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.

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.

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.

Sudden Cardiac Death in Heart Failure: A 20-Year Perspective From a Mediterranean Cohort.

BACKGROUND: The prediction of sudden cardiac death (SCD) in heart failure (HF) remains an unmet need. The aim of our study was to assess the prevalence of SCD over 20 years in outpatients with HF managed in a Mediterranean multidisciplinary HF Clinic, and to compare the proportion of SCD (SCD/all-cause death) to the expected proportional occurrence based on the validated Seattle Proportional Risk Model (SPRM) score. METHODS AND RESULTS: This prospective observational registry study included 2772 outpatients with HF admitted between August 2001 and May 2021. Patients were included when the cause of death was known and SPRM score was available. Over the 20-year study period, 1351 patients (48.7%) died during a median follow-up period of 3.8 years (interquartile range 1.6-7.6). Among these patients, the proportion of SCD out of the total of deaths was 13.6%, whereas the predicted by SPRM was 39.6%. This lower proportion of SCD was observed independently of left ventricular ejection fraction, ischemic etiology, and the presence of an implantable cardiac defibrillator. CONCLUSIONS: In a Mediterranean cohort of outpatients with HF, the proportion of SCD was lower than expected based on the SPRM score. Future studies should investigate to what extend epidemiological and guideline-directed medical therapy patterns influence SCD.

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.

Electrophysiological effects of adipose graft transposition procedure (AGTP) on the post-myocardial infarction scar: A multimodal characterization of arrhythmogenic substrate.

Objective: To assess the arrhythmic safety profile of the adipose graft transposition procedure (AGTP) and its electrophysiological effects on post-myocardial infarction (MI) scar. Background: Myocardial repair is a promising treatment for patients with MI. The AGTP is a cardiac reparative therapy that reduces infarct size and improves cardiac function. The impact of AGTP on arrhythmogenesis has not been addressed. Methods: MI was induced in 20 swine. Contrast-enhanced magnetic resonance (ce-MRI), electrophysiological study (EPS), and left-ventricular endocardial high-density mapping were performed 15 days post-MI. Animals were randomized 1:1 to AGTP or sham-surgery group and monitored with ECG-Holter. Repeat EPS, endocardial mapping, and ce-MRI were performed 30 days post-intervention. Myocardial SERCA2, Connexin-43 (Cx43), Ryanodine receptor-2 (RyR2), and cardiac troponin-I (cTnI) gene and protein expression were evaluated. Results: The AGTP group showed a significant reduction of the total infarct scar, border zone and dense scar mass by ce-MRI (p = 0.04), and a decreased total scar and border zone area in bipolar voltage mapping (p < 0.001). AGTP treatment significantly reduced the area of very-slow conduction velocity (<0.2 m/s) (p = 0.002), the number of deceleration zones (p = 0.029), and the area of fractionated electrograms (p = 0.005). No differences were detected in number of induced or spontaneous ventricular arrhythmias at EPS and Holter-monitoring. SERCA2, Cx43, and RyR2 gene expression were decreased in the infarct core of AGTP-treated animals (p = 0.021, p = 0.018, p = 0.051, respectively). Conclusion: AGTP is a safe reparative therapy in terms of arrhythmic risk and provides additional protective effect against adverse electrophysiological remodeling in ischemic heart disease.

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.

Personalized assessment of the cumulative complication risk of the atrial fibrillation ablation track: The AF-TRACK calculator.

Background: Atrial fibrillation (AF) ablation strategy is associated with a non-negligible risk of complications and often requires repeat procedures (AF ablation track), implying repetitive exposure to procedural risk. Objective: The purpose of this study was to develop and validate a model to estimate individualized cumulative risk of complications in patients undergoing the AF ablation track (Atrial Fibrillation TRAck Complication risK [AF-TRACK] calculator). Methods: The model was derived from a multicenter cohort including 3762 AF ablation procedures in 2943 patients. A first regression model was fitted to predict the propensity for repeat ablation. The AF-TRACK calculator computed the risk of AF ablation track complications, considering the propensity for repeat ablation. Internal (cross-validation) and external (independent cohort) validation were assessed for discrimination capacity (area under the curve [AUC]) and goodness of fit (Hosmer-Lemeshow [HL] test). Results: Complications (N = 111) occurred in 3.7% of patients (2.9% of procedures). Predictors included female sex, heart failure, sleep apnea syndrome, and repeat procedures. The model showed fair discrimination capacity to predict complications (AUC 0.61 [0.55-0.67]) and likelihood of repeat procedure (AUC 0.62 [0.60-0.64]), with good calibration (HL χ2 12.5; P = .13). The model maintained adequate discrimination capacity (AUC 0.67 [0.57-0.77]) and calibration (HL χ2 5.6; P = .23) in the external validation cohort. The validated model was used to create the Web-based AF-TRACK calculator. Conclusion: The proposed risk model provides individualized estimates of the cumulative risk of complications of undergoing the AF ablation track. The AF-TRACK calculator is a validated, easy-to-use, Web-based clinical tool to calibrate the risk-to-benefit ratio of this treatment strategy.

Merged two-way mapping technique: an alternative 3D electroanatomical mapping approach to guide challenging ablation procedures of accessory pathways with bidirectional conduction properties.

BACKGROUND: Catheter ablation of accessory pathways (AP) with bidirectional conduction may be challenging due to issues related to anatomical course or location. OBJECTIVE: We describe an alternative electro-anatomical mapping technique which aims at depicting the entire anatomic course of the AP from the atrial toward the ventricular insertion in order to guide catheter ablation. METHODS: Twenty consecutive patients with confirmed bidirectional AP conduction and at least one previous ablation procedure or para-Hisian location were included. 3-D electro-anatomical mapping was used to depict the merged 10-ms isochrone area of maximum early activation of both the ventricular and atrial signals during sinus rhythm and ventricular pacing/orthodromic tachycardia, respectively. Catheter ablation was performed within the depicted earliest isochrone area. RESULTS: Acute bidirectional AP conduction block was achieved in all patients 4.2 ± 1.7 s after the first radiofrequency energy pulse was delivered, without reconnection during a 30 ± 10 min post-ablation observation time. No procedural complications were seen. After a mean follow-up period of 9 ± 7 months (range 3 to 16), no recurrences were documented. CONCLUSION: This merged two-way mapping technique is a safe, efficient, and effective technique for ablation of APs with bidirectional conduction.

Integration of imaging and circulating biomarkers in heart failure: a consensus document by the Biomarkers and Imaging Study Groups of the Heart Failure Association of the European Society of Cardiology.

Circulating biomarkers and imaging techniques provide independent and complementary information to guide management of heart failure (HF). This consensus document by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) presents current evidence-based indications relevant to integration of imaging techniques and biomarkers in HF. The document first focuses on application of circulating biomarkers together with imaging findings, in the broad domains of screening, diagnosis, risk stratification, guidance of treatment and monitoring, and then discusses specific challenging settings. In each section we crystallize clinically relevant recommendations and identify directions for future research. The target readership of this document includes cardiologists, internal medicine specialists and other clinicians dealing with HF patients.

Atrioventricular Node Ablation to Enhance Resynchronization Therapy Response in a Patient With Complete Atrioventricular Block.

Up to one-third of patients who undergo cardiac resynchronization therapy do not obtain clinical benefit. A systematic approach can identify treatable causes in many nonresponding patients. We present a case of nonresponse to cardiac resynchronization therapy that resolved by ablation of the atrioventricular node in a patient with complete atrioventricular block. (Level of Difficulty: Advanced.).

Reduction in new cardiac electronic device implantations in Catalonia during COVID-19.

AIMS: During the COVID-19 pandemic, concern regarding its effect on the management of non-communicable diseases has been raised. However, there are no data on the impact on cardiac implantable electronic devices (CIED) implantation rates. We aimed to determine the impact of SARS-CoV2 on the monthly incidence rates and type of pacemaker (PM) and implantable cardiac defibrillator (ICD) implantations in Catalonia before and after the declaration of the state of alarm in Spain on 14 March 2020. METHODS AND RESULTS: Data on new CIED implantations for 2017-20 were prospectively collected by nine hospitals in Catalonia. A mixed model with random intercepts corrected for time was used to estimate the change in monthly CIED implantations. Compared to the pre-COVID-19 period, an absolute decrease of 56.5% was observed (54.7% in PM and 63.7% in ICD) in CIED implantation rates. Total CIED implantations for 2017-19 and January and February 2020 was 250/month (>195 PM and >55 ICD), decreasing to 207 (161 PM and 46 ICD) in March and 131 (108 PM and 23 ICD) in April 2020. In April 2020, there was a significant fall of 185.25 CIED implantations compared to 2018 [95% confidence interval (CI) 129.6-240.9; P < 0.001] and of 188 CIED compared to 2019 (95% CI 132.3-243.7; P < 0.001). No significant differences in the type of PM or ICD were observed, nor in the indication for primary or secondary prevention. CONCLUSIONS: During the first wave of the COVID-19 pandemic, a substantial decrease in CIED implantations was observed in Catalonia. Our findings call for measures to avoid long-term social impact.

Previously Undetected Obstructive Sleep Apnea in Patients With New-Onset Atrial Fibrillation.

Obstructive sleep apnea-hypopnea syndrome (OSA) compromises the efficacy of atrial fibrillation (AF) control strategies. Continuous positive airway pressure (CPAP) may ameliorate arrhythmia control especially in early AF stages (new-onset AF). We investigated a practical screening strategy to determine the likelihood of CPAP indication in new-onset AF patients. Seventy-seven consecutive patients with new-onset (<1 month) AF were prospectively evaluated. Of them, 4 were excluded due to previously diagnosed OSA. The remaining 73 (68% persistent AF) fulfilled the Epworth, Berlin and STOP-BANG questionnaires, an ambulatory polysomnography being performed thereafter in all them in order to determine the apnea-hipopnea index (AHI). CPAP was indicated following conventional criteria. The variables associated with the diagnosis of OSA, with the AHI value and with CPAP indication were investigated by means of descriptive, univariate and multivariate analysis. The prevalence of OSA of any degree and CPAP indication was 82% and 37%, respectively. The variables associated (p < 0.05) with a higher AHI were male gender, body mass index, obesity, hypertension, and high-risk scoring at the Berlin and STOP-BANG questionnaires. In the multivariate analysis, the STOP-BANG scoring proved superior to conventional risk factors and became the only variable predicting CPAP indication (odds ratio 4.5 [1.9 to 10.6]; p = 0.01), an optimized cutoff value of ≥4 being newly established (sensitivity/specificity 76/65%). In conclusion, in patients referred with new-onset AF we documented a high risk of OSA and of need for CPAP. A STOP-BANG scoring of ≥4 in our population was a practical screening alternative to direct polysomnography in this setting.

Magnetic Resonance Imaging-Guided Fibrosis Ablation for the Treatment of Atrial Fibrillation: The ALICIA Trial.

BACKGROUND: Myocardial fibrosis is key for atrial fibrillation maintenance. We aimed to test the efficacy of ablating cardiac magnetic resonance (CMR)-detected atrial fibrosis plus pulmonary vein isolation (PVI). METHODS: This was an open-label, parallel-group, randomized, controlled trial. Patients with symptomatic drug-refractory atrial fibrillation (paroxysmal and persistent) undergoing first or repeat ablation were randomized in a 1:1 basis to receive PVI plus CMR-guided fibrosis ablation (CMR group) or PVI alone (PVI-alone group). The primary end point was the rate of recurrence (>30 seconds) at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6, and 12 months. The analysis was conducted by intention-to-treat. RESULTS: In total, 155 patients (71% male, age 59±10, CHA2DS2-VASc 1.3±1.1, 54% paroxysmal atrial fibrillation) were allocated to the PVI-alone group (N=76) or CMR group (N=79). First ablation was performed in 80% and 71% of patients in the PVI-alone and CMR groups, respectively. The mean atrial fibrosis burden was 12% (only ≈50% of patients had fibrosis outside the pulmonary vein area). One hundred percent and 99% of patients received the assigned intervention in the PVI-alone and CMR group, respectively. The primary outcome was achieved in 21 patients (27.6%) in the PVI-alone group and 22 patients (27.8%) in the CMR group (odds ratio: 1.01 [95% CI, 0.50-2.04]; P=0.976). There were no differences in the rate of adverse events (3 in the CMR group and 2 in the PVI-alone group; P=0.68). CONCLUSIONS: A pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing atrial fibrillation ablation with low fibrosis burden. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02698631.

Diagnosis-to-ablation time in atrial fibrillation: A modifiable factor relevant to clinical outcome.

INTRODUCTION: Recurrences after atrial fibrillation (AF) ablation are still common. Among the reported clinical and imaging predictors of recurrences, diagnosis-to-ablation time (DAT) has been defined as a predictor of ablation outcome in single-center studies. We aimed to validate DAT in a multicenter real-life cohort. METHODS: This was a multicenter study including consecutive patients undergoing first paroxysmal and persistent AF ablation with radiofrequency or cryoballoon catheters during 2013. Cox proportional hazard regression models were performed to identify predictors of recurrence. RESULTS: In total, 309 patients were included across nine centers (71% men, 57 ± 10 years old, 46% with hypertension, and 66% with CHA2 DS2 -VASc ≤ 1). Most patients had paroxysmal AF (67%) and underwent radiofrequency ablation (68%) with a median DAT of 51 (43) months. Patients with DAT ≤ 1 year (16.6%) were less likely to have repeat procedures (4% vs 18%; P = .017). The adjusted proportional hazards Cox model identified hypertension (P = .005), heart failure (P = .011), nonparoxysmal AF (P = .038), DAT > 1 year (P = .007), and LA diameter (P = .026) as independent predictors for AF recurrence. DAT > 1 year was the only modifiable factor independently associated with recurrence (HR 4.2 [95% CI, 1.5-11.9]) CONCLUSION: Diagnosis-to-ablation time is a modifiable factor independently associated with recurrent arrhythmia and repeat ablation after first AF ablation. An early intervention strategy during the first year from AF diagnosis might improve outcomes.

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.

Contemporary Yield of 24-hour Holter Monitoring: Role of Inter-Atrial Block Recognition.

BACKGROUND: The diagnostic yield of 24-hour ECG Holter monitoring (24H) is currently overcome by alternative ECG monitoring techniquesand it needs to be optimized. The recognition of inter-atrial block (IAB) has emerged as a reliable indicator of patients at risk of atrial fibrillation relapses, and its role enhancing the yield of 24H is yet to be determined. We hypothesized that a presumably low yield of 24H may be ameliorated by means of incorporating the assessment for IAB. METHODS: We retrospectively analyzed 1017 consecutive 24H registers performed in a Multidisciplinary Integrated Health Care Institution, in which a restrictive definition of diagnostic 24H findings was used. A univariate and multivariate regression analysis served to determine the variables associated with a higher 24H's yield, including the requesting medical specialty, type of indication and a number of clinical, echocardiographic and ECG variables, including IAB. RESULTS: The mean age of our population was 62 ± 17 years (55% males). The majority of 24H were indicated from the Cardiology department (48%). The overall yield was 12.8%, higher for the assessment of the integrity of the electrical conduction system (26.1%) and poorer for the assessment of syncope (3.2%) and cryptogenic stroke (4.6%). The variables associated with higher diagnostic performance were indication from Cardiology (p < 0.001), IAB (p = 0.004), structural heart disease (p = 0.008) and chronic renal failure (p = 0.009). Patients ≤ 50 years old only retrieved a 7% yield. In the multivariate analysis, indication from Cardiology and IAB remained significant predictors of higher 24H's yield. In a secondary analysis including echocardiographic data, only identification of IAB remained statistically significant. CONCLUSIONS: The recognition of IAB and the type of indication are major determinants of a higher 24H's diagnostic yield and may help to optimize the selection of candidates.

Incidence and predictors of new-onset atrioventricular block requiring pacemaker implantation after sutureless aortic valve replacement.

OBJECTIVES: In high-risk patients with severe aortic stenosis, aortic valve replacement (AVR) with a sutureless Perceval prosthesis (SU-AVR) can be performed instead of conventional AVR or transcatheter aortic valve implantation. Little data are available regarding postoperative conduction disorders after SU-AVR. We aimed to determine the incidence and predictors of new-onset complete atrioventricular block (NO-AVB) requiring permanent cardiac stimulation following SU-AVR. METHODS: We studied consecutive patients who underwent SU-AVR between 2013 and 2015. Early patients underwent partial aortic decalcification and subannular valve implantation (standard technique), while later patients underwent complete/symmetrical decalcification and intra-annular valve deployment (modified technique). Predictive baseline and procedural variables and electrocardiographic parameters were identified using a logistic regression model. RESULTS: We included 140 patients (mean age, 78 ± 6.5 years; mean Log EuroSCORE II, 8.9 ± 10%; 28.6% concomitant myocardial revascularization). The most common postoperative conduction disturbances were LBBB (25%), NO-AVB (12.1%) and first-degree atrioventricular block (AVB) (7.9%). The incidence of NO-AVB was 61% lower with the modified versus the standard technique (P= 0.04). NO-AVB predominantly appeared within 24 h post-surgery, occurring >24 h post-surgery in only 2 patients (both with baseline conduction defects). Independent predictors of NO-AVB included baseline left QRS axis deviation (LaQD; P= 0.03), first-degree AVB (P< 0.01) and standard surgical technique (P= 0.02). CONCLUSIONS: NO-AVB is a frequent complication following SU-AVR, and its incidence strongly depends on the surgical technique. Baseline first-degree AVB and LaQD independently predict NO-AVB and should be considered when deciding the duration of postoperative electrocardiographic monitoring.