Aims: Data regarding the efficacy of catheter ablation in heart failure patients with severely dilated left atrium and reduced left ventricular ejection fraction (LVEF) are scanty. We sought to assess the efficacy of catheter ablation in patients with reduced LVEF and severe left atrial (LA) enlargement, and to compare it to those patients with preserved left ventricular function and equally dilated left atrium. Methods and results: Three patient groups with paroxysmal or persistent atrial fibrillation (AF) undergoing a first pulmonary vein isolation (PVI) were considered: Group 1 included patients with normal or mildly abnormal LA volume (≤41 mL/m2) and normal LVEF; Group 2 included patients with severe LA enlargement (>48 mL/m2) and normal LVEF; and Group 3 included patients with severe LA enlargement and reduced LVEF. Time to event analysis was used to investigate AF recurrences. The study cohort includes 439 patients; Group 3 had a higher prevalence of cardiovascular risk factors. LA enlargement was associated with a two-fold in risk of AF recurrence, on the contrary only a smaller non-significant increase of 30% was shown with the further addition of LVEF reduction. Conclusions: The long-term outcome of patients with severe LA dilatation and reduced LVEF is comparable to those with severe LA enlargement but preserved LVEF. Long-term efficacy of PVI is certainly affected by the enlargement of the left atrium, but less so by the addition of a reduced LVEF. CA remains the best strategy for rhythm control both in paroxysmal and persistent AF in this subgroup of patients.

Increased sympathetic and reduced vagal activity predict increased mortality in patients with congestive heart failure (CHF). Experimentally, vagal stimulation (VS) is protective both during acute myocardial ischemia and in chronic heart failure. In man, VS is used in refractory epilepsy but has never been used in cardiovascular diseases. Thus, there is a strong rationale to investigate the effects of chronic VS in patients with CHF. We assesses the feasibility and safety of chronic VS with CardioFit (BioControl Medical), a VS implantable system delivering pulses synchronous with heart beats to the right cervical vagus nerve in a preliminary pilot study in eight advanced CHF patients with favorable results, and subsequently in a larger multicenter study. Overall, 32 patients have been successfully implanted (mostly in NYHA Class III; mean age 56 years, ischemic etiology in 69%; prior implantable cardioverter-defibrillator (ICD) in 63%; concomitant beta blocker and angiotensin converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) in 100%). Preliminary results confirm feasibility of the study, an acceptable side effect profile and promising preliminary efficacy data. Several mechanisms may contribute to the beneficial effect observed in patients with heart failure. Should these results be confirmed in larger controlled studies, chronic vagal stimulation could be a further treatment option for CHF patients, possibly integrated with defibrillator and resynchronization therapies.

Introduction Enhancement of vagal nerve activity has a strong experimental rationale as a potential therapeutic approach to patients with severe Congestive Heart Failure (CHF). The CardioFit (BioControl Medical, Ltd.) is an implantable system capable of delivering chronic vagus nerve stimulation (CVNS) synchronized with the heart beat via a multipolar stimulation lead. Methods Twenty-nine patients with stable CHF, NYHA class II–IV, LVEF ≤ 35% on optimal medical therapy were enrolled and successfully implanted in a 7-site international 6-month safety and efficacy pilot study. Optimization of CVNS parameters occurred during a four week run-in period, two to four weeks post-implantation. Results Twenty subjects (mean age 57 years, range 30 –75; ischemic etiology in 70%; prior ICD in 50%) completed six-month follow-up; one NYHA class IV subject died due to worsening HF two months after implantation. At 6-months, 14 subjects had improved their NYHA class, and 6 remained stable. A significant improvement (p < 0.05) was found in the subjects’ quality of life (MLwHF® questionnaire); exercise capacity (6-minute walk test; see graph); and blindly evaluated LV ejection fraction (from 24 ± 2% to 29 ± 2%). The most commonly reported transient adverse events were expected side-effects of CVNS such as pain at cuff site (n = 6), cough (n = 7), and voice alteration (n = 5), which were resolved by optimizing stimulation parameters. Conclusions Chronic Vagus Nerve Stimulation in patients with advanced heart failure is feasible and appears to be well tolerated and safe. Initial data suggest a favorable trend of clinical outcomes. At this point a large scale randomized controlled study is warranted. Download figure

Nowadays, Magnetic Resonance Imaging (MRI) is considered the gold standard for imaging the brain, spinal cord, musculoskeletal system, head and neck, and complex congenital heart malformations; consequentially, the number of MRI scans in patients with implantable electronic devices has simultaneously increased. During the entire length of the MRI exam, patients are exposed to electromagnetic fields with different characteristics (static, low frequency, radiofrequency fields), which are related to different risks. The scarce available literature about MRI-induced heating on cardiac stents suggests that excessive temperature rise occurs only in unfavorable cases. Ideally, RF safety assessment could be performed during the anamnestic process, but this simulation process’s results are too slow to be performed before patient MRI examination. In this context, we developed a dedicated measurement set-up by focusing our target on the measurement of the heating of a cardiac stent during an MRI examination. Results for the temperature rise trend along the entire stent length during a clinical MRI protocol are shown together with the local Specific Absorption Rate (SAR) values and cumulative equivalent minutes at 43 °C (CEM43°C), in order to ensure the safety of patients with MR-conditional devices, also with a view to not inappropriately preclude their access to MRI scans. The obtained results show that the maximum temperature rise (4.12 °C) is within the limit of 5 °C stated in the stent manual for 15 min of continued scanning with the specific conditions. The maximum temperature rise was in correspondence with the stent tips and calculated SAR confirms the fact that two hotspots are present near the tips of the stent. Finally, the calculated CEM43°C remained well below the proposed threshold for muscle tissue.