Electrocardiographic markers in patients with type 2 diabetes and the role of diabetes duration.

BACKGROUND: The association between type 2 diabetes and electrocardiographic (ECG) markers are incompletely explored and the dependence on diabetes duration is largely unknown. We aimed to investigate the electrocardiographic (ECG) changes associated with type 2 diabetes over time. METHODS: In this cross-sectional study, we matched people with type 2 diabetes 1:1 on sex, age, and body mass index with people without diabetes from the general population. We regressed ECG markers with the presence of diabetes and the duration of clinical diabetes, respectively, adjusted for sex, age, body mass index, smoking, heart rate, diabetes medication, renal function, hypertension, and myocardial infarction. RESULTS: We matched 988 people with type 2 diabetes (332, 34% females) with as many controls. Heart rate was 8 bpm higher (p < 0.001) in people with vs. without type 2 diabetes, but the difference declined with increasing diabetes duration. For most depolarization markers, the difference between people with and without type 2 diabetes increased progressively with diabetes duration. On average, R-wave amplitude was 6 mm lower in lead V5 (p < 0.001), P-wave duration was 5 ms shorter (p < 0.001) and QRS duration was 3 ms (p = 0.03). Among repolarization markers, T-wave amplitude (measured in V5) was lower in patients with type 2 diabetes (1 mm lower, p < 0.001) and the QRS-T angle was 10 degrees wider (p = 0.002). We observed no association between diabetes duration and repolarization markers. CONCLUSIONS: Type 2 diabetes was independently associated with electrocardiographic depolarization and repolarization changes. Differences in depolarization markers, but not repolarization markers, increased with increasing diabetes duration.

Clinical Predictors of Device-Detected Atrial Fibrillation During 2.5 Years After Cardiac Surgery: Prospective RACE V Cohort.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a frequent complication after cardiac surgery that is associated with late atrial fibrillation (AF) recurrences (late-POAF) and increased morbidity and long-term mortality. OBJECTIVES: This study sought to determine device-detected POAF incidence and to identify clinical variables associated with POAF, both in patients with and without preoperative AF history. METHODS: A total of 133 consecutive patients undergoing cardiac surgery were prospectively enrolled and continuously monitored with an implantable loop recorder for 2.5 years after surgery. Preoperative transthoracic echocardiography, 12-lead electrocardiogram, blood biomarkers, and clinical data were analyzed to develop prediction models for early- and late-POAF. RESULTS: In patients without preoperative AF history, early-POAF within the first 90 postoperative days occurred in 41 (47.1%) of 87 patients. Late-POAF after the first 90 postoperative days occurred in 22 (25%) of 87 patients, and 20 of these patients also had early-POAF during the first 90 days (20 of 22 [91%]). Increased right atrial minimum volume indexed for body surface area (RAVImin) and early-POAF were independently associated with late-POAF. A prediction model for late-POAF, which included RAVImin >11 mL/m2, age >65 years, and early-POAF, achieved an area under the curve of 0.82 (95% CI: 0.72-0.92). For patients with preoperative AF-history, late-POAF recurrences were frequent (22 of 33 [67%]). Increased RAVImin was independently associated with a higher incidence of late-POAF. CONCLUSIONS: In patients with and without AF history, late-POAF recurrences are frequent, including in patients undergoing surgical AF ablation. In patients with no history of AF, late-POAF might be predicted with excellent accuracy by using a combination of preoperative variables. In patients with a history of AF, signs of advanced AF substrate (eg, increased right atrial volumes) were associated with long-term AF recurrences. [Reappraisal of Atrial Fibrillation: Interaction Between Hypercoagulability, Electrical Remodeling, and Vascular Destabilisation in the Progression of AF; NCT03124576].

Adherence to a handheld device-based atrial fibrillation screening protocol is associated with clinical outcomes.

OBJECTIVE: To evaluate adherence and adherence consistency to the handheld ECG device-based screening protocol and their association with adverse cerebral and cardiovascular outcomes in two systematic atrial fibrillation (AF) screening programmes. METHODS: In 2012 (Systematic ECG Screening for Atrial Fibrillation Among 75-Year Old Subjects in the Region of Stockholm and Halland, Sweden (STROKESTOP) study) and 2016 (Stepwise mass screening for atrial fibrillation using N-terminal pro b-type natriuretic peptide (STROKESTOP II) study), half of all 75- and 76-year-old inhabitants of up to two Swedish regions were invited to participate in a systematic AF screening programme. Participants were instructed to perform 30-second measurements twice daily in STROKESTOP and four times daily in STROKESTOP II for 2 weeks. Adherence was defined as the number of measurements performed divided by the number of measurements asked, whereas adherence consistency was defined as the number of days with complete registrations. RESULTS: In total, 6436 participants (55.7% female) from STROKESTOP and 3712 (59.8% female) from STROKESTOP II were included. Median adherence and adherence consistency were 100 (92-100)% and 12 (11-13) days in STROKESTOP and 90 (75-98)% and 8 (3-11) days in STROKESTOP II. Female sex and lower education were factors associated with both optimal adherence and adherence consistency in both studies. In STROKESTOP, low adherence and adherence consistency were associated with higher risk of adverse cerebral and cardiovascular outcomes (HR for composite primary endpoint 1.30 (1.11 to 1.51), p=0.001), including stroke (HR 1.68 (1.22 to 2.32), p=0.001) and dementia (1.67 (1.27 to 2.19), p<0.001). CONCLUSIONS: Adherence to twice daily handheld ECG measurements in STROKESTOP was higher than to four times daily measurements in STROKESTOP II. Female sex and lower educational attainment were associated with ≥100% adherence and adherence consistency. Low adherence and adherence consistency were associated with a higher risk of adverse outcomes.

Inhibition of the acetylcholine-regulated potassium current prevents transient apnea-related atrial arrhythmogenic changes in a porcine model.

BACKGROUND: More than 50% of patients with atrial fibrillation (AF) suffer from sleep disordered breathing (SDB). Obstructive respiratory events contribute to a transient, vagally mediated atrial arrhythmogenic substrate, which is resistant to most available antiarrhythmic drugs. OBJECTIVE: The purpose of this study was to investigate the effect of pharmacologic inhibition of the G-protein-gated acetylcholine-regulated potassium current (IK,ACh) with and without acute autonomic nervous system activation by nicotine in a pig model for obstructive respiratory events. METHODS: In 21 pigs, SDB was simulated by applying an intermittent negative upper airway pressure (INAP). AF inducibility and atrial effective refractory periods (aERPs) were determined before and during INAP by an S1S2 atrial pacing-protocol. Pigs were randomized into 3 groups-group 1: vehicle (n = 4); group 2: XAF-1407 (IK,ACh inhibitor) (n = 7); and group 3: nicotine followed by XAF-1407 (n = 10). RESULTS: In group 1, INAP shortened aERP (ΔaERP -42.6 ms; P = .004) and transiently increased AF inducibility from 0% to 31%. In group 2, XAF-1407 prolonged aERP by 25.2 ms (P = .005) during normal breathing and prevented INAP-induced aERP shortening (ΔaERP -3.6 ms; P = .3) and AF inducibility. In group 3, INAP transiently shortened aERP during nicotine perfusion (ΔaERP -33.6 ms; P = .004) and increased AF inducibility up to 61%, which both were prevented by XAF-1407. CONCLUSION: Simulated obstructive respiratory events transiently shorten aERP and increase AF inducibility, which can be prevented by the IK,ACh-inhibitor XAF-1407. XAF-1407 also prevents these arrhythmogenic changes induced by obstructive respiratory events during nicotine perfusion. Whether IK,ACh channels represent a target for SDB-related AF in humans warrants further study.

Pericardial Fat Is Associated With Less Severe Multiorgan Failure Over Time in Patients With Coronavirus Disease-19: The Maastricht Intensive Care COVID Cohort.

PURPOSE: Pericardial fat (PF) and epicardial adipose tissue (EAT) may enhance the proinflammatory response in corona virus-19 (COVID-19) patients. Higher PF and EAT volumes might result in multiorgan failure and explain unfavorable trajectories.The aim of this study was to examine the association between the volume of PF and EAT and multiorgan failure over time. MATERIALS AND METHODS: All mechanically ventilated COVID-19 patients with an available chest computed tomography were prospectively included (March-June 2020). PF and EAT volumes were quantified using chest computed tomography scans. Patients were categorized into sex-specific PF and EAT tertiles. Variables to calculate Sequential Organ Failure Assessment (SOFA) scores were collected daily to indicate multiorgan failure. Linear mixed-effects regression was used to investigate the association between tertiles for PF and EAT volumes separately and serial SOFA scores over time. All models were adjusted. RESULTS: Sixty-three patients were divided into PF and EAT tertiles, with median PF volumes of 131.4 mL (IQR [interquartile range]: 115.7, 143.2 mL), 199.8 mL (IQR: 175.9, 221.6 mL), and 318.8 mL (IQR: 281.9, 376.8 mL) and median EAT volumes of 69.6 mL (IQR: 57.0, 79.4 mL), 107.9 mL (IQR: 104.6, 115.1 mL), and 163.8 mL (IQR: 146.5, 203.1 mL). Patients in the highest PF tertile had a statistically significantly lower SOFA score over time (1.3 [-2.5, -0.1], P =0.033) compared with the lowest PF tertile. EAT tertiles were not significantly associated with SOFA scores over time. CONCLUSION: A higher PF volume is associated with less multiorgan failure in mechanically ventilated COVID-19 patients. EAT volumes were not associated with multiorgan failure.

Predictors of Nocturnal Hypoxemic Burden in Patients Undergoing Elective Coronary Artery Bypass Grafting Surgery.

Background: Nocturnal hypoxemia has been linked to increased cardiovascular morbidity and mortality. Several common diseases, such as sleep-disordered breathing (SDB), heart failure (HF), obesity, and pulmonary disease, coincide with an elevated nocturnal hypoxemic burden with and without repetitive desaturations. Research question: This study aimed to evaluate the association of relevant common diseases with distinctive metrics of nocturnal hypoxemic burden with and without repetitive desaturations in patients undergoing coronary artery bypass grafting surgery. Study design and methods: In this subanalysis of the prospective observational study, CONSIDER-AF (NCT02877745) portable SDB monitoring was performed on 429 patients with severe coronary artery disease the night before cardiac surgery. Pulse oximetry was used to determine nocturnal hypoxemic burden, as defined by total recording time spent with oxygen saturation levels < 90% (T90). T90 was further characterized as T90 due to intermittent hypoxemia (T90desaturation) and T90 due to nonspecific and noncyclic SpO2-drifts (T90non-specific). Results: Multivariable linear regression analysis identified SDB (apnea-hypopnea-index ≥ 15/h; B [95% CI]: 6.5 [0.4; 12.5], p = 0.036), obesity (8.2 [2.5; 13.9], p = 0.005), and mild-to-moderate chronic obstructive pulmonary disease (COPD, 16.7 [8.5; 25.0], p < 0.001) as significant predictors of an increased nocturnal hypoxemic burden. Diseases such as SDB, obesity and HF were significantly associated with elevated T90desaturation. In contrast, obesity and mild-to-moderate COPD were significant modulators of T90non-specific. Interpretation: SDB and leading causes for SDB, such as obesity and HF, are associated with an increased nocturnal hypoxemic burden with repetitive desaturations. Potential causes for hypoventilation syndromes, such as obesity and mild-to-moderate COPD, are linked to an increased hypoxemic burden without repetitive desaturations. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02877745.

A worldwide survey on incidence, management, and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: the POTTER-AF study.

AIMS: Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. METHODS AND RESULTS: This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. CONCLUSION: Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

Imaging approaches for pulmonary vein isolation in patients after lobectomy or pneumonectomy: a case series.

Background: In patients who underwent pneumonectomy, pulmonary vein isolation for atrial fibrillation by catheter ablation may be complicated by the anatomical alterations caused by the surgical intervention. Pre- and peri-procedural imaging can visualize and guide the procedure to assure safety and procedural success. Case summary: This case series describes different imaging and ablation strategies in three cases from three different ablation centres with the unusually challenging and complex anatomical conditions in patients following lobectomy or pneumonectomy. Discussion: Pulmonary vein isolation in patients with previous pulmonary resection was feasible by both radiofrequency and cryocatheter ablation despite the anatomical alterations caused by the surgery. Pre- and peri-procedural imaging by cardiac computed tomography and transoesophageal echocardiography contributed to an increased understanding of the complex anatomical substrate.

Atrial fibrillation and chronic obstructive pulmonary disease: diagnostic sequence and mortality risk.

BACKGROUND AND AIMS: Chronic obstructive pulmonary disease (COPD) is present in 13% of atrial fibrillation (AF) patients. In patients diagnosed with both AF and COPD, we aimed to assess overall mortality risk and its association with temporal sequence in AF and COPD diagnosis. METHODS: This nationwide study assessed all patients aged 18-85 years diagnosed with both COPD and AF between 1999 and 2018 in Denmark. Three groups were defined according to the temporal sequence of diagnosis: COPD diagnosed at least 6 months before AF (COPD-First), AF diagnosed at least 6 months before COPD (AF-First) and COPD, and AF diagnosed within a 6-months' time frame (AF∼COPD). RESULTS: We included 62 806 patients (75.0 years; 56.5% males). After 5 years of follow-up, 31 494 (50.1%) died. Mortality was highest in the COPD-First group (COPD-First: 52.8%; AF-First: 46.0%; AF∼COPD 50.6%). In a multivariable Cox-regression model adjusted for age, sex, type 2 diabetes, history of acute myocardial infarction, hypertension, heart failure, dyslipidemia, cancer, chronic kidney disease, and stroke, the AF∼COPD group (HR 1.19, 95% CI 1.16-1.23; P < 0.001) and COPD-First group (HR 1.30, 95% CI 1.27-1.33; P < 0.001) had a higher risk of death compared with the AF-First group. A restricted cubic spline analysis showed that the earlier the COPD was diagnosed, the worse is the prognosis. CONCLUSION: Patients with concomitant AF and COPD had a very poor prognosis and the temporal sequence in diagnosis was differentially associated with prognosis, where a COPD diagnosis preceding an AF diagnosis was accompanied with a higher mortality risk compared with a COPD diagnosis following an AF diagnosis.

Advances in Cardiac Electrophysiology.

Despite the global COVID-19 pandemic, during the past 2 years, there have been numerous advances in our understanding of arrhythmia mechanisms and diagnosis and in new therapies. We increased our understanding of risk factors and mechanisms of atrial arrhythmias, the prediction of atrial arrhythmias, response to treatment, and outcomes using machine learning and artificial intelligence. There have been new technologies and techniques for atrial fibrillation ablation, including pulsed field ablation. There have been new randomized trials in atrial fibrillation ablation, giving insight about rhythm control, and long-term outcomes. There have been advances in our understanding of treatment of inherited disorders such as catecholaminergic polymorphic ventricular tachycardia. We have gained new insights into the recurrence of ventricular arrhythmias in the setting of various conditions such as myocarditis and inherited cardiomyopathic disorders. Novel computational approaches may help predict occurrence of ventricular arrhythmias and localize arrhythmias to guide ablation. There are further advances in our understanding of noninvasive radiotherapy. We have increased our understanding of the role of His bundle pacing and left bundle branch area pacing to maintain synchronous ventricular activation. There have also been significant advances in the defibrillators, cardiac resynchronization therapy, remote monitoring, and infection prevention. There have been advances in our understanding of the pathways and mechanisms involved in atrial and ventricular arrhythmogenesis.

Association between comorbidities and left and right atrial dysfunction in patients with paroxysmal atrial fibrillation: Analysis of AF-RISK.

BACKGROUND: To identify the association between comorbidities and left atrial (LA) and right atrial (RA) function in patients with paroxysmal atrial fibrillation (AF). METHODS: This is a cross-sectional study. Speckle-tracking echocardiography was performed in 344 patients with paroxysmal AF at baseline, and available in 298 patients after 1-year follow-up. The number of comorbidities (hypertension, diabetes mellitus, coronary artery disease, body mass index > 25 kg/m2, age > 65 years, moderate to severe mitral valve regurgitation and kidney dysfunction (estimated glomerular filtration rate < 60 ml/min/1.73 m2)) was determined and the association with atrial strain was tested. RESULTS: Mean age of the patients was 58 (SD 12) years and 137 patients were women (40%). Patients with a higher number of comorbidities had larger LA volumes (p for trend <0.001), and had a decrease in all strain phases from the LA and RA, except for the RA contraction phase (p for trend 0.47). A higher number of comorbidities was associated with LA reservoir and conduit strain decrease independently of LA volume (p < 0.001, p < 0.001 respectively). Patients with 1-2 comorbidities, but not patients with 3 or more comorbidities, showed a further progression of impaired LA and RA function in almost all atrial strain phases at 14 [13-17] months follow-up. CONCLUSIONS: In patients with paroxysmal AF, individual and combined comorbidities are related to lower LA and RA strain. In patients with few comorbidities, impairment in atrial function progresses during one year of follow-up. Whether comorbidity management prevents or reverses decrease in atrial function warrants further study.

First catheter-based high-density endocardial 3D electroanatomical mapping of the right atrium in standing horses.

BACKGROUND: Three-dimensional electroanatomical mapping is of potential interest in equine cardiology to identify arrhythmia mechanisms, characterise electroanatomical substrates and guide ablation strategies. OBJECTIVES: To describe three-dimensional electroanatomical mapping in standing horses. STUDY DESIGN: Research methodology, proof of concept study. METHODS: Four Standardbred horses (2 geldings, 2 mares, median age 4.5 [4-9] years, mean bodyweight 485 [440-550] kg) were sedated and placed in stocks. Via the jugular vein, a high-density multipolar grid catheter (Advisor™ HD Grid Mapping Catheter with EnSite VelocityTM, Abbott Medical) was used for endocardial mapping of the right atrium. The P-wave on the surface ECG was used as a timing reference for simultaneous local activation time- and bipolar voltage-mapping. For a positional reference a 10-pole catheter (Abbott Medical) was placed in the caudal vena cava. RESULTS: Endocardial right atrial mapping guided by the three-dimensional mapping system and local electrograms was successfully performed in all four horses. A median of 32719 [25499-65078] points, covering the entire right atrium, were collected. Three-dimensional electroanatomical mapping provided detailed information about activation patterns and electrogram-characteristics of the sinoatrial node, intervenous tubercle and cavotricuspid isthmus. Additionally, transvenous biopsy forceps connected to the mapping system were visualised on screen to guide biopsy collection. MAIN LIMITATIONS: The feasibility of electroanatomical mapping for the left atrium and in larger breeds requires further study. CONCLUSIONS: High-density three-dimensional electroanatomical mapping of the right atrium is feasible in the standing horse.

Chronic obstructive pulmonary disease and atrial fibrillation: an interdisciplinary perspective.

Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be ∼25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening.

Complex interaction of obesity, intentional weight loss and heart failure: a systematic review and meta-analysis.

OBJECTIVE: The aim of the meta-analysis was to determine the association of obesity and heart failure (HF) and the cardiac impact of intentional weight loss following bariatric surgery on cardiac structure and myocardial function in obese subjects. METHODS: MEDLINE, Embase and Web of Science were searched up to 3 April 2018. Studies reporting association and prognostic impact of obesity in HF and the impact of intentional weight loss following bariatric surgery on cardiac structure and myocardial function in obesity were included in the meta-analysis. RESULTS: 4959 citations were reviewed. After exclusions, 29 studies were analysed. A 'J curve' relationship was observed between body mass index (BMI) and risk of HF with maximum risk in the morbidly obese (1.73 (95% CI 1.30 to 2.31), p<0.001, n=11). Although 'obesity paradox' was observed for all-cause mortality, the overweight group was associated with lower cardiovascular (CV) mortality (OR=0.86 (95% CI 0.79 to 0.94), n=11) with no significant differences across other BMI groups. Intentional weight loss induced by bariatric surgery in obese patients (n=9) without established HF, atrial fibrillation or known coronary artery disease, was associated with a reduction in left ventricular mass index (p<0.0001), improvement in left ventricular diastolic function (p≤0.0001) and a reduction in left atrial size (p=0.02). CONCLUSIONS: Despite the increased risk of HF with obesity, an 'obesity paradox' is observed for all-cause mortality. However, the nadir for CV mortality is observed in the overweight group. Importantly, intentional weight loss was associated with improvement in indices of cardiac structure and myocardial function in obese patients. TRIAL REGISTRATION NUMBER: APP 74412.

German Cardiac Society Working Group on Cellular Electrophysiology state-of-the-art paper: impact of molecular mechanisms on clinical arrhythmia management.

Cardiac arrhythmias remain a common challenge and are associated with significant morbidity and mortality. Effective and safe rhythm control strategies are a primary, yet unmet need in everyday clinical practice. Despite significant pharmacological and technological advances, including catheter ablation and device-based therapies, the development of more effective alternatives is of significant interest to increase quality of life and to reduce symptom burden, hospitalizations and mortality. The mechanistic understanding of pathophysiological pathways underlying cardiac arrhythmias has advanced profoundly, opening up novel avenues for mechanism-based therapeutic approaches. Current management of arrhythmias, however, is primarily guided by clinical and demographic characteristics of patient groups as opposed to individual, patient-specific mechanisms and pheno-/genotyping. With this state-of-the-art paper, the Working Group on Cellular Electrophysiology of the German Cardiac Society aims to close the gap between advanced molecular understanding and clinical decision-making in cardiac electrophysiology. The significance of cellular electrophysiological findings for clinical arrhythmia management constitutes the main focus of this document. Clinically relevant knowledge of pathophysiological pathways of arrhythmias and cellular mechanisms of antiarrhythmic interventions are summarized. Furthermore, the specific molecular background for the initiation and perpetuation of atrial and ventricular arrhythmias and mechanism-based strategies for therapeutic interventions are highlighted. Current "hot topics" in atrial fibrillation are critically appraised. Finally, the establishment and support of cellular and translational electrophysiology programs in clinical rhythmology departments is called for to improve basic-science-guided patient management.

Nocturnal hypoxemic burden is associated with epicardial fat volume in patients with acute myocardial infarction.

BACKGROUND: Increased epicardial fat volume (EFV) is a common feature of patients with sleep-disordered breathing (SDB), is considered as an established marker of cardiovascular risk, and is associated with adverse cardiovascular events after myocardial infarction (MI). METHODS: To investigate the association between different measures of SDB severity and EFV after acute MI, we enrolled 105 patients with acute MI in this study. Unattended in-hospital polysomnography was performed to determine the number of apneas and hypopneas per hour during sleep (apnea-hypopnea index, AHI). To determine nocturnal hypoxemic burden, we used pulse oximetry and applied a novel parameter, the hypoxia load representing the integrated area of desaturation divided by total sleep time (HLTST). Of 105 patients, 56 underwent cardiovascular magnetic resonance to define EFV. RESULTS: HLTST was significantly associated with EFV (r2 = 0.316, p = 0.025). Multivariate linear regression analysis accounting for age, sex, body mass index, smoking, and left ventricular mass demonstrated that the HLTST was an independent modulator of EFV (B-coefficient 0.435 (95% CI 0.021-0.591); p = 0.015). In contrast, AHI or established measures of hypoxemia did not correlate with EFV. CONCLUSIONS: HLTST, a novel parameter to determine nocturnal hypoxemic burden, and not AHI as an event-based measure of SDB, was associated with EFV in patients with acute MI. Further studies are warranted to confirm the link between nocturnal hypoxemia and EFV and to determine the prognostic value of a more detailed characterization of nocturnal hypoxemic burden in patients with high cardiovascular risk.