Emerging Applications for Transseptal Left Heart Catheterization

A case report of atrial septal puncture "mistakenly" penetrated the aorta during left bypass radiofrequency ablation

INTRODUCTION

Transseptal punctures (TSPs) are widely used in left atrium and left ventricle surgery. Accidental puncture of the puncture needle into the aorta is a rare complication that is rarely reported but has serious consequences. The appropriate management of this complication remains unclear.

PATIENT CONCERNS

This report describes a case of a male with the chief complaint: paroxysmal palpitation for 1 year, aggravated for 1 month.

DIAGNOSIS

The electrophysiological diagnosis was atrioventricular reentrant tachycardia caused by left-side bypass.

INTERVENTIONS

Radiofrequency ablation of the heart was a necessary treatment and a TSP operation was needed, in which a puncture was mistakenly believed to have entered the aorta, a series of measures were taken urgently. Although the surgical procedure in this case was a false alarm, we still initiated a series of emergency plans. Emergency measures to address the complications were effectively implemented, and the emergency measures were promptly terminated after it was clear that complications had been misjudged.

OUTCOMES

At last, it was confirmed that the angiogram was a pulmonary artery image, not an aorta image. Then the atrial septal puncture operation was successfully completed, and under the guidance of the Carto system, the ablation was successfully completed. Postoperative fluoroscopy showed no complications, such as pericardial effusion. After 2 years of follow-up, there was no reoccurrence of tachycardia, and there were no complications. It is crucial that emergency procedures are terminated in a timely manner after a clear miscarriage of performance. Although accidental puncture into the aorta is urgent and serious, performing a blockage or even thoracotomy in an emergency if complications are not clearly confirmed can cause further damage to the patient and would be a definitively wrong strategy.

CONCLUSION

Strict and standardized TSP operations can avoid complications. Correct judgment of the authenticity of complications is crucial, and remedial measures that may cause further damage should not be blindly adopted. The retention of the aortic guide wire can provide convenient access for further differential diagnosis and remedial treatment.

Flexible electronics for cardiovascular healthcare monitoring

Cardiovascular diseases (CVDs) are one of the most urgent threats to humans worldwide, which are responsible for almost one-third of global mortality. Over the last decade, research on flexible electronics for monitoring and treatment of CVDs has attracted tremendous attention. In contrast to conventional medical instruments in hospitals that are usually bulky, hard to move, monofunctional, and time-consuming, flexible electronics are capable of continuous, noninvasive, real-time, and portable monitoring. Notable progress has been made in this emerging field, and thus a number of significant achievements and concomitant research prospects deserve attention for practical implementation. Here, we comprehensively review the latest progress of flexible electronics for CVDs, focusing on new functions provided by flexible electronics. First, the characteristics of CVDs and flexible electronics and the foundation of their combination are briefly reviewed. Then, four representative applications of flexible electronics for CVDs are elaborated: blood pressure (BP) monitoring, electrocardiogram (ECG) monitoring, echocardiogram monitoring, and direct epicardium monitoring. Their operational principles, progress, merits and demerits, and future efforts are discussed. Finally, the remaining challenges and opportunities for flexible electronics for cardiovascular healthcare are outlined.

Impact of Persistent Iatrogenic Atrial Septal Defect following MitraClip

BACKGROUND

Prior studies have reported conflicting results of persistent iatrogenic atrial septal defect (iASD) and its impact following a transcatheter edge-to-edge repair (TEER) procedure. This study aims to evaluate the incidence of iASD and its clinical and hemodynamic impact after a TEER.

METHODS

Consecutive patients who underwent a TEER procedure from June 2014 to September 2020 at the Mayo Clinic were identified. The presence of iASD was retrospectively identified on post-procedure transthoracic echocardiography (TTE) to group patients into an iASD+ group and an iASD- group for comparison of prognosis and cardiac function.

RESULTS

A total of 316 patients were included; the mean age was 79.1 ± 9.1 years, and 67.7% were male. Persistent iASD was diagnosed in 108 (34.2%) patients. There was no difference concerning all-cause mortality, heart failure hospitalization, and stroke/TIA between groups at follow-up (median follow-up of 9 months). Post-procedure TTE demonstrated no differences regarding right ventricle (RV) and left ventricle (LV) dimensions and function, including TAPSE (15.2 ± 4.6 vs. 15.4 ± 5.5 mm, p = 0.875), and LV ejection fraction (51.1 ± 14.0% vs. 51.3 ± 13.9%, p = 0.933). However, patients with iASD had higher RV systolic pressure (48.7 ± 14.4 vs. 45.5 ± 14.5 mmHg, p = 0.042) compared with patients without iASD.

CONCLUSION

Notwithstanding higher RV pressures, patients with persistent iASD had no hemodynamic compromise and an equal prognosis compared with those without a residual atrial defect after a TEER procedure. These findings support the mid-term safety of procedures in which an interatrial defect needs to be created and would argue against the need for interventional closure.

Biomechanical Sensing Systems for Cardiac Activity Monitoring

Cardiovascular disease is consistently ranked high among the causes of death on a global scale. Monitoring of cardiovascular signs throughout the course of a long period of time and in real time is necessary in order to discover anomalies and begin early intervention at the appropriate time. To this purpose, a significant amount of interest among researchers has been directed toward the creation of flexible sensors that may be worn or implanted and are capable of constant, immediate observation of a variety of main physiological indicators. The real-time readings of the heart and arteries' pressure fluctuations can be reflected directly by mechanical sensors, which are one of the many types of sensors. Potential benefits of mechanical sensors include excellent accuracy and considerable versatility. Capacitive, piezoresistive, piezoelectric, and triboelectric principles are the foundations of the four types of mechanical sensors that are discussed in this article as recent developments for the purpose of monitoring the cardiovascular system. The biomechanical systems that are present in the cardiovascular system are then detailed, along with their monitoring, and this includes blood and endocardial pressure, pulse wave, and heart rhythm. In conclusion, we examine the usefulness of the use of continuous health monitoring for the treatment of vascular disease and highlight the difficulties associated with its translation into clinical practice.

Use of Percutaneous Atrioseptotosmy for Left Heart Decompression During Veno-Arterial Extracorporeal Membrane Oxygenation Support: An Observational Study

Background

Left ventricular overload is frequent under veno‐arterial extracorporeal membrane oxygenation, which is associated with a worsening of the prognosis of these patients. Several left heart decompression (LHD) techniques exist. However, there is no consensus on their timing and type. We aimed to describe characteristics and outcomes of patients undergoing LHD and to compare percutaneous atrioseptostomy (PA) to other LHD techniques.

Methods and Results

Retrospective analysis was conducted of consecutive and prospectively collected patients supported by veno‐arterial extracorporeal membrane oxygenation for refractory cardiac arrest or cardiogenic shock between January 2015 and April 2018, with a 90‐day follow‐up in our tertiary center. Patients were divided according to the presence of LHD, and then according to its type (PA versus others). Thirty‐nine percent (n=63) of our patients (n=163) required an LHD. Patients with LHD had lower left ventricular ejection fraction, more ischemic cardiomyopathy, and no drug intoxication‐associated cardiogenic shock. PA was frequently used for LHD (41% of first‐line and 57% of second‐line LHD). PA appears safe and fast to realize (6.3 [interquartile range, 5.8–10] minutes) under fluoroscopic and echocardiographic guidance, with no acute complications. PA was associated with fewer neurological complications (12% versus 38%, P=0.02), no need to insert a second LHD (0% versus 19%, P=0.04), and higher 90‐day survival compared with other techniques (42% versus 19%, log‐rank test P=0.02), despite more sepsis (96% versus 73%, P=0.02) and blood transfusions (13.5% versus 7%, P=0.01). Multivariate analysis confirms the association between PA and 90‐day survival (hazard ratio, 2.53 [1.18–5.45], P=0.019).

Conclusions

LHD was frequently used for patients supported with veno‐arterial extracorporeal membrane oxygenation, especially in cases of ischemic cardiomyopathy and low left ventricular ejection fraction. PA seems to be a safe and efficient LHD technique associated with greater mid‐term survival justifying the pursuit of research on this topic.

Mechanical Sensors for Cardiovascular Monitoring: From Battery-Powered to Self-Powered

Cardiovascular disease is one of the leading causes of death worldwide. Long-term and real-time monitoring of cardiovascular indicators is required to detect abnormalities and conduct early intervention in time. To this end, the development of flexible wearable/implantable sensors for real-time monitoring of various vital signs has aroused extensive interest among researchers. Among the different kinds of sensors, mechanical sensors can reflect the direct information of pressure fluctuations in the cardiovascular system with the advantages of high sensitivity and suitable flexibility. Herein, we first introduce the recent advances of four kinds of mechanical sensors for cardiovascular system monitoring, based on capacitive, piezoresistive, piezoelectric, and triboelectric principles. Then, the physio-mechanical mechanisms in the cardiovascular system and their monitoring are described, including pulse wave, blood pressure, heart rhythm, endocardial pressure, etc. Finally, we emphasize the importance of real-time physiological monitoring in the treatment of cardiovascular disease and discuss its challenges in clinical translation.

Pneumopericardium— An Unusual Complication Following Transseptal Puncture

Transseptal puncture (TSP) is performed to access the left side of the heart from the venous circulation. Performed under fluoroscopy with echocardiographic guidance, it is a procedure associated with complications. Pneumopericardium leading to cardiac tamponade is rare following TSP. We present 3 cases of pneumopericardium during TSP and its identification, probable mechanism, and management. (Level of Difficulty: Advanced.)

Incidence and clinical relevance of persistent iatrogenic atrial septal defect after percutaneous mitral valve repair

Percutaneous mitral valve repair (PMVR) requires transseptal puncture and results in iatrogenic atrial septal defect (iASD). The impact of persistent iASD was previously investigated. However, data were diverse and inconclusive. 53 patients who underwent MITRACLIP were retrospectively included. Based on the presence of iASD in transesophageal echocardiography (TEE) after 6 months, patients were divided in two groups (iASD group vs. non-iASD group). Impact of iASD on outcome at 6 months and at two years was evaluated. Persistent iASD was detected in 62% of patients. Independent predictors for persistent iASD were female gender and reduced left ventricular ejection fraction. At 6-month follow-up, there was no difference in reduction of NYHA class (ΔNYHA = 1.3 ± 1 in iASD group vs. 0.9 ± 1 in non-iASD group, p = 0.171). There was a significant difference in right ventricular end diastolic diameter (RVEDd) (42 ± 8 mm in iASD-group vs. 39 ± 4 mm in non-iASD group, p = 0.047). However, right ventricular systolic function (TAPSE) (14 ± 7 mm in iASD group vs. 16 ± 8 mm in non-iASD group, p = 0.176) and right ventricular systolic pressure (RVSP) (40 ± 12 mmHg in iASD group vs. 35 ± 10 mmHg in non-iASD group, p = 0.136) were still comparable between both groups. At 2 years follow-up, there was no significant difference regarding rate of rehospitalization (24% vs 15%, p = 0.425) or mortality (12% vs 10%, p = 0.941) between both groups. Incidence of persistent iASD after MITRACLIP is markedly high. Despite the increase in right ventricular diameter in patients with persistent iASD, these patients were not clinically compromised compared to patients without persistent iASD.

3-Dimensional Transseptal Puncture Based on Electrographic Characteristics of Fossa Ovalis: A Fluoroscopy-Free and Echocardiography-Free Method

OBJECTIVES

This study sought to define electrographic characteristics of the fossa ovalis (FO) and use these findings in developing a 3-dimensional (3D) transseptal puncture (TSP) technique that does not rely on fluoroscopy or echocardiography.

BACKGROUND

Traditional TSP method based on fluoroscopy or echocardiography is basically a 2-dimensional (2D) technique. A valid 3D method of TSP has not been sufficiently clarified.

METHODS

The shape of the FO and its center were "electrographically" defined by comparing their potential characteristics to those of the surrounding limbus. After validation by intracardiac echocardiography, this FO mapping was incorporated into 3D electroanatomical reconstruction of the right atrium. Using a new catheter connection, the transseptal needle could be visualized nonfluoroscopically and directed to the precise localization of the FO on the electroanatomic map.

RESULTS

A total of 276 patients who underwent atrial fibrillation ablation were included. The central FO was identified in all cases with atrial electrogram voltage at 0.33 ± 0.21 mV. The amplitude of atrial potential at the FO annulus was 1.70 ± 0.72 mV (p < 0.001). By incorporating the electrographically defined FO into the 3D electroanatomic mapping and using the transseptal needle visualization approach, TSP was successful in all patients, with 91% of the cases at the first attempt. Atrial fibrillation ablation was completed in all patients with no major complication.

CONCLUSIONS

Electrographic characteristics of the FO center are distinct from those of the surrounding regions. This information can be leveraged to define the FO on 3D electroanatomic mappings, thereby facilitating safe TSP without the need of ancillary imaging with fluoroscopy or echocardiography.

One stage or two? A cohort analysis of anterior-posterior spinal fusions for severe pediatric scoliosis

STUDY DESIGN

Retrospective case-series study of prospectively collected data.

OBJECTIVE

We sought to identify the differences in outcomes between one-stage (single surgical episode) and two-stage (separate day) anterior and posterior spinal fusion and segmental spinal instrumentation surgeries in severe non-idiopathic and idiopathic scoliosis cases.

BACKGROUND

Patients with severe pediatric spine deformity may require combined anterior and posterior fusion procedures. Given their increased complexity and morbidity, surgeons may consider staging these procedures on separate days.

METHODS

A retrospective cohort study was performed on a prospective Pediatric Spine Database. Patients 21 years of age or under with pediatric scoliosis who underwent primary anterior and posterior spinal deformity correction surgery either through a one-stage or planned two-stage sequence with greater than 2-year follow-up were included. Differences in demographics, comorbidities, surgical details, perioperative morbidity, complications, and outcomes were assessed based on scoliosis etiology. Multivariate models were utilized to control for confounders.

RESULTS

There were 70 non-idiopathic (14 two-stage vs. 56 one-stage) and 65 idiopathic scoliosis (8 two-stage vs. 57 one-stage) patients. Mean follow-up was 90.1  ± 54.7 months. In non-idiopathic scoliosis patients, two-stage surgery was independently associated with a 140-min increased surgical time (95% confidence interval: 52-229 min, p = 0.002) and an 8.2-day (95% confidence interval: 2.3-14.1 days, p = 0.007) increased hospital length of stay. In idiopathic scoliosis patients, two-stage surgery was independently associated with a 2108 ml increase in crystalloid use (95% confidence interval: 834-3381 ml p = 0.002) and a 5.3-day increased hospital length of stay (95% confidence interval: 4.0-6.5 days, p < 0.001). There were no significant differences in blood loss, transfusions, complications, or post-operative curves on multivariate analysis between one-stage and two-stage surgery cohorts in either non-idiopathic or idiopathic scoliosis patient groups.

CONCLUSION

Two-stage surgery was associated with increased crystalloid use in idiopathic scoliosis patients and longer operative times in non-idiopathic scoliosis patients, and longer hospital length of stay in both populations, without significant difference in complications or deformity correction. In the appropriate patient, one-stage anterior-posterior scoliosis surgery may be preferable to two-stage surgery.

LEVEL OF EVIDENCE

Level III Retrospective Comparative Study.

Use of an angioplasty wire in transseptal puncture: A new application of an old technique

OBJECTIVE

We wondered if a modification of the conventional transseptal puncture technique performed with an angioplasty wire could be useful in patients with contrast hypersensitivity or allergy-like reactions.

METHODS

This study comprised our initial experience in 22 patients with atrial fibrillation who were scheduled for an electrophysiology study (EPS) and pulmonary vein ablation and who had a contraindication for iodinated contrast administration.

RESULTS

Of the 22 patients, 16 were men and ages ranged from 27 to 74 years (mean 56 years). Overall successful transseptal access was achieved in all 22. A control echocardiogram was performed in all patients. There were no complications in any case and no significant differences were found from the conventional transseptal puncture technique regarding procedure or fluoroscopy time.

CONCLUSIONS

A modification of the conventional transseptal puncture technique performed with fluoroscopy and EPS catheters for anatomical reference and an angioplasty wire is an option in cases with severe contrast hypersensitivity.

The influence of iatrogenic atrial septal defect on the prognosis of patients with atrial fibrillation between cryoablation and radiofrequency ablation

OBJECTIVE

The present study was to compare the incidence of septal defect (SD) in patients with atrial fibrillation (AF) who received radiofrequency ablation or cryoablation.

METHODS

A total of 293 AF patients were performed with radiofrequency ablation and cryoablation. Cardiac ultrasonography was performed to calculate left atrial diameter (LAD), left atrial ejection fraction (LAEF%), strain rate (SR), left ventricular systolic (SRs), left ventricular diastolic (SRe), and left atrial systole (SRa) before surgery, 3 months and 1 year after surgery. The patients were followed up to observe statin and angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) medication, AF recurrence, 6-min walk test, stroke, any symptoms caused by arrhythmia, and re-hospitalization.

RESULTS

The levels of LAD and SD were higher, while SRe and SRa were lower in the cryoablation group in the comparison with the radiofrequency ablation group after surgery (P<0.05). LAEF was lower in the cryoablation group than the radiofrequency ablation group after 3 months (P<0.05). After 1-year follow-up, no right-to-left shunt occurred in all patients with SD. The AF recurrence rate in SD group was higher than that in the normal group (P<0.05). The use of statin and the application of ACEI/ARB were protective factors, whereas hypertension, LAD, left atrial operation time, and surgical plan were risk factors.

CONCLUSION

SD affects left atrial function and increases the risk of AF recurrence. Hypertension, LAD, and left atrial operation time are risk factors for SD, whereas statin and ACEI/ARB drugs can reduce SD.

Interatrial septum dissection and atrial wall hematoma following transseptal puncture: A systematic review of the literature

BACKGROUND

Interatrial septum (IAS) dissection due to transseptal puncture (TSP) is a rare, underreported complication of the procedure. Data on the mechanism, diagnosis, and management of this complication are lacking.

METHODS

We conducted a systematic review of all reported cases of IAS dissection with or without associated LA hematoma due to TSP, by thoroughly searching MEDLINE and EMBASE through May 2019.

RESULTS

After screening of n = 882 studies, eight studies with a total of 19 patients addressed the complication of IAS dissection and/or LA hematoma secondary to TSP. Median age was 63 years with a 1:1 male to female ratio. Ablation of atrial fibrillation was the most frequently reported procedure (84%). Diagnosis was established using fluoroscopy with contrast injection (58%), TEE (32%) or intracardiac echocardiography (5%). The mechanism identified involved puncture of the septum secundum portion of the IAS, leading to transient needle passage into the extracardiac space. In the majority of patients, the hematoma remained localized in the IAS and management was conservative with progressive resolution of the hematoma during follow-up (95%). Two patients (11%) required further intervention by either pericardiocentesis or surgical drainage due to hemodynamic instability.

CONCLUSIONS

IAS dissection with or without hematoma after TSP remains an underdiagnosed entity. The main mechanism involves lesion to the septum secundum portion of the IAS, resulting in needle passage into the extracardiac space and local bleeding. Although conservative management may be sufficient in the majority of cases, interventional cardiologists should be familiar with this complication and its diagnosis.

Automated segmentation of the atrial region and fossa ovalis towards computer-aided planning of inter-atrial wall interventions

BACKGROUND AND OBJECTIVE

Image-fusion strategies have been applied to improve inter-atrial septal (IAS) wall minimally-invasive interventions. Hereto, several landmarks are initially identified on richly-detailed datasets throughout the planning stage and then combined with intra-operative images, enhancing the relevant structures and easing the procedure. Nevertheless, such planning is still performed manually, which is time-consuming and not necessarily reproducible, hampering its regular application. In this article, we present a novel automatic strategy to segment the atrial region (left/right atrium and aortic tract) and the fossa ovalis (FO).

METHODS

The method starts by initializing multiple 3D contours based on an atlas-based approach with global transforms only and refining them to the desired anatomy using a competitive segmentation strategy. The obtained contours are then applied to estimate the FO by evaluating both IAS wall thickness and the expected FO spatial location.

RESULTS

The proposed method was evaluated in 41 computed tomography datasets, by comparing the atrial region segmentation and FO estimation results against manually delineated contours. The automatic segmentation method presented a performance similar to the state-of-the-art techniques and a high feasibility, failing only in the segmentation of one aortic tract and of one right atrium. The FO estimation method presented an acceptable result in all the patients with a performance comparable to the inter-observer variability. Moreover, it was faster and fully user-interaction free.

CONCLUSIONS

Hence, the proposed method proved to be feasible to automatically segment the anatomical models for the planning of IAS wall interventions, making it exceptionally attractive for use in the clinical practice.

Transseptal Access to the Left Atrium: Tips and Tricks to Keep it Safe Derived from Single Operator Experience and Review of the Literature

BACKGROUND

Transseptal puncture (TSP) remains a demanding procedural step in accessing the left atrium with inherent risks and safety concerns, mostly related to cardiac tamponade.

OBJECTIVE

Based on our own experience with 249 TSP procedures and in-depth literature review, we present our results and offer several tips and tricks that may render TSP successful and safe.

METHODS

This prospective study comprised 249 consecutive patients (146 men), aged 41.6±17.4 years, undergoing TSP by a single operator for ablation of a variety of arrhythmias, mostly related to left accessory pathways (n=145) or left atrial tachycardias (n=33) and more recently, atrial fibrillation (n=70). TSP was guided by fluoroscopy alone in all patients without the use of echocardiography imaging. In addition, an extensive literature review of TSP-related topics was carried out in PubMed, Scopus and Google Scholar.

RESULTS

Among 249 patients, 33 patients were children or young adolescents (aged 7-18 years); 14 patients were undergoing a repeat procedure. Patients with a manifest accessory pathway were the youngest (mean age 33.7±15.9) and patients with atrial fibrillation the oldest (mean age 56.0±10.8 years). A successful TSP was accomplished in 247 patients (99.2%). Two (0.8%) procedures were complicated by cardiac tamponade managed successfully with pericardiocentesis or surgical drainage. Review of the literature revealed no systematic reviews and meta-analyses of TSP studies; however, several patient series have documented that fluoroscopy-guided TSP, with various modifications in the technique employed in the present series, have been effective in 95-100% of the cases with a complication rate ranging from 0.0% to 6.7%, albeit with a mortality rate of 0.018%- 0.2%. Echo imaging techniques were employed in cases with difficult TSP.

CONCLUSION

Employing a standardized protocol with use of fluoroscopy alone minimized serious complications to 0.8% (2 patients) among 249 consecutive patients undergoing TSP for ablation of a variety of cardiac arrhythmias. Based on this single-operator experience and review of the literature, a list of practical tips and tricks is provided for a successful and safe procedure, reserving the more expensive and patient inconveniencing echo-imaging techniques for difficult or failed cases.

Through-needle all-optical ultrasound imaging in vivo: a preclinical swine study

High-frequency ultrasound imaging can provide exquisite visualizations of tissue to guide minimally invasive procedures. Here, we demonstrate that an all-optical ultrasound transducer, through which light guided by optical fibers is used to generate and receive ultrasound, is suitable for real-time invasive medical imaging in vivo. Broad-bandwidth ultrasound generation was achieved through the photoacoustic excitation of a multiwalled carbon nanotube-polydimethylsiloxane composite coating on the distal end of a 300-μm multi-mode optical fiber by a pulsed laser. The interrogation of a high-finesse Fabry-Pérot cavity on a single-mode optical fiber by a wavelength-tunable continuous-wave laser was applied for ultrasound reception. This transducer was integrated within a custom inner transseptal needle (diameter 1.08 mm; length 78 cm) that included a metallic septum to acoustically isolate the two optical fibers. The use of this needle within the beating heart of a pig provided unprecedented real-time views (50 Hz scan rate) of cardiac tissue (depth: 2.5 cm; axial resolution: 64 μm) and revealed the critical anatomical structures required to safely perform a transseptal crossing: the right and left atrial walls, the right atrial appendage, and the limbus fossae ovalis. This new paradigm will allow ultrasound imaging to be integrated into a broad range of minimally invasive devices in different clinical contexts.

Recognizing and reacting to complications of trans-septal puncture

INTRODUCTION

The transseptal puncture (TSP) enables access to the left heart, through the fossa ovalis (FO), both in electrophysiology and in cardiac interventional procedures. TSP is usually safe in experienced hands. Sometimes TSP can be technically demanding and carries the risk of severe complications in approximately 1%. While performing a TSP, every effort should be taken in order to avoid complications. In the event of complications, prompt recognition and reaction are essential and a combined 'heart-team' management may be the most effective approach. Areas covered: Main TSP-related complications are cardiac tamponade, aortic root puncture, embolic stroke, transient ST elevation of inferior leads and iatrogenic atrial septal defect. A challenging TSP may be expected in presence of difficult IAS-FO anatomies, previous TSP, IAS occluder device and previous IAS surgical repair. Use of echo imaging and special needles (ie., radiofrequency needle and J-shaped guidewire) may avoid TSP-related complications in difficult settings. Expert commentary: Some tools are available to help minimize the risks of TSP. However, their availability might be limited. To increase safety of TSP, an adequate training of physicians, identification of patients in whom it might be difficult and a prompt recognition of complications seem to be the most important background.

Sequential Venous Percutaneous Transluminal Angioplasty and Balloon Dilatation of the Interatrial Septum during Percutaneous Edge-to-Edge Mitral Valve Repair

Percutaneous edge-to-edge mitral valve repair (PMVR) is widely used for selected, high-risk patients with severe mitral valve regurgitation (MR). This report describes a case of 81-year-old woman presenting with severe and highly symptomatic mitral valve regurgitation (MR) caused by a flail of the posterior mitral valve leaflet (PML). PMVR turned out to be challenging in this patient because of a stenosis and tortuosity of both iliac veins as well as sclerosis of the interatrial septum, precluding the vascular and left atrial access by standard methods, respectively. We managed to achieve atrial access by venous percutaneous transluminal angioplasty (PTA) and balloon dilatation of the interatrial septum. Subsequently, we could advance the MitraClip® system to the left atrium, and deployment of the clip in the central segment of the mitral valve leaflets (A2/P2) resulted in a significant reduction of MR.

Transseptal puncture - Review of anatomy, techniques, complications and challenges

In recent years, the transseptal puncture approach has enabled passage of increasingly large and complex devices into the left atrium. Traditional tools remain effective in creating and dilating the initial puncture, with an acceptable safety profile. Even for skilled operators, the procedure is technically demanding and requires sound understanding of atrial anatomy. Intracardiac echocardiography is useful in cases of previous septal repair, poorly defined fossa ovalis anatomy or when considering patent foramen ovale portal crossing. Iatrogenic atrial septal defect (iASD) is the most commonly encountered long-term complication and there is increasing evidence that larger devices are leading to symptomatic defects. The size of the sheath crossing the septum is the strongest predictor of iASD formation but other factors such as longer procedure times, significant catheter manipulation and high pulmonary pressures also contribute. Transcatheter mitral valve repair involves the use of large 22 Fr catheters which carry alarmingly high rates of defect persistence with precipitation of symptoms and possible influence on mortality. Long-term follow up data, particularly beyond the 12-month period are lacking and resultantly, evidence to guide management is sparse. Refinements of conventional instruments, as well as innovations to puncture the septum without mechanical pressure, herald a progressively safer future for the transseptal technique.

Modified Transseptal Puncture Technique in Challenging Septa: A Randomized Comparison to Conventional Technique

Background. Transseptal puncture (TSP) can be challenging. We compared safety and efficacy of a modified TSP technique (“mosquito” technique, MOSQ-TSP) to conventional TSP (CONV-TSP). Method. Patients undergoing AF ablation in whom first attempt of TSP did not result in left atrial (LA) pressure (failure to cross, FTC) were randomized to MOSQ-TSP (i.e., puncture of the fossa via a wafer-thin inner stylet) or CONV-TSP (i.e., additional punctures at different positions). Primary endpoint was LA access. Secondary endpoints were safety, time, fluoroscopic dose (dose-area product, DAP), and number of additional punctures from FTC to final LA access. Result. Of 384 patients, 68 had FTC (MOSQ-TSP, n = 34 versus CONV-TSP, n = 34). No complications were reported. In MOSQ-TSP, primary endpoint was 100% (versus 73.5%, p < 0.002), median time to LA access was 72 s [from 37 to 384 s] (versus 326 s [from 75 s to 1936 s], p < 0.002), mean DAP to LA access was 1778 ± 2315 mGy/cm² (versus 9347 ± 10690 mGy/cm², p < 0.002), and median number of additional punctures was 2 [1 to 3] (versus 0, p < 0.002). Conclusion. In AF patients in whom the first attempt of TSP fails, the “mosquito” technique allows effective, safe, and time sparing LA access. This approach might facilitate TSP in elastic, aneurysmatic, or fibrosed septa.

Novel Solutions Applied in Transseptal Puncture: A Systematic Review

Access to the left atrium is required for several minimally invasive cardiac interventions in the left heart. For this purpose, transseptal puncture (TSP) technique is often performed, perforating the atrial septum under fluoroscopic or/and ultrasound imaging guidance. Although this approach has been used for many years, complications/failures are not uncommon mainly in patients with abnormal atrial anatomy and repeated TSP. Thus, this study presents an overview of methods and techniques that have been proposed to increase the safety and feasibility of the TSP. A systematic review of literature was conducted through the analysis of the articles published between 2008 and 2015. The search was performed in PubMed, Scopus, and ISI Web of Knowledge using the expression “transseptal puncture.” A total of 354 articles were retrieved from the databases, and 64 articles were selected for this review. Moreover, these 64 articles were divided into four categories, namely: (1) incidence studies, (2) intraprocedural guidance techniques, (3) preprocedural planning methods, and (4) surgical instruments. A total of 36 articles focused on incidence studies, 24 articles suggested novel intraprocedural guidance techniques, 5 works focused on preprocedural planning strategies, and 21 works proposed surgical instruments. The novel 3D guidance techniques, radio-frequency surgical instruments, and pre-interventional planning approaches showed potential to overcome the main procedural limitations/complications, through the reduction of the intervention time, radiation, number of failures, and complications.

Suction catheter for enhanced control and accuracy of transseptal access

AIMS

Percutaneous structural heart therapies, such as mitral value repair, require site-specific transseptal access (TSA). This can be challenging for interventional cardiologists. We describe a TSA catheter (TSAC) that utilises suction for enhanced control and puncture accuracy. Here, we aim to evaluate the safety and efficacy of the device.

METHODS AND RESULTS

Ex vivo interatrial septum preparations were dissected from swine (n=8) and diseased human hearts (n=6) to quantify TSAC suction and needle puncture force. TSAC suction was 6.5-fold greater than the opposing needle puncture force, and thus provides sufficient stabilisation for punctures. The safety and efficacy of TSAC was evaluated in a chronic mitral regurgitation swine model (n=10) and compared to a conventional TSA device. MR was induced by disrupting one to three mitral chordae tendineae, and the progression of heart disease was followed for three weeks. During device testing, procedure time and fluoroscopy exposure were not statistically different between devices. TSAC reduced septal displacement from 8.7±0.30 mm to 3.60±0.19 mm (p<0.05) and improved puncture accuracy 1.75-fold.

CONCLUSIONS

TSAC provides controlled TSA and improves puncture accuracy, while maintaining procedure time and workflow. These findings provide a strong rationale for a first-in-man study to demonstrate the clinical utility of the device.

Transseptal puncture by CTP-2 method: Results from cardiac computed tomography analysis and clinical application

The current used parameters for transseptal puncture (TSP) under fluoroscopic guidance is from left atriography and need to be verified by precise anatomic measurement. From February 2009 to July 2013, consecutive patients who received computed tomography (CT) were included. Landmarks and parameters were preliminary studied by right atriography, and further evaluated on the CT images of 1001 patients. A method (CTP-2) was proposed for guiding TSP. In right anterior oblique 45° view, the CTP-2 method was defined by points C, T, and P, and 2 areas: point C is in coronary sinus; point T is at a distance of dCT (usually 1.5 ± 0.2 vertebral height) over point C; then point P, the optimal puncture site, was located at 0.5 ± 0.2 vertebral body height posterior to point T; puncture should avoid the aortic root area and the rear triangle area; the aortic root area could be negatively revealed by right atriography at the orifice of inferior vena cava, and the rear triangle area is demarcated by points C, C', and T' (C' and T' are 2 points horizontally posterior to, and at dCT away from points C and T, respectively). The initial application of CTP-2 in 2820 patients showed that it might be helpful in reducing the need of left atriography and the possibility of cardiac perforation.

Direct transatrial pericardiocentesis for tamponade caused by left atrial perforation after trans-septal puncture

Trans-septal puncture is associated with risks of serious complications. We report a case of an obese 52-year-old man with hypertrophic cardiomyopathy who underwent preoperative coronary angiography and cardiac catheterisation complicated by left atrial perforation. We describe a direct transatrial pericardiocentesis approach to treating cardiac tamponade.

Morphological study of fossa ovalis and its clinical relevance

AIMS

Patent foramen ovale (PFO) has been implicated in the etiology of a number of different pathologies, including cryptogenic stroke, decompression sickness in divers, etc. It can act as a channel for paradoxical embolism. PFO is not an uncommon condition, with a probe-patency in 15-35% population. The fossa ovalis (FOv) varies in size and shape from heart to heart; the prominence of annulus FOv also varies. The entire FOv may be redundant and aneurysmal. The anatomico-functional characterization of interatrial septum seems to be of paramount importance for both atrial septal defect (ASD) and PFO, not only for the device selection, but also for the evaluation of the outcome of this procedure.

METHOD

This study was conducted in 50 apparently normal hearts available in Department of Anatomy. After opening the right atrium, the shape of FOv was observed. The size was measured with the digital vernier caliper; the prominence and extent of limbus, and the redundancy or otherwise of FOv were noted; probe patency was confirmed.

RESULTS

In the majority, FOv was oval (82%); average transverse diameter was 14.53mm and vertical 12.60mm. In 90%, the rim of the annulus was raised; in 20%, a recess was found deep to the margin of the annulus; and 18% showed probe patency.

CONCLUSION

As no study of this nature has been carried out in the Indian population, this provides pertinent information on the morphology of FOv, which may be useful for device selection in treating ASD and PFO.

Transcardiac endograft delivery for endovascular treatment of the ascending aorta: a feasibility study in pigs

PURPOSE

To compare the technical feasibility and hemodynamic alterations during antegrade transcardiac access routes vs conventional transfemoral access (TFA) for endovascular treatment of the ascending aorta in a porcine model.

METHODS

Antegrade transseptal access (TSA), transapical access (TAA), and TFA were used for implantation of custom-made endografts into the ascending aorta under fluoroscopy (6 pigs each). Hemodynamic parameters, myocardial and cerebral blood flow, and carotid artery blood flow were evaluated during baseline (T1), sheath advancement (T2), after sheath retraction (T3), and after endograft deployment (T4).

RESULTS

Endograft deployment was feasible in all animals; all coronary arteries remained patent. Hemodynamic parameters were comparable in all 3 study groups during all measurements. During T2, transient hemodynamic alteration occurred in all groups, with transient severe valve insufficiency in TSA and TAA reflected by the higher pulmonary to mean arterial pressure ratio (p<0.05) as compared with TFA. Values stabilized again at T3 and remained stable until T4. The innominate artery was partially occluded in 4 (TSA), 3 (TAA), and 5 (TFA) animals. There was no deterioration of myocardial or cerebral perfusion during the procedures. Endograft deployment and fluoroscopy times during TAA were shorter than in TSA and TFA.

CONCLUSIONS

TSA, TFA, and TAA to the ascending aorta are feasible for endograft delivery to the ascending aorta in a porcine model. Transient hemodynamic instability in TSA and TAA recovered to near preoperative values. TAA appeared technically easier.

Intracardiac echocardiography guided transeptal catheter injection of microspheres for assessment of cerebral microcirculation in experimental models

The use of microspheres for the determination of regional microvascular blood flow (RMBF) has previously used different approaches. This study presents for the first time the intracardiac injection of microspheres using transeptal puncture under intracardiac echocardiography guidance. Five Merino sheep were instrumented and cardiovascularly supported according to local guidelines. Two catheter sheaths into the internal jugular vein facilitated the introduction of an intracardiac probe and transeptal catheter, respectively. Five million colour coded microspheres were injected into the left atrium via this catheter. After euthanasia the brain was used as proof of principle and the endpoint for determination of microcirculation at different time points. Homogeneous allocation of microspheres to different regions of the brain was found over time. Alternate slices from both hemispheres showed the following flow ranges: for slice 02; 0.57–1.02 mL/min/g, slice 04; 0.45–1.42 mL/min/g, slice 06; 0.35–1.87 mL/min/g, slice 08; 0.46–1.77 mL/min/g, slice 10; 0.34–1.28 mL/min/g. A mixed effect regression model demonstrated that the confidence interval did include zero suggesting that the apparent variability intra- and intersubject was not statistically significant, supporting the stability and reproducibility of the injection technique. This study demonstrates the feasibility of the transeptal injection of microspheres, showing a homogeneous distribution of blood flow through the brain unchanged over time and has established a new interventional model for the measurement of RMBF in ovine models.

Implantation of the AMPLATZER™ Cardiac Plug: tips and tricks

The AMPLATZER™ Cardiac Plug device is designed for percutaneous occlusion of the left atrial appendage (LAA) for stroke prophylaxis in patients with atrial fibrillation (AF) who are contraindicated or intolerant to oral anticoagulation. While updated guidelines start to refer to this therapy (Camm A, Eur Heart J, doi:10.1093/eurheartj/ehs253, 2012) and operators gain experience with this relatively new technique, continuing efforts are focused on maximizing the safety of the implantation procedure. This paper is aimed at explaining and illustrating the distinct steps and specific considerations related to the implantation of the AMPLATZER™ Cardiac Plug.

Added value of transoesophageal echocardiography during transseptal puncture performed by inexperienced operators

AIMS

Transseptal puncture (TP) appears to be safe in experienced hands; however, it can be associated with life-threatening complications. The aim of our study was to demonstrate the added value of routine use of transoesophageal echocardiography (TEE) for the correct positioning of the transseptal system in the fossa ovalis, thus potentially preventing complications during fluoroscopy-guided TP performed by inexperienced operators.

METHODS AND RESULTS

Two hundred and five patients undergoing pulmonary vein isolation procedure (PVI) for drug-resistant paroxysmal or persistent atrial fibrillation were prospectively included. When the operator (initially blinded to TEE) assumed that the transseptal system was in a correct position according to fluoroscopical landmarks, the latter was then checked with TEE unblinding the physician. If necessary, further refinement of the catheter position was performed. Refinement >10 mm, or in case of catheter pointing directly at the aortic root or posterior wall were considered as major repositioning. Thirty-four patients required major repositioning. Regression analysis revealed age (P: 0.0001, Wald: 12.9, 95% confidence interval: 1.04-1.16), left atrial diameter (P: 0.01, Wald: 6.6, 95% confidence interval: 1.04-1.34), previous PVI (P: 0.01, Wald: 6.3, 95% confidence interval: 1.31-8.76), and atrial septal thickness (P: 0.03, Wald: 4.5, 95% confidence interval: 1.05-3.4) as independent predictors of major revision with TEE.

CONCLUSION

Routine 2D TEE in addition to traditional fluoroscopic TP appears to be very useful to guide the TP assembly in a correct puncture position and thus, to avoid TP-related complications. However, further randomized prospective comparative studies are necessary to support these suggestions.

Percutaneous transseptal left atrial drainage for decompression of the left heart in an adult patient during percutaneous cardiopulmonary support

A 28-year-old male with hemophagocytic lymphohistiocytosis presented with left ventricular dysfunction and cardiac arrest. Percutaneous cardiopulmonary support (PCPS) was initiated, but left heart distension developed with associated aggravation of pulmonary edema. Percutaneous transseptal left atrial sheath (28-Fr) drainage was incorporated into the PCPS venous circuit under fluoroscopic guidance to enable left heart decompression 1 days after PCPS initiation. The patient's pulmonary edema improved markedly, and distention of his left heart diminished. He was successfully weaned from PCPS 5 days later. Percutaneous transseptal left atrial drainage with large venous cannulae is feasible and effective in decompressing the left heart in adult patients during PCPS.

Transseptal left heart catheterization and the incidence of persistent iatrogenic atrial septal defects

INTRODUCTION

Access to the left atrium for invasive and interventional cardiac procedures requires a transseptal (TS) puncture that creates an iatrogenic atrial septal defect (iASD). The utilization of TS access is increasing in cardiology, and the frequency of iASD is, therefore, likely to increase as well. Here, we discuss the TS technique, review existing series of iASD with regard to incidence and clinical significance of residual iASD, and present emerging techniques utilizing TS access where iASD may result.

METHODS AND RESULTS

A PubMed search for "iatrogenic atrial septal defects" was performed to identify prospective series addressing the incidence of iASDs after TS procedures. We identified 10 series with primary attention to iASD. Cases involving TS access included electrophysiology ablation procedures, atrial appendage closure, and percutaneous balloon mitral valvuloplasty. Immediate postprocedural incidence of iASD was as high as 87%, with decreased incidence of residual iASD detected over time. At 18 months of follow-up, up to 15% of iASD cases persisted. Residual iASDs were not associated with clinical sequelae of embolism, cyanosis, or right heart failure.

CONCLUSIONS

iASDs are frequent following TS access and a majority resolve over time. Available evidence suggests iASDs are well tolerated but late term follow-up is limited. With the increased utilization of TS transcatheter procedures, the frequency and size of iASDs may rise. Understanding the rare but serious clinical implications of iASD and the need for systematic surveillance in the future is warranted.

Transradial catheter ablation of left accessory pathway in patient with severe chest deformity

A 45-year-old woman with severe chest deformity and great vessel tortuosity successfully underwent left accessory pathway ablation of atrioventricular reentrant tachycardia via right transradial arterial access. Transradial catheter ablation of left accessory pathway was safe and efficacious without complications. When transfemoral or transseptal access was impossible, transradial access was a good alternative route.