Ablation of ectopic atrial foci for successful management of symptomatic bradycardia: A case series (bradycardia and ectopic atrial beats).

Atrial premature contractions (PACs) that block at the atrio-ventricular (AV) nodal level and occurring in a bigeminal frequency are recognized as a cause of symptomatic bradycardia. Appropriate suppression of the PACs often results in restoration of a regular rhythm with resolution of bradycardia-related symptoms. We report a series of three patients with non-conducted bigeminal PACs arising from the mitral annulus that resulted in symptomatic bradycardia and who were referred for consideration of cardiac pacing. Focal ablation suppressed PACs restoring a normal heart rate and resolution of symptoms without resorting to cardiac pacing.

Step-wise medial collateral ligament needle puncturing in extension leads to a safe and predictable reduction in medial compartment pressure during TKA.

PURPOSE: Medial soft tissue release in a varus deformity knee during total knee arthroplasty is essential for accurate balancing of the reconstruction. This study attempts to quantify the effect of sequential needle puncturing of the medial collateral ligament (MCL) using a pressure sensor insert (Verasense by OrthoSensor) and gap measurement under tension. METHODS: Cruciate-retaining arthroplasties were placed in 14 cadaveric knees. The MCL was elongated by step-wise perforation, in five sets of five perforations, with the use of an 18-gauge needle, followed by valgus stress. Following the fifth set of needle perforations, blade perforation was performed on the remaining tense fibers of the MCL. Following each step-wise perforation, corresponding medial compartment pressures and gap measurements under tension were recorded. RESULTS: Sensor measurements correlated closely with step-wise tissue release (R = 0.73, p < 0.0001), and a significant decrease in pressure was found in early needle puncturing (mean 49 N after 5, 83 N after 15, p values < 0.05), although changes diminished at later stages of needle perforation (90 N after 20). Gap measurement demonstrated small gradual changes with early puncturing, but showed significant opening in the later stages of release. There was minimal variation in pressure or gap measurements in flexion versus extension. This finding suggests that MCL needle puncture will not lead to unequal gaps between flexion and extension. There were no cases of MCL over-release after 15 punctures, one case after 20 punctures, and three after blade perforation. CONCLUSION: Needle puncturing of the MCL in extension for up to 15 punctures can be a safe and predictable way to achieve medial opening when balancing a varus knee during TKA as demonstrated in this cadaveric model. Blade perforation should be used with caution to avoid over-release. The needle puncture method can be used by surgeons to achieve reliable reductions in medial compartment pressures, to help achieve a balanced TKA, with minimal risk of over-release.

Acute Kidney Injury After First-Stage Joint Revision for Infection: Risk Factors and the Impact of Antibiotic Dosing.

BACKGROUND: Scarce literature exists regarding risk factors associated with postoperative acute kidney injury (AKI) after first-stage revision procedures. The purpose of this study was to determine risk factors for AKI and the efficacy of intra-articular antibiotics in infection eradication. METHODS: We retrospectively identified 247 patients who underwent a 2-stage revision procedure for the treatment of hip or knee periprosthetic joint infection. We applied previously published diagnostic criteria for AKI to determine its incidence and risk factors for its development. RESULTS: A 26% incidence of AKI was found after first-stage joint revision for infection. Higher body mass index (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.01-1.13; P = .02), lower baseline hemoglobin level (OR, 0.70; 95% CI, 0.51-0.96; P = .03), and existence of a comorbid condition (OR, 2.67; 95% CI, 1.26-5.64; P = .01) were significant risk factors for AKI. Neither a higher dose of vancomycin (OR, 0.99; 95% CI, 0.88-1.11; P = .83) nor tobramycin (OR, 0.89; 95% CI, 0.77-1.04; P = .15) used in the cement spacer increased the risk of AKI. Each unit increase in vancomycin dose in the cement spacer decreased the odds of failing to clear the infection at 1 and 2 years by a factor of 0.82 (95% CI, 0.70-0.95; P = .01). CONCLUSION: AKI after first-stage revision procedures for periprosthetic joint infection occurs more commonly than previously reported. Patients with identified risk factors should be managed carefully with attention paid to hemoglobin levels, to avoid AKI after this procedure. Further research is needed to determine the optimal local antibiotic type and dosing to maximize infection clearance and minimize potential side effects.

Redefining the Acetabular Component Safe Zone for Posterior Approach Total Hip Arthroplasty.

BACKGROUND: Acetabular component orientation influences joint stability in total hip arthroplasty (THA). The purpose of this study was to evaluate the effect of cup orientation and other variables on hip dislocation risk and to define a posterior approach specific safe zone. METHODS: A cohort of 1289 posterior approach primary THA cases was prospectively followed and component position measured radiographically. RESULTS: Cup malposition, with respect to the Lewinnek safe zone, was an independent risk factor for dislocation (OR1.88). Modifying the anteversion safe zone limits to 10-25° strongly predicted increased dislocation risk (OR2.69). No dislocations occurred within a zone defined by a circle centered at 41.4° abduction and 17.1° anteversion, radius 4.3°. CONCLUSION: Utilizing a posterior approach specific safe zone of 10-25° anteversion and 30-50° abduction may minimize THA dislocations. LEVEL OF EVIDENCE: Level III.

Anatomically Based Ablation of Left Ventricular Summit Premature Ventricular Complexes Guided by Intracardiac Echocardiography.

Catheter ablation of premature ventricular contractions (PVCs) arising from the left ventricular summit (LVS) presents technical challenges due to the regional anatomy and frequent intramural site of origin (SOO). Intracardiac echocardiography (ICE) and the CARTOSOUND® (Biosense Webster, Diamond Bar, CA, USA) module allow the operator to directly reconstruct and visualize the dimensions and orientation of the LVS live and present it in relation to neighboring structures. We retrospectively reviewed consecutive cases between January 2021 and December 2022 of patients undergoing PVC ablation for a presumed LVS origin. The LVS was reconstructed by creating a three-dimensional representation of the left ventricular septum, using two-dimensional ICE sections. The earliest site in each chamber was tagged on the reconstructed LVS, and the presumed SOO was localized using a geometrical center point from all sites. Ablation was first delivered to the earliest site, except when the presence of coronary branches precluded radiofrequency delivery within the great cardiac vein. Of 20 patients (8 women, 62.4 ± 7.1 years old) with a presumed LVS origin, 12 had PVC recurrence within the monitoring period after the initial ablation for 192.5 ± 37.2 s at the earliest site. Among them, earliest activation was seen at the sinus of Valsalva (SoV), coronary venous system (CVS), and left ventricular endocardium (LVE) in four, six, and two patients, respectively. Using the reconstructed LVS, the anatomically closest site to the SOO was identified in the SoV, CVS, and LVE in four, two, and six cases, respectively. Throughout the study period (14.5 months; range, 9.3-19.7 months), 17 patients (85%) had complete elimination of PVCs as evaluated by 24-h event monitors at the 12-month visit. In 50% of cases, among patients in whom ablation at the earliest signal was unsuccessful, the site of successful ablation did not correlate with the second earliest signal or had no identifiable signal during initial activation mapping. The reconstructed LVS not only guided activation mapping but also identified sites proximal to the center point that had either a late activation signal, a low-amplitude signal, or no signal at all.

Vein of Marshall ethanol infusion for recurrent atrial fibrillation in patients with durably isolated pulmonary veins.

BACKGROUND: Vein of Marshall (VoM) ethanol ablation has a proven benefit in patients with persistent atrial fibrillation (AF) undergoing index procedure; however, its role in repeat ablation is unknown. We sought to evaluate the benefit of empiric VoM ethanol ablation in addition to posterior wall isolation (PWI) during the repeat procedure in patients with durable pulmonary vein (PV) isolation from prior ablation. METHODS: Twenty-three patients (age 67.1 + / - 7.4, 74% males) who received empiric VoM ethanol infusion in addition to PWI were matched for age, gender, ejection fraction, and left atrial size with forty-six patients receiving empiric PWI alone. All patients in the study group underwent additional ablation on mitral isthmus to complete the lateral mitral isthmus line. Additional ablation was based on program and trigger stimulation. Primary outcome was freedom from AF after a blanking period of 3 months by qualification of symptoms, EKG, wearable, or implantable monitor or device. RESULTS: The study group had a higher average BMI (35.07 + / - 8.98 vs. 30.85 + / - 5.65, p = 0.033) and rate of persistent AF (83.0% vs. 54.3%, p = 0.029) versus the control. The 1-year AF-free survival for the study and control groups was 20 (86.96%) and 28 (60.1%) patients (p = 0.027). Cox proportional hazard regression analysis showed a significant reduction in AF recurrence in the study group (HR 0.25, 95% CI 0.073-0.843, p = 0.026). CONCLUSION: Among patients undergoing repeat catheter ablation for recurrent AF with durably isolated PVs, the addition of VoM ethanol infusion increased the likelihood of remaining free from AF at 12 months.

A Novel Risk Score to Predict One-Year Mortality in Patients Undergoing Complex High-Risk Indicated Percutaneous Coronary Intervention (CHIP-PCI).

OBJECTIVE: To identify patients undergoing complex, high-risk indicated percutaneous coronary intervention (CHIP-PCI) and compare their outcomes with non-CHIP patients. We created a CHIP score to risk stratify these patients. BACKGROUND: Risk stratification of PCI patients remains difficult because most scoring systems reflect hemodynamic instability and predict early mortality. METHODS: CHIP-PCI was defined as any of the following: age >80 years; ejection fraction <30%; dialysis; prior bypass surgery; treatment of left main trunk; chronic total occlusion; or >2 lesions in >1 coronary artery. The primary endpoint was 1-year all-cause mortality. Logistic regression identified independent predictors of 1-year mortality and the odds ratios (ORs) for those predictors were used to create a CHIP score. Patients were then classified as low, intermediate, and high risk. RESULTS: Among 4478 patients, a total of 1730 (38.6%) were CHIP. There were 85 deaths (2.2%) at 1 year (4.1% in CHIP patients and 1.0% in non-CHIP patients; P<.001). CHIP-PCI was an independent predictor of mortality (OR, 2.57; 955 confidence interval, 1.52-4.32; P<.001). Four CHIP criteria were independent predictors of mortality: age >80 years (3 points); dialysis (6 points); ejection fraction <30% (2 points); and number of lesions treated >2 (2 points). Accordingly, there were 2752 low-risk (score of 0), 889 intermediate-risk (score of 2-3), and 267 high-risk patients (score of 4-13). The 1-year mortality rates among these 3 groups were 1.24%, 2.47%, and 10.86%, respectively (P<.001). CONCLUSION: Compared with non-CHIP, CHIP-PCI is associated with increased risk of 1-year mortality, which is particularly evident among those fulfilling >1 CHIP criterion.

Ticagrelor vs Clopidogrel in Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention: Insights From a Single Institution Registry.

Dual-antiplatelet therapy is recommended for all patients with acute coronary syndromes (ACS), regardless of performance of revascularization. Ticagrelor (T) was shown to be superior to clopidogrel (C) in a large, randomized clinical trial, but data from real-world practice are lacking. We identified ACS patients from our institutional registry who underwent percutaneous coronary intervention and received one of the two drugs at hospital discharge based on physician preference. Among 1439 patients, there were 774 patients (53.8%) in the C group and 665 patients (46.2%) in the T group. T and C patients were similar except for a higher incidence of ST-elevation myocardial infarction (MI) and lower frequency of prior MI in the T group (P<.05 for both). The primary endpoint - 1-year all-cause death - occurred in 58 C patients and 48 T patients (6.9% vs 7.9%, respectively; P=.42). Sixty percent of these deaths (n = 62; 31 C and 31 T) were considered cardiovascular in nature based on chart review. By multivariable logistic regression model, only dialysis (hazard ratio [HR], 2.64; 95% confidence interval [CI], 1.50-4.64; P=.01), age (HR, 1.83; 95% CI, 1.49-2.24 per 10 years; P<.001), and prior heart failure (HR, 1.78; 95% CI, 1.12-2.82; P=.02) were independent predictors of 1-year death. Treatment with T was not a predictor of death (HR, 1.21; 95% CI, 0.81-1.82; P=.35) or cardiovascular death (HR, 1.18; 95% CI, 0.72-1.94; P=.52). Landmark analysis from day 10 showed similar results (HR, 1.13; 95% CI, 0.71-1.84; P=.59). Thus, we conclude that C and T have similar rates of 1-year all-cause mortality, which is predominantly affected by age, end-stage renal disease, and pre-existing heart failure.

Has the risk of dislocation after total hip arthroplasty performed for displaced femoral neck fracture improved with modern implants?

BACKGROUND: Displaced femoral neck fractures (DFNF) in the elderly can be treated with hemiarthroplasty or total hip arthroplasty (THA). One concern with utilizing THA in this setting is post-operative dislocation. The purposes of this study were to determine the incidence of hip dislocation following THA for DFNF and to identify risk factors for dislocation. METHODS: The charts of 66 posterior-approach THA cases performed for DFNF with mean post-operative follow-up of 4.4 years were retrospectively reviewed. Pre-operative patient demographic data and intra-operative clinical data were recorded including age, race, gender, height, weight, body mass index (BMI), femoral head diameter, acetabular cup diameter, use of an elevated liner, and cementing of femoral component. For patients with available post-operative pelvis radiographs, acetabular cup inclination and version angles were also calculated. RESULTS: Four dislocation (4/66, 6%) events occurred at an average of 51 days after surgery. No specific risk factors for dislocation were identified but the use of a cemented femoral stem did approach significance (p = 0.06). 47% of the acetabular cups were located outside of the Lewinnek safe zone. Although the dislocation rate of THAs with acetabular cups outside of the safe zone was higher than the dislocation rate for THAs with cups in the safe zone (12.5% vs 0%), placement of acetabular cups outside of the safe zone was not a risk factor for dislocation. CONCLUSIONS: Posterior THA with proper cup positioning and meticulous soft tissue repair is an effective treatment option for DFNF with low dislocation risk.

Assessment of Proximal Junctional Kyphosis and Shoulder Balance With Proximal Screws versus Hooks in Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective review of a prospectively collected multicenter database. OBJECTIVE: To assess the effect of proximal hooks versus screws on proximal junctional kyphosis (PJK) as well as shoulder balance in otherwise all pedicle screw (>80%) posterior spinal fusion (PSF) constructs in adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Less rigid forms of fixation at the top of constructs in degenerative lumbar PSF have been postulated to decrease the risk of PJK. METHODS: A multicenter AIS surgical database was reviewed to identify all patients who underwent PSF with all pedicle screw (>80%) constructs and minimum 2-year follow-up. Patients in the "hook" group had two hooks used at the top of the construct, whereas the "screw" group used only pedicle screws at all levels. RESULTS: A total of 354 patients were identified, 274 (77%) in the screw group, and 80 (23%) in the hook group. There were no significant preoperative differences with regards to curve type, coronal/sagittal Cobb angle, or curve flexibility for either group. At 2 years post-op, the coronal Cobb correction was similar for both groups (60%). There was no difference in correction of shoulder asymmetry and T1 rib angle, including when the groups were matched for preoperative shoulder balance. PJK, defined as the sagittal Cobb angle between the uppermost instrumented and uninstrumented vertebrae, was similar for the screw versus hook group as well (7.1° vs. 6.2°, P = 0.2). CONCLUSION: The use of different anchors (pedicle screws vs. hooks) at the top of an otherwise all pedicle screw PSF construct for AIS did not have any significant bearing on the correction of shoulder asymmetry and coronal Cobb angle at 2 years postoperative. There was also no significant difference in the magnitude of PJK or incidence of marked PJK (>15°) between either group at 2 years. LEVEL OF EVIDENCE: 3.