Case report: Left bundle branch pacing guided by real-time monitoring of current of injury and electrocardiography.

Background: Left bundle branch (LBB) pacing (LBBP) has recently emerged as a physiological pacing mode. Current of injury (COI) can be used as the basis for electrode fixation position and detection of perforation. However, because the intermittent pacing method cannot monitor the changes in COI in real time, it cannot obtain information about the entire COI change process during implantation. Case summary: Left bundle branch pacing was achieved for treatment of atrioventricular block in a 76-year-old female. Uninterrupted electrocardiogram and electrogram were recorded on an electrophysiology system. In contrast to the interrupted pacing method, this continuous pacing and recording technique enables real-time monitoring of the change in ventricular COI and the paced QRS complex as the lead advances into the interventricular septum. During the entire screw-in process, the COI amplitude increased and then decreased gradually after reaching the peak, followed by a small but significant, rather than dramatic, decrease. Conclusion: This case report aims to demonstrate the clinical significance of changes in COI and QRS morphology for LBBP using real-time electrocardiographic monitoring and filtered and unfiltered electrograms when the lead is deployed using a continuous pacing technique. The technique could be used to confirm LBB capture and avoid perforation.

Genetic Polymorphism of Matrix Metalloproteinase-9 and Susceptibility to Myocardial Infarction: A Meta-Analysis.

OBJECTIVE: Current findings on the association between MMP-9 rs3918242 and susceptibility to myocardial infarction (MI) are inconsistent, and their definite relationship is discussed in this meta-analysis. METHODS: Eligible literatures reporting MMP-9 rs3918242 and susceptibility to MI were searched in PubMed, Cochrane Library, CNRI, and VIP using keywords such as "MMP-9", "matrix metallopeptidase-9" and "myocardial infarction", "acute myocardial infarction", "AMI", and "polymorphism". Data from eligible literatures were extracted for calculating OR and corresponding 95% CI using RevMan 5.3 and STATA12.0. RESULTS: Ten independent literatures reporting MMP-9 rs3918242 and susceptibility to MI were enrolled. Compared with subjects carrying CT&TT genotype of MMP-9 rs3918242, susceptibility to MI was lower in those carrying CC genotype (OR = 1.49, 95%CI = 1.19-1.86, P = 0.0004). Such a significance was observed in the overdominant (OR = 1.27, 95%CI = 1.14-1.41, P < 0.0001) and allele genetic models (OR = 1.43, 95%CI = 1.17-1.74, P = 0.0005) as well. This finding was also valid in the Asian population. CONCLUSIONS: Mutation on MMP-9 rs3918242 has a potential relevance with susceptibility to MI.

High-pass filter settings and the role and mechanism of discrete ventricular electrograms in left bundle branch pacing.

Objective: The characteristics of discrete intracardiac electrogram (EGM) in selective left bundle branch (SLBB) pacing (SLBBP) have not been described in detail previously. This study aimed to examine the effect of different high-pass filter (HPF) settings on discrete local ventricular components in an intracardiac EGM and to analyze its possible mechanisms. Methods: This study included 144 patients with indications of permanent cardiac pacing. EGMs were collected at four different HPF settings (30, 60, 100, and 200 Hz) with a low-pass filter at 500 Hz, and their possible mechanisms were analyzed. Results: LBBP was successfully achieved in 91.0% (131/144) of patients. SLBBP was achieved in 123 patients. The occurrence rates of discrete local ventricular EGM were 16.7, 33.3, 72.9, and 85.4% for HPF settings of 30, 60, 100, and 200 Hz, respectively. The analysis of discrete EGM detection showed significant differences between the different HPF settings. By using the discrete local ventricular component and isoelectric interval as the SLBB capture golden standard, the results of EGMs revealed that the 30 Hz HPF has a sensitivity of 19% and specificity of 100%. The 60 Hz HPF had a sensitivity of 39% and a specificity of 100%. The 100 Hz HPF had a sensitivity of 85% and a specificity of 100%. The 200 Hz HPF had a sensitivity of 100% and specificity of 100%. Conclusion: An optimal HPF setting of 200 Hz is recommended for discrete local ventricular EGM detection. A discrete local ventricular EGM should exhibit an isoelectric interval. A steep deflection and high-frequency ventricular EGM morphology nearly identify an intrinsic EGM morphology.

Association of stent diameter and target vessel revascularization in patients undergoing percutaneous coronary intervention: a secondary retrospective analysis based on a Chinese cohort study.

BACKGROUND: In the treatment of coronary heart disease, target vessel revascularization (TVR) has attracted increasing attention as an efficient means of percutaneous coronary intervention (PCI). The purpose of this study was to explore the association between stent diameter and TVR in patients undergoing PCI. METHODS: This was a secondary retrospective analysis involving patients with PCI with at least one stent implanted. Information was obtained from the Dryad Digital Repository. Multivariable logistic regression models, interaction analyses, subgroup analyses and piecewise linear regression models were used to evaluate the association between stent diameter and TVR. RESULTS: A total of 2522 patients were eventually enrolled in this study, of which 122 (4.8%) had undergone TVR. Significant positive associations were observed between stent diameter and TVR (continuous: odds ratio [OR] 0.485, 95% confidence interval [CI] 0.305-0.773, P = 0.002; categorical variable: T2 vs. T1, OR 0.541, 95% CI 0.348-0.843; T3 vs. T1, OR 0.520, 95% CI 0.334-0.809; P for trend = 0.005). The association remained stable in the fully adjusted model (continuous: OR 0.526, 95% CI 0.306-0.902, P = 0.020; categorical variable: T2 vs. T1, OR 0.510, 95% CI 0.310-0.839; T3 vs. T1, OR 0.585, 95% CI 0.352-0.973; P for trend = 0.042). Among the subgroups of differing clinical presentations, stent diameter was a powerful protective factor for TVR, especially in the delayed PCI group (P for interaction = 0.002). The association was highly consistent across all the other subgroups studied (all P for interaction > 0.05). In the piecewise linear regression model, the need for TVR decreased with an increase in stent diameter when this ranged between 2.5 and 2.9 mm (OR 0.01, 95% CI: 0.01-0.13, P < 0.001). CONCLUSIONS: A large stent diameter is a powerful protective factor for TVR in PCI patients, especially in the delayed PCI group. This "bigger-is-better" protective effect is remarkable in stents with diameter 2.5-2.9 mm.

Outcomes of non-left bundle branch block conduction abnormalities after transcatheter aortic valve replacement.

Transcatheteraortic valve replacement (TAVR) is a revolutionized treatment for severe aortic valve stenosis. Although new and improved TAVR devices are constantly being developed, cardiac conduction abnormalities post-TAVR requiring permanent pace14353maker implantation (PPMI) still occur frequently. Previously, pre-existing right bundle branch block (RBBB) has been shown to be predictive of PPMI after TAVR compared with patients without RBBB, while occurrence of new left bundle branch block (LBBB) was associated with a higher rate of PPMI. However, less attention has been paid to the clinical values of new onset non-LBBB conduction disturbances such as RBBB, left anterior fascicular block (LAFB) or atrioventricular block (AVB). To our knowledge, this is the first report focus on the association of new-onset non-LBBB and PPMI after TAVR. The study was approved by the Ethics Committee of HwaMei Hospital, University of Chinese Academy of Sciences.

Successful upgrade to cardiac resynchronization therapy for cardiac implantation-associated left subclavian vein occlusion: A case report.

BACKGROUND: Subclavian vein stenosis or occlusion may be caused by a transvenous pacemaker, which makes the reimplantation of a new pacemaker lead difficult. Transvenous pacemaker lead implantation-related subclavian vein occlusion may present difficulty with regard to cardiac resynchronization therapy (CRT) upgrade. CASE SUMMARY: We report the case of a 46-year-old man who was admitted with total subclavian vein occlusion caused by a permanent pacemaker that had been implanted 2 years previously. We successfully treated this patient with an upgrade to a CRT pacemaker by utilizing transferable interventional coronary and radiological techniques. The patient recovered uneventfully during the follow-up period. CONCLUSION: CRT upgrade is still a viable technique for the treatment of subclavian vein obstruction caused by previous pacemaker implantation.

Association between sleep disturbance with motoric cognitive risk syndrome in Chinese older adults.

BACKGROUND AND PURPOSE: Sleep disturbance and cognitive impairment are common and related in the elderly population worldwide. The aim of the present study was to explore the association between sleep disturbance and motoric cognitive risk (MCR) syndrome, which is characterized by subjective cognitive complaints and objective slow gait in older individuals without dementia or any mobility disability in the community-dwelling elderly Chinese population. METHODS: We recruited 940 participants aged ≥65 years from November 2016 to March 2017 in the Ningbo Community Study on Aging (NCSA). Self-reported sleep duration and sleep-quality variables, comprehensive geriatric evaluation, as well as indicators for diagnosing MCR syndrome were evaluated in this cross-sectional study. RESULTS: Multiple logistic regression analysis showed that a 1-SD increase in night (1.1 h) and 24-h sleep duration (1.3 h) was associated, respectively, with a 21% (95% confidence interval [CI], 1%-47%; p = 0.04) and 30% (95% CI, 3%-64%; p = 0.03) higher odds of having MCR syndrome. Considering sleep duration as a categorical variable, longer night-sleep duration (>8.5 h) was associated with MCR syndrome (OR, 2.03; p = 0.02) compared to shorter night-sleep duration (<8 h). For sleep-quality factors, increasing frequency of trouble falling asleep, waking early or easily, nightmares, and taking sleep drugs were significantly associated with MCR syndrome after adjusting for potential covariables (all p for trend < 0.05), but not for self-perceived sleep quality (p for trend = 0.10). CONCLUSIONS: Long sleep duration, poor sleep quality, and taking sleep drugs were associated with higher odds of having MCR syndrome in the community-dwelling elderly Chinese population. Further research is needed to explore the underlying mechanisms.

Predictive Value of Blood Interleukin-6 Level in Patients with Acute Coronary Syndrome: A Meta-analysis.

OBJECTIVE: Conflicting results have been reported on the association between blood level of interleukin-6 and adverse outcomes in patients with acute coronary syndrome (ACS). The current meta-analysis aimed to evaluate the predictive utility of elevated blood interleukin-6 level in patients with ACS. METHODS: A systematically literature search was performed using PubMed and Embase databases up to December 31, 2019. Observational studies or post hoc analysis of randomized controlled trials investigating the values of blood interleukin-6 level for predicting major adverse cardiovascular events (MACE including death, re-infarction, revascularization, angina, heart failure, malignant arrhythmia, or stroke), all-cause mortality or cardiovascular mortality in ACS patients were eligible. The predictive values were summarized by pooling the multivariable-adjusted risk ratio (RR) and 95% confidence intervals (CI) for the highest versus lowest category of interleukin-6 level. RESULTS: Thirteen studies enrolling 30,289 patients with ACS were included. When comparing the highest with lowest category of interleukin-6 level, the pooled RR was 1.29 (95% CI 1.12-1.48) for MACE, 1.50 (95% CI 1.35-1.67) for all-cause mortality, and 1.55 (95% CI 1.06-2.28) for cardiovascular mortality, respectively. Moreover, the predictive values of interleukin-6 level on MACE were consistently found in different study designs, subtypes of patients, sample sizes, follow-up duration, and cutoff value of interleukin-6 elevation subgroups. CONCLUSION: Increased blood level of interleukin-6may be independently associated with higher risk of MACE, cardiovascular and all-cause mortality in patients with ACS. Measurement of blood interleukin-6 level has potential to improve risk stratification of ACS.

Prognostic value of geriatric nutritional risk index in elderly patients with heart failure: a meta-analysis.

BACKGROUND: Geriatric Nutritional Risk Index (GNRI) is a promising tool for predicting nutrition-related complications. This meta-analysis sought to determine the prognostic utility of GNRI in elderly patients with heart failure. METHODS: We comprehensively searched the PubMed and Embase databases from their inception to July 2019. Original studies investigating the prognostic value of GNRI in patients with heart failure were included. Outcome of interests were all-cause mortality and major cardiovascular events. The prognostic value of GNRI was expressed as risk ratios (RR) with 95% confidence intervals (CI) for the lowest versus the highest GNRI category or continuous GNRI analysis. RESULTS: Eleven articles (10 studies) involving 10,589 elderly heart failure patients were included. Meta-analysis indicated that heart failure patients with the lowest GNRI had an increased risk of all-cause mortality (RR 2.11; 95% CI 1.72-2.58) and major cardiovascular events (RR 2.00; 95% CI 1.24-3.22) after adjustment for confounding. In addition, each unit reduction in GNRI significantly increased 6% risk of all-cause mortality. CONCLUSION: Lower GNRI independently predicts all-cause mortality and major cardiovascular events in elderly patients with heart failure. Determination of nutritional status using GNRI may improve risk stratification in elderly patients with heart failure.