Atrial Position Research Articles

Feasibility of transthoracic echocardiographic guidance for multicatheter electrophysiological mapping studies in horses.

Improved characterization of arrhythmias is based on minimally invasive catheterizations. However, these catheterizations have been poorly explored in horses because apart from 3-dimensional (3D) mapping systems, continuous guidance of the catheter's position with adequate detail is difficult using current imaging modalities. Position multiple electrophysiology catheters simultaneously at predetermined strategical positions in the heart using transthoracic echocardiographic guidance. Eight adult healthy horses. Observational study. Two electrophysiological studies were performed: 1 procedure with catheters positioned in the right heart in the standing sedated horse and 1 procedure under general anesthesia with catheters positioned in the left heart. Except for the coronary sinus catheter, each catheter positioning was simultaneously guided by right-parasternal transthoracic echocardiography and 3D electro-anatomical mapping. For each catheter position, a central imaging plane was taken as the starting point, after which the imaging probe was shifted, rotated, and angulated to visualize the catheter over its entire length, including its distal electrode. Catheter positionings in the right heart and left ventricle were successfully guided in the majority of the horses whereas catheter positionings in the left atrium, and especially the pulmonary veins, were challenging to guide echocardiographically. Ultrasound guidance of catheters to specific positions useful for electrophysiological mapping was feasible in the right heart and left ventricle but challenging for the left atrium. This approach creates a perspective for minimally invasive arrhythmia diagnosis without the need for a 3D mapping system. Left parasternal views and intracardiac echocardiography might provide better guidance for left atrial positions.

Revealing intracavitary catheter positions: artificial intelligence-enhanced localization with an electrogram-driven variational autoencoder model

Abstract Background The acquisition of electroanatomical (EA) maps in clinical electrophysiology procedures typically depends on locating intracardiac mapping catheters through magnetic triangulation with external patches placed on the patient's skin. However, this configuration is hampered by shifts in the reference system if the patient moves or if the setup changes during the procedure. Leveraging the feature extraction capabilities of artificial intelligence models, it becomes possible to assess catheter positions within the atria solely based on the information encoded in intracavitary electrograms (EGMs). Consequently, a neural network model could serve as an alternative or complementary system for locating EA mapping catheters, eliminating the need for external reference patches. Purpose We aimed to create a deep learning model utilizing a disentangled variational autoencoder (d-VAE) and unipolar EGM signals. The goal was to extract the precise position of a multi-electrode catheter within the left atrium and predict the specific atrial region in which it is situated, relying solely on the information derived from unipolar EGMs. Methods The model was trained using data from 51 patients with persistent atrial fibrillation who underwent pulmonary vein ablation. We exported 3D EA maps obtained with a 20-pole multi-electrode catheter, comprising a total of 40,000 unipolar EGMs with a duration of 30 seconds. Atrial geometries were segmented into 12 different areas (refer to the Figure). Subsequently, the d-VAE model was trained with unipolar EGMs to acquire encoded features, which were then input into a classifier model. The classifier was combined with atrial positions using one-hot encodings as the ground truth. The optimal architecture was selected through a grid search involving different layer numbers, sizes, and fine-tuning. For the encoding part, we assessed the negative evidence lower bound (ELBO) and Pearson’s correlation. Regarding the classifier, we evaluated accuracy, extended accuracy (indicating accuracy in predicting the region or an adjacent one), and the area under the curve (AUC). Results The best-performing autoencoder architecture presented a negative ELBO of -0.087 and a Pearson’s correlation of 0.971; and the classifier obtained an accuracy of 38.1%, an extended accuracy of 75.2%, and an AUC of 0.814. Conclusion We introduced an alternative method for localizing intracardiac catheters within the atrial chambers based on deep-learning techniques. In contrast to traditional hardware technologies, our proposed method eliminates the need for external magnetic or impedance reference patches. This approach is not limited to AF and can be extended to other supra-ventricular procedures. The results of our proposed method are promising, suggesting potential advancements in alternative systems for locating intracardiac catheters to complement existing classical hardware methods in the future.Variational autoencoder architecture

Non-invasive estimation of atrial fibrillation driver position using long-short term memory neural networks and body surface potentials

Background and ObjectiveAtrial Fibrillation (AF) is a supraventricular tachyarrhythmia that can lead to thromboembolism, hearlt failure, ischemic stroke, and a decreased quality of life. Characterizing the locations where the mechanisms of AF are initialized and maintained is key to accomplishing an effective ablation of the targets, hence restoring sinus rhythm. Many methods have been investigated to locate such targets in a non-invasive way, such as Electrocardiographic Imaging, which enables an on-invasive and panoramic characterization of cardiac electrical activity using recording Body Surface Potentials (BSP) and a torso model of the patient. Nonetheless, this technique entails some major issues stemming from solving the inverse problem, which is known to be severely ill-posed. In this context, many machine learning and deep learning approaches aim to tackle the characterization and classification of AF targets to improve AF diagnosis and treatment. MethodsIn this work, we propose a method to locate AF drivers as a supervised classification problem. We employed a hybrid form of the convolutional-recurrent network which enables feature extraction and sequential data modeling utilizing labeled realistic computerized AF models. Thus, we used 16 AF electrograms, 1 atrium, and 10 torso geometries to compute the forward problem. Previously, the AF models were labeled by assigning each sample of the signals a region from the atria from 0 (no driver) to 7, according to the spatial location of the AF driver. The resulting 160 BSP signals, which resemble a 64-lead vest recording, are preprocessed and then introduced into the network following a 4-fold cross-validation in batches of 50 samples. ResultsThe results show a mean accuracy of 74.75% among the 4 folds, with a better performance in detecting sinus rhythm, and drivers near the left superior pulmonary vein (R1), and right superior pulmonary vein (R3) whose mean sensitivity bounds around 84%-87%. Significantly good results are obtained in mean sensitivity (87%) and specificity (83%) in R1. ConclusionsGood results in R1 are highly convenient since AF drivers are commonly found in this area: the left atrial appendage, as suggested in some previous studies. These promising results indicate that using CNN-LSTM networks could lead to new strategies exploiting temporal correlations to address this challenge effectively.

Localization and characterization of atrial depolarization waves on the surface electrocardiogram in dogs with rapid supraventricular tachycardia.

Supraventricular tachycardias (SVTs), despite having various anatomical substrates and pathophysiological mechanisms, frequently show similar electrocardiographic presentations. To locate and characterize atrial deflections (ADs) on 12-lead electrocardiograms in dogs with sustained rapid SVT and assess the utility of different electrocardiographic variables in differentiating types of tachycardia. Ninety-two dogs with orthodromic atrioventricular reciprocating tachycardia, 17 with atrial flutter, 33 with focal atrial tachycardia recorded and confirmed by electrophysiological study, and 40 dogs with sinus tachycardia. Atrial deflection position on the 12-lead surface electrocardiogram was assessed according to the sequence of intracardiac activation. Its features were evaluated together with the relationship between AD and QRS complex interval (AD-R) and QRS complex and AD interval (R-AD). Orthodromic atrioventricular reciprocating tachycardia was characterized by an AD-AD interval of 213 ± 30 ms, mean electrical axis (MEA) of AD of -90 (-90/-78)°, R-AD interval of 75 (65-80) ms, and R-AD/AD-R of 0.54 (0.45-0.64). Atrial flutter was characterized by an AD-AD interval of 199 ± 57 ms, MEA of 76° (72/81), R-AD of 120 (72-144) ms, and R-AD/AD-R of 0.81 (0.63-1.13). Focal atrial tachycardia was characterized by an AD-AD interval of 270 ± 38 ms, MEA of 49 (-72/76)°, R-AD of 160 (120-200) ms, and R-AD/AD-R of 1.45 (0.92-1.67). Sinus tachycardia was characterized by an AD-AD interval of 292 ± 31 ms, MEA of 66° (52/73), R-AD of 215 (192-222) ms, and R-AD/AD-R of 2.68 (2.25-3.08). Analyzing AD on 12-lead electrocardiogram is helpful in differentiating the most common SVTs in dogs.

Long-term performance of domestic active-fixation endocardial pacing leads

Aim. The aim of the study was to evaluate the long-term results of implantation of domestic endocardial leads (EL) with active fixation ELBI 233C-53 and ELBI 233C-58, implanted in the atrial and ventricular positions, respectively.Methods. A total of 165 patients were included in the retrospective, single-center study. 239 EL were implanted from 2016 to 2018 (55 ELBI 233C-53 and 184 ELBI 233C-58). The median age was 78 years (43 to 92 years). 846 programming protocols were analyzed, which were carried out on the 1st day after implantation, and then every 6 months. Complications are divided into early (1-7 days) and late (8 days or more).Results. In the EL ELBI 233C-53 group, there were no statistically significant changes in the pacing parameters during the observation period. There were 6 complications (10.9%): exit block (n=1, 1.8%), dislocation of the EL (n=3, 5.4%), damage to the EL structure (n=2, 3.7%). The number of reoperations was 3 (5.4%). In the ELBI 233C-58 group, a statistically significant increase in the pacing threshold was found (p=0.026). 13 (7.0%) complications were registered, including an increase in the pacing threshold (n=11.6%), exit block (n=1, 0.5%), damage to the EL structure (n=1, 0.5%). The number of reoperations in this group was 2 (1%).Conclusion. EL ELBI 233C-53 and ELBI 233C-58 demonstrated acceptable pacing parameters and safety during observation. Complications occurred mainly in the first year after implantation. The number of repeated operations was low. There were no deaths caused by complications after lead implantation.

Non-invasive Estimation of Atrial Fibrillation Driver Position With Convolutional Neural Networks and Body Surface Potentials.

Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns, and AF onset locations and drivers responsible for its perpetuation are the main targets for ablation procedures. ECG imaging (ECGI) has been demonstrated as a promising tool to identify AF drivers and guide ablation procedures, being able to reconstruct the electrophysiological activity on the heart surface by using a non-invasive recording of body surface potentials (BSP). However, the inverse problem of ECGI is ill-posed, and it requires accurate mathematical modeling of both atria and torso, mainly from CT or MR images. Several deep learning-based methods have been proposed to detect AF, but most of the AF-based studies do not include the estimation of ablation targets. In this study, we propose to model the location of AF drivers from BSP as a supervised classification problem using convolutional neural networks (CNN). Accuracy in the test set ranged between 0.75 (SNR = 5 dB) and 0.93 (SNR = 20 dB upward) when assuming time independence, but it worsened to 0.52 or lower when dividing AF models into blocks. Therefore, CNN could be a robust method that could help to non-invasively identify target regions for ablation in AF by using body surface potential mapping, avoiding the use of ECGI.

Myths and Legends: Electrocardiographic Position Control of Central Venous Catheters - Where Does the P Come from?

Misplacement of central venous accesses can be associated with deleterious iatrogenic complications. Electrocardiography is often used to guide the placement of central venous catheters and to confirm the correct position of the catheter tip. A characteristically peaked p-wave is traditionally considered to indicate the entrance of the catheter tip into the right atrium. However, recent data show that intraarterial and even extravascular localisation might result in an increased amplitude. The peaked p-wave most likely detects the pericardial reflection rather than a right atrial catheter position, hence real-time ultrasound is to be recommended as a superior technique to confirm a correct catheter position.

Safety and efficacy of placement of tunneled hemodialysis catheter without the use of fluoroscopy.

The implantation of acute or chronic vascular accesses for hemodialysis (HD) in end-stage kidney disease patients is a critical skill procedure for nephrologists, with an impact on short- and long-term outcomes of the modality and patient survival. Placement circumstances, however, may depend on the availability of technological support and will likely vary across the world. We retrospectively reviewed our local experience with ultrasound-guided tunneled dialysis catheter (TDC) insertions but without access to fluoroscopic guidance. Data were available for 63 patients with TDCs placed by faculty nephrologists at the dialysis unit procedure rooms between March 2015 and February 2018. We reviewed circumstances of TDC placement, patient characteristics, and procedural outcomes. The mean age was 62 (±41) years, and 46% of the patients were male. All TDC placements were technically successful and no major complications occurred. Most TDCs (52.8%) were a de novo placement. In the de novo patient group, there were 27 right-sided internal jugular vein (IJV) and 6 left-sided IJV cannulations. Blood pump flow was 284.6 (±58) mL/min via the temporary catheter 1month before and 316.7 (±46) mL/min 1month after TDC placement (p < 0.0001). The majority of catheter tips (63%) reached the right atrial placement position successfully. Technologically successful TDC placement can be performed without fluoroscopic tip guidance and result in improved access flows and dialysis efficacy when compared to temporary hemodialysis catheters.

Detection of high-frequency artifact as a function of pulse generator algorithms and outer-insulation material

A high rate of malfunction, predominantly intermittent high-frequency artifacts (HFAs), has been recently reported in Abbott Medical Tendril pacing leads. To investigate the factors associated with the occurrence of HFAs on Tendril leads using a commonly used comparator lead for a control. We reviewed institutional data for Medtronic CapSureFix 5076 and Abbott Medical Tendril pace-sense leads retrospectively. Recordings deemed to be due to electromagnetic interference and far-field oversensing were not included in the classification of HFAs. A total of 7673 leads were analyzed: 1628 Optim-insulated Tendril leads, 825 non-Optim Tendril leads, and 5220 CapSureFix 5076. HFAs were seen in 212 leads and were more frequently observed in Tendril compared to CapSureFix leads during a mean follow-up of 4.1 ± 3.6 years. Lower age at implant, defibrillator systems, atrial position, and connection to an Abbott Medical generator were associated with increased HFA. In multivariable analysis, only connection to Abbott Medical generators (odds ratio 7.686, P < .001) and age (odds ratio 0.988 per year, P = .016) were independently associated with HFAs on pace-sense leads. In an Abbott-generator-only analysis, Optim-insulated Tendril leads were more likely to display HFAs than non-Optim Tendril leads but not Medtronic CapSureFix 5076 leads. Abbott Medical pulse generators independently predict HFA in Tendril and CapSureFix 5076 leads, likely the result of displaying short or low-amplitude noise episodes that other devices do not record. When restricted to Abbott generators only, Optim-insulated Tendril leads show an increased incidence of HFAs when compared to non-Optim Tendril leads but not CapSureFix 5076 leads.

P1159The signal averaged P-wave and acute procedural related effects after atrial fibrillation ablation in 12-lead electrocardiogram and novel atrial lead positions

P1159The signal averaged P-wave and acute procedural related effects after atrial fibrillation ablation in 12-lead electrocardiogram and novel atrial lead positions

Influence of echocardiographic and radiographic characteristics on atrial sensing amplitude in patients with Linox Smart S DX defibrillation leads.

Single-lead for implantable cardioverter-defibrillator (ICD) with floating atrial sensing dipole is a new diagnostic tool with the potential advantage in terms of arrhythmia discrimination. We sought to determine whether right heart size and dipole position influence atrial sensing. Atrial sensing (AS) amplitude was measured during implantation (PP, periprocedural), predischarge (IHFU, in-hospital follow-up) and 3-6 months after the procedure (AFU, ambulatory follow-up). Results were related to atrial dipole position in the right atrium (RA) on the basis of chest X-ray examination as well as right heart dimensions at echocardiography. Twenty-four patients were included into final analysis. In 14 (58.3%) patients, sensing dipole was located in regions 1 and 2 of the RA. AS amplitude was greater in regions 1 and 2 when com¬pared to other locations (3.15 vs. 1.2 mV, p = 0.045, 7.53 vs. 3.8 mV, p < 0.001 and 5.63 vs. 2.44 mV, p = 0.017 for PP measurements, IHFU and AFU, respectively). There was a significant negative correlation between AS-PP and short RA dimension (RADs) (r = -0.56, p = 0.02), AS-IHFU and RA area (RAA) (r = -0.45, p < 0.05), AS-AFU and long RA dimension (RADl) (r = -0.46; p = 0.02), AS-AFU and RADs (r = -0,48, p = 0.02), and AS-AFU and RAA (and r = -0.52, p < 0.01). There was no relationship between AS and other right heart dimensions. Larger RA size and low sensing dipole location were associated with lower AS amplitude in single-lead dual chamber ICD.

Immediate post-insertion tip migration of peripherally inserted central catheters dependent on arm position and depth of inspiration.

The purpose of this study is to assess the degree of PICC tip migration with breathing and arm movement to determine whether accurate positioning is feasible or futile. A prospective cohort of 218 consecutive patients undergoing PICC insertion at our institution between January and August 2015 was selected, of which 129 met inclusion criteria. The position of insertion was used as control with the arm at 90° during inspiration, followed by three study images: expiration with arm unchanged, inspiration with arm fully adducted and inspiration with arm fully abducted. Mean and standard deviations (SD) of change in PICC position were determined. ANOVA, Pearson correlation coefficients and Chi-square tests were used to assess the effects of vessel choice, PICC calibre and angle of arm abduction. Complications were recorded. Movement was predominantly caudal with a mean of 10.4mm (SD 16.5) with similar degrees of movement in the expiration (12.3mm) and adduction (12.9mm) views (P=0.709). Arm abduction resulted in a mean caudal movement of 6.5mm. (SD 18.6); however, the degree of abduction had no predictable effect on PICC movement. Thirty-two per cent of cases demonstrated movement into the right atrium. Neither vessel choice nor type of PICC was shown to have a significant effect on PICC movement. There is large amplitude of PICC tip position change with depth of inspiration and arm position resulting in frequent right atrial position. Despite this there were no associated complications in our cohort which compliments emerging international opinion regarding intra-atrial PICC tip position.

Solving Inaccuracies in Anatomical Models for Electrocardiographic Inverse Problem Resolution by Maximizing Reconstruction Quality.

Electrocardiographic Imaging has become an increasingly used technique for non-invasive diagnosis of cardiac arrhythmias, although the need for medical imaging technology to determine the anatomy hinders its introduction in the clinical practice. This paper explores the ability of a new metric based on the inverse reconstruction quality for the location and orientation of the atrial surface inside the torso. Body surface electrical signals from 31 realistic mathematical models and four AF patients were used to estimate the optimal position of the atria inside the torso. The curvature of the L-curve from the Tikhonov method, which was found to be related to the inverse reconstruction quality, was measured after application of deviations in atrial position and orientation. Independent deviations in the atrial position were solved by finding the maximal L-curve curvature with an error of 1.7 ± 2.4 mm in mathematical models and 9.1 ± 11.5 mm in patients. For the case of independent angular deviations, the error in location by using the L-curve was 5.8±7.1° in mathematical models and 12.4° ± 13.2° in patients. The ability of the L-curve curvature was tested also under superimposed uncertainties in the three axis of translation and in the three axis of rotation, and the error in location was of 2.3 ± 3.2 mm and 6.4° ± 7.1° in mathematical models, and 7.9±10.7 mm and 12.1°±15.5° in patients. The curvature of L-curve is a useful marker for the atrial position and would allow emending the inaccuracies in its location.

Right atrial lead fixation type and lead position are associated with significant variation in complications.

Optimal atrial pacemaker lead position and fixation mechanism have not been determined with regard to effect on complications. We aimed to determine the association between atrial lead-related complications and varying atrial lead tip positions and lead fixation mechanisms. All patients who underwent dual-chamber pacemaker implant between 2004 and 2014 were retrospectively reviewed for atrial lead tip position and fixation type. Lead-related complications were assessed by electronic medical record review. Complication rates were compared at 1year by chi-square analysis and at 5years using a Kaplan-Meier analysis. During the study period, 3451 patients (mean age 73.9, 53.4% male) underwent dual-chamber pacemaker placement. Active fixation leads were associated with a higher incidence of pericardial effusion (81 (2.9%) vs. 6 (1.0%), p = 0.005) and pericardiocentesis (46 (1.6%) vs. 2 (0.3%), p = 0.01) at 1year compared to passive fixation leads. There was no difference in overall complication rates by fixation type (161 (5.7%) vs. 29 (4.6%), p = 0.26). Low atrial septal lead tip position was associated with a higher rate of lead dislodgement (10 (15.2%)) compared to appendage (46 (1.6%)), free wall (10 (2.1%)), or high atrial septal (2 (4.7%)) positions (p < 0.001). This difference was also reflected in a significantly increased need for lead revision and overall complications. A multivariate analysis which included potential confounders confirmed the association of active fixation leads with an increased rate of perforation-related complications (p = 0.03) and septal lead location with increased rates of dislodgement (p < 0.001). Active compared to passive lead fixation increases the risk for pericardial effusion requiring pericardiocentesis. There is a clear association between low atrial septal lead position and lead dislodgement requiring lead revision.

Timing of vitamin K antagonist re-initiation following intracranial hemorrhage in mechanical heart valves: Systematic review and meta-analysis

BackgroundWhile evidence supports resumption of vitamin K antagonists (VKAs) among mechanical heart valve (MHV) patients presenting with anticoagulant-associated intracranial hemorrhage (ICH), ideal timing of resumption is uncertain. ObjectiveTo determine the optimal timing of VKA re-initiation and its associated clinical outcomes. MethodsWe performed a systematic review and a meta-analysis of studies published from January 1950 to August 2015. We extracted data on the location of initial ICH, use of cranial surgery, presence of atrial fibrillation, MHV type and position, number of MHVs, and timing of VKA resumption. Outcomes including valve thrombosis, thromboembolic events or ICH recurrence were recorded. Meta-regression analysis was conducting with controlling for covariates. We calculated absolute risks, and assessed the effect of anticoagulant resumption timing on ICH recurrence. Results23 case-series and case-reports were identified. Overall ICH recurrence was 13% (95% confidence interval [CI], 7%–25%), while valve thrombosis and ischemic strokes occurred at 7% (95% CI, 3%–17%) and 12% (95% CI, 5%–23%) respectively. A trend towards lower ICH recurrence was observed with delayed VKA resumption (slope estimate −0.2154, p=0.10). Recurrence rate ranged from 50% with VKA resumption at 3days to 0% with resumption at 16days. ConclusionAmong patients with MHV, there is inadequate data to suggest an optimal timing of VKA re-initiation following an ICH, though delayed restart appears to be protective against recurrence but is associated with higher risk of thrombosis. Our analysis suggests 4–7days might be an ideal time with least risk of thrombosis or ICH recurrence.

9:12 AMAbstract No. 444 - Single-incision technique vs. conventional method of central venous access in a pediatric population

cavoatrial junction, was 100%. There was follow-up until port removal or death in 94% (34/36) of patients. Two patients, one patient with two simultaneous ports, were lost to follow-up. There were no immediate or delayed complications. Median port dwell time from initial insertion to shortening was 131 days (range 3-1325). Median total port dwell was 574 days (range 55-3201). Median length of shortening was 3 cm (range 1-7 cm). Indication for repositioning was symptomatic arrhythmia in 8 ports and imaging findings of malposition in 30. Tip location prior to repositioning was atrial in 26 ports, ventricular in 11, and IVC in 1. One port required a second shortening procedure at a later date for recurrent atrial tip position. Ports were used until death from primary disease (22/ 37, 59%), removed due to completion of therapy (7/37, 19%), lost to follow-up (3/37, 8%), or are currently in use (5/37, 14%). Conclusions: Percutaneous revision is an effective method for shortening too-long port catheters, allowing uninterrupted use of the port. Long term outcomes of this approach are excellent.

A simple method for Bachmann's bundle pacing with indigenous modification of J-stylet

BackgroundPacing in the Bachmann's bundle (BB) area (upper atrial septum) appears superior to right atrial appendage or free wall stimulation for the prevention of paroxysmal atrial fibrillation in patients with atrial conduction delay. However, insertion of active fixation lead in the upper atrial septal position is difficult and time consuming with conventional stylet, inhibiting application of this pacing method in routine practice. MethodsThe technique of positioning the atrial lead in BB with hand-made stylet is presented with emphasis on electrocardiographic P-wave pattern and fluoroscopic landmarks. ResultsThe results demonstrate an acute implantation and short-term success of BB pacing of 14 patients out of 15 patients without major complications. Pacing parameters at implantation and 3 months postprocedure were noted which were within normal limits. ConclusionThese favorable initial results indicate that the positioning of active fixation atrial lead in BB with fluoroscopic landmarks is feasible and reproducible with a simple technique.

Paediatric vascular access

### Key points Obtaining reliable vascular access in small children is frequently made challenging by anatomical factors—in particular, small, mobile veins and an excess of subcutaneous fat which make visualization and palpation of veins difficult. Paediatric patients are often less co-operative, and the potential for psychological trauma, especially with repeated procedures in the conscious patient, further complicates matters. Short-term vascular access is frequently required in hospitalized children for the delivery of i.v. fluids, medication, and blood product administration. Longer-term vascular access devices are required for repeated medication delivery (e.g. enzyme replacement therapy in inherited metabolic diseases), chemotherapy, immunotherapy, total parenteral nutrition, and extracorporeal procedures such as plasmapheresis and haemodialysis. In addition, vascular access devices may be needed for repeated blood sampling and invasive haemodynamic monitoring. The choice of vascular access device depends upon the condition and preference of the patient or parent/guardian, the likely duration and frequency of treatment, and the properties of the infusate. Infusates with vesicant properties (drugs with the potential to cause blistering with tissue injury, e.g. calcium solutions and amphotericin B), hypertonic solutions, and those with pH 9 will necessitate central venous access. Vasopressors and inotropes are preferentially administered centrally as they require reliable access and extravasation may cause tissue necrosis. It is important to try to predict future needs for vascular access as poor prospective management …

Durable Bi-ventricular Support in INTERMACS 1 Patients Using the Heartware HVAD System in the Right Atrial Position

Durable Bi-ventricular Support in INTERMACS 1 Patients Using the Heartware HVAD System in the Right Atrial Position

Formulas for prediction of insertion depths of internal jugular vein catheters adjusted to body height categories.

Whether formulas for prediction of central venous catheter (CVC) insertion depths have different applicability in patients with different body heights is not known. Goal of study was to test formulas for catheterizations of internal jugular veins (IJVs) in a population of different body height classes with correct CVC tip positions. Consecutive adult patients requiring CVC for cardiac surgery were enrolled and those with tip positions at the junction of the superior vena cava and the right atrium ±1 cm underwent formula analysis. Precision of formula prediction was calculated for three classes of body height. Of the 635 included patients, 254 underwent right IJV catheterization and 381 underwent left IJV catheterization, respectively. Formula-guided approach for both right [formulas (height/10) (in cm) and (height/10) -1 (in cm)] and left [formula (height/10) + 4 (in cm)] IJV CVC was more precise in patients with a body height of 170-180 cm compared with patients with a body height &lt;170 cm (who required deeper insertion than predicted by formula) and patients with a body height &gt;180 cm (who required a more proximal insertion than predicted by formula). Independent from body height classes, all formulas calculated a relatively low likelihood of atrial positions but high risks of proximal mal-positioning. Thus, considering inter-individual differences of vascular anatomy and for safety reasons, formulas cannot be recommended.