Aveir VR real-world performance and chronic pacing threshold prediction using mapping and fixation electrical data.

AIMS: Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated. METHODS: Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width. RESULTS: Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000). CONCLUSION: Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT.

Personalized cardiac resynchronization therapy guided by real-time electrocardiographic imaging for patients with non-left bundle branch block.

BACKGROUND: Patients with heart failure and a non-left bundle branch block (non-LBBB) QRS pattern have a limited response to biventricular pacing (BVP). OBJECTIVE: A personalized cardiac resynchronization therapy (CRT) implantation approach guided by real-time electrocardiographic imaging (ECGi) was studied. METHODS: Twenty patients with left ventricular ejection fraction (LVEF) ≤ 35%, QRS duration ≥ 120 ms, and non-LBBB [13 (65%) with right bundle branch block and 7 (35%) with intraventricular conduction delay] were recruited. During CRT implantation, right atrial, right ventricular, coronary sinus, His-bundle, and/or left bundle leads were inserted. The total activation time (TAT) with different pacing combinations were measured in real time during implantation by ECGi. The configuration producing the shortest TAT was chosen. Clinical response was defined as ≥1 New York Heart Association class improvement. Echocardiographic response was defined as left ventricular end-systolic volume reduction ≥ 15% and/or LVEF improvement ≥ 10% at 6 months. RESULTS: After ECGi-guided CRT implantation, LVEF improved from 26% ± 6% to 34% ± 11% (P < .01) and New York Heart Association class improved from 3.0 ± 0.5 to 2.0 ± 0.6 (P < .01). Both clinical and echocardiographic response rates were 70%. The ECGi approach resulted in better acute electrical resynchronization over BVP as measured by TAT reduction (40% vs 14%; P < .01). The percentage of TAT reduction was found to be a strong predictor for echocardiographic response (area under the curve for the receiver operating characteristic curve 0.91; 95% confidence interval 0.78-1.00). A strong positive correlation between percentage TAT reduction and percentage LVEF improvement (Pearson R = 0.70; P = .001) was found. CONCLUSION: ECGi-guided CRT implantation in patients with non-LBBB generates superior acute electrical resynchronization compared with BVP and is associated with favorable clinical and echocardiographic outcomes.

Automatic algorithmic driven monitoring of atrioventricular nodal re-entrant tachycardia ablation to improve procedural safety.

Background: During slow pathway modification for atrioventricular nodal reentrant tachycardia, heart block may occur if ablation cannot be stopped in time in response to high risk electrogram features (HREF). Objectives: To develop an automatic algorithm to monitor HREF and terminate ablation earlier than human reaction. Methods: Digital electrogram data from 332 ablation runs from February 2020 to June 2022 were included. They were divided into training and validation sets which contained 126 and 206 ablation runs respectively. HREF in training set was measured. Then a program was developed with cutoff values decided from training set to capture all these HREF. Simulation ablation videos were rendered using validation set electrogram data. The videos were played to three independent electrophysiologists who each determined when to stop ablation. Timing of ablation termination, sensitivity, and specificity were compared between human and program. Results: Reasons for ablation termination in the training set include short AA time, short VV time, AV block and VA block. Cutoffs for the program were set to maximize program sensitivity. Sensitivity and specificity for the program in the validation set were 95.2% and 91.1% respectively, which were comparable to that of human performance at 93.5% and 95.4%. If HREF were recognized by both human and program, ablations were terminated earlier by the program 90.2% of times, by a median of 574 ms (interquartile range 412-807 ms, p < 0.001). Conclusion: Algorithmic-driven monitoring of slow pathway modification can supplement human judgement to improve ablation safety.

ResultsMyWay: combining Fast Healthcare Interoperability Resources (FHIR), Clinical Quality Language (CQL), and informational resources to create a newborn screening application.

Newborn screening (NBS) can be life-changing for the families of infants who test positive for a rare condition. While resources exist to support these families, there can be delays in sharing these resources due to communication lag between the laboratory, result interpreting clinician, family of the newborn, and additional care providers. This delay can also be exacerbated when additional health history is required from the mother and infant. ResultsMyWay is a proof-of-concept application that uses Clinical Quality Language (CQL) to automate the search for this additional health history. It also translates the NBS results into Fast Healthcare Interoperability Resources (FHIR), increasing both the ease of exchange and the future utility of these data points. After the families are given the NBS results, ResultsMyWay then acts as a hub for several types of informational resources about the recently diagnosed condition.

Intraoperative vasopressors and thrombotic complications in free flap breast reconstruction.

OBJECTIVE: The purpose of this study was to critically examine intraoperative vasopressor usage as it relates to free flap perfusion and its effect on perioperative complications in autologous breast reconstruction. METHODS: A retrospective cohort study was performed involving all free autologous breast reconstructions at a single institution over a 5 year period. Data collection focused on perioperative care, specifically fluid administration, urine output (UOP), use of vasopressors, and case duration. Outcomes included major intraoperative and postoperative complications. Patients who received intraoperative vasopressors were compared to all patients who did not. The use, type, and timing of the vasopressor agent were assessed with standard statistical analyses and regression modelling. RESULTS: Six hundred and eighty-two patients reconstructed with 1039 flaps were included. Of these, 475 (69.6%) patients received vasopressors. The vasopressor cohort was older (p = 0.001), with higher rates of hypertension (p = 0.02). They had a greater number of hypotensive episodes (2.3 vs 0.8, p < 0.0001) and received a greater volume of fluid (4653.0 vs 4291.7 ml, p = 0.004). Examining complications, no increase in intraoperative thrombotic events (arterial or venous) or flap loss was noted with vasopressor administration. A higher rate of minor complications was, however, noted (53.1% vs 43.0%, p = 0.016). CONCLUSIONS: This study demonstrates that the use of intraoperative vasopressor agents in the anaesthetic care of free flap breast reconstruction patients is common, but likely does not impact thrombotic events or flap loss. Minor complications may, however, be more common in these patients.

Intraoperative perfusion management impacts postoperative outcomes: an analysis of 682 autologous breast reconstruction patients.

INTRODUCTION: Anesthetic management remains an understudied aspect of free autologous breast reconstruction. This study aims to critically examine intraoperative anesthetic management as it relates to free flap perfusion and its effect on major complications. METHODS: A retrospective cohort study was performed examining all abdominally based free autologous breast reconstructions from 2005 to 2011 at a single institution. Analysis focused on perioperative care and specifically fluid administration, urine output (UOP), vasopressor administration, and case duration. Outcomes included major intraoperative and postoperative complications. A post-hoc analysis was performed to determine anesthetic factors associated with thrombotic events. RESULTS: Overall, 682 patients (1033 flaps) were included. Patients with low UOP had lower rates of intraoperative fluid infusion rates/kg (p=0.0001), Estimated Blood Loss (EBL) (p=0.006) and pressor administration (p=0.03), but no significant differences were noted in intraoperative thrombotic events according to UOP. However, the below normal UOP cohort demonstrated a significant increased rate of delayed postoperative thromboses (p=0.03). A post hoc analysis of postoperative thrombotic events revealed that low rates of fluid resuscitation (OR=3.01, p=0.04) and low intraoperative UOP (OR=3.67, p=0.04) were independently associated with delayed thrombosis. A sub-analysis demonstrated that patients with ≥2 comorbidities and below normal UOP were at particular risk (any delayed thrombotic event OR=4.3, p=0.03; any delayed venous thrombosis OR=9.1, p=0.03). CONCLUSIONS: This study demonstrates that intraoperative fluid under-resuscitation may place patients at increased risk for postoperative flap thrombosis, and low UOP is an important metric whereby intraoperative resuscitation should be gauged. Patients with comorbid conditions and below normal intraoperative UOP should be monitored particularly closely for delayed thrombotic events. LEVEL OF EVIDENCE: Prognostic/risk category, level II.

A 30-day risk assessment of mastectomy alone compared to immediate breast reconstruction (IBR).

UNLABELLED: Immediate breast reconstruction (IBR) is emerging as a favourable reconstruction option for breast cancer patients. Understanding the factors associated with complications following IBR will enhance care delivery, risk counselling and management, and potentially improve patient satisfaction. Women undergoing mastectomy alone and mastectomy with IBR from 2005-2011 were identified in the ACS-NSQIP datasets. Specific complications examined included surgical (flap or prosthesis loss and unplanned reoperation), wound (superficial/deep surgical site infection and wound dehiscence), and medical complications. Bivariate and multivariate analyses were performed to identify predictors of outcomes. A total of 47,443 patients were identified. For patients who underwent IBR compared to mastectomy alone, total complications (11.2% vs 9.2%, p < 0.001) and surgical complications (7.8% vs 4.7%, p < 0.001) were more frequent. In adjusted analysis, a common predictor of complications was class III obesity (BMI ≥ 40 kg/m(2)) for mastectomy alone (OR = 1.79, p < 0.001) and implant-based IBR (OR = 2.20, p < 0.001), and class II obesity (BMI 35-39.9) for autologous IBR (OR = 1.62, p = 0.003). Wound complications were found to be associated with autologous reconstruction (p < 0.001 kg/m(2)), smoking (p < 0.001), bilateral procedures (p = 0.005), patient comorbidity (p = 0.006), obesity (p < 0.001), and diabetes (p < 0.001). The strongest predictors of wound complications were class II obesity (OR = 2.12), class III obesity (OR = 3.09), and smoking (OR = 1.70). Risk factors for medical morbidity included: immediate autologous (p < 0.001), recent chemotherapy (p = 0.013), ASA physical status (p < 0.001), bilateral procedure (p = 0.002), patient comorbidity (p < 0.001), and obesity (p < 0.001). The strongest predictors of medical morbidity were immediate autologous reconstruction (OR = 3.54) and comorbidity burden of ≥2 comorbid conditions (OR = 2.28). In conclusion, undergoing IBR is associated with a modality-specific increased risk of morbidity relative to mastectomy alone. However, other modifiable risk factors appear to be strongly correlated with postoperative complications. LEVEL OF EVIDENCE: prognostic/risk category, level II.