Background: Left bundle branch area pacing (LBBAP) represents an advanced physiologic conduction system pacing technique.However, the long-term stability of stylet-driven leads (SDLs) in LBBAP remains uncertain, with limited documented reports on lead fractures.Case presentation: An 81-year-old male with a history of chronic kidney disease, heart failure, and paroxysmal atrial fibrillation (AF) was admitted for medical management.The patient experienced persistent dyspnea and dizziness attributable to bradycardia and required ongoing rhythm control medication for paroxysmal AF.Given the presence of an underlying left bundle branch block with a mildly reduced left ventricular ejection fraction, a dual-chamber pacemaker (Enitra 8 DR-T; Biotronik, DDDR) with LBBAP using SDL (Solia S50) was implanted.As the patient underwent dialysis via the left arm, pacemaker implantation was performed through the right axillary vein.At 30 months post-implantation, elevated lead impedance exceeding 2,000 and complete ventricular lead dysfunction were highly suggestive of lead fracture despite fluoroscopic imaging showing no definitive evidence of fracture.During ventricular lead extraction, severe adhesions and right axillary vein obstruction were encountered, requiring an 11Fr TightRail device for successful removal.The extracted lead displayed a distinct bend near the interelectrode segment, confirming a typical SDL fracture in LBBAP.Conclusions: This case highlights the typical characteristics of lead fracture and precautions associated with SDL-LBBAP and emphasizes that such fractures can occur beyond previously reported timeframes.To prevent SDL-LBBAP fracture, careful attention to lead manipulation during rotational adjustments is essential during the procedure.

Abstract Background New-onset postoperative atrial fibrillation (nPOAF) is a common complication after cardiac surgery (30–50%), being associated with unfavorable long-term outcomes. Using the Society of Thoracic Surgeons National Adult Cardiac Database, we used machine learning (ML) to predict nPOAF and related 30-day outcomes following mitral valve (MV) surgery. A total of 27,856 MV operations were performed at 910 centers between 7/1/2017 and 6/30/2020 on patients without AF or a prior permanent pacemaker. The primary endpoint was nPOAF postoperatively. ML techniques utilized included penalized logistic regression, gradient boosting, decision trees, and random forests. Results The overall incidence of nPOAF was 35.4% and that of new pacemaker insertion was 5.6%. Patients who developed nPOAF were older (67 ± 10 vs 60 ± 13 years), had more mitral valve stenosis (14.1% vs 11.7%), and hypertension (72.1% vs 63.3%). They underwent more mitral valve replacement (39.1% vs 32.7%) and coronary artery bypass grafting (23.9% vs 16%). For predicting nPOAF, ML methods offer sensitivity, specificity and precision superior to logistic regression. The accuracy rate was identical with penalized and non-penalized logistic regression (0.672). Conclusions Predicting nPOAF and its short-term sequelae following MV surgery remains highly challenging. Machine learning methods offer a moderate degree of improvement in predicting nPOAF even in large national-level studies, in the absence of multi-modal data, such as real-time wearables data, electrocardiograms, heart rhythm monitoring, or cardiac imaging.

IntroductionAtrial fibrillation (AFib) is a common dysrhythmia and a risk factor for stroke and heart failure. Early detection and treatment are key to avoiding complications (especially in sustained AFib). Here, we systematically review the potential of wearable smartwatches (WSWs) to screen for AFib.MethodA literature search was conducted, and only those validation studies were shortlisted where the screening ability of WSWs was compared with EKG, and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and Kappa statistic were provided.ResultTwelve studies were included with a combined sample size of 1,075,088. Most validation measures of WSWs were above 90% and comparable with KardiaBand by AliveCor (KB), which is an FDA-approved device to detect AFib.ConclusionWSWs have the potential to reliably and continuously screen for AFib and detect it in a timely manner. The inconclusive results produced by WSWs are a significant problem. Once the inconclusive results are rectified, WSWs may be used for widespread screening of AFib in those people who are at high risk of developing AFib.

In the context of ARVC, a systematic review of the validation of the ARVC risk score can provide insights into the accuracy and reliability of this score in identifying patients at high risk of ARVC. Digital databases were searched to identify the relevant studies using Medical Subject Headings (MeSH). A total of 8 studies were included in this systematic review. A total of 8 studies were included in this review. The review found that the sensitivity of the ARVC risk scores ranged from 80 to 95%, and the specificity ranged from 31 to 79%. The PPV was 55%, and the NPV was 88%. The ARVC score provided a C-index for a 5-year VA risk prediction of 0.84 [95% CI (0.74–0.93)] and a Harrell C-index of 0.70 (95% CI 0.65–0.75). The calibration slope was 1.01 (95% CI 0.99–1.03). ARVC score demonstrated a significant event 5-year threshold between 15 and 20% and the classical ARVC 5-years/freedom-from-VA rate was 0.76(0.66–0.89) and the non-classical form 5-years/freedom-from-VA rate was 0.58 (0.43–0.78). In conclusion, the validation of ARVC risk scores is an essential step toward improving the accuracy of ARVC diagnosis and risk stratification. Further studies are needed to establish the accuracy and reliability of ARVC risk scores and to address the limitations of the current evidence.

Atrial fibrillation (AF) patients are often high risk being elderly and having multiple comorbidities. Many risk factors are established to be associated with new onset incident AF, as well as AF-related complications such as stroke and hospitalisations. Multimorbidity AF patients are high risk and require a holistic approach to care, which should be proactively managing with an integrated care or holistic approach as per the ABC (atrial fibrillation better care) pathway.

IntroductionRelative bradycardia(RB) is a relatively low heart rate response to rise in body temperature that occurs in several infectious diseases and can be an important clinical sign. In previous case reports, RB was presented in some patients with Coronavirus disease 2019 (COVID-19) COVID-19.Objective and MethodsTo investigate the correlation between temperature and heart rate, we retrospectively reviewed 249 febrile patients with documented COVID-19 patients. RB was defined as a rise in the heart rate from a basal heart rate of less than 10 beats/minute/°C rise in temperature.ResultsIn this study, the prevalence of RB in patients with COVID-19 was 60.6%. When the HR at peak temperatures for patients with COVID-19 were compared with reference valve (general temperature-heart rate response in infectious disease), our findings demonstrate a relatively lower heart rate at all peak temperatures recorded. Despite differences in heart rate response, there were not significant differences in clinical outcomes (pulmonary manifestation, intensive care unit admission, Death).ConclusionsMost patients with COVID-19 are associated with relative bradycardia, not related to clinical outcomes. RB in COVID-19 can be considered as the clinical features for differential diagnosis from other febrile conditions.

BackgroundIn many low- to middle-income countries in Asia, patients with NVAF usually received warfarin for thromboembolic prevention due to cost-effectiveness. The SAMe-TT2R2 score has been proposed to predict TTR in NVAF patients. However, the SAMe-TT2R2 score has not been much validated in Asian population. Interestingly, it may overestimate patients who had TTR < 65% due to regarding being Asians as a risk factor.ObjectivesTo determine the factors predicting poor anticoagulant control on warfarin, create new scoring system, and compare with the SAMe-TT2R2 score in a Thai population with NVAF.MethodsThis is a retrospective study in a tertiary care hospital. We enrolled NVAF patients who received warfarin from January 2014 to December 2018. TTR was calculated based on Rosendaal method. Multiple logistic regression and AUC-ROC curve were used for analysis.ResultsA total of 864 patients were enrolled with mean age of 73.6 ± 11.58 years. The mean TTR was 48.1 ± 25.2%. Using multivariate regression analysis, the predictive factors for TTR < 65% were antiplatelet use (OR 4.49, p ≤ 0.001), LVEF < 40% (OR 1.92, p = 0.037), chronic kidney disease (GFR < 50 ml/min/1.73 m2) (OR 1.68, p = 0.013), history of CHF (OR 1.7, p = 0.047), and age ≥ 75 years (OR 1.4, p = 0.037). Based on the regression coefficients, we developed the new scoring system called ACAChE score [A, antiplatelet use (4 points); C, chronic kidney disease, GFR < 50 ml/min/1.73 m2 (2 points); A, age ≥ 75 years (1 point); Ch, history of CHF (2 points); E, LVEF < 40% (2 points)]. ROC curve showed discrimination performance of the ACAChE score and SAMe-TT2R2 score for prediction of TTR < 65% with the C-statistic of 0.62 (95%CI 0.57–0.65) and 0.54 (95%CI 0.50–0.58), respectively.ConclusionIn Thai NVAF patients, the ACAChE score (antiplatelet use, chronic kidney disease (GFR < 50 ml/min/1.73 m2), age ≥ 75 years, history of congestive heart failure, and LVEF < 40%) has better prediction for TTR < 65% than SAMe-TT2R2 score. Thus, it expected to guide the selection of oral anticoagulation in Asian patients with NVAF.

BackgroundAtrioventricular (AV) node normally has decremental conduction property and a longer refractory period than His-Purkinje system (HPS). This results in AV conduction delay or block at the level of AV node in response to short-coupled atrial premature beats. Prolonged refractoriness in HPS can produce unusual physiological patterns of AV conduction such as conduction delay or infra-nodal block in the distal elements of HPS.Case presentationWe present a case in which atrial premature stimulation produces infra-nodal Wenckebach conduction block which initiates long-short cycle sequence within the bundle branches resulted in alternating bundle branch block and atypical pattern of Ashman phenomenon.ConclusionsThis case highlights the importance of recognizing the unusual physiological AV conduction patterns of HPS. The long-short cycle sequence in the bundle branches of distal HPS and linking phenomenon can result in alternating bundle branch block without the presence of HPS disease.

Background and objectivesAthlete’s heart is characterized by structural cardiac changes, including enlargement and hypertrophy. However, exercise-induced cardiac electrical remodeling is not well known in Asian athletes. We sought to evaluate the association between vigorous exercise and the development of abnormal late potential on signal-averaged electrocardiogram (SAECG).MethodWe analyzed 48 Korean professional soccer players and 71 healthy sedentary controls who underwent SAECG and transthoracic echocardiography at Kyung Hee University Hospital. An SAECG was considered abnormal (positive for ventricular late potential) when any one of the three following criteria was met: filtered QRS duration > 114 ms, root-mean-square voltage in the terminal 40 ms < 20 uV, or a voltage < 40 uV for more than 38 ms.ResultsFragmented QRS was more commonly found in athletes (1.4% vs. 10.4%). Athletes demonstrated significantly higher proportion of filtered QRS duration > 114 ms (7.0% vs. 22.9%, P = 0.013) and lower terminal QRS root-mean-square voltage < 20 uV (5.6% vs. 20.8%, P = 0.012). Ventricular late potential on SAECG was significantly more frequent in athletes (15.5% vs. 35.4%, P = 0.012). Regarding echocardiographic parameters, the athletes had larger cardiac chamber size; however, these differences became non-significant after adjustment for body surface area, except left ventricular mass index (65.7 ± 12.7 g/m2 vs. 84.7 ± 17.7 g/m2, P < 0.001).ConclusionAbnormal SAECG findings were significantly more common in athletes than in controls. Further study is needed to determine the clinical impact of these abnormal SAECGs in athletes and cardiac outcomes in the long term.

BackgroundRight ventricular pacing (RVP) increases heart failure, AF, and death rates in pacemaker patients and ventricular arrhythmias (VAs) in defibrillator patients. However, the impact of RVP on VAs burden and its clinical significance in pacemaker patients with normal range LVEF of > 50–55% remains unknown. We sought to evaluate the relationship of RVP and VAs and its clinical impact in a pacemaker patient population.MethodsRecords of 105 patients who underwent denovo dual-chamber pacemaker implant or a generator change (Medtronic™ or Boston Scientific™) for AV block and sinus node disease at a tertiary care center between September 1, 2015, and September 1, 2016, were retrospectively reviewed.ResultsData from 105 patients (51% females, mean age 76 ± 1 years, mean LVEF 61 ± 0.7%) without history of VAs (98.2%) were reviewed over 1044 ± 23 days. Dependent patients (100% RVP) exhibited the lowest VAs burden when compared to < 100% RVP (isolated PVCs, PVC runs of < 4 beats, and NSVT; p ≤ 0.001). Patients with < 1% RVP also exhibited low VA burden with intermediate RVP (1–99.9%) being most arrhythmogenic for PVC runs (p = 0.04) and for isolated PVCs (p = 0.006). Antiarrhythmics/beta and calcium channel blockers use and stress tests performed to evaluate VAs which were positive requiring intervention did not differ significantly. Burden of > 1/h of PVC runs and increasing PVC runs/h were significantly associated with hospitalization (p = 0.04) and all-cause mortality (p = 0.03), respectively.ConclusionsIn pacemaker patients with normal range LVEF (> 50–55%), 100% RVP is associated with the lowest burden of NSVT. Furthermore, patients with < 1% RVP also exhibit low VA burden; however, intermittent RVP seems to significantly correlate with non-sustained VAs.