Electrocardiographic analysis for his bundle pacing at implantation and follow-up

His bundle pacing (HBP) is steadily gaining interest for providing physiological cardiac stimulation. Careful analysis of the electrocardiogram (ECG) is crucial to confirm capture of conduction tissue, which is a prerequisite for successful HBP at implantation and follow-up. However, interpretation of the ECG with HBP can be challenging. This review provides the reader with practical guidance on how to best use and troubleshoot the 12-lead ECG for HBP in daily clinical practice

Skin changes in chronic lymphatic filariasis

Seventeen men and 31 women with unilateral lower limb lymphoedema attributed to chronic lymphatic filariasis were examined in the filarial out-patient clinic of the Government General Hospital, Madras, India. Skin changes such as skin fold thickening, hyperkeratosis, hypo-or hypertrichosis, pachydermia, pigmentary changes, chronic ulceration, epidermal and sub-epidermal nodules, and clinical intertrigo were observed and compared between the different lymphoedema grades. These lesions are not specific to chronic lymphatic filariasis, and have been described in other conditions displaying lymphostasis. They are thought to be favoured by secondary infections, which should be dealt with appropriately to prevent the progression of the disease and the onset of elephantiasi

Troubleshooting Programming of Conduction System Pacing

Conduction system pacing (CSP) comprises His bundle pacing and left bundle branch area pacing and is rapidly gaining widespread adoption. Effective CSP not only depends on successful system implantation but also on proper device programming. Current implantable impulse generators are not specifically designed for CSP. Either single chamber, dual chamber or CRT devices can be used for CSP depending on the underlying heart rhythm (sinus rhythm or permanent atrial arrhythmia) and the aim of pacing. Different programming issues may arise depending on the device configuration. This article aims to provide an update on practical considerations for His bundle and left bundle branch area pacing programming and follow-up

Electrophysiological abnormalities in patients with paroxysmal atrial fibrillation in the absence of overt structural heart disease

AbstractPurposeThe aim of the present study was to define the atrial electrical substrate in patients with paroxysmal atrial fibrillation (AF) occurring in the absence of overt structural heart disease and to assess if electrophysiological parameters could predict AF recurrence after radiofrequency ablation in this population.Methods and results45 consecutive patients (39 male, age 59 ± 10 years) with paroxysmal AF and without overt structural heart disease, referred for radiofrequency catheter ablation, were prospectively enrolled. A cohort of 12 age-matched patients without a history of AF, served as a control group. Atrial electrical substrate was assessed by P-wave signal-averaging, intracardiac conduction delays and refractory periods. Total P wave duration during signal-averaging was longer in patients with paroxysmal AF than in controls (140 ± 19 ms vs 123 ± 13 ms, p = 0.004). Patients with paroxysmal AF showed an increase in right intra-atrial (40.2 ± 11.3 ms vs 31.7 ± 11.8 ms, p = 0.02) and inter-atrial conduction delays (87.93 ± 22.0 ms vs 65.3 ± 15.6 ms, p = 0.001) in sinus rhythm. Refractory periods in the right atrium were longer in patients with paroxysmal AF (265 ± 44 ms vs 222 ± 32 ms, p = 0.002). After ablation, 22 patients had AF recurrence but showed no differences in electrophysiological parameters compared to patients without recurrence.ConclusionElectrophysiological abnormalities are present in patients with paroxysmal AF without overt structural heart disease. Neither signal-averaged P-wave duration nor intracardiac atrial electrophysiology could predict arrhythmia recurrence after pulmonary vein isolation

Sense-B-noise: an enigmatic cause for inappropriate shocks in subcutaneous implantable cardioverter defibrillators.

AIMS Subcutaneous implantable cardioverter defibrillators (S-ICDs) are well established. However, inappropriate shocks (IAS) remain a source of concern since S-ICDs offer very limited troubleshooting options. In our multicentre case series, we describe several patients who experienced IAS due to a previously unknown S-ICD system issue. METHODS AND RESULTS We observed six patients suffering from this novel IAS entity. The IAS occurred exclusively in primary or alternate S-ICD sensing vector configuration (therefore called 'Sense-B-noise'). IAS were caused by non-physiologic oversensing episodes characterized by intermittent signal saturation, diminished QRS amplitudes, and disappearance of the artefacts after the IAS. Noise/oversensing could not be provoked by manipulation, X-ray did not show evidence for lead/header issues and impedance measurements were within normal limits. The pooled experience of our centres implies that up to ∼5% of S-ICDs may be affected. The underlying root cause was discussed extensively with the manufacturer but remains unknown and is under further investigation. CONCLUSION Sense-B-noise is a novel cause for IAS due to non-physiologic signal oversensing, arising from a previously unknown S-ICD system issue. Sense-B-noise may be suspected if episodes of signal saturation in primary or alternate vector configuration are present, oversensing cannot be provoked, and X-ray and electrical measurements appear normal. The issue can be resolved by reprogramming the device to secondary sensing vector

Effect of lead design and pacing vector on electrical parameters of quadripolar coronary sinus leads: The RALLY-X4 study

Abstract Background Various lead designs have been developed to accommodate different coronary sinus anatomies. Our objectives were to compare electrical parameters of straight and spiral left ventricular leads, to evaluate capture thresholds and impedances using different pacing vectors, and to study evolution of thresholds over time. Methods The RALLY-X4 study enrolled patients implanted with a lead from the Acuity X4 family (Straight, Spiral Short or Spiral Long). Electrical parameters (including capture thresholds from all 17 vectors) were measured at baseline and follow-up. Results Data from 795 patients who were successfully implanted were analysed. Straight and spiral leads had similar proportions of patients with thresholds 80% of patients. Pacing vectors significantly affect electrical parameters, with higher thresholds in more proximal electrodes and lower thresholds with unipolar and extended bipolar configurations. Capture thresholds slightly decreased over a mean follow-up of one year. This article is protected by copyright. All rights reservedPeer reviewe

A review of multisite pacing to achieve cardiac resynchronization therapy

Non-response to cardiac resynchronization therapy remains a significant problem in up to 30% of patients. Multisite stimulation has emerged as a way of potentially overcoming non-response. This may be achieved by the use of multiple leads placed within the coronary sinus and its tributaries (dual-vein pacing) or more recently by the use of multipolar (quadripolar) left ventricular pacing leads which can deliver pacing stimuli at multiple sites within the same vein. This review covers the role of multisite pacing including the interaction with the underlying pathophysiology, the current and planned studies, and the potential pitfalls of this technolog

Effects of remote monitoring on clinical outcomes and use of healthcare resources in heart failure patients with biventricular defibrillators: results of the MORE-CARE multicentre randomized controlled trial

Aims: The aim of this study was to evaluate the clinical efficacy and safety of remote monitoring in patients with heart failure implanted with a biventricular defibrillator (CRT-D) with advanced diagnostics. Methods and results: The MORE-CARE trial is an international, prospective, multicentre, randomized controlled trial. Within 8 weeks of de novo implant of a CRT-D, patients were randomized to undergo remote checks alternating with in-office follow-ups (Remote arm) or in-office follow-ups alone (Standard arm). The primary endpoint was a composite of death and cardiovascular (CV) and device-related hospitalization. Use of healthcare resources was also evaluated. A total of 865 eligible patients (mean age 66 \ub1 10 years) were included in the final analysis (437 in the Remote arm and 428 in the Standard arm) and followed for a median of 24 (interquartile range = 15\u201326) months. No significant difference was found in the primary endpoint between the Remote and Standard arms [hazard ratio 1.02, 95% confidence interval (CI) 0.80\u20131.30, P = 0.89] or in the individual components of the primary endpoint (P > 0.05). For the composite endpoint of healthcare resource utilization (i.e. 2-year rates of CV hospitalizations, CV emergency department admissions, and CV in-office follow-ups), a significant 38% reduction was found in the Remote vs. Standard arm (incidence rate ratio 0.62, 95% CI 0.58\u20130.66, P < 0.001) mainly driven by a reduction of in-office visits. Conclusions: In heart failure patients implanted with a CRT-D, remote monitoring did not reduce mortality or risk of CV or device-related hospitalization. Use of healthcare resources was significantly reduced as a result of a marked reduction of in-office visits without compromising patient safety. Trial registration: NCT00885677