Junction Of Superior Vena Cava Research Articles

Real-time localization for port-implanted catheter tip by echocardiographic guidance

The clinical data of 23 patients undergoing real-time echocardiography-guided infusion port implantation in the Breast Center of Tsinghua Changgung Hospital in Beijing from January to July 2021 were analyzed. The length of catheter insertion L1 was initially estimated using surface measurement method in all patients. Intraoperatively, transthoracic echocardiography was applied using the parasternal four-chamber view to visualize the catheter image within the right atrium, and the length of catheter insertion L2 was recorded under the guidance of echocardiography. Postoperatively, chest radiographs were taken in the upright position to observe the position of the catheter tip. According to chest CT scans, the ideal length (L) for catheter tip placement was calculated when it was located at the junction of superior vena cava and right atrium. Bland-Altman scatter plot analysis and linear regression fitting test were used on L1 and L2 respectively with L to evaluate the consistency. A total of 23 patients were included in this study, among which one case of left breast cancer patient undergoing breast-conserving surgery had difficulty in identifying the catheter tip position due to residual pleural effusion obscuring the imaging of the cardiac apex four-chamber view. In 22 patients, the results of intraoperative ultrasound imaging were good, including 1 case of catheter ectopic to azygos vein, and 21 cases of right atrial catheter could be detected by ultrasound. Statistical analysis showed that there was a good consistency between L1 and L, L2 and L, and the difference between them was d=0.28 cm (95%CI:-1.76-2.31 cm) and d=0.20 cm(95%CI:-0.84-1.23 cm), respectively, with no statistical significance (P>0.05). In the linear regression model, L2 and L had a higher fit than L1, and the difference was statistically significant (R²=0.954, P<0.001). This study found that real-time echocardiographic localization technique can be applied in adult port surgery to replace X-ray-guided real-time catheter tip detection and adjustment to the optimal position.

Right-sided approach to left bundle branch area pacing combined with atrioventricular node ablation in a patient with persistent left superior vena cava and left bundle branch block: a case report

BackgroundLeft bundle branch area pacing (LBBAP) is an alternative to right ventricular (RV) and biventricular (BiV) pacing in patients scheduled for pace and ablate treatment strategy. However, current delivery sheaths are designed for left-sided implantation, making the right-sided LBBAP lead implantation challenging.Case presentationWe report a case of a right-sided LBBAP approach via right subclavian vein in a heart failure patient with a persistent left superior vena cava scheduled for pace and ablate treatment of refractory atrial flutter. To enable adequate lead positioning and support for transseptal screwing, the delivery sheath was manually modified with a 90-degree curve at the right subclavian vein and superior vena cava junction to allow right-sided implantation. The distance between the reshaping point and the presumed septal region was estimated by placing the sheath on the body surface under fluoroscopy. With the reshaping of the delivery sheath, we were able to achieve LBBAP with relatively minimal torque. Radiofrequency ablation of the atrioventricular node was performed the next day and the pacing parameters remained stable in short-term follow-up.ConclusionWith the modification of currently available tools, LBBAP can be performed with the right-sided approach.

Venous Thrombosis of the Mammary Vein Following Peripherally Inserted Central Catheter for Total Parenteral Nutrition Relying on Ecg Tip Confirmation Technology

Total parenteral nutrition (TPN) is a life-saving therapy for patients who are not able to utilize the gastrointestinal tract. There are several different types of central venous catheters (CVC) used to deliver TPN. To safely deliver hyperosmotic TPN solutions, CVC tip position should be in the in lower superior vena cava (SVC) or at the junction of SVC and right atrium (RA). New techniques such as intravascular electrocardiogram (ECG) are being used for tip confirmation to help facilitate expedient use of PICC lines replacing the need for chest x-ray (CXR) confirmation. We present a case of a TPN patient who had a PICC line placed, and ECG confirmed tip as being in the SVC. The patient developed chest pain with flushing of the PICC prompting surgical service to obtain a CXR. The CXR suggested the line was in the either in mammary vein or aorta and recommended replacement. Interventional radiology flushed a small amount of contrast through the PICC and fluoroscopy confirmed the PICC tip was in the left internal mammary vein with reflux of contrast in the left innominate vein. The left innominate vein was occluded due to thrombosis and vasospasm. The patient required increased level of care (PCU) for 2 days, but was eventually discharged with home total parenteral nutrition and has done well. We conclude that care should be taken when using ECG confirmation for PICC tip placement and we feel that patients requiring hyperosmotic TPN should still require CXR confirmation to ensure tip appropriate tip location.

The Perimetric Protuberance-Periosteal Chondroma

Total parenteral nutrition (TPN) is a life-saving therapy for patients who are not able to utilize the gastrointestinal tract. There are several different types of central venous catheters (CVC) used to deliver TPN. To safely deliver hyperosmotic TPN solutions, CVC tip position should be in the in lower superior vena cava (SVC) or at the junction of SVC and right atrium (RA). New techniques such as intravascular electrocardiogram (ECG) are being used for tip confirmation to help facilitate expedient use of PICC lines replacing the need for chest x-ray (CXR) confirmation. We present a case of a TPN patient who had a PICC line placed, and ECG confirmed tip as being in the SVC. The patient developed chest pain with flushing of the PICC prompting surgical service to obtain a CXR. The CXR suggested the line was in the either in mammary vein or aorta and recommended replacement. Interventional radiology flushed a small amount of contrast through the PICC and fluoroscopy confirmed the PICC tip was in the left internal mammary vein with reflux of contrast in the left innominate vein. The left innominate vein was occluded due to thrombosis and vasospasm. The patient required increased level of care (PCU) for 2 days, but was eventually discharged with home total parenteral nutrition and has done well. We conclude that care should be taken when using ECG confirmation for PICC tip placement and we feel that patients requiring hyperosmotic TPN should still require CXR confirmation to ensure tip appropriate tip location

235Anatomic guided ablation of the right ganglionated plexus is enough for cardiac autonomic denervation in patients with significant bradyarrhythmias

Abstract Background In patients with significant bradyarrhytmias, cardiac denervation is an alternative therapeutic approach. Previous reports proposed different methods (as high frequency ednocardial stimulation of ganglionated plexus and specific atrial electrogram identification) and targets (right and left atrial ganglionated plexus) for adequate denervation. There is no consensus on the best way to perform these procedures, in spite the right atrial ganglia plexus (GP) ablation seeming to be the most contributive to its success. Purpose To assess the results of a purely anatomic approach for ablation of just the right atrial plexus in patients with severe vagal bradyarrhytmias. Methods We enrolled patients referred for ablation of cardiac parasympathetic ganglia, with or without atrial fibrillation ablation. We performed eletroanatomic mapping of the right and left atria and used an irrigated tip catheter for ablation, aiming at the anterior right GP at the right pulmonary veins antrum along with ablation at the superior vena cava junction and the inferior right GP at the posterior aspect of the right inferior pulmonary vein along with ablation of the right aspect of the interatrial septum, between the posterior wall and coronary sinus ostium (Figure 1). We assessed the PW and Wenckenback cycle lengths (CL) pre and post procedure in patients with sinus arrest or AV block, respectively, and the patients had new 24h holter readings at least 30 days from the index procedure. Results We enrolled 12 patients: 9 males (75%), median age of 49,5 years (IQR 36-61,75). All patients had structurally normal hearts. 7 patients had only ablation of the parasympathetic ganglia and 5 patients had simultaneous pulmonary vein isolation for previously documented atrial fibrillation. 7 patients (58,3%) had sinus bradycardia (2 patients had sinus arrest with pauses of 8 and 13 seconds), 2 patients with cardioinhibitory syncope (with pauses of 23 and 28 seconds) and 3 patients had transient high degree AV block. The ablation procedure led to a median sinus rate acceleration of 15 bpm (IQR 3-29), a median decrease of 320 ms in PW (IQR 23,75-609,5) in patients with sinus arrest and a decrease of 80 ms in wenckenback CL (IQR 60-200) in patients with AV block. With a median follow up of 133,50 days (IQR 36-61,75), no patient had recurrence of symptoms or conduction disturbances. Conclusions In selected patients with severe functional paroxysmal bradyarrhytmias, cardiac denervation using an ablation strategy purely based on anatomic aspects and targeting only the right GP, seems to be an effective therapeutic approach. Abstract Figure 1: Abl of right ganglionated plex

Surface measurement, intracardiac electrocardiogram and tracheal bifurcation techniques for locating the catheter tips of totally implantable venous access port

BackgroundThe purpose of our study is to compare the reliability and consistency of three commonly used techniques, which are surface measurement, intracardiac electrocardiogram (IECG) and tracheal bifurcation methods in measuring the tip location of totally implantable venous access port (TIVAP) in the same patient. MethodsThe thirty-five patients scheduled for implantation of TIVAP were included and right subclavian vein was selected for venous access. We used surface measurement method (Group L) to estimate the length and position of catheter before catheterization, and then we used IECG method (Group E) to confirm the position of catheter during catheterization and after catheterization used tracheal bifurcation method by CT (Group T) for measurement. The differences of catheter length measured by three methods were compared by non-parametric Kruskal–Wallis test. Intraclass correlation coefficient (ICC) was used to evaluate the reliability of three methods and Bland-Altman chart was used to evaluate consistency. ResultsThere are no difference in the length of TIVAP catheter between L and T groups (P > 0.05), but they have significant differences comparing with E group (P < 0.05). The three positioning methods have a good consistency (ICC = 0.886, P < 0.05).Through linear regression analysis, the regression equation are: catheter length (mm) = 77.32 + 0.66 × height (cm), 36.25 + 0.81 × height (cm) and 68.82 + 0.70 × height (cm). The distances from catheter tip to the junction of superior vena cava and right atrium measured by IECG (Group E) was closer to the target value. ConclusionsAll three methods can be used to measure the length of TIVAP catheter, and IECG method is the most accurate. And similar to most studies, returning the catheter 20 mm after positioning can avoid catheter entering the right atrium, but we found that 10 mm is a sufficient length to achieve this.

A Study of Malposition of Central Venous Catheter – A Comparative Study between Ultrasound Guided and Anatomical Landmark Technique

Introduction: Central venous catheterization is a routine procedure for long-term infusion therapy and central venous pressure measurement. Sometimes, the catheter tip may be unintentionally placed at the position other than the junction of superior vena cava and right atrium. This is called malposition and can lead to erroneous pressure measurement, increase risk of thrombosis, venous obstruction or other life threatening complications like pneumothorax, cardiac temponade.Objectives: This study aimed to observe the incidence of the malposition and compare the same between ultrasound guided catheterization and blind anatomical landmark technique.Methodology: This study was a prospective comparative study conducted at the intensive care unit of Birat Medical College and Teaching Hospital for two-year duration. All the catheterizations were done either with the use of real time ultrasound or blind anatomical landmark technique. The total numbers of central venous catheterization, the total incidences of malposition were observed. Finally the incidences were compared between real time ultrasound guided technique and blind anatomical landmark technique.Results: In two-year duration of the study, a total of 422 central venous cannulations were successfully done. The real time ultrasound was used for 280 cannulations while blind anatomical landmark technique was used for 162 patients. The study observed various malposition in 36 cases (8.5%). The most common malposition was observed for subclavian vein to ipsilateral internal jugular vein (33.3%) followed by subclavian to subclavian vein (27.8%) and internal jugular to ipsilateral subclavian vein (16.7%). In four patients the catheter had a reverse course in the internal jugular vein while the tip was placed in pleural cavity in three cannulations. There was coiling of the catheter inside left subclavian vein in one patient. The malposition was significantly reduced with the use of the real time ultrasound (P&lt; 0.001). However there is no significant difference in the incidence of the various malposition between ultrasound guidance technique and blind anatomical landmark technique when compared individually.Conclusion: The malposition of the central venous catheter tip was common complication with the overall incidence of 8.5%. The most common malposition was subclavian vein to internal jugular vein. The use of real time ultrasound during the catheterization procedure can significantly reduced the risk of malposition.Birat Journal of Health SciencesVol.2/No.3/Issue 4/Sep- Dec 2017, Page: 277-281

Revisiting thoracic surface anatomy in an adult population: A computed tomography evaluation of vertebral level.

To compare key thoracic anatomical surface landmarks between healthy and patient adult populations using Computed Tomography (CT). Sixteen slice CT images of 250 age and gender matched healthy individuals and 99 patients with lung parenchymal disease were analyzed to determine the relationship of 17 thoracic structures and their vertebral levels using a 32-bit Radiant DICOM viewer. The structures studied were: aortic hiatus, azygos vein, brachiocephalic artery, gastroesophageal junction (GEJ), left and right common carotid arteries, left and right subclavian arteries, pulmonary trunk bifurcation, superior vena cava junction with the right atrium, carina, cardiac apex, manubriosternal junction, xiphisternal joint, inferior vena cava (IVC) crossing the diaphragm, aortic arch and junction of brachiocephalic veins. The surface anatomy of all structures varied among individuals with no significant effect of age. Binary logistic regression analysis showed a significant association between individual health status and vertebral level for brachiocephalic artery (P = 0.049), GEJ (P = 0.020), right common carotid (P = 0.009) and subclavian arteries (P = 0.009), pulmonary trunk bifurcation (P = 0.049), carina (P = 0.004), and IVC crossing the diaphragm (P = 0.025). These observations differ from those reported in a healthy white Caucasian population and from the vertebral levels of the IVC, esophagus, and aorta crossing the diaphragm in an Iranian population. The differences observed in this study provide insight into the effect of lung pathology on specific thoracic structures and their vertebral levels. Further studies are needed to determine whether these are general changes or pathology-specific. Clin. Anat. 30:227-236, 2017. © 2017 Wiley Periodicals, Inc.

Non Surgical Management of Mini Guide Wire Embolism with Self Made Guide Wire Snare

A 5 3 years old male presented in emergency department of local hospital with acute inferior wall myocardial infarction During his initial course of treatment he dev eloped symptomatic bradycardia and 2:1 artioventricular block, for which he was tried for implantation of temporary pacing lead through right subclavian vein with 6 F venous sheath. During the procedure the operator embolized the J-tip mini guide wire in the heart, for which the patient was shifted to our hospital for the management of the embolised guide wire and coronary angiography. The patient was immediately brought to cardiac catheterization laboratory and the position of mini guide wire was located under fluoroscopy. Its upper end was lying near the junction of superior vena cava with right atrium and the lower end was in the right common iliac vein. ContinuedÂ

Bailout innominate vein—right atrial bypass for innominate vein disruption

Disruption of the innominate vein during cardiac surgery is an uncommon emergency, is life threatening, and may result in an extreme severity of superior vena cava syndrome. The innominate vein at the superior vena cava junction was injured, requiring surgical occlusion. As bailout procedure to avoid superior vena cava syndrome, a venous bypass between the innominate vein and the right atrium was constructed. Subsequent three-graft coronary bypass was performed. This conduit was patent at 48 h and four postoperative weeks. The patient did not develop superior vena cava syndrome.

ABSTRACT 503

Background and aims: CVC is widely used in PICU for resuscitation, nutritional support, and long-term vascular access.Young children are more susceptible to mechanical complications of CVC insertion than adolescents or adults.Technical knowledge of deep anatomy minimizes complications and the adequate positioning. Aims: 1) Descriptive analysis of the CVCs inserted in our PICU; 2) Correlation of the adequate position of the CVC by anatomic landmarks and confirmation thorax radiography; 3) Analysis of CVC insertion complications. Methods: Retrospective chart review of all patients admitted in a private,tertiary PICU between July 2012-July 2013.Age, sex, primary reason for CVC insertion, access site, type of catheter, complications and positioning adequacy with thorax radiography were analyzed. Arterial insertion, pneumothorax, thrombosis, catheter infection and obstruction were the complications analyzed. The correct position of the catheter tip in the X-ray was considered in the junction of superior vena cava (SVC)and right atrium.The study was approved by IRB. Results: Records of 141 cannulations were evaluated in 122 patients. Of the 122 patients, 75 (61,5%) were males. Median age was 3,5 years (1 month to 18,3 years). Primary reason for insertion was: absence of peripheric access 56 (45,9%), post-surgical 34 (27,8%), shock 21 (17,2%) and oncologic 11 (9,1%). Malpositions occurred in 15 (10,6%) patients. Access sites were internal jugular vein 74 (52,5%), subclavian vein 10 (7,1%), femoral vein 8(5,7%) and PICC 49 (34,7%). Type of catheters inserted included short-term 86 (70,5%), long-term (7,3%) and PICC (40,1%). There were 2 catheter-related infections,no pneumothorax, 1 arterial insertion, 3 obstructions and 4 catheter-related thrombosis. Conclusions: Incidence of malposition and complications was low in our population when compared with the literature.One reason for lesser complications was the use of ultrasound to guide the venous catheter insertion.

An Echocardiographic Measurement of Superior Vena Cava to Inferior Vena Cava Distance in Patients

In normal pediatric echocardiograms, the distance from the junction of superior vena cava (SVC) and right atrium to inferior vena cava (IVC) and right atrium is linearly related to height. We examine this relation in children listed for heart transplant with idiopathic dilated cardiomyopathy (IDC) compared with the previously defined normal distribution of SVC-IVC to improve matching of heart sizes. Measurements of SVC-IVC and left ventricular end-diastolic diameter in 55 pediatric patients with IDC were correlated with height, weight, and body surface area. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared SVC-IVC in patients with IDC with normal SVC-IVC values from 254 patients. There was a strong linear relation in patients with IDC between SVC-IVC and height (R2=0.84) and a logarithmic relation to weight (R2=0.80). Left ventricular end-diastolic diameter did not correlate with SVC-IVC or any other parameter. In 87% of patients with IDC, SVC-IVC was over 2 SDs above predicted normal values (mean z-score=4.3±2.1). In conclusion, predicted SVC-IVC in patients with IDC was different from published norms (p<0.001). SVC-IVC in pediatric patients with IDC, although linearly related to height, is consistently above normal values.

A Novel Echocardiographic Measurement in Pediatric Heart Transplant Recipients with Dilated Cardiomyopathy: Can We Maximize the Donor Supply?

Purpose In normal pediatric echocardiograms, the distance from the junction of superior vena cava and right atrium to inferior vena cava and right atrium (SVC-IVC) is linearly related to height. We examine this relationship in children listed for heart transplant with dilated cardiomyopathy (DCM) compared to a previously defined normal distribution of SVC-IVC in order to maximize potential donor acceptance. Methods and Materials Measurements of SVC-IVC and left ventricular end-diastolic diameter (LVEDd) in 55 patients (pts) with DCM (age 2 months - 19 years, median 7.8 years) were correlated with height, weight, body surface area (BSA), and BSA0.5. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared DCM to normal SVC-IVC values from 254 pts. Results There was a strong linear relationship in DCM pts between SVC-IVC and height (R2=0.84) and a logarithmic relationship to weight (R2=0.80). LVEDd did not correlate to SVC-IVC or any other parameter. In 89% of DCM pts, SVC-IVC was over 2 standard deviations above predicted normal values (mean z-score = 4.3±2.1). Predicted SVC-IVC in DCM pts was different than published norms (p Conclusions SVC-IVC in pediatric DCM pts, while linearly related to height, is consistently above normal values (figure). When matching pediatric heart recipients to donors, SVC-IVC may help accurately size donor hearts, especially for bicaval anastomosis, and substantially increase the donor pool. [ figure 1 ]

A NOVEL ECHOCARDIOGRAPHIC MEASUREMENT IN PEDIATRIC HEART TRANSPLANT RECIPIENTS WITH DILATED CARDIOMYOPATHY: CAN WE MAXIMIZE THE DONOR SUPPLY?

Purpose In normal pediatric echocardiograms, the distance from the junction of superior vena cava and right atrium to inferior vena cava and right atrium (SVC-IVC) is linearly related to height. We examine this relationship in children listed for heart transplant with dilated cardiomyopathy (DCM) compared to a previously defined normal distribution of SVC-IVC in order to maximize potential donor acceptance. Methods and Materials Measurements of SVC-IVC and left ventricular end-diastolic diameter (LVEDd) in 55 patients (pts) with DCM (age 2 months - 19 years, median 7.8 years) were correlated with height, weight, body surface area (BSA), and BSA0.5. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared DCM to normal SVC-IVC values from 254 pts. Results There was a strong linear relationship in DCM pts between SVC-IVC and height (R2=0.84) and a logarithmic relationship to weight (R2=0.80). LVEDd did not correlate to SVC-IVC or any other parameter. In 89% of DCM pts, SVC-IVC was over 2 standard deviations above predicted normal values (mean z-score = 4.3±2.1). Predicted SVC-IVC in DCM pts was different than published norms (p Conclusions SVC-IVC in pediatric DCM pts, while linearly related to height, is consistently above normal values (figure). When matching pediatric heart recipients to donors, SVC-IVC may help accurately size donor hearts, especially for bicaval anastomosis, and substantially increase the donor pool. [ figure 1 ]

Complex TAPVC-Experience with Six Patients

Total anomalous pulmonary venous connection becomes a totally different subset when associated with complex congenital anomalies. The combination of two separate life-threatening congenital heart defects complicates the management of these patients. Six patients with total anomalous pulmonary venous connection associated with complex congenital heart disease were studied. There were 2 girls and 4 boys. Three of them were less than 5 kg in weight, and the other 3 were more than 5 kg in weight. Four patients had severe pulmonary arterial hypertension and 2 patients had pulmonary stenosis. Three patients had supracardiac type with a right vertical vein, one had drainage to the right atrium superior vena cava junction, one patient had supra cardiac type but split flow to both the superior vena cava and one patient had cardiac type. Three patients had double outlet right ventricle. Three patients had atrioventricular canal defect and 2 patients had preoperative pulmonary vein obstruction. All patients underwent rerouting of pulmonary veins. Concomitant procedures included intraventricular tunnel repair of ventricular septal defect and infundibular resection in double outlet right ventricle. Atrioventricular canal repair was done for Rastelli type A atrioventricular canal. Superior vena caval plasty, atrioventricular canal repair and pulmonary artery banding were done in unbalanced atrioventricular septal defect and large double outlet right ventricle. Intracardiac repair through transatrial approach was done for tetralogy of Fallot. Right ventricle-pulmonary artery conduit was done for truncus arteriosus. Single ventricle repair was done for corrected transposition of great arteries. There were 2 hospital deaths.

A technical approach to dissecting and assessing cadaveric veins pertinent to chronic cerebrospinal venous insufficiency in multiple sclerosis

Objective: To establish a detailed technical procedure for studying the anatomical correlates of chronic cerebrospinal venous insufficiency in cadavers of multiple sclerosis and control subjects, and to present our findings of the normal anatomic venous structures, with reference to previous descriptions from the literature.Methods: This study examined the internal jugular veins (IJVs), the brachiocephalic veins, and the azygos vein from 20 cadavers (10 control and 10 multiple sclerosis). These veins were exposed, isolated by clamps from the rest of the venous system, flushed with water, and then injected with fluid silicone from the superior ends of both IJVs. After the silicone cured to its solid state, the venous tree was removed en bloc and dissected longitudinally to expose the luminal surface. All vein segments were analyzed for anatomic variation. Anatomical analysis for this manuscript focused on normal vein architecture and its variants.Results: Thirty-seven of 40 IJVs contained valves: 29 bicuspid, 6 tricuspid, and 2 unicuspid. The average circumferences of the right and left IJVs were 2·2 and 1·8 cm, respectively. Thirteen of 20 azygos veins contained a valve, located on average 3·6 cm away from the superior vena cava junction. Nine of the 13 azygos valves were bicuspid; four were tricuspid. Only one of the 40 brachiocephalic veins contained a valve.Discussion: We detailed a technical approach for harvesting cadaveric neck and thoracic veins with relevance to chronic cerebrospinal venous insufficiency. The anatomy of the venous system has significant variability, including differing number of valves in different regions and variable characteristics of the valves. Average vein circumference was less than that typically reported in imaging studies of live patients.

Three-dimensional reconstruction of the anatomic course of the right phrenic nerve in humans by pace mapping

Endocardial catheter ablation at the right atrial to superior vena cava junction or right pulmonary vein isolation, especially in balloon-guided procedures, is associated with risk for phrenic nerve palsy. The purpose of this study was to obtain a three-dimensional reconstruction of the individual phrenic nerve course. Electroanatomic reconstruction (CARTO, Biosense Webster) of the superior vena cava, right atrium, left atrium, and right superior and inferior PVs was performed. The phrenic nerve pace map was obtained using maximal stimulation output (10 V, 2.9 ms) and annotated on the three-dimensional map. Eighteen patients with paroxysmal atrial fibrillation (12 men and 6 women, mean age 61 +/- 10 years) were included in the study. The phrenic nerve course was reconstructed over a mean craniocaudal length of 40 +/- 17 mm (mediolateral 11 +/- 4 mm). Median phrenic nerve distance to the right superior PV ostium was 12 mm (range 2-39 mm). The phrenic nerve could be captured in 16 of 18 patients but only in 7 of 18 patients from the right superior PV. The complete electroanatomic map was performed in 48 +/- 23 minutes, including the phrenic nerve pace map (14 +/- 6 min). Pace mapping of the phrenic nerve using electroanatomic mapping can be performed within a reasonable time frame and provides important information on the true anatomic course of the phrenic nerve. The three-dimensional display of its position in relation to potential ablation targets may be of value in preventing phrenic nerve palsy, particularly when innovative ablation energies are used. However, phrenic nerve pacing exclusively from the right superior PV appears insufficient to exclude a close anatomic relationship.

Twiddlers syndrome

A 70 year old gentleman received a dual chamber pacemaker (DDDR) following a diagnosis of sick sinus syndrome. A pre-discharge chest X-ray revealed leads well positioned in right atrial (RA) appendage and right ventricular (RV) apex (Fig. 1). Pre-discharge implant parameters were satisfactory. On follow up at 3 months an ECG revealed loss of capture. Radiological evaluation revealed the RA lead lying at right subclavian and SVC junction and RV lead in the RA, with coiling of the leads around the pulse generator (Fig. 2). The patient denied having manipulated the implant. The leads were repositioned and pacemaker box sutured in place. Since then patient is doing well. Fig. 2Chest X-ray at 3 months follow up shows RA lead at right subclavian and superior vena cava junction, RV lead in RA. Note that the leads coiled around the pulse generator. View Large Image Figure Viewer Download Hi-res image

Right Atrial Perforation Resulting From Pulmonary Artery Catheter Insertion During Coronary Artery Bypass Surgery

An 84-year-old man presenting with triple-vessel coronary artery disease and unstable angina pectoris associated with mitral valve stenosis was scheduled for coronary artery bypass graft surgery and mitral valve replacement. His medical history was significant for chronic pulmonary obstructive disease and moderate left ventricular dysfunction, thus warranting the use of a PAC for the accurate monitoring of hemodynamic parameters. Although transesophageal echocardiography has been widely used during cardiac surgery, the use of a PAC is still an alternative when TEE is not available in the operating room. The patient was premedicated with a combination of midazolam, 5 mg, and fentanyl, 50 g, intravenously, 30 minutes before surgery. PAC insertion was performed by using a modified Seldinger technique. The right internal jugular vein was punctured with a 22-G seeker needle at the angle formed by the bellies of the sternocleidomastoid muscle near the level of the cricoid cartilage. The vessel was cannulated with an 18-G straight introducer needle to a depth of 2 to 3 cm. Dark, nonpulsatile venous blood was obtained by aspiration during needle placement. A J-tip wire guide was inserted through the needle without difficulty, and an 8.5F introducer sheath of the PAC was placed over a dilator, which was introduced to its full length. Once again dark, nonpulsatile venous blood was easily aspirated from the sheath. A 7.5F PAC (model 831F75, Baxter Edwards, Irvine, CA) was inserted via the introducer into the right internal jugular vein. The balloon had been previously checked for proper inflation over the end of the catheter. After the insertion of 25 cm of the PAC with the balloon inflated, a significant resistance to pass the catheter into the RV was experienced. After several attempts that took about 5 minutes and without taking any additional measures, the catheter was successfully introduced into the right ventricle and then into the pulmonary artery, as assessed by the corresponding pressure waves. The final position of the catheter was at about 50 cm of insertion. There were no significant alterations in hemodynamic parameters or in electrocardiographic tracings during the wire guide or PAC insertion. General anesthesia was induced by using a combination of fentanyl, 300 g, and etomidate, 10 mg; pancuronium, 6 mg, was used for neuromuscular blockade. Anesthesia was maintained with isoflurane, 1.5% to 2% in oxygen. The chest was opened with a median sternotomy incision. After opening the pericardium, the presence of blood within the pericardial sac led to the identification of a perforation in the right atrium. It was an elliptically-shaped perforation with about 1 mm of diameter in the inferior portion of the atrial lateral wall, about 2 to 3 cm from the superior vena cava junction. The perforation was then sutured, and the patient underwent coronary artery bypass graft surgery without presenting further complications. Recovery was uneventful, and the patient was discharged 10 days after surgery with no residual complications.

Direction of the J-Tip of the Guidewire, in Seldinger Technique, Is a Significant Factor in Misplacement of Subclavian Vein Catheter: A Randomized, Controlled Study

Misplacement of central venous catheters, predisposing to poor functioning including inability to aspirate blood, is common with the subclavian approach. In this prospective study we sought to determine whether the direction of the guidewire J-tip influenced the catheter tip placement during right subclavian catheterization. In this randomized, double-blind clinical study, we observed the placement of catheters via the right subclavian vein while keeping the J-tip directed either caudad in Group 1 (n=147) or cephalad in Group 2 (n=148) patients. The majority of catheters (97% and 57%) in Groups 1 and 2 respectively entered the superior vena cava/right atrium (P <0.05). The incidence of catheter misplacement into the ipsilateral internal jugular vein was 2% and 40% in Groups 1 and 2, respectively (P = <0.01). Subsequent experimental study confirmed that the direction of the J-tip was retained inside a model of vascular tubes and its tip led the guidewire into the tubing on the same side even at the acute angulation formed between tubings representing the subclavian, internal jugular, and superior vena cava junction complex. The authors conclude that the simple measure of keeping the guidewire J-tip directed caudad increased correct placement of central venous catheters towards the right atrium during right subclavian catheterization.