Search

Aims This study aims to determine procedural characteristics, acute success rates, and medium-term outcomes of consecutive patients undergoing His bundle pacing (HBP); and learning curves of experienced electrophysiologists adopting HBP. Methods and results Consecutive HBP patients at three hospitals were recruited. Clinical characteristics, acute procedural details, and medium-term outcomes were extracted from electronic medical records. Two hundred and thirty-three patients [mean age 74.6 ± 10.1 years, 48% female, 68% narrow QRS, 71% normal left ventricular ejection fraction (LVEF), 55.8% atrioventricular block] underwent HBP. Acute procedural success was 81.1% (mean procedural and fluoroscopic times of 105.5 ± 36.5 and 13.8 ± 9.3 min). Broad QRS was associated with lower HBP success (odds ratio 0.39, P = 0.02). Fluoroscopic and procedural times decreased and plateaued after 30–40 cases per operator. Implant HBP threshold was 1.3 ± 0.7 V at 1.0 ± 0.2 ms and R wave was 5.0 ± 3.9 mV. During follow-up, loss of HBP occurred in a further 12.4% and 11.3% of patients experienced a ≥1 V increase in HBP threshold. Five (2.6%) patients required HBP revision for pacing difficulties. About 8.6% of patients had a >50% decrease in R wave but lead revision for sensing issues was not necessary. On an intention to treat basis, 56.7% of patients in whom HBP was attempted had persisting HBP capture and thresholds of Conclusion Physicians adopting HBP should be cognizant of the learning curve and preferentially select non-dependent patients with normal QRS and LVEF, to minimize risk of lead revision. Further rises in HBP threshold may increase battery drain and need for reoperations, important considerations when choosing HBP for cardiac resynchronization therapy.

Pacing leads with extendable-retractable helix (EHL) are alternatives to fixed-helix leads (FHL) for conduction system pacing (CSP), but data on handling characteristics are limited. This study evaluated a dual-center experience of lead handling and performance during CSP.Consecutive patients with His-bundle pacing (HBP) or left bundle branch pacing (LBBP) were evaluated for the primary outcome of lead failure, defined as structural damage to the lead necessitating lead replacement. Differences in pacing characteristics were compared. Among 280 patients (mean age 74 ± 11 years, 44% male, 50% LBBP), 246 (88%) received FHL and 34 (12%) received EHL. Of 299 leads used, lead failure occurred more frequently among patients with EHL than FHL (29% vs. 2%, p .001), regardless of CSP modality. Majority of damaged leads (89%) in the form of helix deformation were successfully removed, with failure occurring in only two patients, both EHL, leading to helix fracture and retention within the septal myocardium. EHL, compared to FHL, was associated with 25-fold increased odds of lead failure (odds ratio: 25.21, 95% confidence interval: 7.35-86.51), and persisted after adjustment in turn for age, pacing modality and indication. CSP implant success rates did not differ by lead design (FHL 80% vs. EHL 71%, p = .18), with similar pacing thresholds at implant and follow-up.Helix deformation and fracture were more frequent with EHL in CSP despite similar implant success. These findings have significant implications for lead selection during CSP and raises concerns about the long-term extractability of EHL in CSP.

Optimal left ventricular (LV) lead placement improves response to cardiac resynchronization therapy (CRT) but can be hindered by unfavorable venous anatomy. Interventional procedures in the coronary veins have been described with promising short-term outcomes.The purpose of this study was to establish the safety and efficacy of percutaneous coronary venoplasty (PCV) during CRT implantation and assess medium-term lead performances and clinical outcomes against matched controls not requiring PCV.Each consecutive PCV case was matched according to age, gender, and bundle branch morphology to 2 controls from a large prospective registry of CRT recipients. Demographics, procedural success, lead performance, and response to CRT were tracked using a comprehensive electronic medical records system.Of 422 consecutive CRT recipients treated between 2012 to 2018, 29 patients (6.9%; mean age 65.7 ± 10.7 years; 7 female; 17 ischemic cardiomyopathy; 22 left bundle branch block) required PCV, which was successful in 21 cases (72%). Target veins measuring 1.1 ± 0.6 mm were dilated by noncompliant balloons with mean diameter 2.8 ± 0.5 mm. No complications occurred. Fluoroscopic and procedural durations were longer in the PCV group (P.01) Over mean follow-up of 33.0 ± 25.0 months, no differences in lead performance, CRT response, or 2-year survival were observed compared to the control group.PCV during CRT device implant is typically successful, safe and associated with long-term clinical outcomes comparable to patients who did not need PCV. This is an important technique to optimize LV lead placement and maximize CRT response.

The global left ventricular (LV) contractility index, dσ*/dtmax measures the maximal rate of change in pressure-normalized LV wall stress. We aim to describe the trend of dσ*/dtmax in differing severity of aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) and the association of dσ*/dtmax with clinical outcomes in moderate AS and severe AS. We retrospectively studied a total of 1738 patients with AS (550 mild AS, 738 moderate AS, 450 severe AS) and preserved LVEF ≥ 50% diagnosed from 1st January 2001 to 31st December 2015. dσ*/dtmax worsened with increasing severity of AS despite preserved LVEF (mild AS: 3.69 ± 1.28 s−1, moderate AS: 3.17 ± 1.09 s−1, severe AS: 2.58 ± 0.83 s−1, p dσ*/dtmax −1 was independently associated with a higher composite outcome of aortic valve replacement, congestive cardiac failure admissions and all-cause mortality (adjusted hazard ratio 1.48, 95% CI: 1.25–1.77, p dσ*/dtmax declined with worsening AS despite preserved LVEF. Low dσ*/dtmax −1 was independently associated with adverse clinical outcomes in moderate AS and severe AS with preserved LVEF.

Limited data exists about management of syncope in Asia. The American College of Emergency Physicians (ACEP) and European Society of Cardiology (ESC) guidelines have defined the high-risk syncope patient. This study aims to determine the effectiveness of managing syncope in an Asian healthcare system and whether strict adherence of international guidelines would reduce hospitalizations.Patients attending the Emergency Department of a Singaporean tertiary hospital with syncope were identified. Clinical journeys of all patients were meticulously mapped by interrogation of a comprehensive electronic medical record system and linkages with national datasets. Primary endpoint was hospitalization. Secondary endpoints were recurrent syncope within 1year and all-cause mortality. Expected admission rates based on application of ACEP/ESC guidelines were calculated.638 patients (43.8±22.4years, 49.0% male) presented with syncope. 48.9% were hospitalized for 2.9±3.2days. Yields of common investigations ranged from 0 to 11.5% and no diagnosis was reached in 51.5% of patients. Diuretics use (HR 5.1, p=0.01) and prior hospitalization for syncope (HR 6.9, p0.01) predicted recurrent syncope. Over 2.8 SD 0.3years of follow-up, 40 deaths occurred. 24 patients who died within 12months of presentation were admitted or had a firm diagnosis upon discharge. Application of guidelines did not significantly reduce hospitalisations, with limited agreement which patients warrant admission. (Actual 376, ACEP 354, ESC 391 admissions, p=NS).Unstructured management of syncope results in nearly half of patients being admitted and substantial healthcare expenditures, yet with limited diagnostic yield. Strict adoption of ACEP or ESC guidelines does not reduce admissions.

Introduction We evaluated the relationship between visit-to-visit low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) variability and 5-year clinical outcomes in patients who presented with ST-segment elevation myocardial infarction (STEMI). Methods 130 patients presenting with STEMI and surviving to discharge were analyzed. Visit-to-visit LDL-C and HDL-C variability was evaluated from 2 months after discharge on the basis of corrected variation independent of mean (cVIM, primary measure), coefficient of variation and standard deviation. Major adverse cardiac event (MACE) included death, myocardial infarction, stroke, unplanned revascularization, and heart failure admission. Results After an average of 62.4 ± 30.5 months follow-up, 41 patients (31.5%) had experienced MACE. Compared with the non-MACE group, the MACE group had a higher visit-to-visit LDL-C variability (cVIM: 0.23 ± 0.11 vs. 0.19 ± 0.08; p = 0.049; coefficient of variation: 0.24 ± 0.12 vs. 0.19 ± 0.00; p = 0.019; standard deviation: 24.1 ± 14.5 vs. 17.6 ± 10.0; p = 0.006), mean follow-up LDL-C (p = 0.033) and a higher prevalence of diabetes mellitus (p = 0.012). After adjusting for mean follow-up cholesterol levels and diabetes mellitus, each 0.01 cVIM increase in LDL-C and HDL-C variability increased the risk of MACE by 3.4% (HR: 1.034; 95% CI: 1.004 to 1.065; p = 0.025) and 6.8% (HR: 1.068; 95% CI: 1.003 to 1.137; p = 0.04), respectively. Results derived from coefficient of variation and standard deviation as measures of cholesterol variability were similar. Conclusion This is the first report to show an independent association between visit-to-visit LDL-C and HDL-C variability and long-term MACE in patients presenting with STEMI.

Pulmonary embolism (PE) poses a challenge to physicians, as it can be difficult to diagnose but results in significant mortality and morbidity in patients. Diagnosing PE requires an integrated approach using clinical findings, electrocardiography (ECG), blood investigations and imaging modalities. Abnormalities in ECG are common among patients with massive acute PE and can serve as a prognostic indicator. In this article, we describe the ECG presentations of two patients diagnosed with PE, and review the literature on the various types of ECG presentations and their role in predicting the prognosis of PE.