Effectiveness of Different Etching Agents on Enamel Surface and Shear Bond Strength: An In Vitro Evaluation.

Background Enamel etching is of utmost importance during the orthodontic bonding procedure. Phosphoric acid, hydrofluoric acid, and citric acid are used in specific concentrations to create surface irregularities on enamel surfaces, enhancing the bond strength of the orthodontic attachment. Therefore, it is essential to evaluate the type of etchant for reliable orthodontic bracket bonding with minimal damage to the enamel surface. Aims and objectives This study aimed to investigate the morphological changes on the enamel surface after treatment with different surface etchants, assess the depth of penetration, and evaluate the shear bond strength (SBS) of orthodontic brackets. Materials and methods One hundred and one extracted premolar teeth were used to investigate morphological changes on the enamel surface treated with 37% phosphoric acid, 11% hydrofluoric acid, and 20% citric acid. It was evaluated on a scanning electron microscope (Jeol Scientific Equipment, Jeol Limited, Akishima, Japan), and the SBS of brackets on enamel treated with different etching agents was evaluated using an Instron Universal Testing Machine (UTM; Instron Model: 5982, Universal Testing Systems, Norwood, MA). Group A had 60 test samples. Group B had 40 test samples. One control without any acid etching was used in both groups. Subgroup A1 (n = 30) was evaluated for surface characteristics of acid-etched enamel. Subgroup A2 was assessed for the penetration depth of various etchants. Group B (n = 40) was tested for SBS. The results were tabulated and analyzed using IBM SPSS Statistics, version 20.0 (IBM Corp., Armonk, NY). Post hoc Tukey HSD test and one-way analysis of variance were used to assess SBS and penetration depth of etchants (P ≤ 0.05). Pearson's correlation test was used to correlate SBS, etching pattern, and penetration depth. The chi-square test was used to test the frequency of types of etching patterns.  Results Intergroup correlations between etching depth, etching pattern evaluated on SEM, and SBS evaluated on the UTM showed a high statistical correlation between etching depth & SBS, etching depth & etching pattern, and SBS & etching pattern between A1, A2, and group B (P ≤ 0.001). A highly significant negative correlation between SBS & etching pattern (P = 0.42) was observed among intra-group correlation. Non-significant correlations were found between etching depth & SBS and etching depth & etching pattern within the 20% citric acid etch group (P = 0.370 and 0.141, respectively). Conclusion Penetration depth obtained was highest with 11% hydrofluoric acid, followed by 37% phosphoric acid and 20% citric acid. In addition, 11% hydrofluoric acid showed the highest bond strength. Acid etching showed better penetration depth and bond strength than control.

Removable versus fixed myo-functional appliances in class II malocclusion among Indians.

It is of interest to compare two myofunctional appliances (frankal appliance and twin bloc) and two fixed orthodontic appliances (PowerScope and Forsus) in management of class II div 1 malocclusion. A total of 56 Class II division 1 malocclusion patients indicated for treatment with myofunctional appliances and fixed functional appliances were randomized. They were equally divided among frankal appliance (n=14), twin block appliance (n=14), PowerScope (American Orthodontics) (n=14), Forsus (3M Unitek Corp) groups (n=14). Skeletal and dentoalveolar effects of all appliances were compared. SNB increased remarkably by 4.2° in the Twin block group and it was high among all treatment groups. There was a significant decrease in vertical dimensions (SN-GoGn) in the Twin block (p = 0.002). Early treatment of Class II due to mandibular retrusion with Twin block functional appliance is recommended due to its favorable skeletal effect.

Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience.

BACKGROUND: The ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks. METHODS: We describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected. RESULTS: Normal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s. CONCLUSIONS: Preliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

Sinus Node Sparing Hybrid Thoracoscopic Ablation Outcomes in Patients with Inappropriate Sinus Tachycardia (SUSRUTA-IST) Registry.

BACKGROUND: Medical treatment of inappropriate sinus tachycardia (IST) remains suboptimal. Radiofrequency sinus node (RF-SN) ablation has poor success and higher complication rates. OBJECTIVE: We aimed to compare clinical outcomes of the novel SN sparing hybrid ablation technique with those of RF-SN modification for IST management. METHODS: This is a multicenter prospective registry comparing the SN sparing hybrid ablation strategy with RF-SN modification. The hybrid procedure was performed using an RF bipolar clamp, isolating superior vena cava/inferior vena cava with the creation of a lateral line across the crista terminalis while sparing the SN region (identified by endocardial 3-dimensional mapping). RF-SN modification was performed by endocardial and/or epicardial mapping and ablation at the site of earliest atrial activation. RESULTS: Of the 100 patients (hybrid ablation group, n = 50; RF-SN group, n = 50), 82% were women, and the mean age was 22.8 years. Normal sinus rhythm and rate were restored in all patients in the hybrid group (vs 84% in the RF-SN group; P = .006). Hybrid ablation was associated with significantly better improvement in mean daily heart rate and peak 6-minute walk heart rate compared with RF-SN ablation. The RF-SN group had a significantly higher rate of redo procedures (100% vs 8%; P < .001), phrenic nerve injury (14% vs 0%; P = .012), lower acute pericarditis (48% vs 92%; P < .0001), permanent pacemaker implantation (50% vs 4%; P < .0001) than did the hybrid ablation group. CONCLUSION: The novel sinus node sparing hybrid ablation procedure appears to be more efficacious and safer in patients with symptomatic drug-resistant IST with long-term durability than RF-SN ablation.

Diagnostic Utility of Smartwatch Technology for Atrial Fibrillation Detection - A Systematic Analysis.

BACKGROUND: Smartphone technologies have been recently developed to assess heart rate and rhythm, but their role in accurately detecting atrial fibrillation (AF) remains unknown. OBJECTIVE: We sought to perform a meta-analysis using prospective studies comparing Smartwatch technology with current monitoring standards for AF detection (ECG, Holter, Patch Monitor, ILR). METHODS: We performed a comprehensive literature search for prospective studies comparing Smartwatch technology simultaneously with current monitoring standards (ECG, Holter, and Patch monitor) for AF detection since inception to November 25th, 2019. The outcome studied was the accuracy of AF detection. Accuracy was determined with concomitant usage of ECG monitoring, Holter monitoring, loop recorder, or patch monitoring. RESULTS: A total of 9 observational studies were included comparing smartwatch technology, 3 using single-lead ECG monitoring, and six studies using photoplethysmography with routine AF monitoring strategies. A total of 1559 patients were enrolled (mean age 63.5 years, 39.5% had an AF history). The mean monitoring time was 75.6 days. Smartwatch was non-inferior to composite ECG monitoring strategies (OR 1.06, 95% CI 0.93 - 1.21, p=0.37), composite 12 lead ECG/Holter monitoring (OR 0.90, 95% CI 0.62 - 1.30, p=0.57) and patch monitoring (OR 1.28, 95% CI 0.84 - 1.94, p=0.24) for AF detection. The sensitivity and specificity for AF detection using a smartwatch was 95% and 94%, respectively. CONCLUSIONS: Smartwatch based single-lead ECG and photoplethysmography appear to be reasonable alternatives for AF monitoring.

Creating a safe workplace by universal testing of SARS-CoV-2 infection in asymptomatic patients and healthcare workers in the electrophysiology units: a multi-center experience.

BACKGROUND: As the coronavirus cases continue to surge, the urgent need for universal testing to identify positive cases for effective containment of this highly contagious pandemic has become the center of attention worldwide. However, in spite of extensive discussions, very few places have even attempted to implement it. We evaluated the efficacy of widespread testing in creating a safe workplace in our electrophysiology (EP) community. Furthermore, we assessed the new infection rate in patients undergoing EP procedure, to see if identification and exclusion of positive cases facilitated establishment of a risk-free operating environment. METHODS: Viral-RNA and serology tests were conducted in 1670 asymptomatic subjects including patients and their caregivers and staff in our EP units along with the Emergency Medical Service (EMS) staff. RESULTS: Of 1670, 758 (45.4%) were patients and the remaining 912 were caregivers, EMS staff, and staff from EP clinic and lab. Viral-RNA test revealed 64 (3.8%) positives in the population. A significant increase in positivity rate was observed from April to June 2020 (p = 0.02). Procedures of positive cases (n = 31) were postponed until they tested negative at retesting. Staff testing positive (n = 33) were retested before going back to work after 2 weeks. Because of suspected exposure, 67 staff were retested and source was traced. No new infections were reported in patients during or within 2 weeks after the hospital-stay. CONCLUSIONS: Universal testing to identify positive cases was helpful in creating and maintaining a safe working environment without exposing patients and staff to new infections in the EP units. TRIAL REGISTRATION: Trial Registration Number: clinicaltrials.gov : NCT04352764.

Safety and efficacy of leadless pacemaker for cardioinhibitory vasovagal syncope.

BACKGROUND: Single-chamber leadless pacemakers (LPs) have been shown to be an effective alternative to conventional transvenous pacemakers (CTPs), but their benefit in the context of cardioinhibitory vasovagal syncope (CI-VVS) is unknown. OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of LP compared with dual-chamber CTP for CI-VVS. METHODS: We conducted a multicenter, retrospective study comparing patients who received LP or dual-chamber CTP for drug-refractory CI-VVS. CI-VVS was diagnosed clinically and supported by cardiac monitoring and head-up tilt table testing. The primary efficacy endpoint was freedom from syncope during follow-up. Secondary endpoints included device efficacy and safety estimated by device-related major and minor adverse events (AEs). RESULTS: Seventy-two patients (24 LP, 48 CTP; age 32 ± 5.5 years; 90% female; syncope frequency 7.6 ± 3.4 per year) were included. At 1 year, 91% of patients (22/24) in the LP group and 94% of patients (43/48) in the CTP group met the primary efficacy endpoint (P = .7). Device efficacy endpoint was met in 92% of the LP group and 98% of the CTP group (P = .2). Early major AEs occurred in 2 of 24 in the LP group and 3 of 48 in the CTP group (P = .4). Late major AEs occurred in 0 of 24 in the LP group and 2 of 48 in the CTP group (P = 1). CONCLUSION: In patients with CI-VVS, single-chamber LP demonstrated equivalent efficacy in reducing syncopal events compared to dual-chamber CTP, with a similar safety profile.

A Rare Case of Bronchopericardial Fistula Following Atrial Fibrillation Ablation.

Radiofrequency ablation (RFA) for atrial fibrillation (AF) has emerged as an effective and reliable treatment modality. Since its introduction in the 1990s, major and minor complications have been identified. Major complications include periprocedural death, atrioesophageal (AE) fistula, stroke, cardiac perforation and tamponade, pulmonary venous stenosis, phrenic nerve injury, retroperitoneal hematoma, and arrhythmias. Minor complications include pseudoaneurysms and arteriovenous fistulas . We report an extremely rare and life-threatening complication of bronchopericardial fistula following AF ablation resulting in respiratory complications.

Advanced Anderson-Fabry disease presenting with left ventricular apical aneurysm and ventricular tachycardia.

A 54-year-old female with Anderson-Fabry disease (AFD)-R342Q missense mutation on exon 7 in alpha-galactosidase A (GLA) gene - presented with sustained ventricular tachycardia. Imaging confirmed the presence of a new left ventricular apical aneurysm (LVAA) and a significantly reduced intra-cavitary gradient compared to two years prior. AFDcv is an X-linked lysosomal storage disorder caused by GLA enzyme deficiency. The phenotypic expression of AFD in the heart is not well described. Cardiac involvement can include left ventricular hypertrophy (LVH), which is typically symmetric, but can also mimic hypertrophic cardiomyopathy (HCM). Left ventricular apical aneurysm is a rare finding in HCM. We suggest a shared mechanism of LVAA formation in AFD and HCM, independent of the underlying cardiomyopathy. Mechanisms of LVAA formation in HCM include genetic predisposition and long-standing left ventricular wall stress from elevated intra-cavitary systolic pressures due to mid-cavitary obstruction. Both mechanisms are supported in this patient (a brother with AFD also developed a small LVAA). Screening for AFD should be considered in cases of unexplained LVH, particularly in patients with the aneurysmal variant of HCM.

Using amniotic membrane allografts in the treatment of neuropathic foot ulcers.

Neuropathic foot ulcers are a common complication in patients with diabetes. These ulcers are often slow to heal and can lead to infection, further tissue destruction, osteomyelitis, and amputation. These patients pose a challenge to clinicians who must determine the best treatment options while balancing the risks, benefits, and costs. Conservative therapies often present disappointing results, and a number of newer "biologic bandages" have been developed to better assist the healing process. We describe results from diabetic patients with neuropathic foot ulcers treated with a new amniotic membrane-based allograft.

Ankle-brachial index performance among internal medicine residents.

The ankle-brachial index (ABI) is the standard test used in clinical practice to detect peripheral artery disease (PAD) and is a powerful predictor of adverse cardiovascular outcomes. This study sought to measure the baseline knowledge of the ABI test among a sample of internal medicine residents and to examine the impact of an educational intervention on performance of the test. A total of 29 residents were asked to perform three tasks, with the performance of each task being assessed using a point-based scoring system: measure an ABI on a normal volunteer (15 points), calculate the ABI based on data from a hypothetical patient (3 points), and interpret a range of ABI values (6 points). A standardized educational intervention was then provided and post-education performance was assessed for each task using the same scoring system. At baseline, 4% of residents correctly measured the ABI, 10% correctly calculated the ABI, and 45% correctly interpreted the ABI. Baseline performance was unaffected by year of residency training. Following the educational intervention, 50% of residents correctly measured the ABI, 75% correctly calculated the ABI, and 88% correctly interpreted the ABI. The mean score for the tasks of ABI measurement, calculation and interpretation between baseline and post-education were 4.6 +/- 3 and 13.9 +/- 1.6 (p < 0.0001), 1 +/- 0.9 and 2.3 +/- 1.2 (p = 0.002), and 4.9 +/- 1.6 and 5.9 +/- 0.3 (p = 0.008), respectively. In conclusion, baseline knowledge of the ABI test was poor among a sample of internal medicine residents. These results suggest that instruction regarding the ABI test is deficient in medical school and residency programs and requires action by those responsible for the education of medical students and residents.

Clinical outcomes using aggressive approach to anatomic screening and endovascular revascularization in a veterans affairs population with critical limb ischemia.

BACKGROUND: This study sought to examine the impact of an aggressive approach to anatomic screening and endovascular revascularization in a veterans administration population with critical limb ischemia (CLI) on the primary treatments received and overall clinical outcomes. METHODS: The baseline clinical and angiographic characteristics and clinical outcomes of the first consecutive fifty veterans who were referred for the evaluation and treatment of CLI using the strategy outlined were assessed by retrospective review of the computerized medical record and angiographic data. RESULTS: Among the entire cohort, the primary treatments received were as follows--revascularization n = 44 (88%), primary amputation n = 1 (2%), medical treatment n = 3 (6%), and primary minor amputation n = 2 (4%). Endovascular revascularization was the dominant mode of revascularization (94%), with a procedural success rate of 91%. Repeat revascularization was required in 19% of patients who had an initially successful endovascular procedure. A total of eight deaths and four major amputations occurred in the entire cohort over a mean follow-up of 397 +/- 190 days. The 1-year Kaplan-Meier estimates for survival and amputation-free survival for the entire cohort were 90 and 81%, respectively. Resolution of rest pain or complete wound healing was achieved in 85% of patients at a mean of 157 +/-126 days. CONCLUSIONS: An aggressive approach to anatomic screening and contemporary endovascular treatment of CLI resulted in a higher rate of revascularization as the primary treatment for CLI than previously reported, and was associated with high rates of overall and amputation-free survival.