artery and vein connection was a significantly more common form of anastomosis in patients who died as a result of infection. Important parameters of mortality in our study were the position of the arteriovenous fistula, age, and the diastolic component of arterial blood pressure.

Pulmonary Arteriovenous Malformations in Heterotaxy Syndrome

We report a surgical approach using hepatic vein-to-azygos vein connection without cardiopulmonary bypass or deep hypothermic circulatory arrest in a patient with heterotaxy syndrome and interrupted inferior vena cava with persistence of pulmonary arteriovenous malformations (PAVMs) after previous Fontan completion. We advocate early performance of hepatic vein-to-azygos vein connection following the Kawashima operation for heterotaxy with functionally univentricular heart and interrupted inferior vena cava. We review the physiology of heterotaxy syndrome with congenital heart disease and justify our approach in the context of a review of previous surgical strategies used in this patient population.

Cavopulmonary pathway modification in patients with heterotaxy and newly diagnosed or persistent pulmonary arteriovenous malformations after a modified Fontan operation

Pulmonary arteriovenous malformations are an important but uncommon complication of cavopulmonary connection, particularly in patients with heterotaxy. Absence of hepatic venous effluent in pulmonary arterial blood seems to be a predisposing factor. Pulmonary arteriovenous malformations are most common after superior cavopulmonary anastomosis, but may develop, progress, or persist in 1 lung after Fontan completion if hepatic venous blood streams completely or primarily to the contralateral lung. Among 53 patients with heterotaxy and inferior vena cava interruption who underwent a modified Fontan procedure from 1985 to 2005, 8 had unilateral streaming of hepatic venous flow and clinically significant pulmonary arteriovenous malformations after hepatic venous inclusion and underwent reconfiguration of the cavopulmonary pathway. In all 8 patients, the hepatic vein-pulmonary artery pathway was contralateral to and offset from the pulmonary artery anastomosis of the single or dominant superior vena cava. Pathway reconfiguration included pulmonary arterial stenting (n=2), revision of the superior vena cava-pulmonary artery connection (n=1), construction of a branched hepatic vein-pulmonary artery conduit (n=2), and surgical or transcatheter construction of a direct hepatic vein-azygous vein pathway (n=5). Hepatic vein-azygous vein connection led to improvement in 4 of 5 patients; other approaches typically did not lead to improvement. Resolution of hypoxemia after cavopulmonary pathway reconfiguration in patients with unilateral pulmonary arteriovenous malformations and hepatic venous flow-streaming after Fontan completion supports the importance of hepatic venous effluent in the pathogenesis of pulmonary arteriovenous malformations and the practice of cavopulmonary pathway revision in such patients. Completion or reconfiguration of the Fontan circulation with direct hepatic vein-azygous vein connection may provide the most reliable mixing and bilateral distribution of hepatic venous blood in this population of patients.

Catheter Ablation in a Patient With Paroxysmal Atrial Fibrillation and Partial Anomalous Pulmonary Vein Connection

Catheter Ablation in a Patient With Paroxysmal Atrial Fibrillation and Partial Anomalous Pulmonary Vein Connection

Partial anomalous pulmonary venous connection of left pulmonary veins to brachiocephalic vein evaluated by multislice computed tomography

Partial anomalous pulmonary venous drainage with intact atrial septum is a rare congenital anomaly. We report the case of a 47-year-old woman who recently had dyspnea on exertion and was found to have pulmonary hypertension, right atrial enlargement and right ventricular enlargement by two-dimensional transthoracic echocardiography. Multislice computed tomography demonstrated anomalous venous drainage of the left lung into the brachiocephalic vein with an intact interatrial septum. This case illustrates the importance of multislice computed tomography in determining extracardiac vascular malformations.

Mouse Models of Congenital Heart Defects

One of the puzzling things about genetic disruptions in mice that affect heart development is the overwhelming number of conotruncal anomalies and the infrequency with which certain other malformations are reported. For instance, venous malformations such as total anomalous pulmonary venous return (TAPVR) or partial anomalous pulmonary venous return (PAPVR) have not been reported in a mutant mouse. Coronary artery anomalies are reported infrequently, and when they are reported it is because they are obvious. Conotruncal anomalies such as common trunk, double-outlet right ventricle, and pulmonary stenosis with overriding aorta are frequently associated with mouse germ line and conditional gene deletions. Although conotruncal malformations represent the highest percentage of congenital heart defects in the human population, TAPVR and PAPVR occur in a significant number of babies. Further, coronary anomalies affecting the stems of the coronary arteries frequently are seen in conotruncal malformations in babies but are rarely reported in mouse models. Article see p 314 Isolated TAPVR is a rare lesion and occurs in only about 1 in 17 000 live births.1 PAPVR is much more common and has been reported in 1 in 160 individuals (0.6%) and 0.4% to 0.7% of postmortem examinations, with 90% of these associated with an atrial septal defect.2 The majority of patients with TAPVR have symptoms of cyanosis and congestion within the first year of life. If left untreated, about 80% would die. In contrast, PAPVR frequently is not discovered until adulthood and is not usually a cause of death. Although the overall incidence of PAPVR in autopsy cases has been estimated to be 0.7%,3 the true prevalence may be higher,4 as several reports have appeared with PAPVR as an incidental finding that in most of these cases is asymptomatic. PAPVR can present as an isolated structural abnormality, but it …

Noninvasive real-time mapping of an incomplete pulmonary vein isolation using electrocardiographic imaging

Establishing entrance and exit block from pulmonary veins is an endpoint for pulmonary vein isolation (PVI) procedures (1). Reestablished pulmonary vein connection is a common cause of atrial fibrillation (AF) recurrence in patients who have previously undergone PVI. Here we provide images from a noninvasive cardiac electrophysiology imaging system (ECGI) performed during PVI. The ECGI procedure has been described previously (2) (3). 250 carbon electrodes were applied to the patient’s torso before a pre-procedural contrast-enhanced CT scan, which provided torso-electrode positions and atrial geometry in the same reference frame. The electrodes were removed, then replaced on the day of the PVI procedure in the same configuration, and remained on the patient throughout the procedure. ECGI performed during the procedure noninvasively generated epicardial isochrone activation maps. After circumferential ablation around the antrum of the right pulmonary veins, a lasso catheter in the right inferior pulmonary vein (RIPV) demonstrated entrance block. However, high-output pacing from within the RIPV captured the atrium, revealing incomplete exit block. Panel A displays the real-time ECGI isochrone map during RIPV pacing, showing earliest activation in the superior-posterior antrum of the RIPV (red is earliest), with radial spread across the posterior LA. A 60-ms delay is seen from the pacing breakthrough (red) to posterior LA (green) activation, consistent with incomplete line of block created by the ablation. The invasive electroanatomic map (Panel B) shows the final ablation lesion set and the additional ablation necessary for exit block from the RIPV (pink marker). This location on the invasive electroanatomic map corresponds closely to the exit site determined by ECGI in Panel A. Panel C shows an ECGI isochrone map during high-output pacing from within the RIPV after the complete ablation. Pacing failed to capture the atrium, and the earliest LA activation in sinus rhythm was near Bachmann’s bundle (red). Posterior LA activation is limited superiorly and inferiorly with lines of block (white dotted lines) corresponding to the ablation lines on the LA roof and posterior wall seen in panel B. Three PV’s also demonstrate electrical isolation (blue). Although the RSPV in Panel C appears to have electrical connection in sinus rhythm, the appearance of activation is due to far-field signal from the posterior right atrium in close proximity. Invasive testing of the RSPV demonstrated entrance and exit block. Rigorous prospective study is needed, but if real-time ECGI can accurately identify areas of incomplete PVI isolation, it may shorten procedure time and improve long-term success rates by pinpointing sites of incomplete linear ablation.