Rick A. Veasey

The relationship between right ventricular pacing and atrial fibrillation burden and disease progression in patients with paroxysmal atrial fibrillation: the long-MinVPACE study.

AIMS In patients requiring permanent pacemaker implantation for sinus node disease (SND) or atrioventricular (AV) block, right ventricular (RV) pacing has been demonstrated to increase the risk of developing atrial fibrillation (AF). The effects of RV pacing in patients with paroxysmal AF are less well defined. Short- and medium-term studies have suggested no significant correlation between RV pacing and atrial fibrillation burden (AFB) measurement; we sought to assess for an effect in the long-term. METHODS AND RESULTS Sixty-six patients were randomized to receive either conventional dual chamber pacing (DDDR, n = 33), or dual chamber minimal ventricular pacing (MinVP, n = 33), for a period of at least 1 year. Patients were reviewed every 6 months and all pacemaker data were downloaded. The primary outcome measures were device-derived AFB and progression to persistent AF. The mean duration of study follow-up was 1.4 ± 0.6 years. Mean ventricular pacing was less in the MinVP cohort compared with the DDDR cohort (5.8 vs. 74.0%, P < 0.001). At follow-up, the device-derived AFB was significantly lower in the MinVP cohort when compared with the DDDR cohort (12.8 ± 15.3% vs. DDDR 47.6 ± 42.2%, P < 0.001). Kaplan-Meier estimates of time to onset of persistent AF showed significant reductions in the rates of persistent AF for MinVP pacing (9%) when compared with conventional DDDR pacing (42%), P = 0.004. CONCLUSION Right ventricular pacing induces increased AFB in patients with paroxysmal AF in the long term. Dual chamber MinVP algorithms result in reduced AFB and reduced disease progression from paroxysmal to persistent AF in the long term.

Tissue Doppler–Derived Contractile Reserve Is a Simple and Strong Predictor of Cardiopulmonary Exercise Performance across a Range of Cardiac Diseases

Resting echocardiographic measures of cardiac function such as left ventricular ejection fraction correlate poorly with exercise capacity. Assessment during exercise using measures less dependent on hemodynamic loading conditions, such as tissue Doppler imaging (TDI), may more accurately characterize the relationship between cardiac function and exercise capacity.

The relationship between high-frequency right ventricular pacing and paroxysmal atrial fibrillation burden

AIMS Right ventricular pacing increases the risk of persistent atrial fibrillation (AF) in the long term. The effects of right ventricular pacing on paroxysmal AF (PAF) are unknown. The aim was to examine the effect of right ventricular pacing on AF burden (AFB) in patients with symptomatic drug-resistant PAF. Pooled analysis of pacemaker-derived counters and AF diagnostic data from the Atrial Fibrillation Therapy (AFT) and Pacemaker Atrial Fibrillation Suppression (PAFS) randomized anti-AF pacemaker algorithm trials were used. METHODS AND RESULTS Five hundred and fifty-four patients from the AFT (n = 372) and PAFS (n = 182) were studied. The individual percentages of pacing, Atrial Sense Ventricular Pace (ASVP), Atrial Pace Ventricular Pace (APVP), and Atrial Pace Ventricular Sense (APVS) as well as total ventricular pacing during synchronous rhythm (VPinSR, %) were examined for an effect on AFB. Three hundred and twenty-one (AFT, age 64 +/- 11, 55% male) and 79 (PAFS, age 71 +/- 8, 54% male) patients had complete data for analysis. Increased VPinSR was weakly associated with an increased AFB (effect size-10% VPinSR increased AFB by only 0.03%) in AFT (P = 0.04) but not PAFS (P = 0.98) or the pooled analysis (P = 0.95). None of the synchronous paced modalities (ASVP, APVP, APVS) significantly increased AFB compared with sinus rhythm (Atrial Sense Ventricular Sense) (P = ns). CONCLUSION No pacing modality, atrial or ventricular, had a significant effect on AFB. On the basis of these data, the detrimental effect of high-frequency right ventricular pacing on AFB in paced PAF patients, unlike with persistent AF, appears to be minimal in the short term.

The Effect of Bipole Tip‐to‐Ring Distance in Atrial Electrodes upon Atrial Tachyarrhythmia Sensing Capability in Modern Dual‐Chamber Pacemakers

Introduction: Accurate atrial arrhythmia discrimination is important for dual chamber pacemakers and defibrillators. The aim was to assess the accuracy of atrial arrhythmia recording using modern devices and relate this to atrial tip‐to‐ring (TTR) distance.

It’s good to talk! Changes in coronary revascularisation practice in PCI centres without onsite surgical cover and the impact of an angiography video conferencing system

Introduction:  Percutaneous coronary intervention (PCI) activity has increased more than 6 fold in the last 15 years. Increased demand has been met by PCI centres without on‐site surgical facilities. To improve communication between cardiologists and surgeons at a remote centre, we have developed a video conferencing system using standard internet links. The effect of this video data link (VDL) on referral pattern and patient selection for revascularisation was assessed prospectively after introduction of a joint cardiology conference (JCC) using the system.

The evaluation of pulmonary vein isolation and wide-area left atrial ablation to treat atrial fibrillation in patients with implanted permanent pacemakers: the Previously Paced Pulmonary Vein Isolation Study

Background The practise of catheter ablation for atrial fibrillation (AF) is increasing rapidly and is recommended as the treatment of choice in many patient subgroups. At present, the efficacy of this procedure has been assessed by means of electrocardiographic recording, intermittent Holter monitoring and evaluation of patient symptoms. We sought to evaluate the true efficacy of this procedure in patients with sophisticated permanent pacemakers capable of continuous long-term cardiac rhythm monitoring. Methods Twenty-five patients (aged 63.7 (9.4), 20 men), seven with persistent AF and 18 with prolonged paroxysmal AF, underwent a mean of 1.7 AF ablation procedures. All the patients had previously been implanted with a pacemaker or atrial defibrillator device. Data were downloaded from the device Holter before catheter ablation and at 2, 4, 6 and 8 months postprocedure(s). The primary outcome measure was AF burden. The secondary outcomes were patient symptom and quality-of-life measures. Results Initial AF burden was 43.8 (35.5)%. After catheter ablation(s), this was significantly reduced at 2 months to 23.8 (35.4)% (p=0.023), at 4 months to 21.4 (34.1)% (p=0.008), at 6 months to 14.5 (28.1)% (p=0.002) and at 8 months to 15.0 (29.4%) (p=0.003). Only nine (36%) of 25 patients demonstrated no recurrence of arrhythmia during follow-up completion, consistent with a long-term cure. Quality-of-life indices showed significant improvement after ablation. Conclusions Catheter ablation for AF significantly improves patient symptoms and reduces AF burden after long-term beat-to-beat monitoring by implanted cardiac pacemaker and defibrillator devices. However, AF recurrence is common after these procedures.

40 Right ventricular high septal pacing vs. right ventricular apical pacing following av node ablation: 20 years follow up

Introduction Right ventricular septal (RVS) pacing is often recommended as a more physiological alternative to right ventricular apical (RVA) pacing. Most comparisons between the two sites have had short follow up and few trials have assessed the different pacing sites following atrioventricular node (AVN) ablation. We analysed 200 consecutive patients (pts) aged 66–96 (51% male) who underwent implantation of a pacemaker prior to AVN ablation with either RVA- or RVS-pacing between 1996 to 2016. Methods All hospital notes were retrieved and reviewed. Radiographic data for the site of V lead, all hospitalisations, change in echocardiography ejection fraction (EF), QRS width trend and lead parameters were collated. All pts additionally underwent dyssynchrony echocardiography. Results See tables 1 and 2. Conclusions (i) EF of less than 40%; (ii) prior diagnosis of IHD and (iii) dilated cardiomyopathy independently predict HF admission following AVN ablation. However, there was no decrease in EF and no difference in inter-ventricular or intra-ventricular dyssynchrony with either pacing site after up to 20 year follow up. There was a decreased mortality rate with RVA pacing following AVN ablation after longterm follow up. We now prophylactically use CRT pacing in all pts with EF 40% and known IHD. Their outcome is part of ongoing follow up.Abstract 40 Table 1 Baseline characteristicsAbstract 40 Table 2 Patient characteristics with and without left ventricular decompensation

39 The prevalence of sleep disordered breathing in elderly patients with persistent atrial fibrillation

Introduction Epidemiological data have demonstrated an independent association between sleep-disordered breathing (SDB) and atrial fibrillation (AF). We have developed an efficient and reliable screening service investigating SDB in patients (pts)>65 years with persistent AF. Polysomnography (PSG) in a sleep laboratory (lab) is the gold standard diagnostic tool but expense and waiting lists for sleep centres have resulted in a search for alternative methods. The Watch PAT (WP) is efficient and reliable with strong correlation to PSG, potentially negating the requirement for sleep lab investigation. Methods 20 pts>65 years, mean age 71 (45% male), with persistent AF awaiting treatment were investigated for SDB with WP. Total device expenditure including pt and technician cost were compared with predictive cost of PSG and sleep lab studies. Results See table 1. According to the UK NICE definition 18/20 (90%) had evidence of SDB. 8/20 (40%) could be considered to have severe sleep apnoea. The mean REM sleep percentage was 20.4% and mean snoring intensity was 40.9 dB. WP cost was significantly less than predictive cost of PSG (p<0.0001). Conclusion: There is a high prevalence of SDB in older pts with AF and use of the WP as a screening option is feasible. The higher than average non-REM sleep and only mildly elevated snoring intensity implicates a central component in these pts related to cardiac co-morbidity. Further study is ongoing to assess AF therapy outcomes in such pts.Abstract 39 Table 1 Sleep Test results in pts with persistent AF >65 screened for sleep-disordered breading

Defining Exercise Synchrony in Fit Young Adults: A Tissue Doppler Study

OBJECTIVE Exercise-induced changes in the synchrony of left ventricular contraction may be an important therapeutic target in heart failure. There are limited data to support the feasibility of exercise assessments. In addition, the effect of exercise on synchrony in healthy individuals is undetermined. METHODS Eleven healthy young men underwent tissue Doppler assessments before and immediately after maximal cardiopulmonary exercise. Left ventricular synchrony was assessed using pulsed wave tissue Doppler of the lateral, septal, inferior, and anterior walls. The maximal dispersion times between the walls for onset and peak systolic velocities were used as synchrony indices. RESULTS The proportion of the cardiac cycle taken between Q wave and time to onset or peak systolic motion was constant at rest and peak exercise. There was no significant exercise-induced change seen in either interventricular or intraventricular synchrony. CONCLUSION Exercise synchrony assessment is technically feasible. Synchronization of cardiac contraction is maintained after maximal exercise in healthy individuals.