Complete interatrial block in a left-atrial dependent atrioventricular node.

INTRODUCTION: A middle-age woman underwent an electrophysiologic study due to recurrent atypical atrial flutter. METHODS AND RESULT: Radiofrequency ablation of cavotricuspid isthmus and anterior mitral line was performed. During energy delivery on the anterior left atrial wall, interatrial dissociation and complete block of the sinus impulse to the atrioventricular (AV) node was observed. AV node activation became dependent on a subsidiary left atrial rhythm. CONCLUSION: Anatomical location of intra and inter-atrial connections must be taken into account when performing extensive ablation procedures, specially in cases with prior cardiac surgeries.

Multiple ICD shocks in a patient with dilated cardiomyopathy: What is the mechanism?

We present the case of a 45-year-old male patient with dilated cardiomyopathy who suffers from multiple implantable cardioverter defibrillator (ICD) shocks. The analysis of the ICD tracing and the electrophysiological study allows to conclude that bundle branch re-entrant tachycardia is the most likely diagnosis, even in absence of conduction abnormalities in his basal electrocardiography.

Super-response to cardiac resynchronization therapy may predict late phrenic nerve stimulation.

Aims: Changes in the anatomical relationship between left phrenic nerve and coronary veins may occur due to the reverse remodelling observed in super-responders to cardiac resynchronization therapy (CRT) and might be the underlying mechanism in patients developing late-onset phrenic nerve stimulation (PNS) without evidence of lead dislodgement (LD). In this study, we sought to evaluate the role of super-response (SR) to CRT as a potential predictor of late-onset PNS. Methods and results: Consecutive patients implanted with a left ventricular (LV) lead in a single centre were retrospectively analysed. Phrenic nerve stimulation was classified as 'early' when it occurred within 3 months of implantation and 'late' for occurrences thereafter. 'Late' PNS was considered related to LD (LD-PNS) when LV threshold differed by > 1 V or impedance >250 Ω from baseline values or in case of radiological displacement. Cases not meeting the former criteria were classified as 'non-LD-PNS'. Super-response was defined as a decrease ≥30% of the left ventricluar end-systolic volume at 1-year echocardiography. At 32 ± 7 months follow-up, PNS occurred in 20 of 139 patients. Late non-LD-PNS incidence was significantly higher in the SR group (8/61; 13.1%) when compared with the non-SR (1/78; 1.3%) (P = 0.010). Super-response remained the only predictor of non-LD-PNS at multivariate analysis (odds ratio: 11.62, 95% confidence interval 1.41-95.68, P = 0.023). Conclusion: Incidence of late non-LD-PNS is higher among SR to CRT, suggesting a potential role of the changes in the anatomical relationship between left phrenic nerve and coronary veins.

Entrapment of "PV-Tracker" guidewire in the pulmonary veins during atrial fibrillation ablation with PVAC Gold.

We report the entrapment of Pulmonary Vein Ablation Catheter (Medtronic, Minneapolis, MN, USA) and its guidewire within the right pulmonary veins in two patients. The catheters could be retrieved without complications but they were disabled in both cases. This nondescribed incident should be recognized by PVAC users since it may be a source of potential severe complications during pulmonary vein isolation procedures.

Phrenic paralysis during cardiac electronic device implantation: incidence, causes and clinical course.

AIMS: Phrenic paralysis is a known complication of central venous catheterization, but it is not listed as a complication related to cardiac implantable electronic device (CIED) implants. The aim of this study is to describe the incidence, causes, clinical picture, and management of phrenic paralysis occurring in this scenario. METHODS AND RESULTS: We retrospectively analysed data from our CIED implantation database and identified those patients who suffered phrenic paralysis during the implantation procedure. Four of 891 patients (subclavian puncture in 626) developed phrenic paralysis during pacemaker or defibrillator implant procedures. Severe respiratory failure needing ventilatory support occurred in two, being the phrenic paralysis transient in all of the cases. CONCLUSIONS: Transient phrenic paralysis may occur during CIED implantation probably related to the infiltration of local anaesthesia in the subclavian area. Mechanism, prevention, and management are discussed.

Atrial Rate-Responsive Pacing and Incidence of Sustained Atrial Arrhythmias in Patients with Implantable Cardioverter Defibrillators.

BACKGROUND: Atrial rate-responsive pacing (RRP) has proved to be safe in pacemaker recipients with chronotropic incompetence. Although RRP is available in all current implantable cardioverter defibrillators (ICDs), the outcomes of this pacing mode in ICD patients are unknown. The aim is to evaluate the relationship between atrial RRP and atrial arrhythmias in ICD recipients. METHODS: Dual-chamber and triple-chamber ICD patients were included in this multicenter cohort study. Patients with permanent atrial fibrillation (AF) or VVI pacing mode were excluded. The number and duration of atrial tachycardia (AT)/AF episodes were assessed. RESULTS: Data from 415 patients and 80,707 AT/AF episodes (median duration: 0.4 hours) were collected after a 21.3 ± 14.1-month follow-up. Atrial RRP was programmed in 90 (21.7%) patients and was associated with a higher atrial pacing percentage in the overall study population (51.2 ± 33.8% vs 18.4 ± 25.7%, P < 0.001) and to a higher ventricular pacing percentage among dual-chamber devices (22.3 ± 37.6% vs 9.3 ± 25%, P < 0.001). Independent factors associated with sustained AT/AF episodes (>23 hours) were previous AF (odds ratio [OR]: 7.98; 95% confidence interval [CI]: 4.11-15.47; P < 0.001) and atrial RRP (OR: 3.58; 95% CI: 1.82-7.03; P < 0.001). RRP was related to a lower sustained AT/AF episodes-free survival both in patients with a history of AF (43% vs 70%, P = 0.035) and without a history of AF (82% vs 97%, P = 0.004) at 2 years. CONCLUSIONS: Atrial RRP in ICD patients was related to a higher incidence of sustained atrial arrhythmias. This pacing mode may have an atrial proarrhythmic effect on ICD patients, especially among those with a history of AF.

Catheter ablation vs. antiarrhythmic drug treatment of persistent atrial fibrillation: a multicentre, randomized, controlled trial (SARA study).

BACKGROUND: Catheter ablation (CA) is a highly effective therapy for the treatment of paroxysmal atrial fibrillation (AF) when compared with antiarrhythmic drug therapy (ADT). No randomized studies have compared the two strategies in persistent AF. The present randomized trial aimed to compare the effectiveness of CA vs. ADT in treating persistent AF. METHODS AND RESULTS: Patients with persistent AF were randomly assigned to CA or ADT (excluding patients with long-standing persistent AF). Primary endpoint at 12-month follow-up was defined as any episode of AF or atrial flutter lasting >24 h that occurred after a 3-month blanking period. Secondary endpoints were any atrial tachyarrhythmia lasting >30 s, hospitalization, and electrical cardioversion. In total, 146 patients were included (aged 55 ± 9 years, 77% male). The ADT group received class Ic (43.8%) or class III drugs (56.3%). In an intention-to-treat analysis, 69 of 98 patients (70.4%) in the CA group and 21 of 48 patients (43.7%) in the ADT group were free of the primary endpoint (P = 0.002), implying an absolute risk difference of 26.6% (95% CI 10.0-43.3) in favour of CA. The proportion of patients free of any recurrence (>30 s) was higher in the CA group than in the ADT group (60.2 vs. 29.2%; P < 0.001) and cardioversion was less frequent (34.7 vs. 50%, respectively; P = 0.018). CONCLUSION: Catheter ablation is superior to medical therapy for the maintenance of sinus rhythm in patients with persistent AF at 12-month follow-up. CLINICAL TRIAL REGISTRATION INFORMATION: NCT00863213 (http://clinicaltrials.gov/ct2/show/NCT00863213).

Cavo-tricuspid isthmus radiofrequency ablation using a novel remote navigation catheter system in patients with typical atrial flutter.

AIMS: A new remote catheter system (AMIGO™ Remote Catheter System) compatible with conventional ablation catheters is now commercially available but no data about its performance in clinical use during ablation have been reported. This study evaluates the feasibility, efficacy, and safety of cavo-tricuspid isthmus (CTI) ablation with this system in patients with typical atrial flutter (AFl). METHODS AND RESULTS: Sixty patients with typical AFl underwent CTI ablation using the new remote catheter navigation system with 8 mm tip or irrigated catheters in three centres following each centre's routine practice. The endpoint was stable bidirectional CTI block. CTI ablation was successful in 98% of patients. Ablation was completed manually in one patient. The overall procedure, fluoroscopy, and radiofrequency times (median ± standard deviation, range) were 123 ± 42 (50-250), 24 ± 13 (3-82), and 10 ± 8 (1.17-43.3) min, respectively. Three patients had vascular complications not requiring surgical intervention. There were no complications related to the remote catheter manipulation system. CONCLUSION: Cavo-tricuspid isthmus ablation for typical AFl can be safely and effectively performed with the AMIGO™. The learning curve seems to be short even for physicians with limited ablation experience.

Intravenous lidocaine decreases tumor necrosis factor alpha expression both locally and systemically in pigs undergoing lung resection surgery.

BACKGROUND: Lung resection surgery is associated with an inflammatory reaction. The use of 1-lung ventilation (OLV) seems to increase the likelihood of this reaction. Different prophylactic and therapeutic measures have been investigated to prevent lung injury secondary to OLV. Lidocaine, a commonly used local anesthetic drug, has antiinflammatory activity. Our main goal in this study was to investigate the effect of IV lidocaine on tumor necrosis factor α (TNF-α) lung expression during lung resection surgery with OLV. METHODS: Eighteen pigs underwent left caudal lobectomy. The animals were divided into 3 groups: control, lidocaine, and sham. All animals received general anesthesia. In addition, animals in the lidocaine group received a continuous IV infusion of lidocaine during surgery (1.5 mg/kg/h). Animals in the sham group only underwent thoracotomy. Samples of bronchoalveolar lavage (BAL) fluid and plasma were collected before initiation of OLV, at the end of OLV, at the end of surgery, and 24 hours after surgery. Lung biopsy specimens were collected from the left caudal lobe (baseline) before surgery and from the mediastinal lobe and the left cranial lobe 24 hours after surgery. Samples were flash-frozen and stored to measure levels of the following inflammatory markers: interleukin (IL) 1ß, IL-2, IL-10, TNF-α, nuclear factor κB, monocyte chemoattractant protein-1, inducible nitric oxide synthase, and endothelial nitric oxide synthase. Markers of apoptosis (caspase 3, caspase 9, Bad, Bax, and Bcl-2) were also measured. In addition, levels of metalloproteinases and nitric oxide metabolites were determined in BAL fluid and in plasma samples. A nonparametric test was used to examine statistical significance. RESULTS: OLV caused lung damage with increased TNF-α expression in BAL, plasma, and lung samples. Other inflammatory (IL-1ß, nuclear factor κB, monocyte chemoattractant protein-1) and apoptosis (caspase 3, caspase 9, and BAX) markers were also increased. With the use of IV lidocaine there was a significant decrease in the levels of TNF-α in the same samples compared with the control group. Lidocaine administration also reduced the inflammatory and apoptotic changes observed in the control group. Hemodynamic values, blood gas values, and airway pressure were similar in all groups. CONCLUSIONS: Our results suggest that lidocaine can prevent OLV-induced lung injury through reduced expression of proinflammatory cytokines and lung apoptosis. Administration of lidocaine may help to prevent lung injury during lung surgery with OLV.

[Translated article] Pharmaceutical care in respiratory diseases: Current situation and opportunities for hospital pharmacy in Spain.

OBJECTIVE: Respiratory diseases present a challenge for the healthcare system due to their prevalence and clinical impact. The aim of this study was to explore the current situation of hospital pharmacy in the field of respiratory diseases. METHOD: Observational, cross-sectional study, with a national scope, divided into 2 parts. In an initial phase, the activity and level of pharmaceutical care in respiratory diseases was evaluated through an online questionnaire using REDCap. The survey was addressed to department chiefs and consisted of 17 items, divided into 2 modules: general data and general activity. The second phase was open to hospital pharmacists, with the aim of exploring their opinion on care, training, and improvement needs. The number of items in this phase was 19, divided into 5 modules: general data, pharmaceutical care, competencies, training, and degree of satisfaction. RESULTS: In the first phase, 23 hospitals were included. Most of them (n=20) had a pharmacist in charge of respiratory diseases. However, a large proportion of them dedicated less than 40% of their working day to this activity. The pharmacist's activity occurred at the level of external patients (n=21), hospitalised patients (n=16), and secondarily in management (n=8). Integration is greater in pathologies such as asthma, IPF, pulmonary hypertension, and bronchiectasis. Participation in committees was present in 15 hospitals, with variability in pathologies and degree of involvement. In the second phase, 164 pharmacists participated, who considered pharmaceutical care in cystic fibrosis, asthma, and lung transplant as a priority. 51% considered integration to be adequate and 91% considered it necessary to implement prioritisation criteria. Professional competencies ranged from 6.5 to 6.9 out of 10 points. Only 45% of participants had received specific training in the last 4 years, indicating greater priority for asthma, pulmonary hypertension, and IPF. CONCLUSIONS: Most centers have pharmacists specialised in respiratory diseases. However, there is room for improvement in terms of subspecialisation, participation in multidisciplinary committees, implementation of prioritisation criteria, diversification in pathologies treated, as well as greater specific training in this area.

Pharmaceutical care in respiratory diseases: Current situation and opportunities for Hospital Pharmacy in Spain. / Atención farmacéutica en enfermedades respiratorias: situación y oportunidades de la farmacia hospitalaria en España.

OBJECTIVE: Respiratory diseases present a challenge for the healthcare system due to their prevalence and clinical impact. The aim of this study was to explore the current situation of hospital pharmacy in the field of respiratory diseases. METHOD: Observational, cross-sectional study, with a national scope, divided into 2 parts. In an initial phase, the activity and level of pharmaceutical care in respiratory diseases was evaluated through an online questionnaire using REDCap. The survey was addressed to department chiefs and consisted of 17 items, divided into 2 modules: general data and general activity. The second phase was open to hospital pharmacists, with the aim of exploring their opinion on care, training, and improvement needs. The number of items in this phase was 19, divided into 5 modules: general data, pharmaceutical care, competencies, training and degree of satisfaction. RESULTS: In the first phase, 23 hospitals were included. Most of them (n=20) had a pharmacist in charge of respiratory diseases. However, a large proportion of them dedicated less than 40% of their working day to this activity. The pharmacist's activity occurred at the level of external patients (n=20), hospitalized patients (n=16), and secondarily in management (n=8). Integration is greater in pathologies such as asthma, IPF, pulmonary hypertension, and bronchiectasis. Participation in committees was present in 15 hospitals, with variability in pathologies and degree of involvement. In the second phase, 164 pharmacists participated, who considered pharmaceutical care in cystic fibrosis, asthma and lung transplant as a priority. Fifty-one percent considered integration to be adequate and 91% considered it necessary to implement prioritization criteria. Professional competencies ranged from 6.5-6.9 out of 10 points. Only 45% of participants had received specific training in the last four years, indicating greater priority for asthma, pulmonary hypertension and IPF. CONCLUSIONS: Most centers have pharmacists specialized in respiratory diseases. However, there is room for improvement in terms of sub specialization, participation in multidisciplinary committees, implementation of prioritization criteria, diversification in pathologies treated, as well as greater specific training in this area.

Ivabradine for controlling heart rate in permanent atrial fibrillation: A translational clinical trial.

BACKGROUND: Pharmacological options for rate control in atrial fibrillation are scarce. Ivabradine was postulated to reduce the ventricular rate in this setting. OBJECTIVES: The objectives of this study were to evaluate the mechanism of inhibition of atrioventricular conduction produced by ivabradine and to determine its efficacy and safety in atrial fibrillation. METHODS: The effects of ivabradine on atrioventricular node and ventricular cells were studied by in vitro whole-cell patch-clamp experiments and mathematical simulation of human action potentials. In parallel, a multicenter, randomized, open-label, phase III clinical trial compared ivabradine with digoxin for uncontrolled permanent atrial fibrillation despite ß-blocker or calcium channel blocker treatment. RESULTS: Ivabradine 1 µM inhibited "funny" current and rapidly activating delayed rectifier potassium channel current by 28.9% and 22.8%, respectively (P < .05). The sodium channel current and L-type calcium channel current were reduced only at 10 µM. Ivabradine slowed the firing frequency of a modeled human atrioventricular node action potential by 10.6% and induced a minimal prolongation of ventricular action potential. Thirty-five (51.5%) patients were randomized to ivabradine and 33 (49.5%) to digoxin. The mean daytime heart rate decreased by 11.6 beats/min (-11.5%) in the ivabradine arm (P = .02) vs 19.6 (-20.6%) in the digoxin arm (P < .001), although the noninferiority margin of efficacy was not met (Z = -1.95; P = .97). The primary safety end point occurred in 3 patients (8.6%) on ivabradine and in 8 (24.2%) on digoxin (P = .10). CONCLUSION: Ivabradine produced a moderate rate reduction in patients with permanent atrial fibrillation. The inhibition of funny current in the atrioventricular node seems to be the main mechanism responsible for this reduction. Compared with digoxin, ivabradine was less effective, was better tolerated, and had a similar rate of serious adverse events.

Impact of Coronavirus Disease 2019 on Cardiac Arrhythmia Care: Experience of a Spanish Tertiary Hospital During the Health Crisis Triggered by the First Wave of the Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has resulted in a deep restructuring of cardiovascular care, especially in the setting of cardiac arrhythmia units, which are characterized by a wide variety of clinical and interventional activities. We describe the experience of a large university hospital deeply hit during the COVID-19 health crisis (first outbreak of the pandemic), focusing on the exceptional measures implemented and their impact in terms of outcomes. We performed a retrospective study comparing the human and structural resources and the activity of a cardiac arrhythmia unit in a Spanish tertiary hospital for two consecutive periods: from January 12, 2020, to March 8, 2020 ("pre-COVID stage"), and from March 9, 2020, to May 2, 2020 ("COVID stage"). Data were contextualized within the number of confirmed COVID-19 cases in the region of Madrid. The measures implemented were promotion of non-face-to-face consultations, selection of urgent procedures, design of a "COVID-free" circuit for outpatient interventions, and protocolization for patients with COVID-19. A total of 3,526 consultations and 362 procedures were performed. During the COVID stage, the number of consultations remained stable, and the electrophysiology rooms' activity decreased by 55.2% with a relative increase in the number of urgent-hospitalized cases attended (11.8% COVID-19-positive patients). The electrophysiology rooms' activity returned to "normal" in the last week of the COVID stage, with no contagion being detected among patients or professionals. In conclusion, the measures implemented allowed us to respond safely and efficiently to the health care needs of patients with arrhythmias during the COVID-19 crisis and may be useful for other institutions facing similar situations.