Real-world experience of leadless left ventricular endocardial cardiac resynchronization therapy: A multicenter international registry of the WiSE-CRT pacing system

Background

Biventricular endocardial pacing (BiV ENDO) is a therapy for heart failure patients who cannot receive transvenous epicardial cardiac resynchronization therapy (CRT) or have not responded adequately to CRT. BiV ENDO CRT can be delivered by a new wireless LV ENDO pacing system (WiSE-CRT system; EBR Systems, Sunnyvale, CA), without the requirement for lifelong anticoagulation.

Objective

The purpose of this study was to assess the safety and efficacy of the WiSE-CRT system during real-world clinical use in an international registry.

Methods

Data were prospectively collected from 14 centers implanting the WiSE-CRT system as part of the WiCS-LV Post Market Surveillance Registry. (ClinicalTrials.gov Identifier: NCT02610673).

Results

Ninety patients from 14 European centers underwent implantation with the WiSE-CRT system. Patients were predominantly male, age 68.2 ± 10.5 years, left ventricular ejection fraction 30.6% ± 8.9%, mean QRS duration 180.7 ± 27.0 ms, and 40% with ischemic etiology. Successful implantation and delivery of BiV ENDO pacing was achieved in 94.4% of patients. Acute (<24 hours), 1- to 30-day, and 1- to 6-month complications rates were 4.4%, 18.8%, and 6.7%, respectively. Five deaths (5.6%) occurred within 6 months (3 procedure related). Seventy percent of patients had improvement in heart failure symptoms.

Conclusion

BiV ENDO pacing with the WiSE-CRT system seems to be technically feasible, with a high success rate. Three procedural deaths occurred during the study. Procedural complications mandate adequate operator training and implantation at centers with immediately available cardiothoracic and vascular surgical support.

The effect of mechanically-induced cricoid force on lower oesophageal sphincter pressure in anaesthetised patients

In the United Kingdom, cricoid force is central to upper airway management in obstetric and emergency anaesthesia. A reduction in oesophageal barrier pressure (OBP) in these patients may increase regurgitation risk. This study investigated whether the application of cricoid force to anaesthetised patients reduced lower oesophageal sphincter pressure (LOSP) and consequently OBP. Anaesthesia was induced in 29 patients using a standard protocol. An oesophageal balloon catheter was inserted and gastric trace identified. The catheter was withdrawn incrementally and pressure readings recorded at each position before and during the application of 30 N cricoid force, with a sudden rise in pressure indicating lower oesophageal sphincter position. Oesophageal barrier pressure was calculated as the difference between LOSP and gastric pressure. Application of cricoid force significantly reduced OBP without influencing gastric pressure (p < 0.001). The use of cricoid force may increase the risk of gastroesophageal reflux in anaesthetised patients.

Glass bottle workers exposed to low-dose irritant fumes cough but do not wheeze

Workers exposed to irritant fumes experience symptoms both during the acute episode and afterwards. High-dose irritant exposure can result in permanent asthma, but the effects of chronic low-dose irritant exposure are not known. Glass bottle workers are exposed to irritant fumes, and have previously been reported to have an excess of symptoms. We designed a study to compare irritant-exposed glass bottle workers with hospital workers matched for socioeconomic group, area of residence, age, sex, smoking habit, and allergic history. Symptoms reported, spirometry, flow cytometric indices of lymphocyte activation, and past medical and employment histories were compared. We also investigated the prevalence of bronchial hyperresponsiveness to inhaled methacholine and the cough response after inhalation of citric acid and capsaicin. Glass bottle workers showed an excess of upper respiratory tract symptoms, cough, and shortness of breath compared with matched hospital control workers. There was a significant excess of cough induced by citric acid and capsaicin in the bottle workers. However, wheeze, baseline spirometry, flow cytometry, and methacholine challenge were not significantly different between the two groups. These findings suggest that chronic irritant exposure produces an excess of symptoms and increased cough sensitivity but not asthma.

British Heart Rhythm Society Clinical Practice Guidelines on the Management of Patients Developing QT Prolongation on Antipsychotic Medication

The British Heart Rhythm Society’s Clinical Practice Guidelines on the Management of Patients Developing QT Prolongation on Antipsychotic Medication are written for heart rhythm consultants, primary care physicians, specialist registrars, nurses and physiologists who may be requested to review ECGs or advise on cases where antipsychotic-induced QT prolongation is suspected or proven. The guidance is adapted from the latest Maudsley Prescribing Guidelines in Psychiatry, published in 2018.

An assessment of the ability of impedance respirometry distinguish oesophageal from tracheal intubation

Accidental oesophageal intubation is still an important cause of anaesthetic morbidity and mortality. This study investigated the use of impedance respirometry to determine the position of a tracheal tube. Seventy-nine patients undergoing general anaesthesia requiring tracheal intubation with muscle relaxation were recruited to the study. After pre-oxygenation, tracheal tubes were placed in both the oesophagus and trachea; a breathing system was attached to one tube chosen randomly. A blinded observer was required to correctly identify the position of the tube within six tidal ventilations. The position of every tube connected to the breathing system was correctly identified. The median time to correctly identify tracheal and oesophageal tubes was 3 and 5 s, respectively. The median number of breaths to identify tracheal and oesophageal tubes was two for both groups. Every tube position was identified within the required six breaths. Impedance respirometry is a reliable method for diagnosing tracheal tube position.

The use of impedance respirometry to confirm tracheal intubation in children

Accidental oesophageal intubation can occur in children and is a cause of morbidity and mortality. This study investigated the use of impedance respirometry to determine tracheal tube position in children aged 1-10 years. Eighty children were recruited and, after induction of anaesthesia, two identical tracheal tubes were inserted: one into the trachea and one into the oesophagus. The breathing system was attached to one of the tubes chosen at random. A blinded observer was asked to identify the position of the tube within six breaths using impedance respirometry. The positions of 76 out of 80 tubes were correctly identified. Of those incorrectly identified, one was in the trachea and three were in the oesophagus. The sensitivity of the test was 0.975 and the specificity 0.925. The median number of breaths needed to identify the position of the tubes was 2.0 for both groups. This is not a perfect technique in the population studied but when used with other methods of tracheal tube position identification, its use could decrease the time taken to identify incorrect placement.

Flumazenil: a twelve-month survey of use in a New Zealand public hospital

As part of a program of postmarketing surveillance, the use of flumazenil was monitored prospectively in a New Zealand public hospital for a period of twelve months. A questionnaire on usage, efficacy and side-effects was completed by clinicians for 118 patients receiving the drug. Our conclusions are these: 1. Flumazenil was used most frequently after anaesthesia and in the initial management of intentional drug overdose. 2. In two-thirds of cases, flumazenil was used to antagonise benzodiazepines in the presence of non-benzodiazepine drugs and its efficacy was primarily determined by the presence of these latter drugs. 3. The complications of flumazenil are mild although important complications may arise from interaction with other drugs and unmasking of conditions such as postoperative pain. 4. Resedation was common (24%), although rarely a problem unless large doses of benzodiazepine agonist had been administered or if other hypnosedatives were given subsequently.

Cricoid yoke: the effect of surface area and applied force on discomfort experienced by conscious volunteers

BACKGROUND AND OBJECTIVE

The application of cricoid force is central to techniques that reduce the risk of gastric regurgitation and the subsequent pulmonary aspiration associated with obstetric and emergency anaesthesia. The discomfort associated with cricoid force in awake preoperative patients increases the incidence of coughing, struggling and pain during induction of anaesthesia. This study determined if increasing the surface area of a cricoid yoke reduced the associated discomfort in volunteers.

METHODS

Fifty volunteers participated in a randomized single-blinded study. The cricoid yoke was positioned using standard anatomical landmarks and forces of 10, 20, 30 and 40 N were applied in a random order for 20s, using two different yoke attachments with surface areas of 3 and 10 cm2. A rest of 30s was allowed between the application of forces. Discomfort was graded by volunteers on a scale from 0 to 10 (0: no discomfort; 10: worse discomfort imaginable). A score of 10 was allocated if the volunteers could not tolerate the applied force for 20s.

RESULTS

Median scores for the small yoke were always higher than those for the large yoke at each force. There were significant differences between the scores for the small and large yokes at 10 and 20 N (P < 0.001) and 30 N (P = 0.0233), but there was no significant difference at 40 N.

CONCLUSIONS

The larger yoke was tolerated better by volunteers when clinically relevant cricoid forces were applied.

Sarcoidosis presenting as complete heart block in a 45-year-old farmer: an aetiology not to miss

Sarcoidosis should always be part of the differential diagnosis when faced with a young patient with significant cardiac conduction disease.

863Leadless endocardial pacing improves symptoms in patients with failed conventional CRT implant in long term follow up

Funding Acknowledgements

EBR Systems, Inc

OnBehalf

WiSE-CRT and LV-SELECT study and POST-M REGISTRY

Background

The WiSE-CRT (Wireless stimulation endocardial) system has advantages over conventional epicardial CRT. Whenever conventional CRT failed to implant or failed to echocardiographic response, the WiSE-CRT was implanted as part of the WiSE CRT study (N = 13), as part of the LV-SELECT study (N = 35) or as part of the POST-M REGISTRY (N = 117) over the last 8 years. All these studies have reported high rates of clinical and echocardiographic response compared to conventional CRT.

Objectives

The purpose of this analysis was to determine the safety and clinical response in the largest available number of implanted patients (pts) with long term follow up of 2 years and the first, second and third generation of WiSE-CRT devices.

Method

All pts undergoing a WiSE-CRT implantation as part of the WiSE CRT study (N = 13), as part of the LV-SELECT study (N = 35) or as part of the POST-M REGISTRY (N = 117) were analysed (N = 165). Pts were followed-up for 24 months and considered CRT responders if an improvement in NYHA ≥ 1 class from baseline (pre-implant) was achieved.

Results

In total, 165 pts were implanted, demographics include: 68.2 ± 9.6 year’s old, 81.8% male, 49.7% with history of AFib and 54.5% non-ischaemic aetiology. The mean intrinsic QRS duration was 165.0 ± 32.3 msec (28 pts pace-maker dependent). 161 pts had the system successfully implanted with no major complications, 3 (1.8%) pts developed a pericardial effusion and 1 (0.6%) electrode was lost during implantation and recovered surgically. During the 24-month follow-up period, 20 (12.1%) pts died from any cause, 4 (2.4%) pts developed TIA or Stroke and 15 (9.1%) pts had pocket or transmitter infection. There was a significant improvement in NYHA functional class in 63.6% pts and an average improvement of -26.1 (-45.1, -7.1) msec in QRS duration.

Conclusion

Despite a history of failed conventional CRT implantation, pts undergoing CRT upgrades with a WiSE-CRT have a high success rate and a complication rate similar to previously described. In addition endocardial LV pacing led to symptomatic improvements in 64% of patients reaching the 24 month of follow up.

Abstract Figure 1: Forest Plot NYHA Responder Rat