Axis Deviation Research Articles

Guided Access Cavity Preparation Using Cost-Effective 3D Printers

IntroductionThe purpose of this in vitro study was to evaluate the accuracy and precision of desktop 3D printers when fabricating stents for guided endodontics. MethodsA stent was designed using planning software for guided endodontic access on a typodont model. Four different 3D printers were used to fabricate an identical stent, one per printer. Each stent was then used to gain access to the artificial endodontic canal on a typodont tooth and was repeated 10 times per stent by the same operator. Each of the accessed typodont teeth were scanned by a reference scanner and then imported into the inspection software. Inspection software used a best-fit alignment to automatically calculate absolute deviation at the base and tip of the bur. ResultsThe mean distances between the planned and actual positions of the bur were low, ranging from 0.31 to 0.68 mm. Statistically significant differences were found among the 4 groups (F3,36 = 10.67, P < .05). Post hoc comparison revealed that Group Form2 significantly varied from Groups Form3 and Carbon (P < .05 and P < .05, respectively). Group Form3 obtained the most accurate and most precise axial deviations both coronally and apically. ConclusionsAll of the printers tested produced stents for guided access that allowed for a high level of accuracy in obtaining access to the artificial endodontic canal, which would justify the trial of cost-effective 3D printers for guided endodontic access and necessitates further clinical research on teeth with pulp canal obliteration.

Evaluation of superimposed bending behaviour of laminated channel beams in modular steel buildings subjected to lateral load

The cooperation between adjacent floor and ceiling beams has been verified to effectively enhance the seismic performance of modular steel buildings. However, the structural performance of laminated double beam in the modular steel building subjected to lateral load has not been fully understood. In this study, the lateral tests, simplified finite element simulations, and theoretical derivations were conducted to systematically evaluate the superimposed bending behaviour of laminated channel beams under lateral loads. The results showed that the moment of inertia and interfacial shearing stiffness of the laminated beams were enhanced with the increase in the ceiling beam size and mechanical connector, and thereby the antisymmetric flexural properties of the double beam structures were enhanced. The strain neutral axes of the floor and ceiling layers deviated to the interface for the strongly laminated beams with interfacial bolt connections, indicating superimposition of these double beams. The interfacial slips, characterized by a symmetric parabola distribution mode, highly affected the combined action of the laminated channel beams. The remarkable increase in the slip-load rate led to yielding development of the laminated beams in modular steel buildings. Most importantly, analytical models for the effective bending stiffness were established considering the strain neutral axes deviation, which could quantify the superimposition effect of laminated beams subjected to lateral load.

Many Radiographic and Magnetic Resonance Imaging Assessments for Surgical Decision Making in Pediatric Patellofemoral Instability Patients Demonstrate Poor Interrater Reliability

To evaluate the interrater reliability of several common radiologic parameters used for patellofemoral instability and to attempt to improve reliability for measurements demonstrating unacceptable interrater reliability through consensus training. Fifty patients with patellar instability between the ages of 10 and 19 years were selected from a prospectively enrolled cohort. For measurements demonstrating unacceptable interrater reliability (intraclass correlation coefficient [ICC]: <0.6), raters discussed consensus methods to improve reliability and re-examined a subset of 20 images from the previous set of images. If reliability was still low after the second round of assessment, the measure was considered unreliable. Of the 50 included subjects, 22 (44%) were male and the mean age at the time of imaging was 14 ± 2 years. With 1 or fewer consensus training sessions, the interrater reliability of the following radiograph indices were found to be reliable: trochlea crossing sign (ICC: 0.625), congruence angle (ICC: 0.768), Caton-Deshamps index (ICC: 0.644), lateral patellofemoral angle (ICC: 0.768), and mechanical axis deviation on hip-to-ankle alignment radiographs (ICC: 0.665-0.777). Reliable magnetic resonance imaging (MRI) indices were trochlear depth (ICC: 0.743), trochlear bump (ICC: 0.861), sulcus angle (ICC: 0.684), patellar tilt (ICC: 0.841), tibial tubercle to trochlear groove distance (ICC: 0.706), effusion (ICC: 0.866), and bone marrow edema (ICC: 0.961). With 1 or fewer consensus training sessions, the interrater reliability of the following patellofemoral indices were found to be reliable for trochlear morphology: trochlea crossing sign and congruence angle on radiograph and trochlear depth, trochlear bump, and sulcus angle on MRI. Reliable patellar position measurements included: Caton-Deshamps index and lateral patellofemoral angle on radiograph and patellar tilt and tibial tubercle to trochlear groove distance on MRI. Additional global measurements (e.g., mechanical axis deviation on standing radiographs) and MRI assessments demonstrated acceptable reliability. II, prospective diagnostic study.

A Long-Term Study of Alignment Correction Following Proximal Femoral Varus Osteotomy and Pemberton Osteotomy in Children With Legg-Calvé-Perthes Disease and Developmental Dysplasia of the Hip.

Proximal femoral varus osteotomy (PFVO) is a common procedure performed in children with developmental dysplasia of the hip (DDH) and Legg–Calvé–Perthes disease (LCPD). However, the long-term effect on angular deformities of the knees and ankles following PFVO remains controversial. This study investigated the relationship between PFVO and alignment changes in the knee and ankle after the procedure. Twenty-five patients undergoing PFVO procedure with a minimum 4-year evaluation period were enrolled in the study, including 14 unilateral LCPD and 11 unilateral DDH. The standing scanogram examinations were collected before the operation, immediately following surgery, after a 1-year follow-up, after a 3-year follow-up, and at the final visit to the clinic. The radiographic parameters included leg length, femoral neck-shaft angle (FNSA), femorotibial angle (FTA), mechanical axis deviation (MAD), tibiotalar angle (TTA), and mechanical lateral distal femoral angle (mLDFA). At the final examination, FNSA demonstrated insignificant change between the operative and non-operative limbs in the DDH group. Compared with the postoperative result, FNSA significantly improved in the LCPD group (p = 0.039). Both groups did not develop statistical significance in TTA, mLDFA, MAD, and leg length discrepancy after more than a 5-year follow-up. From a biomechanical perspective that the foot passes more medial to the knee under the center of leg mass, varus knee was prone to develop. In order to correct the mechanical axis, the knee reverted to a valgus position gradually. Our study indicates that patients with LCPD or DDH receiving PFVO and Pemberton osteotomy narrow the gap of angular growth in knees and ankles between the operative and non-operative limbs after a long-term follow-up.

Prognostic Value of Cardiac Axis Deviation in Systemic Sclerosis-Related Pulmonary Hypertension.

Systemic sclerosis-related pulmonary hypertension (SSc-PH) is a common complication of SSc associated with accelerated mortality. The present study was undertaken to investigate whether cardiac axis deviation indicates abnormalities in cardiac function allowing for prognostication of disease severity and mortality. This was a retrospective study in which electrocardiograms (ECGs) were reviewed for cardiac axis deviation and their association with echocardiography and cardiopulmonary hemodynamics on right-sided heart catheterization. The primary outcome observed was all-cause mortality from the time of PH diagnosis. ECG results were reviewed from 169 patients with SSc-PH. Right axis deviation (RAD) and left axis deviation (LAD) occurred in 28.4% and 30.8% of patients with SSc-PH, respectively. Compared to those without RAD, patients with RAD exhibited predominantly right-sided cardiac disease on echocardiography and increased PH severity by cardiopulmonary hemodynamics including a greater mean ± SD pulmonary artery pressure (42.0 ± 12.5 mm Hg versus 29.8 ± 7.0 mm Hg) and mean± SD pulmonary vascular resistance (645.6 ± 443.2 dynes · seconds/cm5 versus 286.3 ± 167.7 dynes · seconds/cm5 ). LAD was associated with predominantly left-sided cardiac disease on echocardiography but was not associated with PH severity on cardiopulmonary hemodynamics. Both RAD (hazard ratio 10.36 [95% confidence interval 4.90-21.93], P < 0.001) and LAD (hazard ratio 2.94 [95% confidence interval 1.53-5.68], P = 0.001) were associated with an increased hazard for all-cause mortality. RAD and LAD reflect structural cardiac abnormalities and are associated with poor prognosis in patients with SSc-PH. These findings support the importance of electrocardiography, an inexpensive, widely available noninvasive test, in risk stratification.

A Study of Surgical Accuracy with X-Ray-Based Patient-Specific Instrument (X3DPSI®) vs Conventional Instrument in Total Knee Arthroplasty Surgeries.

Patient-specific instruments (PSI) have been shown to be a good solution in getting accurate bone cuts in total knee arthroplasty (TKA) in many studies. However, the need for an extra CT/MRI makes the existing PSI method costly and unsafe. X-ray-based PSI can solve these problems, if proven to be accurate. The purpose of this study was to introduce a novel method to measure the performance of X-ray to 3D-based PSI (X3DPSI ® ) in achieving planned bone cuts by comparing with conventional instruments (CI). This was a prospective study of a total of ten patients undergoing TKA surgery. Preoperative full length lower limb scanogram was done with specialized calibration strap-on marker to develop X3DPSI ® which was used intraoperatively for the placement of guiding pins for the cutting jig. Similarly, intraoperative guide pins were placed using CI also. Calibrated intraoperative X-ray images, in AP and LAT view, were taken while the cutting-block guiding pins were placed on the distal femur and proximal tibia. These X-ray images were used to calculate the cutting plane alignments for femur and tibia and to simulate the postoperative hip-knee-ankle (HKA) angle and MAD (mechanical axis deviation), in a virtual Tabplan3D environment for both the methods. The results showed that there was a significant difference between the two methods in terms of femoral cutting plane angles and in terms of the HKA angles and MAD. There was no significant difference in the tibial cutting plane angles in the coronal plane. The mechanical axis alignment achieved based on the virtual cuts made using the X3DPSI ® was significantly better than the alignment achieved based on the cuts made using the CI, in terms of both HKA and MAD. This novel method of X-ray-based PSI is a low-cost alternative to CT/MRI-based PSI if found to be accurate in future planned studies.

Feasibility of electrocardiogram screening in the USA prior to high school sport participation

BackgroundSudden cardiac death in young athletes is a catastrophic event with an incidence of 1:40,000–1:80,000. Pre-participation sport screening utilizes a 14-point targeted evaluation. Recently, some states have added an ECG to the traditional history and physical. ObjectivesThe study describes a large-scale ECG screening program for middle and high school students. The aim is to depict important components, partners, and plans that can be adopted by other municipalities to help prevent sudden cardiac arrest in this population. MethodsIn 2019, Brevard County School Board in Florida mandated ECGs before participation in middle and high school sports. They partnered with a non-profit group that provides ECGs for a $20.00 fee. Volunteer pediatric cardiologists interpreted the ECGs. Results were emailed to participants, and abnormal results received a phone call to ensure appropriate follow-up care. ResultsThere were 5877 ECG screenings between 4/1/19–12/31/19 with 3% (199/5877) abnormal: 30% (60/199) ventricular conduction, 26% (51/199) arrhythmias, 13% (25/199) ventricular hypertrophy/chamber enlargement, 11% (21/199) ST-T abnormalities, 8% (16/199) prolonged QTc, 6% (12/199) WPW syndrome, and 4% (7/199) AV conduction and axis deviation. The incidence of critical heart disease with a risk of sudden cardiac arrest was 0.1% (8/5877) in those with a confirmed final diagnosis: 6 who underwent an ablation procedure for WPW syndrome, 1 with gene-positive long QTc, and 1 with left ventricular hypertrophy who is undergoing genetic evaluation for hypertrophic cardiomyopathy. ConclusionsTo our knowledge, this is the first large school district in Florida to mandate this level of cardiovascular screening. This pilot project demonstrates that large volume ECG screening prior to school sport participation is feasible at a low cost when utilizing appropriate manpower and providing access to follow up-care.

Right axis deviation in the canine electrocardiogram for predicting severity of pulmonic stenosis: a retrospective cohort analysis.

To investigate the predictive value of right axis deviation of the mean electrical axis (MEA) in assessing the severity of pulmonic stenosis (PS) in dogs. Records for 218 client-owned dogs diagnosed between 2014 and 2020 with PS as determined by Doppler echocardiography. University of Florida Small Animal Clinic medical records were reviewed, and signalment and clinical risk variables (murmur grade and clinical signs) were extracted. MEA was determined from ECG records by use of leads I and III. Predictive potential of MEA and associated risk factors to diagnose PS severity (mild [< 50 mm Hg], moderate, or severe [> 75 mm Hg]) were assessed by receiver-operating characteristic curve analysis and quantile regression. Records for 88 dogs were eligible for analysis. Greater PS severity was associated with smaller breeds presenting with ECG abnormalities, overt clinical signs, and high-category murmur grades (IV and V). Mean MEA increased with stenosis severity category, with an average of 62° for mild, 113° for moderate, and 157° for severe. Each 10° increase in MEA corresponded to an approximately 5-mm Hg increase in PG. Increasing PS severity was associated with MEA right axis deviation > 100° and the more severe cases (PG > 75 mm Hg) with MEA right axis deviation > -180°. Mean electrical axis right axis deviation may be a useful screening metric for dogs with suspected moderate to severe PS.

Deviation of Mercury's Spin Axis From an Exact Cassini State Induced by Dissipation

AbstractWe compute predictions of the deviation of Mercury's spin axis from an exact Cassini state caused by tidal dissipation as well as viscous and electromagnetic (EM) friction at the core‐mantle boundary (CMB) and inner core boundary (ICB). Viscous friction at the CMB generates a phase lead; viscous and EM friction at the ICB produce a phase lag; the magnitude of the deviation depends on the inner core size, kinematic viscosity, and magnetic field strength, but cannot exceed an upper bound. For a small inner core, viscous friction at the CMB results in a maximum phase lead of 0.027 arcsec. For a large inner core (radius &gt;1,000 km), EM friction at the ICB generates the largest phase lag, but it does not exceed 0.1 arcsec. Elastic deformations induced by the misaligned fluid and solid cores play a first‐order role in the phase lead/lag caused by viscous and EM coupling and contribute to a perturbation in mantle obliquity on par with that caused by tidal deformations. Tidal dissipation results in a phase lag and its magnitude (in units of arcsec) is given by the empirical relation (80/Q), where Q is the quality factor; Q = 80 results in a phase lag of ∼1 arcsec. A large inner core with a low viscosity of the order of 1017 Pa s or lower can significantly affect Q and thus the resulting phase lag. The limited mantle phase lag suggested by observations (&lt;10 arcsec) implies a lower limit on the bulk mantle viscosity of approximately 1017 Pa s.

Mechanical Lateral Distal Femoral Angle (MLDFA), Medial Proximal Tibia Angle (MPTA), and Mechanical Axis Deviation (MAD) Value in Young Adults in North Sumatera

&lt;p&gt;Introduction. Reference value to determine the angle of lower extremity is only based on clinical measurement and radiological assessment, which is limited to tibiofemoral angle (TFA). Although this examination can estimate the lower extremity angle, it is not satisfactory for a comprehensive analysis. Material and Method. A descriptive study in RSUP Haji Adam Malik Hospital in August - September 2019 to measure mechanical lateral distal femoral angle (MLDFA), medial proximal tibia angle (MPTA), and mechanical axis deviation (MAD). Results. Thirty nine subjects were included in this study. The mean age was 26.77±4,65 years old (range: 22 to 39 years); 69,2% were male (n = 27) and 30,8% were female (n = 12). The average mechanical lateral distal femoral angle (MLDFA) was 87,93o ±2,16o . The average medial proximal tibia angle (MPTA) was 86,28o ±2,26o . The average mechanical axis deviation (MAD) was 1.56±1,48 mm. Our results of MLDFA and MPTA measurement, but not in MAD, are consistent with study conducted by Farr, et al. Conclusion. Our MLDFA, MPTA, but not MAD measurement results are similar to studies involving Caucasian population.&lt;/p&gt;&lt;p&gt;Pendahuluan. Nilai acuan sudut pada ekstremitas bawah hanya berdasarkan pemeriksaan klinis dan radiologis, yang terbatas pada sudut tibiofemoral. Pemeriksaan sudut tibiofemoral (STF) tunggal tidak cukup untuk analisis komprehensif ekstremitas bawah. Bahan dan Cara. Penelitian deskriptif di RSUP Haji Adam Malik pada bulan Agustus – September 2019 untuk mengukur sudut mekanik lateral distal femur (SMLDF), sudut medial proksimal tibia (SMPT), dan deviasi aksis mekanik (DAM). Hasil. Sejumlah 39 subjek diteliti. Usia rata-rata 26,77 ± 4,65 tahun (22 - 39 tahun); 69,2% pria (n = 27) dan 30,8% wanita (n = 12). Nilai rata-rata sudut mekanik lateral distal femur (SMLDF) adalah 87,93º ± 2,16º. Nilai rata-rata sudut medial proksimal tibia (SMPT) adalah 86,28º ± 2,26º. Nilai rata–rata deviasi aksis mekanik (DAM) adalah 1.56 ± 1,48 mm. Pada penelitian ini, hasil pengukuran SMLDF dan SMPT sesuai hasil penelitian Farr, et al, tetapi hasil pengukuran DAM tidak sesuai. Simpulan. Nilai SMLDF dan SMPT pada penelitian ini tidak berbeda dengan penelitian pada populasi Kaukasia&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Reverse Septal Contour On Cardiac Magnetic Resonance Imaging- A Mimicker Of Hypertrophic Cardiomyopathy In Transthyretin Cardiac Amyloidosis

Introduction Transthyretin cardiac amyloidosis (ATTR) causes cardiomyopathy secondary to extracellular deposition of transthyretin protein in the heart muscle. Clinical Presentation An 86-year-old man with chronic diastolic heart failure and a recent transcatheter aortic valve replacement (TAVR) (26 mm Edwards Sapien 3 Bioprosthesis) for severe symptomatic aortic stenosis was seen in the TAVR clinic for a follow-up visit. The examination was consistent with mild volume overload. EKG showed an irregular rhythm with left axis deviation. A previous transthoracic echocardiogram showed biventricular hypertrophy with normal biventricular size and ejection fraction. For concerns of restrictive cardiomyopathy, a cardiac MRI (C-MRI) was performed which showed biventricular systolic dysfunction and right ventricular (RV) hypertrophy confirmed via RV mass index. Furthermore, tau inversion recovery imaging was normal (no intramyocardial edema). In addition, reverse septal hypertrophy of the interventricular septum (IVS) (wall thickness of 22 mm) and LV end-diastolic volume 175.61 ml, classically seen in hypertrophic cardiomyopathy patients was observed (Image 1A). Discussion The patient was diagnosed with cardiac amyloidosis based on a diminished longitudinal excursion of the basal segments, marked biventricular transmural homogenous and global amorphous Late Gadolinium Enhancement (LGE), and rapid LGE washout (Image 1 (B-C)). The diagnosis was supported by a positive via 99mTc-PYP scan and normal immunofixation electrophoresis. The patient was started on tafamidis. Transthyretin cardiac amyloidosis (ATTR) causes cardiomyopathy secondary to extracellular deposition of transthyretin protein. CMRI is used for tissue characterization and phenotyping of cardiomyopathies. CMRI methodologies such as T1 mapping, LGE, and basal-apical contractile gradient/longitudinal strain can differentiate HCM phenocopies such as ATTR amyloidosis from a typical HCM phenotype showing reverse septal contour and help in decision making and guide management Conclusion Newer imaging techniques in Cardiac MRI have helped increase diagnostic accuracy in patients with suspected cardiac amyloidosis. This has led to an increase in noninvasive diagnosis of the disease at an earlier stage which helps with prompt management. Transthyretin cardiac amyloidosis (ATTR) causes cardiomyopathy secondary to extracellular deposition of transthyretin protein in the heart muscle. An 86-year-old man with chronic diastolic heart failure and a recent transcatheter aortic valve replacement (TAVR) (26 mm Edwards Sapien 3 Bioprosthesis) for severe symptomatic aortic stenosis was seen in the TAVR clinic for a follow-up visit. The examination was consistent with mild volume overload. EKG showed an irregular rhythm with left axis deviation. A previous transthoracic echocardiogram showed biventricular hypertrophy with normal biventricular size and ejection fraction. For concerns of restrictive cardiomyopathy, a cardiac MRI (C-MRI) was performed which showed biventricular systolic dysfunction and right ventricular (RV) hypertrophy confirmed via RV mass index. Furthermore, tau inversion recovery imaging was normal (no intramyocardial edema). In addition, reverse septal hypertrophy of the interventricular septum (IVS) (wall thickness of 22 mm) and LV end-diastolic volume 175.61 ml, classically seen in hypertrophic cardiomyopathy patients was observed (Image 1A). The patient was diagnosed with cardiac amyloidosis based on a diminished longitudinal excursion of the basal segments, marked biventricular transmural homogenous and global amorphous Late Gadolinium Enhancement (LGE), and rapid LGE washout (Image 1 (B-C)). The diagnosis was supported by a positive via 99mTc-PYP scan and normal immunofixation electrophoresis. The patient was started on tafamidis. Transthyretin cardiac amyloidosis (ATTR) causes cardiomyopathy secondary to extracellular deposition of transthyretin protein. CMRI is used for tissue characterization and phenotyping of cardiomyopathies. CMRI methodologies such as T1 mapping, LGE, and basal-apical contractile gradient/longitudinal strain can differentiate HCM phenocopies such as ATTR amyloidosis from a typical HCM phenotype showing reverse septal contour and help in decision making and guide management Newer imaging techniques in Cardiac MRI have helped increase diagnostic accuracy in patients with suspected cardiac amyloidosis. This has led to an increase in noninvasive diagnosis of the disease at an earlier stage which helps with prompt management.

Mechanical Lateral Distal Femoral Angle (MLDFA), Medial Proximal Tibia Angle (MPTA), and Mechanical Axis Deviation (MAD) Value in Young Adults in North Sumatera

Introduction. Reference value to determine the angle of lower extremity is only based on clinical measurement and radiological assessment, which is limited to tibiofemoral angle (TFA). Although this examination can estimate the lower extremity angle, it is not satisfactory for a comprehensive analysis. Material and Method. A descriptive study in RSUP Haji Adam Malik Hospital in August - September 2019 to measure mechanical lateral distal femoral angle (MLDFA), medial proximal tibia angle (MPTA), and mechanical axis deviation (MAD). Results. Thirty nine subjects were included in this study. The mean age was 26.77±4,65 years old (range: 22 to 39 years); 69,2% were male (n = 27) and 30,8% were female (n = 12). The average mechanical lateral distal femoral angle (MLDFA) was 87,93o±2,16o. The average medial proximal tibia angle (MPTA) was 86,28o±2,26o. The average mechanical axis deviation (MAD) was 1.56±1,48 mm. Our results of MLDFA and MPTA measurement, but not in MAD, are consistent with study conducted by Farr, et al. Conclusion. Our MLDFA, MPTA, but not MAD measurement results are similar to studies involving Caucasian population.&#x0D; &#x0D; Pendahuluan. Nilai acuan sudut pada ekstremitas bawah hanya berdasarkan pemeriksaan klinis dan radiologis, yang terbatas pada sudut tibiofemoral. Pemeriksaan sudut tibiofemoral (STF) tunggal tidak cukup untuk analisis komprehensif ekstremitas bawah. Bahan dan Cara. Penelitian deskriptif di RSUP Haji Adam Malik pada bulan Agustus – September 2019 untuk mengukur sudut mekanik lateral distal femur (SMLDF), sudut medial proksimal tibia (SMPT), dan deviasi aksis mekanik (DAM). Hasil. Sejumlah 39 subjek diteliti. Usia rata-rata 26,77 ± 4,65 tahun (22 - 39 tahun); 69,2% pria (n = 27) dan 30,8% wanita (n = 12). Nilai rata-rata sudut mekanik lateral distal femur (SMLDF) adalah 87,93º ± 2,16º. Nilai rata-rata sudut medial proksimal tibia (SMPT) adalah 86,28º ± 2,26º. Nilai rata–rata deviasi aksis mekanik (DAM) adalah 1.56 ± 1,48 mm. Pada penelitian ini, hasil pengukuran SMLDF dan SMPT sesuai hasil penelitian Farr, et al, tetapi hasil pengukuran DAM tidak sesuai. Simpulan. Nilai SMLDF dan SMPT pada penelitian ini tidak berbeda dengan penelitian pada populasi Kaukasia.&#x0D;

Premature Ventricular Contractions From the Left Anterior Fascicle: Electrocardiographic and Electrophysiological Characteristics, Mapping Strategy, and Immediate and Long-Term Catheter Ablation Results

BackgroundLeft anterior fascicle (LAF) premature ventricular contractions (PVC) are rarely reported. We described the electrocardiographic and electrophysiological characteristics of PVCs originating from LAF and evaluated the results of catheter ablation.MethodsThe baseline AH and HV intervals were recorded during normal sinus rhythm (NSR), and the HV interval of LAF-PVC was measured during the procedure. During the index procedure, the conduction interval from the earliest Purkinje potential (PP) site to the His was labeled as time A, the conduction interval from the earliest site to the onset of the QRS as time B, then the HV interval during NSR (HVNSR) is A + B, and the HV interval during PVC (HVPVC) is B-A; a predicted PP time was calculated using HVNSR and HVPVC. The calculated formula is as follows: Predicted target PP = (HVNSR + HVPVC)/2. During the repeat procedure, the mapping strategy only focuses on the earliest retrograde PP due to the injury or block of LAF sustained at the index procedure.ResultsNotably, 24 patients with LAF-PVC were included. The ECG characteristics of PVC exhibited right bundle branch block (RBBB) morphology with right-axis deviation (RAD) in 18 patients and only RAD in 6 patients. The QRS durations of NSR and PVC were 78.8 ± 7.9 and 106.8 ± 12.3 ms, respectively. There was no significant difference between the predicted and mapped PP site (31.5 ± 8.1 vs. 30.6 ± 7.8 ms; P = 0.17). There was a significant difference between the mean axis deviation before and after ablation (46.3 ± 25.4° vs. 18.3 ± 44.1°; P = 0.001); however, only 10 patients had a complete LAF block. Eight patients had a recurrence, the QRS morphology of LAF-PVC became narrower (95.9 ± 17.2 vs. 105.3 ± 16.9 ms, P = 0.003), and 4 patients’s PVC QRS morphology was similar to NSR. During the repeat procedure, the earliest retrograde PP interval was longer than the index procedure in four patients (12.0 ± 1.9 vs. 37.8 ± 1.1 ms; P < 0.001).ConclusionThe target PP site for ablation of the LAF region can be calculated using the HV interval during NSR and PVC at the index procedure. The mapping strategy at repeat procedures focused on the earliest retrograde PP interval.

Analysis of an adaptive lead weighted ResNet for multiclass classification of 12-lead ECGs

Background. Twelve lead ECGs are a core diagnostic tool for cardiovascular diseases. Here, we describe and analyse an ensemble deep neural network architecture to classify 24 cardiac abnormalities from 12 lead ECGs. Method. We proposed a squeeze and excite ResNet to automatically learn deep features from 12-lead ECGs, in order to identify 24 cardiac conditions. The deep features were augmented with age and gender features in the final fully connected layers. Output thresholds for each class were set using a constrained grid search. To determine why the model made incorrect predictions, two expert clinicians independently interpreted a random set of 100 misclassified ECGs concerning left axis deviation. Results. Using the bespoke weighted accuracy metric, we achieved a 5-fold cross-validation score of 0.684, and sensitivity and specificity of 0.758 and 0.969, respectively. We scored 0.520 on the full test data, and ranked 2nd out of 41 in the official challenge rankings. On a random set of misclassified ECGs, agreement between two clinicians and training labels was poor (clinician 1: κ = −0.057, clinician 2: κ = −0.159). In contrast, agreement between the clinicians was very high (κ = 0.92). Discussion. The proposed prediction model performed well on the validation and hidden test data in comparison to models trained on the same data. We also discovered considerable inconsistency in training labels, which is likely to hinder development of more accurate models.

Persistent Lower Limb Deformities Despite Amelioration of Rickets in X-Linked Hypophosphatemia (XLH) - A Prospective Observational Study.

BackgroundGait deviations, lower limb pain and joint stiffness represent key symptoms in patients with X-linked hypophosphatemia (XLH, OMIM 307800), a rare disorder of mineral homeostasis. While the pathomechanism for rickets is well understood, the direct role of PHEX (Phosphate-regulating neutral endopeptidase) deficiency in non-rachitic features including complex deformities, skull and dental affections remains unclear. FGF23-inhibiting antibody treatment can normalize serum phosphate levels and to improve rickets in XLH patients. However, linear growth remains impaired and effects on lower limb deformity and gait are insufficiently studied.AimsTo characterize and evaluate the course of lower limb deformity in a case series of pediatric XLH patients receiving Burosumab therapy.MethodsComparative assessment of planar radiographs, gait analysis, biochemical and clinical features of pediatric patients before and ≥12 months after initiation of FGF23-inhibiting was performed prospectively. Lower limb maltorsion was quantified by torsional MRI and gait analysis. Standardized deformity analysis of lower limb anteroposterior radiographs was conducted.ResultsSeven patients (age 9.0 +/-3.6 years) were eligible for this study. All patients received conventional treatment before onset of antibody treatment. Maltorsion of the femur was observed in 8/14 legs using torsional MRI (mean antetorsion 8.79°). Maltorsion of the tibia was observed in 9/14 legs (mean external torsion 2.8°). Gait analysis confirmed MRI findings with femoral external malrotation prior to and one year after onset of Burosumab therapy. Internal foot progression (intoeing gait) remained pathological in all cases (mean 2.2°). Knee rotation was pathologically internal 10/14 legs. Mean mechanical axis deviation (MAD) of 16.1mm prior to Burosumab changed in average by 3.9mm. Three children underwent guided growth procedures within the observation period. Mild postprocedural rebound of frontal axis deviation was observed under Burosumab treatment in one patient.ConclusionsThis is the first study to investigate lower limb deformity parameters quantitatively in children with XLH receiving Burosumab. One year of Burosumab therapy was associated with persistent maltorsion and frontal axis deviation (varus/valgus) despite improved rickets in this small, prospective uncontrolled study.

Novel kinematic model of a SCARA-type robot with bi-directional angular positioning deviation of rotary axes

Novel kinematic model of a SCARA-type robot with bi-directional angular positioning deviation of rotary axes

A Case of Pediatric Myocarditis that was Initially Misdiagnosed as Cerebral Concussion

A seven-year-old girl suddenly fell and became unconscious in her house. Her mother, who witnessed the fall called an ambulance. While waiting for the ambulance, she experienced generalized convulsions. The emergency medical technicians reported to the hospital that the patient had experienced cerebral concussion and immediate post-traumatic seizure. During transportation, she experienced generalized convulsions again. Electrocardiography (ECG) showed complete atrioventricular block without QRS complex during the generalized convulsions. On arrival, she regained consciousness. ECG revealed sinus tachycardia with left axis deviation and negative T wave at the I, aVL, V1-V3 leads. Cardiac echo showed good wall motion with a highly echoic epicardium. Head computed tomography revealed no specific findings. The main blood test results were increased cardiac enzyme and inflammatory reaction. The diagnosis was myocarditis and fatal arrhythmia followed by generalized convulsions and/or syncope, not cerebral concussion. She was transported to a children’s hospital for advanced medical care. Her post-admission course was uneventful. Adenovirus was the causative virus of myocarditis. The present case suggests that the heart should be evaluated in addition to the brain when children experience a prolonged period of unconsciousness after a fall.

Left Bundle Branch Pacing: Unexpected Resynchronization Effect of Anodal Capture.

Anodal capture can provide a resynchronization effect on biventricular pacing. However, evidence of such an effect remains unclear in left bundle branch pacing (LBBP). We report a patient with a baseline sinus rhythm with complete atrioventricular block and a ventricular escape rhythm with a right bundle branch (RBB) block QRS morphology and left axis deviation who received LBBP for cardiac resynchronization therapy (CRT), and its anodal capture stimulation (ANS) rendered a near-normal QRS morphology. The resolution of the RBB pattern during bipolar pacing in this patient resulted from a fusion of LBBP and right ventricular septal capture from ANS. In conclusion, CRT can be achieved during LBBP by ANS in patients who do not have retrograde RBB activation.

Evaluation of the 2021 European Society of Cardiology guidelines in pre-existing right bundle branch block patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

AimsThe 2021 European Society of Cardiology guidelines recommend early pacemaker implantation in pre-existing right bundle branch block (RBBB) patients who develop PR prolongation or QRS axis change after transcatheter aortic valve implantation (TAVI). We aimed to evaluate this recommendation in TAVI recipients with a balloon-expandable valve (BEV).Methods and resultsWe retrospectively reviewed 188 pre-existing RBBB patients without pre-existing permanent pacemaker (PPM) who underwent TAVI with a BEV at our institution in 2015–19. Patients who developed high-degree atrioventricular block (HAVB) during TAVI or within 24 h post-TAVI were excluded. Eligible patients were divided according to the guideline-directed criteria (ΔPR interval ≥20 ms and/or QRS axis change). Patients who met the criteria (n = 102, 54.3%), compared with those who did not (n = 86), had a higher prevalence of baseline right axis deviation and were more likely to have received a larger valve with greater oversizing. The 30-day delayed HAVB rate did not differ significantly between the groups (3.9% vs. 4.7%, P = 1.00; odds ratio = 0.84, 95% confidence interval = 0.20–3.45). There was also no significant difference in terms of death (5.0% vs. 8.4% at 1 year; overall log-rank P = 0.94) or a composite of death or PPM implantation (14.8% vs. 16.6% at 1 year; overall log-rank P = 0.94) during follow-up post-TAVI. The majority of PR prolongations (79.4%) and QRS axis changes (52.0%) regressed within the following 24 h.ConclusionThe present data did not demonstrate an association of significant changes in PR interval or QRS axis with heightened delayed HAVB risk in BEV recipients with pre-existing RBBB. Prospective studies are warranted to confirm these findings.

Eisenmenger syndrome with left main compression syndrome: a case report

BackgroundLeft main coronary artery disease secondary to pulmonary artery compression related to Eisenmenger syndrome is an under-suspected condition that can cause fatal outcomes if left untreated. It presents with typical angina but is frequently mistaken for pulmonary hypertension (PH) symptoms. It is now recognized as one of the few important causes of angina in PH.Case presentationA 37-year-old man with a history of unoperated atrial septal defect and Eisenmenger syndrome came to the outpatient department with a chief complaint of angina on exertion. Electrocardiogram showed regular sinus rhythm with right axis deviation, right ventricular hypertrophy, deep T-wave inversion in inferior and anterior leads suggestive of ischemia or strain, and incomplete right bundle branch block. Cardiac CT showed compression of the left main coronary artery due to a dilated main pulmonary artery. Therefore, this patient was diagnosed with Eisenmenger syndrome with left main compression due to dilated pulmonary artery. He was treated successfully with IVUS-guided stent implantation. The patient experienced marked improvement in regular activities, with no recurrence of angina symptoms. Angiography 3 months after the procedure revealed good patency of the stent, without significant stenosis.ConclusionsLeft main coronary artery compression is a complication that should be suspected in patients with Eisenmenger syndrome presenting with angina symptoms. Non-invasive modalities are recommended for diagnostic evaluation, but the gold-standard technique remains coronary angiography. The best treatment is not well-established, with either myocardial revascularization or PH treatment, but a left main coronary artery stenting procedure is considered an ideal emergent treatment to provide a better quality of life for patients in this condition.