Cardiac electronic implantable devices: A call for a new coding system.

Over the last decades, cardiac electronic implantable devices (CEID) have incorporated a myriad of technological capabilities that are not conveniently inferred by using the conventional ICHD and NBG coding systems. We propose a new coding system (i.e., the C-ARL-A coding system) aimed at overcoming this important limitation.

Impact of left atrial appendage closure in patients on anticoagulation for atrial fibrillation and recurrent or chronic gastrointestinal bleeding.

BACKGROUND: Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption. METHODS: Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre. RESULTS: Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed. CONCLUSIONS: LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA.

Mapping potentials adjacent to the cavo-tricuspid isthmus ablation line during incremental pacing: A feasible and highly accurate maneuver to confirm complete CTI conduction block.

BACKGROUND: The diagnostic accuracy of incremental atrial pacing (IP) to determine complete cavo-tricuspid isthmus (CTI) block during typical atrial flutter (AFL) ablation is limited by both an extensive/nonlinear ablation and/or the presence of intra-atrial conduction delay elsewhere in the right atrium. We examined the diagnostic performance of an IP variant based on the assessment of the atrial potentials adjacent to the ablation line which aims at overcoming both limitations. METHODS: From a prospective population of 108 consecutive patients, 15 were excluded due to observation of inconclusive CTI ablation potentials precluding for a straight comparison between the IP maneuver and its variant. In the remaining 93, IP was performed from the low lateral right atrium and the coronary sinus ostium, with the ablation catheter positioned both at the CTI line and adjacent (<5 mm) to its septal and lateral aspect. The IP variant consisted of measuring the interval between the two atrial electrograms situated on the same side of the ablation line, opposite to the pacing site, a ≤10 ms increase indicating complete CTI block. RESULTS: The IP maneuver and its variant were consistent with complete CTI block in 82/93 (88%) and 87/93 (93%) patients, respectively. Four patients had AFL recurrence during follow-up: 2/4 and 4/4 had been adequately classified as incomplete block by the IP maneuver and its variant, respectively. Twenty-three patients (24%) had significant intra-atrial conduction delay elsewhere in the right atrium. The IP maneuver and its variant were suggestive of an incomplete CTI block in 11/23 and 4/23 in this setting (P = .028), with the later best predicting subsequent AFL relapses (2/12 vs 2/4, P = .01). CONCLUSIONS: The IP variant, which was designed to overcome the limitations of the conventional IP maneuver, accurately distinguishes complete from incomplete CTI block and helps to predict AFL recurrences after ablation.

Utility of Amiodarone Pre-Treatment as a Facilitator of the Acute Success of Electrical Cardioversion in Persistent Atrial Fibrillation.

PURPOSE: The usefulness and mechanisms of antiarrhythmic drug (AAD) pre-treatment as a facilitator of the acute success of electrical cardioversion (ECV) in atrial fibrillation (AF) remain controversial. We sought to analyze the role of AAD treatment with this purpose, differentiating its possible utility either facilitating the restoration of sinus rhythm (SR) or reducing immediate AF recurrences (IAFR). METHODS: We analyzed 2962 consecutive patients with persistent AF undergoing ECV prospectively included in 3 national registries. The acute success of ECV was indicated by the reversion to SR without presenting an IAFR (< 2 h). RESULTS: A total of 1410 patients (48%) received AAD treatment prior to ECV (80% amiodarone, 15% class Ic AAD, 2% other AAD). The rate of restoration of SR was similar between the patients treated with amiodarone (92%), class Ic AAD (91%) and who did not receive AAD pre-treatment (91%) (p = 0.92). However, those treated with amiodarone had fewer IAFR than those in the other two groups (amiodarone 3% vs class Ic 7% vs without treatment 6%; p = 0.002), so the ECV success rate was higher in the amiodarone group than in the other groups (amiodarone 89% vs Ic 84% vs without treatment 86%; p = 0.04). After adjusting for multiple variables, amiodarone remained as an independent predictor of a lower occurrence of IAFR (OR = 0.57; p = 0.01) and of a successful ECV (OR 1.37; p = 0.01). CONCLUSIONS: For patients with persistent AF undergoing ECV, AAD has a neutral effect on the restoration of SR but amiodarone increases its effectiveness due to a lower incidence of IAFR.

Three-dimensional myocardial scar characterization from the endocardium: Usefulness of endocardial unipolar electroanatomic mapping.

Epicardial ablation may be required to eliminate ventricular tachycardia (VT) in patients with underlying structural heart disease. The decision to gain epicardial access is frequently based on the suspicion of an epicardial origin for the VT and/or presence of an arrhythmogenic substrate. Epicardial pathology and VT is frequently present in patients with nonischemic right and/or left cardiomyopathies even in the setting of modest or no endocardial bipolar voltage substrate. In this setting, unipolar voltage mapping from the endocardium serves to help identify midmyocardial and/or epicardial VT substrate. The additional value of endocardial unipolar mapping includes its usefulness to predict the clinical outcome after VT ablation, to determine the irreversibility of myocardial disease, and to guide endomyocardial biopsy procedures to specific areas of intramural scarring. In this review, we aim to provide a guide to the use of endocardial unipolar mapping and its appropriate interpretation in a variety of clinical situations.

Ventricular fibrillation in a patient with Wolff-Parkinson-White syndrome unrelated to pre-excited atrial fibrillation.

A 52-year-old man was admitted due to out-hospital cardiac arrest. Recurrent ventricular fibrillation (VF) occurred under therapeutic hypothermia thereafter. Previously inadverted full pre-excitation was documented exclusively and immediately prior to 4 out of the 5 VF relapses. Coronary vasospasm and early repolarization were also documented. An electrophysiological study demonstrated poor anterograde conduction over a left-sided accessory pathway. We theorize that maximum pre-excitation favored in-hospital VF by augmenting the repolarization vulnerability induced by therapeutic hypothermia, with coronary vasospasm accounting as the probable cause of out-hospital VF. A plausible VF mechanism in WPW syndrome unrelated to pre-excited atrial fibrillation is discussed.

Comparison between endocardial and epicardial cardiac resynchronization in an experimental model of non-ischaemic cardiomyopathy.

Aims: Pacing from the left ventricular (LV) endocardium might increase the likelihood of response to cardiac resynchronization therapy. However, experimental and clinical data supporting this assumption are limited and controversial. The aim of this study was to compare the acute response of biventricular pacing from the LV epicardium and endocardium in a swine non-ischaemic cardiomyopathy (NICM) model of dyssynchrony. Methods and results: A NICM was induced in six swine by 3 weeks of rapid ventricular pacing. Biventricular stimulation was performed from 16 paired locations in the LV (8 epicardial and 8 endocardial) with two different atrioventricular (80 and 110 ms) intervals and three interventricular (0, +30, -30 ms) delays. The acute response of the aortic blood flow, LV and right ventricular (RV) pressures, LVdP/dtmax and LVdP/dtmin and QRS complex width and QT duration induced by biventricular stimulation were analysed. The haemodynamic and electrical beneficial responses to either LV endocardial or epicardial biventricular pacing were similar (ΔLVdP/dtmax: +7.8 ± 2.2% ENDO vs. +7.3 ± 1.5% EPI, and ΔQRS width: -16.8 ± 1.3% ENDO vs. -17.1 ± 1.9% EPI; P = ns). Pacing from LV basal regions either from the epicardium or endocardium produced better haemodynamic responses as compared with mid or apical LV regions (P < 0.05). The LV regions producing the maximum QRS complex shortening did not correspond to those inducing the best haemodynamic responses (EPI: r2 = 0.013, P = ns; ENDO: r2 = 0.002, P = ns). Conclusion: Endocardial LV pacing induced similar haemodynamic changes than pacing from the epicardium. The response to endocardial LV pacing is region dependent as observed in epicardial pacing.

Secondary prevention strategies after an acute ST-segment elevation myocardial infarction in the AMI code era: beyond myocardial mechanical reperfusion.

BACKGROUND: The AMI code is a regional network enhancing a rapid and widespread access to reperfusion therapy (giving priority to primary angioplasty) in patients with acute ST-segment elevation myocardial infarction (STEMI). We aimed to assess the long-term control of conventional cardiovascular risk factors after a STEMI among patients included in the AMI code registry. DESIGN AND METHODS: Four hundred and fifty-four patients were prospectively included between June-2009 and April-2013. Clinical characteristics were collected at baseline. The long-term control of cardiovascular risk factors and cardiovascular morbidity/mortality was assessed among the 6-months survivors. RESULTS: A total of 423 patients overcame the first 6 months after the STEMI episode, of whom 370 (87%) underwent reperfusion therapy (363, 98% of them, with primary angioplasty). At 1-year follow-up, only 263 (62%) had adequate blood pressure control, 123 (29%) had LDL-cholesterol within targeted levels, 126/210 (60%) smokers had withdrawn from their habit and 40/112 (36%) diabetic patients had adequate glycosylated hemoglobin levels. During a median follow-up of 20 (11-30) months, cumulative mortality of 6 month-survivors was 6.1%, with 9.9% of hospital cardiovascular readmissions. The lack of assessment of LDL and HDL-cholesterol were significantly associated with higher mortality and cardiovascular readmission rates. CONCLUSIONS: Whereas implementation of the AMI code resulted in a widespread access to rapid reperfusion therapy, its long-term therapeutic benefit may be partially counterbalanced by a manifestly suboptimal control of cardiovascular risk factors. Further efforts should be devoted to secondary prevention strategies after STEMI.

Impact of Body Mass Index in the Cardioverter Efficacy of Amiodarone in Persistent Atrial Fibrillation.

BACKGROUND: Amiodarone is an anti-arrhythmic drug that has extensive tissue distribution and substantial storage in the fat tissue. Different studies have described some implications of body fat composition in its pharmacokinetics and pharmacodynamics. However, no clinical studies have described its implications for clinical efficacy. METHODS: We studied 878 patients with persistent atrial fibrillation (AF) treated with a regimen of amiodarone and referred to electrical cardioversion (ECV), included prospectively in two Spanish registries. We analyzed the influence of body mass index (BMI), as well as overweight and obesity, in the efficacy of amiodarone for achieving pharmacologic cardioversion to sinus rhythm (SR) before ECV. RESULTS: A total of 185 patients (21.1%) reverted to SR before ECV. Patients who reverted to SR had a lower BMI than those who did not revert (27.45 ± 4.36 kg/m2 vs. 29.11 ± 4.09 kg/m2; p < 0.001). We observed a progressively lower probability of reverting to SR in overweight and obese patients (normal weight 28.3%, overweight 21.3%, obesity 13.1%; p < 0.001). In the logistic regression, BMI (kg/m2) adjusted for other related variables remained as the main factor inversely related to reversion to SR (OR = 0.904 × kg/m2); CI 75% 0.864-0.946). CONCLUSIONS: We observed a negative relationship between an increased BMI and the efficacy of amiodarone for reversion to SR, suggesting a negative clinical impact of excess body fat in its efficacy.

Antiarrhythmic and Anti-Inflammatory Effects of Sacubitril/Valsartan on Post-Myocardial Infarction Scar.

BACKGROUND: Sacubitril/valsartan (Sac/Val) is superior to angiotensin-converting enzyme inhibitors in reducing the risk of heart failure hospitalization and cardiovascular death, but its mechanistic data on myocardial scar after myocardial infarction (MI) are lacking. The objective of this work was to assess the effects of Sac/Val on inflammation, fibrosis, electrophysiological properties, and ventricular tachycardia inducibility in post-MI scar remodeling in swine. METHODS: After MI, 22 pigs were randomized to receive ß-blocker (BB; control, n=8) or BB+Sac/Val (Sac/Val, n=9). The systemic immune response was monitored. Cardiac magnetic resonance data were acquired at 2-day and 29-day post MI to assess ventricular remodeling. Programmed electrical stimulation and high-density mapping were performed at 30-day post MI to assess ventricular tachycardia inducibility. Myocardial samples were collected for histological analysis. RESULTS: Compared with BB, BB+Sac/Val reduced acute circulating leukocytes (P=0.009) and interleukin-12 levels (P=0.024) at 2-day post MI, decreased C-C chemokine receptor type 2 expression in monocytes (P=0.047) at 15-day post MI, and reduced scar mass (P=0.046) and border zone mass (P=0.043). It also lowered the number and mass of border zone corridors (P=0.009 and P=0.026, respectively), scar collagen I content (P=0.049), and collagen I/III ratio (P=0.040). Sac/Val reduced ventricular tachycardia inducibility (P=0.034) and the number of deceleration zones (P=0.016). CONCLUSIONS: After MI, compared with BB, BB+Sac/Val was associated with reduced acute systemic inflammatory markers, reduced total scar and border zone mass on late gadolinium-enhanced magnetic resonance imaging, and lower ventricular tachycardia inducibility.

Spanish catheter ablation registry. 22nd official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2022).

INTRODUCTION AND OBJECTIVES: This article presents results of the Spanish catheter ablation registry for the year 2022. METHODS: Data were retrospectively entered into a REDCap platform using a specific form. RESULTS: A total of 103 centers participated (75 public, 28 private), which reported 23 360 ablation procedures, with a mean of 227±173 and a median of 202 [interquartile range, 77-312] procedures per center. Activity significantly increased (+5419 procedures,+30.2%) with more centers participating in the registry (10 more than in 2021). The most common procedure continued to be atrial fibrillation ablation (35%, 8185 procedures) followed by cavotricuspid isthmus ablation (20%, 4640 procedures), and intranodal re-entrant tachycardia (17%, 3898 procedures). There was an increase in all reported substrates, especially atrial fibrillation ablation (+40%), with slightly higher global acute success (96%) and lower complication rates (1.8%) and mortality (0.04%, n=10). In total, 525 procedures were performed in pediatric patients (2.2%) CONCLUSIONS: The Spanish catheter ablation registry systematically and continuously collects the national trajectory, which experienced a significant activity increase in 2022 in all of the reported substrates but especially in atrial fibrillation ablation. Acute success increased, while both complications and mortality decreased.

Influence of body mass index on recurrence of atrial fibrillation after electrical cardioversion.

BACKGROUND: Several studies have shown an independent relationship between body mass index (BMI) and the incidence of atrial fibrillation (AF). However, little is known about the influence of BMI on AF recurrence after electrical cardioversion (ECV). METHODS: We selected 1121 patients who reverted to sinus rhythm after scheduled ECV and were included in three prospective Spanish registries of ECV in persistent AF. The patients were classified according to baseline BMI into three categories (normal weight, overweight, obesity). We assessed the influence of BMI on the rate of AF recurrence at 3 months. RESULTS: We identified 538 patients (48%) who had AF recurrence in the first 3 months after successful ECV. The patients who suffered AF recurrence had a higher BMI than those who remained in sinus rhythm (29.66±4.57 vs. 28.87±4.64 Kg/m2, respectively; p = 0.004). We observed a higher incidence of AF recurrence in the overweight and obese patients (BMI ≥25 kg/m2) than in those classified as normal weight (50.5% vs. 35.6%, respectively; p<0,001). BMI≥25 Kg/m2 was shown to be independently related to of AF recurrence in the multivariate analysis (OR = 1.75, 95% confidence interval = 1.20-2.58; p = 0.004). CONCLUSIONS: Increased BMI is independently related to AF recurrence after ECV. BMI should also be taken into account when making decisions about the indication for ECV in persistent AF.

Inefficient diastolic filling in dual-chamber pacemaker recipients: impact of atrio-ventricular interval shortening (AVI-SHORT study).

BACKGROUND: Adequate synchronization between the passive ("E") and active ("a") left ventricular (LV) diastolic filling contributes to the efficiency of the heartbeat. E/a superposition in dual-chamber pacemaker (PM) recipients is an under-recognized phenomenon that may be corrected by shortening the atrio-ventricular interval (AVI). We aimed at establishing the prevalence of E/a superposition in PM patients and to analyze the clinical, echocardiographic, and biological impact of AVI shortening. METHODS: Seventy patients with dual-chamber PMs (74 ± 8 years old, 12 women) were consecutively enrolled in this study. Patients with baseline E/a superposition were crossed over from default to manually shortened AVI or vice versa in a case-control fashion (intervention group). Patients without baseline E/a superposition (controls) served as a reference for a descriptive comparison with the intervention group. RESULTS: Thirty-three patients had E/a superposition after PM implantation (47%). Controls (n = 37) had higher LV ejection fraction (59 ± 8% vs. 53 ± 10%, p = 0.048) and lower levels of high sensitive troponin T and ST2 (p < 0.05) than intervention group patients. The AVI was shortened at 48 ± 9 ms in order to ensure adequate E/a separation. The walked distance increased from 75 ± 17 to 78 ± 10% (p = 0.049) and the Euro-QoL score from 0.50 ± 0.27 to 0.63 ± 0.19 (p = 0.011) with short AVI. CONCLUSIONS: E/a superposition occurs in approximately half of dual-chamber PM recipients and is associated with reduced LV function and increased myocardial injury biomarkers. AVI shortening produces a modest but significant effect in functional capacity and quality of life.

Biophysical Tissue Characterization of Ventricular Tachycardia Substrate With Local Impedance Mapping to Predict Critical Sites.

BACKGROUND: New tools are needed to improve ventricular tachycardia (VT) substrate characterization and optimize outcomes. LI provides biophysical tissue characterization. OBJECTIVES: The purpose of this study was to test local impedance (LI)-based mapping to predict critical ventricular tachycardia components after myocardial infarction (MI). METHODS: One month after a nonreperfused anterior MI, endo-epicardial high-density electroanatomic mapping and endocardial LI mapping were performed in 23 Landrace Large X White pigs. LI thresholds were set using the blood pool value to define a 10 Ω range: low (blood pool +9Ω). RESULTS: Low LI was detected in low-voltage areas in 100% of cases, but intermediate LI was found in both core (87%) and border zone (12.5%) voltage areas. A total of 17 VTs were induced (VT isthmus identified in 9 animals). VT inducibility was associated with the size of intermediate LI area (OR: 1.19 [95% CI: 1.0-1.4]; P = 0.039) and the presence of specific LI patterns: LI corridor (OR: 15.0 [95% CI: 1.3-169.9]; P = 0.029); LI gradient (OR: 30.0 [95% CI: 2.1-421.1]; P = 0.012), high LI heterogeneity (OR: 21.7 [95% CI: 1.8-260.6]; P = 0.015), and presence of ≥2 low LI regions (OR: 11.3 [95% CI: 1.0-130.2]; P = 0.053). Potential VT isthmuses were in areas of intermediate LI and colocalized to LI patterns associated with VT inducibility in all cases (LI corridors or LI gradient). Low LI regions did not actively participate in the VT circuit (0%). CONCLUSIONS: LI mapping is feasible and may add useful characterization of the VT substrate. Specific LI patterns (ie, corridors, gradients) were associated with VT inducibility and colocalized with the VT isthmus, thus representing a potential new target for ablation in substrate-based procedures.

Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021).

INTRODUCTION AND OBJECTIVES: The results of the 2021 Spanish catheter ablation registry are presented. METHODS: Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers. RESULTS: Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 cases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%). CONCLUSIONS: The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

[Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)]. / Registro español de ablación con catéter. XXI informe oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2021).

Introduction and objectives: The results of the 2021 Spanish catheter ablation registry are presented. Methods: Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers. Results: Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 clases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%). Conclusions: The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

Inappropriate sinus tachycardia in post-COVID-19 syndrome.

Inappropriate sinus tachycardia (IST) is a common observation in patients with post-COVID-19 syndrome (PCS) but has not yet been fully described to date. To investigate the prevalence and the mechanisms underlying IST in a prospective population of PCS patients. Consecutive patients admitted to the PCS Unit between June and December 2020 with a resting sinus rhythm rate ≥ 100 bpm were prospectively enrolled in this study and further examined by an orthostatic test, 2D echocardiography, 24-h ECG monitoring (heart rate variability was a surrogate for cardiac autonomic activity), quality-of-life and exercise capacity testing, and blood sampling. To assess cardiac autonomic function, a 2:1:1 comparative sub-analysis was conducted against both fully recovered patients with previous SARS-CoV-2 infection and individuals without prior SARS-CoV-2 infection. Among 200 PCS patients, 40 (20%) fulfilled the diagnostic criteria for IST (average age of 40.1 ± 10 years, 85% women, 83% mild COVID-19). No underlying structural heart disease, pro-inflammatory state, myocyte injury, or hypoxia were identified. IST was accompanied by a decrease in most heart rate variability parameters, especially those related to cardiovagal tone: pNN50 (cases 3.2 ± 3 vs. recovered 10.5 ± 8 vs. non-infected 17.3 ± 10; p < 0.001) and HF band (246 ± 179 vs. 463 ± 295 vs. 1048 ± 570, respectively; p < 0.001). IST is prevalent condition among PCS patients. Cardiac autonomic nervous system imbalance with decreased parasympathetic activity may explain this phenomenon.