Changes in aortic root dimensions post aortic root enlargement with Y-incision and modified aortotomy.

Background: Lifetime management in aortic stenosis (AS) can be facilitated by aortic root enlargement (ARE) to improve anatomy for future valve-in-valve (ViV) procedures. A mitral valve-sparing ARE technique ("Y-incision") and sinotubular junction (STJ) enlargement ("roof" patch aortotomy) allow upsizing by 3-4 valve sizes, but quantitative analysis of changes in root anatomy is lacking. Methods: Among 78 patients who underwent ARE by Y-incision technique (± roof aortotomy closure) we identified 45 patients with high-quality pre- and post-operative computed tomography angiography (CTA) scans to allow analysis of change in aortic root dimensions. Detailed measurements of the annulus/basilar ring and sinuses were performed by an expert imager on both pre- and post-operative CTAs. The basal ring was defined as the functional annulus when a bioprosthetic valve was present. Results: Average age was 65±11 years, the majority were female (29, 64%), and 9 (20%) had undergone prior aortic valve replacement (AVR). Valve upsizing was ≥3 sizes in 41 (91%). Post-operative mean basal ring diameter was larger compared to the native annular diameter (26.3 vs. 25.3 mm, P<0.01) and substantially larger than prior prosthetic valve in redo AVR (25.6 vs. 19.3 mm, P<0.001). Diameters of the sinuses at pre-operative computed tomography (CT) increased by +7.7±2.8 [right sinuses of Valsalva (R SVS)], +6.7±3.0 [left sinuses of Valsalva (L SVS)], and +6.6±2.9 mm [non-coronary sinuses of Valsalva (N SVS)]. Mean diameter of the STJ increased to 38.3±3.7 post-operative (+8.1±3.2 mm). Left main (LM) and right coronary artery (RCA) heights decreased by -6.3±3.3 and -3.7±3.4 mm respectively due to the supra-annular position of the valve, however, the post-operative valve-to-coronary (VTC) artery distances were 6.6±2.3 and 4.9±2.0 mm, respectively. Conclusion: The Y-incision root enlargement technique significantly enlarges the sinus and STJ diameters by 6-7 mm while preserving VTC distances despite upsizing by 3-4 valve sizes, resulting in post-operative anatomy that is favorable for future transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV).

Rural generalist medicine: a developing approach to health care in rural and island Japan.

INTRODUCTION: Despite universal health coverage and high life expectancy, Japan faces challenges in health care that include providing care for the world's oldest population, increasing healthcare costs, physician maldistribution and an entrenched medical workforce and training system. Primary health care has typically been practised by specialists in other fields, and general medicine has only been certified as an accredited specialty since 2018. There are continued challenges to develop an awareness and acceptance of the primary health medical workforce in Japan. The impact of these challenges is highest in rural and island areas of Japan, with nearly 50% of rural and remote populations considered 'elderly'. Concurrently, these areas are experiencing physician shortages as medical graduates gravitate to urban areas and choose medical specialties more commonly practised in cities. This study aimed to understand the views on the role of rural generalist medicine (RGM) in contributing to solutions for rural and island health care in Japan. METHODS: This was a descriptive qualitative study. Data were collected via semi-structured interviews with 16 participants, including Rural Generalist Program Japan (RGPJ) registrars and supervisors, the RGPJ director, government officials, rural health experts and academics. Interviews were of 35-50 minutes duration and conducted between May and July 2019. Some interviews were conducted in person at the WONCA Asia-Pacific Conference in Kyoto, some onsite in hospital settings and some were videoconferenced. Interviews were recorded and transcribed. All transcripts were analysed through an inductive thematic process based on the grouping of codes. RESULTS: From the interview analysis, six main themes were identified: (1) key issues facing rural and island health in Japan; (2) participant background; (3) local demography and population; (4) identity, perception and role of RGM; (5) RGPJ experience; and (6) suggested reforms and recommendations. DISCUSSION: The RGPJ was generally considered to be a positive step toward reshaping the medical workforce to address the geographic inequities in Japan. While improvements to the program were suggested by participants, it was also generally agreed that a more systematic, national approach to RGM was needed in Japan. Key findings from this study are relevant to this goal. This includes considering the drivers to participating in the RGPJ for future recruitment strategies and the need for an idiosyncratic Japanese model of RGM, with agreed advanced skills and supervision models. Also important are the issues raised by participants on the need to improve community acceptance and branding of rural generalist doctors to support primary care in rural and island areas. CONCLUSION: The RGPJ represents an effort to bolster the national rural medical workforce in Japan. Discussions from participants in this study indicate strong support to continue research, exploration and expansion of a national RGM model that is contextualised for Japanese conditions and that is branded and promoted to build community support for the role of the rural generalist.

Older adults with communication disabilities and their use of communication support at doctor's visits: a nationally representative study.

PURPOSE: Older adults with communication disabilities (CDs) experience barriers to receiving care and face a paucity of accommodations for their disability. Utilizing someone that supports communication with healthcare providers (communication support persons) may be a way that this group self-supports their disability. We examined if this utilization was independently associated with CDs among older adults. We also sought to understand if socioeconomic factors were associated with utilization. METHODS: We used the 2015 National Health and Aging Trends Survey (NHATS) to conduct a cross-sectional analysis of Medicare beneficiaries (n = 5954) with functional hearing, expressive, or cognitive difficulties. We calculated a weighted, population prevalence and an adjusted prevalence ratio (APR) controlling for sociodemographic, health and other disability factors. RESULTS: Among community dwelling older adults, having CDs was associated with higher utilization of a communication support person at medical visits (APR: 1.41 [CI: 1.27 - 1.57]). Among adults with CDs, Black adults and women had lower levels of utilization as compared to White adults and men, respectively. CONCLUSION: Communication support persons may be a way that older adults with CDs self-support their disability. However, not all older adults with CDs bring someone and variation by social factors could suggest that unmet support needs exist.

Over half of older adults with communication disabilities do not utilize a communication support person at doctors' visits, and utilization differs by race and gender.Rehabilitation professionals should educate their older adult patients with communication disabilities on this practice and collaborate with speech-language pathologists (SLPs) and audiologists (AuDs) on how to accommodate this population's disability.SLPs and AuDs can directly train support persons, other rehabilitation professionals, and physicians on accommodating these patients. For patients who don't bring a support person, SLPs and AuDs can plan alternative communication disability supports to use in healthcare settings, so that all older adults with CDs can equitably access their healthcare.

A decade-long study demonstrates that a population of invasive sea lamprey (Petromyzon marinus) can be controlled by introducing sterilized males.

The release of sterilized insects to control pest populations has been used successfully during the past 6 decades, but application of the method in vertebrates has largely been overlooked or met with failure. Here, we demonstrate for the first time in fish, that a small population of sea lamprey (Petromyzon marinus; Class Agnatha), arguably one of the most impactful invasive fish in the world, can be controlled by the release of sterilized males. Specifically, the release of high numbers of sterile males (~ 1000's) into a geographically isolated population of adult sea lamprey resulted in the first multiyear delay in pesticide treatment since treatments began during 1966. Estimates of percent reduction in recruitment of age-1 sea lamprey due to sterile male release ranged from 7 to 99.9% with the precision of the estimate being low because of substantial year-to-year variability in larval density and distribution. Additional monitoring that accounts for recruitment variability in time and space would reduce uncertainty in the degree to which sterile male release reduces recruitment rates. The results are relevant to vertebrate pest control programs worldwide, especially as technical opportunities to sterilize vertebrates and manipulate sex ratios expand.

Selective active resonance tuning for multi-mode nonlinear photonic cavities.

Resonant enhancement of nonlinear photonic processes is critical for the scalability of applications such as long-distance entanglement generation. To implement nonlinear resonant enhancement, multiple resonator modes must be individually tuned onto a precise set of process wavelengths, which requires multiple linearly-independent tuning methods. Using coupled auxiliary resonators to indirectly tune modes in a multi-resonant nonlinear cavity is particularly attractive because it allows the extension of a single physical tuning mechanism, such as thermal tuning, to provide the required independent controls. Here we model and simulate the performance and tradeoffs of a coupled-resonator tuning scheme which uses auxiliary resonators to tune specific modes of a multi-resonant nonlinear process. Our analysis determines the tuning bandwidth for steady-state mode field intensity can significantly exceed the inter-cavity coupling rate g if the total quality factor of the auxiliary resonator is higher than the multi-mode main resonator. Consequently, over-coupling a nonlinear resonator mode to improve the maximum efficiency of a frequency conversion process will simultaneously expand the auxiliary resonator tuning bandwidth for that mode, indicating a natural compatibility with this tuning scheme. We apply the model to an existing small-diameter triply-resonant ring resonator design and find that a tuning bandwidth of 136 GHz ≈ 1.1 nm can be attained for a mode in the telecom band while limiting excess scattering losses to a quality factor of 106. Such range would span the distribution of inhomogeneously broadened quantum emitter ensembles as well as resonator fabrication variations, indicating the potential for the auxiliary resonators to enable not only low-loss telecom conversion but also the generation of indistinguishable photons in a quantum network.

Association of EEG Characteristics with Outcomes Following Pediatric ICU Cardiac Arrest: A Secondary Analysis of the ICU-RESUScitation Trial.

BACKGROUND AND OBJECTIVES: There are limited tools available following cardiac arrest to prognosticate neurologic outcomes. Prior retrospective and single center studies have demonstrated early EEG features are associated with neurologic outcome. This study aimed to evaluate the prognostic value of EEG for pediatric in-hospital cardiac arrest (IHCA) in a prospective, multicenter study. METHODS: This cohort study is a secondary analysis of the ICU-Resuscitation trial, a multicenter randomized interventional trial conducted at 18 pediatric and pediatric cardiac ICUs in the United States. Patients who achieved return of circulation (ROC) and had post-ROC EEG monitoring were eligible for inclusion. Patients <90 days old and those with pre-arrest Pediatric Cerebral Performance Category (PCPC) scores >3 were excluded. EEG features of interest included EEG Background Category, and presence of focal abnormalities, sleep spindles, variability, reactivity, periodic and rhythmic patterns, and seizures. The primary outcome was survival to hospital discharge with favorable neurologic outcome. Associations between EEG features and outcomes were assessed with multivariable logistic regression. Prediction models with and without EEG Background Category were developed and receiver operator characteristic curves compared. RESULTS: Of the 1129 patients with an index cardiac arrest who achieved ROC in the parent study, 261 had EEG within 24 hours of ROC, of which 151 were evaluable. The cohort included 57% males with a median age of 1.1 years (IQR 0.4, 6.8). EEG features including EEG Background Category, sleep spindles, variability, and reactivity were associated with survival with favorable outcome and survival, (all p<0.001). The addition of EEG Background Category to clinical models including age category, illness category, PRSIM score, duration of CPR, first documented rhythm, highest early post-arrest arterial lactate improved the prediction accuracy achieving an AUROC of 0.84 (CI 0.77-0.92), compared to AUROC of 0.76 (CI 0.67-0.85) (p = 0.005) without EEG Background Category. CONCLUSION: This multicenter study demonstrates the value of EEG, in the first 24 hours following ROC, for predicting survival with favorable outcome after a pediatric IHCA.

RIPPLE-VT Study: Multicentre, prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channels to eliminate latest scar potentials without direct ablation.

BACKGROUND: Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden. OBJECTIVE: Limiting ablation within post-infarct scar to conduction channels within the scar to reduce VT recurrence. METHODS: Patients undergoing catheter ablation for recurrent implantable defibrillator (ICD) therapy for post-infarct VT were recruited at 5 centres. Left ventricular maps were collected on CARTO™ using a Pentaray™ catheter. Ripple mapping was used to categorise infarct scar potentials (SPs) by timing. Earliest SPs were ablated sequentially until there was loss of the terminal scar potentials without their direct ablation. The primary outcome measure was sustained VT episodes as documented by device interrogations at 1yr and was compared with VT episodes in the year pre-ablation. RESULTS: 50 pts were recruited (mean LVEF 33%±9) and 37pts (74%) met channel ablation endpoint with successful loss of latest SPs without direct ablation. There were 16 recurrences during 1yr follow up. There was a 90% reduction in VT burden from 30.2±53.9 to 3.1±7.5 (p<0.01) per patient, with a concomitant 88% reduction in appropriate shocks from 2.1±2.7 to 0.2±0.9 (p<0.01). There were 8 deaths during follow-up. Those who met channel ablation endpoint had no significant difference in mortality, recurrence or VT burden but had a significantly lower ablation burden 25.7±4.2 vs 39.9±6.1 mins (p=0.001). CONCLUSION: Scar channel ablation is feasible using ripple mapping and can be an alternative to more extensive substrate modification techniques.

Bariatric surgery partially reverses subclinical proarrhythmic structural, electrophysiological and autonomic changes in obesity.

BACKGROUND: Obesity confers higher risks of cardiac arrhythmias. The extent to which weight loss reverses subclinical proarrhythmic adaptations in arrhythmia-free obese individuals is unknown. OBJECTIVE: To study structural, electrophysiological and autonomic remodelling in arrhythmia-free obese patients, and their reversibility with bariatric surgery using electrocardiographic imaging (ECGi). METHODS: Sixteen arrhythmia-free obese patients (43+12years, 13 female, BMI 46.7+5.5kg/m2) had ECGi pre-bariatric surgery (PreSurg), of which twelve had ECGi post-surgery (PostSurg, 36.8+6.5kg/m2). Sixteen age- and sex-matched lean healthy individuals (42+11 years, BMI 22.8+2.6kg/m2) acted as controls and had ECGi once. RESULTS: Obesity was associated with structural (increased epicardial fat volumes and left ventricular mass), autonomic (blunted heart rate variability) and electrophysiological (slower atrial conduction and steeper ventricular repolarisation gradients) remodelling. Following bariatric surgery, there was partial structural reverse remodelling, with a reduction in epicardial fat volumes (68.7cm3 vs 64.5cm3, p=0.0010) and left ventricular mass (33g/m2.7 vs 25g/m2.7, p<0.0005). There was also partial electrophysiological reverse remodelling with a reduction in mean spatial ventricular repolarisation gradients (26mm/ms vs 19mm/ms, p=0.0009), although atrial activation remained prolonged. Heart rate variability, quantified by standard deviation of successive differences of RR intervals, was also partially improved following bariatric surgery (18.7ms vs 25.9ms, p=0.017). Computational modelling showed PreSurg obese hearts had a greater window of vulnerability to unidirectional block and had earlier spiral-wave break-up with more complex re-entry patterns than PostSurg counterparts. CONCLUSION: Obesity is associated with adverse electrophysiological, structural and autonomic remodelling that is partially reversed after bariatric surgery. These data have important implications for bariatric surgery weight thresholds and weight loss strategies.

Inadequate Spinal Anesthesia in Lumbar Spine Surgery is Related to Volume of the Thecal Sac.

BACKGROUND: Spinal anesthesia (SA) is used in lumbar surgery but initial adequate analgesia fails in some patients. In these cases, spinal redosing or conversion to general endotracheal anesthesia is required, both of which are detrimental to the patient experience and surgical workflow. METHODS: We reviewed cases of lumbar surgery performed under spinal anesthesia from 2017 - 2021. We identified 12 cases of inadequate first dose, then selected 36 random patients as controls. We used a measurement tool to approximate the volume of the dural sac for each patient using T2-weighted sagittal MRI sequences. RESULTS: Patients who had an inadequate first dose of anesthesia had a significantly larger dural sac volume, 22.8 ± 7.9 cm3 in the inadequate dose group, and 17.4 ± 4.7 cm3 in controls (p=0.043). The inadequate dose group was significantly younger, 54.2 ± 8.8 years in failed first dose, and 66.4 ± 11.9 years in control (p=0.001). The groups did not differ by surgical procedure (p=0.238), level (p=0.353), ASA score (p=0.546), or co-morbidities. CONCLUSIONS: We found that age, larger height, and dural sac volume are risk factors for an inadequate first dose of SA. The availability of spinal MRI in patients undergoing spine surgery allows the preoperative measurement of their thecal sac size. In the future, this data may be used to personalize spinal anesthesia dosing based on individual anatomic variables and potentially reduce the incidence of failed spinal anesthesia in spine surgery.

Identification of Babesia microti immunoreactive antigens by phage display cDNA screen.

Human babesiosis is a malaria-like illness caused by protozoan parasites of the genus Babesia. Babesia microti is responsible for most cases of human babesiosis in the United States, particularly in the Northeast and the Upper Midwest. Babesia microti is primarily transmitted to humans through the bite of infected deer ticks but also through the transfusion of blood components, particularly red blood cells. There is a high risk of severe and even fatal disease in immunocompromised patients. To date, serology testing relies on an indirect immunofluorescence assay that uses the whole Babesia microti antigen. Here, we report the construction of phage display cDNA libraries from Babesia microti-infected erythrocytes as well as human reticulocytes obtained from donors with hereditary hemochromatosis. Plasma samples were obtained from patients who were or had been infected with Babesia microti. The non-specific antibody reactivity of these plasma samples was minimized by pre-exposure to the human reticulocyte library. Using this novel experimental strategy, immunoreactive segments were identified in three Babesia microti antigens termed BmSA1 (also called BMN1-9; BmGPI12), BMN1-20 (BMN1-17; Bm32), and BM4.12 (N1-15). Moreover, our findings indicate that the major immunoreactive segment of BmSA1 does not overlap with the segment that mediates BmSA1 binding to mature erythrocytes. When used in combination, the three immunoreactive segments form the basis of a sensitive and comprehensive diagnostic immunoassay for human babesiosis, with implications for vaccine development.

Interpretation and reporting considerations of low-level DNA profiles following MinElute® purification of PowerPlex® 21 amplified products.

The generation of high-quality DNA profiles from trace amounts of DNA continues to be an issue in forensic casework. Several methods have been proposed over the years to increase recovery rates for low input DNA, including purification of PCR products, an increase in PCR cycle numbers and increasing injection time or voltage during electrophoresis. In this study, the characteristics of DNA profiles generated using QIAGEN MinElute® purification of Promega PowerPlex® 21 amplified products for low DNA input samples, ranging from 80 pg down to 4 pg, were evaluated. MinElute® purification was found to be a simple, effective and time efficient method, which can greatly improve the resolution of amplified PCR products, recovering 100% of donor concordant alleles from as little 16 pg of input template DNA and generating sufficient allelic information for interpretation from as low as 4 pg inputs. However, as is commonly observed with low template DNA samples, the results exhibited extensive disparity in the effects of stochastic variation in amplification, including increased heterozygote peak height imbalance, stutter ratios and instances of allelic drop-in and drop-out, both within and between replicates. As such, it is important that the extent and variability of these stochastic effects are appropriately incorporated in the development of robust profile interpretation guidelines for DNA profiles generated from purified PCR products.

Thiol Coordination Softens Liquid Metal Particles To Improve On-Demand Conductivity.

Achieving tunable rupturing of eutectic gallium indium (EGaIn) particles holds great significance in flexible electronic applications, particularly pressure sensors. We tune the mechanosensitivity of EGaIn particles by preparing them in toluene with thiol surfactants and demonstrate an improvement over typical preparations in ethanol. We observe, across multiple length scales, that thiol surfactants and the nonpolar solvent synergistically reduce the applied stress requirements for electromechanical actuation. At the nanoscale, dodecanethiol and propanethiol in toluene suppress gallium oxide growth, as characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. Quantitative AFM imaging produces force-indentation curves and height images, while conductive AFM measures current while probing individual EGaIn particles. As the applied force increases, thiolated particles demonstrate intensified softening, rupturing, and stress-induced electrical activation at forces 40% lower than those for bare particles in ethanol. To confirm that thiolation facilitates rupturing at the macroscale, a laser is used to ablate samples of EGaIn particles. Scanning electron microscopy and resistance measurements across macroscopic samples confirm that thiolated EGaIn particles coalesce to exhibit electrical activation at 0.1 W. Particles prepared in ethanol, however, require 3 times higher laser power to demonstrate a similar behavior. This unique collection of advanced techniques demonstrates that our particle synthesis conditions can facilitate on-demand functionality to benefit electronic applications.

Feasibility and Safety of Oral Risperidone to Treat Prehospital Agitation.

OBJECTIVE: Agitation is a common prehospital problem and frequently presents without a clear etiology. Given the dynamic environment of the prehospital setting, there has historically been a varied approach to treating agitation with a heavy reliance on parenteral medications. Newer best practice guidelines recommend the incorporation of oral medications to treat patients experiencing agitation. Therefore, we evaluated the use of oral risperidone in a single system after a change in protocol occurred. METHODS: This was conducted as a retrospective chart review of an urban/suburban Emergency Medical Services system over the period of 8 months. The first day this medication was implemented throughout the service was included. Charts were included for selection if they included risperidone oral dissolving tablet (ODT) as a charted medication. The primary outcome was administration of additional medications to treat agitation. Exploratory outcome measures included acceptance of medication, documented injury to paramedics, documented injuries to patients, scene times, and adverse events that could possibly be linked to the medication. RESULTS: A total of 552 records were screened for inclusion. Risperidone was offered to 530 patients and accepted by 512 (96.6%). Of these 512 patients, the median age of included patients was 39 years old (IQR 29-52 years old) with a range of 18-89 years old. Rescue or additional medications for agitation were required in 9 (1.8%) cases. There were a total of 4 (0.8%) potential complications following administration of risperidone. There were no reported assaults with subsequent injuries to prehospital personnel or injuries sustained by patients reported in this study. CONCLUSIONS: Risperidone ODT was found to be a safe and effective medication to treat mild agitation in a large urban and suburban EMS system. The need for additional medications to treat agitation was rare, and there were no documented injuries to either patients or paramedics.

Massive Sodium Nitrite Overdose: A Case for Prehospital Methylene Blue.

Sodium nitrite overdose leads to profound methemoglobinemia and may quickly progress to death. It is an increasingly common method of suicide and is often fatal. Methylene blue is an effective but time-sensitive antidote that has the potential to save lives when administered early. In this case report, we describe a fatal sodium nitrite overdose and the subsequent creation of a prehospital protocol for our large urban Emergency Medical Services system.

Digital "flipbooks" for enhanced visual assessment of simple and complex brain tumors.

Typical longitudinal radiographic assessment of brain tumors relies on side-by-side qualitative visualization of serial magnetic resonance images (MRIs) aided by quantitative measurements of tumor size. However, when assessing slowly-growing tumors and/or complex tumors, side-by-side visualization and quantification may be difficult or unreliable. Whole-brain, patient-specific "digital flipbooks" of longitudinal scans are a potential method to augment radiographic side-by-side reads in clinical settings by enhancing the visual perception of changes in tumor size, mass effect, and infiltration across multiple slices over time. In this approach, co-registered, consecutive MRI scans are displayed in a slide deck, where one slide displays multiple brain slices of a single timepoint in an array (e.g. 3x5 "mosaic" view of slices). The flipbooks are viewed similar to an animated flipbook of cartoons/photos so that subtle radiographic changes are visualized via perceived motion when scrolling through the slides. Importantly, flipbooks can be created easily with free, open-source software. This article describes the step-by-step methodology for creating flipbooks and discusses clinical scenarios for which flipbooks are particularly useful. Example flipbooks are provided in the Online Supplemental Material.

Evaluation of post-PCR purification methods and subsequent optimisation of the MinElute® PCR Purification Kit for low input DNA samples amplified with PowerPlex® 21.

Weak and partial DNA profiles are commonly encountered within forensic casework due to amplification of low DNA input samples. One option for increasing allelic detection in such samples is the purification of amplified PCR product using commercially available column-based methods. In this study, four commercially available post-PCR purification methods, QIAGEN MinElute®, Independent Forensics Amplicon™ Rx, Millipore Microcon® and Thermo Fisher Scientific ExoSAP-IT™ were evaluated, comparing the quality of PowerPlex® 21 DNA profiles produced to the standard DNA profile generated prior to purification. An increased detection of alleles above the analytical threshold was observed following purification with the MinElute®, Amplicon™ Rx and Microcon® methods, allowing informative DNA profiles to be recovered using as little as 8 pg DNA. However, post-PCR purification using the ExoSAP-IT™ kit was unsuccessful, with no alleles detected above analytical threshold in samples with ≤16 pg DNA. The MinElute® kit was selected for optimisation on the basis of DNA profile quality, including increased detection of alleles and minimal artefacts. The MinElute® method was optimised by evaluating the number of washes and final elution buffer volume, resulting in a further increase in detection of alleles by reducing the elution buffer volume. Overall, this study showed that PowerPlex® 21 DNA profiles from low input DNA can be successfully enhanced by employing the MinElute® post-PCR purification method.

The Spatial Ventricular Gradient Is Associated With Inducibility of Ventricular Arrhythmias During Electrophysiology Study.

BACKGROUND: Myocardial electrical heterogeneity is critical for normal cardiac electromechanical function, but abnormal or excessive electrical heterogeneity is proarrhythmic. The spatial ventricular gradient (SVG), a vectorcardiographic measure of electrical heterogeneity, has been associated with arrhythmic events during long-term follow-up, but its relationship with short-term inducibility of ventricular arrhythmias (VAs) is unclear. OBJECTIVE: This study was designed to determine associations between SVG and inducible VAs during electrophysiology study. METHODS: A retrospective study was conducted of adults without prior sustained VA, cardiac arrest, or implantable cardioverter-defibrillator who underwent ventricular stimulation for evaluation of syncope and nonsustained ventricular tachycardia or for risk stratification before primary prevention implantable cardioverter-defibrillator implantation. The 12-lead electrocardiograms were converted into vectorcardiograms, and SVG magnitude (SVGmag) and direction (azimuth and elevation) were calculated. Odds of inducible VA were regressed by logistic models. RESULTS: Of 143 patients (median age, 69 years; 80% male; median left ventricular ejection fraction [LVEF], 47%; 52% myocardial infarction), 34 (23.8%) had inducible VAs. Inducible patients had lower median LVEF (38% vs 50%; P < .0001), smaller SVGmag (29.5 vs 39.4 mV·ms; P = .0099), and smaller cosine SVG azimuth (cosSVGaz; 0.64 vs 0.89; P = .0007). When LVEF, SVGmag, and cosSVGaz were dichotomized at their medians, there was a 39-fold increase in adjusted odds (P = .002) between patients with all low LVEF, SVGmag, and cosSVGaz (65% inducible) compared with patients with all high LVEF, SVGmag, and cosSVGaz (4% [n = 1] inducible). After multivariable adjustment, SVGmag, cosSVGaz, and sex but not LVEF or other characteristics remained associated with inducible VAs. CONCLUSION: Assessment of electrical heterogeneity by SVG, which reflects abnormal electrophysiologic substrate, adds to LVEF and identifies patients at high and low risk of inducible VA at electrophysiology study.