Defibrillation threshold in elective subcutaneous implantable defibrillator generator replacements: Time to reduce the size of the pulse generator?

INTRODUCTION: The first step-down defibrillation studies in the subcutaneous implantable cardioverter-defibrillator (S-ICD) described a defibrillation threshold (DFT) of 32.5 ± 17.0 J and 36.6 ± 19.8 J. Therefore, the default shock output of the S-ICD was set at 80 J. In de novo implants, the DFT is lower in optimally positioned S-ICDs. However, a retrospective analysis raised concerns about a high DFT in S-ICD replacements, possibly related to fibrosis. OBJECTIVE: We aimed to find the DFT in patients undergoing S-ICD generator replacement. METHODS: This prospective study enrolled patients who underwent S-ICD generator replacement with subsequent defibrillation testing. A pre-specified defibrillation testing protocol was used to determine the DFT, defined as the lowest shock output that effectively terminated the induced ventricular arrhythmia. RESULTS: A total of 45 patients were enrolled, 6.0 ± 2.1 years after initial implant. Mean DFT during replacement in the total cohort was 27.4 ± 14.3 J. In patients with a body mass index (BMI) 18.5-25 kg/m2 (N = 22, BMI 22.5 ± 1.6), median DFT was 20 J (IQR 17.5-30). In 18/22 patients, the DFT was ≤30 J and 5/22 patients were successfully defibrillated at 10 J. One patient with hypertrophic cardiomyopathy had a DFT of 65 J. In patients with a BMI >25 kg/m2 (N = 23, BMI 29.5 ± 4.2), median DFT was 30 J (IQR 20-40). In 15/23 patients, the DFT was ≤30 J and 4/23 patients had a successful defibrillation test at 10 J. CONCLUSIONS: This study eases concerns about a high DFT after S-ICD generator replacement. The majority of patients had a DFT ≤30 J, regardless of BMI, suggesting that the shock output of the S-ICD could be safely reduced.

Changes in the occlusal function of orthognathic patients with vertical malformations after combined orthodontic surgical therapy: a prospective clinical study.

The aim of this study was to assess the changes in occlusal patterns during combined surgical and orthodontic therapy in patients with vertical jaw malformations. Twenty-six orthognathic patients (18 female, eight male; median age 25 years, interquartile range 11.5 years) and 10 control patients (five female, five male; median age 29.8 years, interquartile range 13.5 years) recruited from neutral configured patients attending the Department of Orthodontics, were investigated. Based on cephalometry, the patients were grouped into vertical skeletal configurations of either open, deep, or natural bite cases. Registrations of the occlusal contacts were taken using a digital occlusal sensor immediately before surgery and at 9 months after the surgical intervention. Before the intervention, open and deep bite patients showed significantly less efficient occlusal patterns than the untreated controls regarding total tooth contact (P < 0.001), time of occlusion (P = 0.002), occlusal asymmetry (P = 0.001), anterior tooth contact (P < 0.001), and posterior tooth contact (P < 0.001). After surgery, the parameters in the deep bite patients were similar to those in the controls; however, in open bite patients, total tooth contact (P = 0.003), occlusal asymmetry (P = 0.011), and posterior tooth contact (P = 0.035) differed significantly. In conclusion, combined orthodontic and surgical correction of vertical malocclusions was found to improve occlusal function in patients with deep bite to the level of controls.

Defibrillation testing during implantation of the subcutaneous implantable cardioverter-defibrillator: a necessary standard or becoming redundant?

Since the publication of the SIMPLE and NORDIC trials, defibrillation testing (DFT) is rarely performed during routine implantation of transvenous implantable cardioverter-defibrillators (ICD). However, the results of these trials cannot be extrapolated to the later introduced subcutaneous ICD (S-ICD) and a class I recommendation to perform DFT during the implantation of these devices remains in the current guidelines. Due to the high conversion success rate of DFT on one hand, and the risk of complications on the other, a significant number of physicians omit DFT in S­ICD recipients. Several retrospective analyses have assessed the safety of the omission of DFT and report contradicting results and recommendations. It is known that implant position, as well as device factors and patient characteristics, influence defibrillation success. A better comprehension of these factors and their relationship could lead to more reliable and safer alternatives to DFT. An ongoing randomised clinical trial, which is expected to end in 2023, is the first study to implement a method that assesses implant position to identify patients who are likely to fail their DFT.

A new approach in three dimensions to define pre- and intraoperative condyle-fossa relationships in orthognathic surgery - is there an effect of general anaesthesia on condylar position?

Incorrect registration of the condylar position in orthognathic surgery is supposed to cause postoperative relapse, condylar resorption and temporomandibular disorders. The aim of this prospective study was to evaluate the influence of general anaesthesia on centric relation (CR). Therefore, CR registered preoperatively in the awake patient and CR registered intraoperatively under general anaesthesia were recorded in 30 patients (14 men, 16 women) undergoing orthognathic surgery (skeletal class I: n=3, II: n=13, III: n=14; symmetric: n=20; asymmetric: n=10). CR records were digitized and, through superimposition on the preoperative cone beam computed tomography of the patient's skull, the superior, anterior and posterior joint space and the volumetric congruence of 120 condyles were analysed. The linear measurements of joint spaces did not demonstrate any clinically relevant discrepancy between the CR measured in the awake and anaesthetized patient. In contrast, volumetric analysis revealed statistically significant differences between both states, with an intraoperative condylar sag predominantly in the posterior-inferior direction. The patient's skeletal class or symmetry had no significant influence on the intraoperative condylar displacement. Thus, the risk of fixing the condyle in an unphysiological position supports the idea of using intraoperative condylar positioning devices to achieve predictable and stable outcomes.

Three-dimensional head shape acquisition in preterm infants - Translating an orthodontic imaging procedure into neonatal care.

BACKGROUND: Head shape and head volume of preterm infants give important information on short- and long-term development. Three-dimensional (3D) assessment of a preterm infant's head would therefore provide more information than currently used two-dimensional methods. AIMS: To evaluate a contactless 3D imaging system to assess head shape and volume in preterm infants. METHODS: A protocol for 3D imaging and reconstruction of an infant's head with a portable stereophotogrammetric camera system was developed. It was validated on a manikin by comparison to an established stationary stereophotogrammetric device. Feasibility for clinical routine and 3D data analysis were assessed in six preterm infants. RESULTS: Ten 3D reconstructions from a manikin were done with ten images each taken from different angles. The accuracy of the 3D reconstruction was measured at the overlapping areas between two images. Comparing the portable to the stationary system, a high concordance was found for the 3D manikin head-reconstructions (mean difference 0.21 ±â€¯0.03 mm). In preterm infants, digital evaluation of the head was proven to be feasible for head circumference (HC), cranial index and asymmetry indices. There was good concordance between manual and digital measurement of the HC (95% CI -0.85 to 0.38 mm). CONCLUSIONS: The portable camera system allowed fast and contactless 3D image capture of a preterm infant's head without any risk or interference with neonatal care. Together with a new software, this technique would allow more precise evaluation of head growth even in very preterm infants and thereby may improve their care and long-term outcome.

Traditional face-bow transfer versus three-dimensional virtual reconstruction in orthognathic surgery.

Face-bow transfer is an essential step in articulator-based orthognathic surgery planning. However, it can be a source of inaccuracy. Virtual computer-based planning avoids this error through the use of direct patient-related three-dimensional imaging data. The aim of this prospective observational study was to determine the error of face-bow transfer three-dimensionally and correlate it to the different types of malocclusion. Orthognathic surgery performed on 38 patients (10 male, 28 female; mean (standard deviation) age 24.7 (6.9) years) was planned twice: first articulator-based with plaster models and second computer-based with surgery planning software. Both models were digitized and compared regarding the angle between the Frankfort horizontal plane and the occlusal plane. In most cases, the angle in the sagittal dimension was higher in the articulator-based model than in the computer-based model. The angle in the transverse dimension was as often under- as over-represented. The type of malocclusion, i.e. skeletal class, vertical relationship, and degree of asymmetry, had no significant impact on the amount of error. In conclusion, this study indicates that computer-based planning should be considered as an advantageous alternative in orthognathic surgery planning.

Comparison of complications and shocks in paediatric and young transvenous and subcutaneous implantable cardioverter-defibrillator patients.

BACKGROUND: Young implantable cardioverter-defibrillator (ICD) patients are prone to complications and inappropriate shocks (IAS). The subcutaneous ICD (S-ICD) may avoid lead-related complications. This study aims to describe the incidence and nature of device-related complications in young transvenous ICD (TV-ICD) and S­ICD patients. METHODS: Single-chamber TV-ICD and S­ICD patients up to and including the age of 25 years implanted between 2002 and 2015 were retrospectively analysed. Complications were defined as device-related complications requiring surgical intervention. IAS were defined as shocks for anything other than ventricular tachycardia or ventricular fibrillation. Follow-up data were collected 5 years post-implantation. Kaplan-Meier estimates for complications at 5­year follow-up were calculated with a corresponding 95% confidence interval. RESULTS: Eighty-one patients (46 TV-ICD, 35 S-ICD) were included (median age 19.0 (IQR 16.0-23.0) and 16.5 (IQR 13.0-20.2) years respectively). Median follow-up was 60 and 40 months respectively. All-cause complication rate was 34% in the TV-ICD group and 25% in the S­ICD group (p = 0.64). TV-ICD patients had more lead complications: 23% (10-36%) versus 0% (p = 0.02). The rate of infections did not differ between TV-ICD and S­ICD: 2% (0-6%) versus 10% (0-21%) (p = 0.15). No systemic infections occurred in the S­ICD patients. The rates of IAS were similar, TV-ICD 22% (9-35%) versus S­ICD 14% (0-30%) (p = 0.40), as were those for appropriate shocks: 25% (11-39%) versus 27% (6-48%) (p = 0.92). CONCLUSION: The rates of all-cause complications in this cohort were equal, though the nature of the complications differed. S­ICD patients did not suffer lead failures or systemic infections. An era effect is present between the two groups.

Facial perception of infants with cleft lip and palate with/without the NAM appliance.

OBJECTIVE: This study aimed to assess adults' subjective perception of infants with a unilateral cleft lip and palate (UCLP) with and without a nasoalveolar molding (NAM) appliance compared to those of controls concerning (1) adult gaze patterns and (2) emotional valence. METHODS: This interdisciplinary study was performed by (1) the Department of Orthodontics and (2) the Department for Psychiatry and Psychotherapy, University Medical Center Goettingen, using eye tracking and a 10-point Likert scale questionnaire. Eye movements and valence rating of 30 unaffected adults (15 women, 15 men; mean age: 25.5 years, standard deviation [SD] = 7.5) were recorded while presenting them infants in three picture categories (1) infant with UCLP, (2) infant with UCLP and inserted NAM appliance and (3) infant without UCLP. Total fixation time in two main areas of interest (AOI upper/lower face) was measured according to picture category as well as participants' valence rating regarding infants' appearance. RESULTS: In pictures of infants with UCLP or UCLP and NAM appliance participants had longer fixation times on AOI lower face compared to reconstructed pictures of infants without UCLP. No significant effect of a NAM appliance on gaze patterns could be detected. The valence of pictures of infants with UCLP was rated more negative compared to pictures of unaffected infants. An inserted NAM appliance improved this rating. CONCLUSIONS: The results bolster the assumption that facial disruptions like UCLP alter adults' perception of infants. Even though the NAM appliance is not able to re-establish usual adult gaze patterns, it can help to improve adults' emotional assessment.

An Overview of Clinical Outcomes in Transvenous and Subcutaneous ICD Patients.

PURPOSE OF REVIEW: Clear guidelines on when to select a subcutaneous ICD (S-ICD) over a transvenous ICD (TV-ICD) are lacking. This review will provide an overview of the most recent clinical data on S-ICD and TV-ICD therapy by pooling comparison studies in order to aid clinical decision making. RECENT FINDINGS: Pooling of observational-matched studies demonstrated an incidence rate ratio (IRR) for device-related complication of 0.90 (95% CI 0.58-1.42) and IRR for lead-related complications of 0.15 (95% CI 0.06-0.39) in favor of S-ICD. The IRR for device infections was 2.00 (95% CI 0.95-4.22) in favor of TV-ICD. Both appropriate shocks (IRR 0.67 (95% CI 0.42-1.06)) and inappropriate shocks (IRR 1.17 (95% CI 0.77-1.79)) did not differ significantly between both groups. With randomized data underway, the observational data demonstrate that the S-ICD is associated with reduced lead complications, but this has not yet resulted in a significant reduction in total number of complications compared to TV-ICDs. New technologies are expected to make the S-ICD a more attractive alternative.

Outpatient treatment with the wearable cardioverter defibrillator: clinical experience in two Dutch centres.

INTRODUCTION: The latest European Society of Cardiology Guidelines recommend consideration of a wearable cardioverter-defibrillator (WCD) for patients with a poor left ventricular ejection fraction (LVEF) who are at risk of sudden arrhythmic death but are not eligible for an implantable defibrillator. For these patients a WCD can be an alternative to long-term hospitalisation. PURPOSE: To evaluate the use of WCD therapy in these patient groups in two Dutch centres. METHODS: All consecutive patients treated with the WCD between 2009 and 2016 were included from two centres in the Netherlands. Data on events and compliance were collected retrospectively through home monitoring systems and adjudicated by the investigators. RESULTS: A total of 79 patients were treated with a WCD. Common indications were newly diagnosed cardiomyopathy without optimal medical treatment in 46 patients (58.2%) and bridge to implantable cardioverter-defibrillator (ICD) implant in 33 patients (41.8%). Bridge to implant indications consisted of contraindications for immediate implantation such as infections (e. g. previous device-related infections) and radiotherapy. Compliance was over 97% per day (median 23.3 h, 22.6-23.7), during a median of 79 days (50.0-109.8.0). Two patients (2.6%) received an appropriate shock (annual rate 13.6%), there was 1 (1.3%) inappropriate shock (annual rate 6.7%). In 24 patients (52.2%) without optimal medical treatment, the LVEF was sufficiently improved and ICD implant was avoided. Eight (10.1%) patients did not receive an ICD. In 45 patients an ICD was implanted (57.0%). CONCLUSION: WCD therapy provides a safe and effective treatment in outpatient setting for patients at high risk for sudden cardiac death and reduces the number of ICDs implanted.