Syncopal high-degree AV block treated with catheter RF ablation without pacemaker implantation.

A 23-year-old-female patient had undergone a very successful gastric banding surgery to treat obesity. Six months later she began to present recurrent syncope due to very frequent, intermittent high-degree AV block referred to as pacemaker implantation. The electrophysiological study showed impaired AV nodal conduction but the His-Purkinje conduction was preserved. Partial catheter radiofrequency ablation of the cardiac autonomic nervous system guided by spectral endocardial mapping (cardioneuroablation) was performed. The electrophysiological parameters were normalized. Holter recordings were normal and the patient was asymptomatic with normal life without pacemaker implantation in a follow-up 21 months later.

Sleep parameters in patients using pacemakers with sleep rate function on.

INTRODUCTION: The cardiovascular system (CVS) is heavily influenced by the autonomic nervous system. Additionally, there is a functional alteration during the various stages of sleep. In nonrapid eye movement (NREM), a state of cardiovascular relaxation occurs during stages three and four. A large amount of rapid ocular movements is concentrated in rapid eye movement (REM) sleep. During this phase, fluctuations in arterial pressure (AP) and heart rate (HR) can be readily noted. Sleep disordered breathing (SDB) has been associated with cardiac rhythm disorders. Recently, cardiac rhythm disorder treatment with pacemaker (PM) highlighted a reduction in abnormal respiratory events during sleep. OBJECTIVE: Comparison of sleep parameters of patients using PM with a sleep rate (SR) algorithm based on its rate-modulated capability during physical activity (Integrity PM with SR function on and off). METHODS: Twenty-two patients (14 women, 8 men), implanted with an Integrity PM (St. Jude Medical Cardiac Rhythm Management Division, Sylmar, CA) with SR function for standard clinical indications, were evaluated utilizing a double-blind protocol. The indication for pacing included sinus node disease (SND), atrium ventricular blockage (AVB), and atrial fibrillation (AF). Following randomization, half of our patients had SR function switched to "on" mode while the other half were on "off" mode. During the first stage of the protocol, all patients underwent two consecutive nights of polysomnographic sleep recordings (PSG). During the first night patients slept in the sleep lab only for adaptation purpose. PSG full recording was carried out in the subsequent night. At a later stage, the programing of SR functions was shifted to "on" or "off" modes. One week later, a third assessment was undertaken. RESULTS: Twelve patients (54%) showed sleep efficiency improvement (total sleeping time/recording time) with PM SR on. This group had the least effective sleep efficiency with PM off, if compared with the others who highlighted no change in this sleep parameter (72 +/- 12 vs 81 +/- 7%, P = 0.01, respectively). This first group displayed a lower latency for REM sleep than the last one (89 +/- 55 vs 174 +/- 107 minutes, P = 0.01, respectively). In 11 (50%) patients, the number per sleep hour of microarousals was reduced when PM SR was switched on. When we compared such findings to the group whose parameters had not changed, we noted that the first set of patients were sleepier (ESE: 9 +/- 4 vs 5 +/- 5, P = 0.04, respectively), and showed more microarousals with PM SR off (20 +/- 14 vs 7 +/- 5 microarousal/hour, P = 0.007). CONCLUSION: In PM patients with sleep-related issues, the SR function activation improved sleep both from a qualitative and quantitative perspective.

"Cardioneuroablation"--new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation.

Cardiac neuroablation is a new technique for management of patients with dominantly adverse parasympathetic autonomic influence. The technique is based on radiofrequency (RF) ablation of autonomic connections in the three main ganglia around the heart. Their connections are identified by Fast-Fourier Transforms (FFTs) of endocardial signals: sites of autonomic nervous connections show fractionated signals with FFTs shifted to the right. In contrast, normal myocardium without these connections does not show these features. RF-ablation is thought to inflict permanent damage on the parasympathetic autonomic influence because its cells are adjacent to the heart whereas sympathetic cells are remote. Twenty-one patients with a mean age of 48 years, neurally mediated reflex syncope in six, functional high grade atrioventricular block in seven and sinus node dysfunction in 13 (there is overlap between the second and third groups) were treated. Follow-up for a mean of 9.2 months demonstrated success in all cases with relief of symptoms. No complications occurred.

A new treatment for atrial fibrillation based on spectral analysis to guide the catheter RF-ablation.

BACKGROUND: By studying the spectrum of atrial potentials by fast Fourier transform (FFT) we have found two types of atrial muscle: the compact (CM) and the fibrillar (FM) myocardium. The former presents normal in-phase conduction inferring a great number of cellular connections, long-lasting refractoriness and leftward FFT-shift. The latter shows anisotropic out-of-phase conduction, fewer cellular connections, short refractoriness and a segmented right-FFT-shift. The compact is the normal predominant muscle and the fibrillar is different and may be neural input, vein insertion, interatrial (1A) septum, left atrial (LA) roof, etc. or pathological tissue, being so by loss of cellular connections this is a possible mechanism for conversion of compact into fibrillar-like myocardium. During atrial fibrillation (AF), clusters of FM (AF nests) present higher frequencies than any surrounding tissue. PURPOSE: The purpose was to describe a new method for paroxysmal AF RF-ablation targeting AF nests. METHOD: Forty patients, six control and 34 having idiopathic drug-refractory paroxysmal or persistent AF were studied and treated. Two catheters were placed in the LA by transseptal approach. RF (30-40 J/60-70 degrees C) was applied to all sites outside the pulmonary veins (PV) presenting right-FFT-shift (AF nests). RESULTS: Numerous AF nests were found in 34/34 AF patients and only in 1/6 controls (only in this case it was possible to induce AF despite an absence of AF history). The main FM sites were: LA roof, LA septum, close to the insertion of the superior PV, near the insertion of the inferior PV, LA posterior wall, RA near the superior vena cava insertion, RA lateral and anterior wall and the right IA septum. Ablation of all AF nests near PV insertions resulted in 35 PV isolations. After 9.9 +/- 5 months only two AF patients presented relapse of a different AF form (coarse AF) which was very well controlled with medication previously ineffective. The AF was more frequent as the ratio FM/CM increased. CONCLUSIONS: The RF-ablation of AF nests decreasing the fibrillar/compact myocardium ratio eliminated 94% of the paroxysmal AF in patients in the FU of 9.9 +/- 5 months. The AF nests may be easily identified by spectral analysis and seem to be the real AF substrate. Paroxysmal AF may be cured or controlled by applying RF in several places outside the PV and, thereby, avoiding PV stenosis.