New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways.

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

Long QT syndrome and left ventricular non-compaction in a family with KCNH2 mutation: A case report.

Background: Left ventricular non-compaction (LVNC) is an abnormality of the myocardium, characterized by prominent left ventricular trabeculae and deep inter-trabecular recesses. Long QT syndrome (LQTS) is a cardiac ion channelopathy presenting with a prolonged QT interval on resting electrocardiogram and is associated with increased susceptibility to sudden death. The association between LVNC and LQTS is uncommon. Case presentation: We report an Italian family with a novel pathogenic KCNH2 variant who presented with clinical features of LVNC and LQTS. The proband came to our attention after two syncopal episodes without prodromal symptoms. His ECG showed QTc prolongation and deep T wave inversion in anterior leads, and the echocardiogram fulfilled LVNC criteria. After that, also his sister was found to have LQTS and LVNC, while his father only presented LQTS. Conclusions: Physicians should be aware of the possible association between LVNC and LQTS. Even if this association is rare, patients with LVNC should be investigated for LQTS to prevent possible severe or even life-threatening arrhythmic episodes.

Impact of coronavirus disease 19 outbreak on arrhythmic events and mortality among implantable cardioverter defibrillator patients followed up by remote monitoring: a single center study from the Veneto region of Italy.

BACKGROUND: The 2020 severe acute respiratory syndrome coronavirus 2 outbreak entailed reduced availability of traditional (in-office) cardiology consultations. Remote monitoring is an alternative way of caring that may potentially mitigate the negative effects of the epidemic to the care of cardiovascular diseases. We evaluated the outcome of implantable cardioverter defibrillator (ICD) carriers followed up remotely in 2020 (epidemic period) versus 2019 (control). METHODS: We included all patients with an ICD who remained remotely monitored from the beginning to the end of each year. The combined end point included: new-onset atrial fibrillation; sustained ventricular tachycardia >170 bpm without ICD intervention; appropriate ICD intervention (either shock or antitachycardia pacing); any-cause death. Multiple events in the same patients were counted separately if occurring ≥48 h apart. RESULTS: In 2020, 52 end points occurred in 37 of 366 (10%) ICD carriers [0.14/patient (95% confidence interval [CI] = 0.11-0.19)] versus 43 end points in 32 of 325 (10%) ICD carriers in 2019 [0.13/patient (95% CI = 0.10-0.18) P  = 0.75]. There was no difference between the distribution of any individual end point in 2020 versus 2019 although a nonsignificant mortality increase was observed (from 2.8% to 4.6%, P  = 0.19). The lowest weekly event rate occurred during the national lock down in spring 2020 but a similar trend occurred also in 2019 suggesting that the effect may not be linked to social distancing measures. CONCLUSIONS: We did not observe an increase in a combined end point including arrhythmic events and mortality in ICD carriers who were remotely monitored in 2020, compared to 2019, despite the negative impact of the coronavirus disease 2019 outbreak on the healthcare system.

Added Value of CCTA-Derived Features to Predict MACEs in Stable Patients Undergoing Coronary Computed Tomography.

Clinical evidence has emphasized the importance of coronary plaques' characteristics, rather than lumen stenosis, for the outcome of cardiovascular events. Coronary computed tomographic angiography (CCTA) has a well-established role as a non-invasive tool for assessing plaques. The aim of this study was to compare clinical characteristics and CCTA-derived information of stable patients with non-severe plaques in predicting major adverse cardiac events (MACEs) during follow-up. We retrospectively selected 371 patients (64% male) who underwent CCTA in our center from March 2016 to January 2021 with Coronary Artery Disease­Reporting and Data System (CAD-RADS) 0 to 3. Of those, 198 patients (53% male) had CAD-RADS 0 to 1. Among them, 183 (49%) had normal pericoronary fat attenuation index (pFAI), while 15 (60% male) had pFAI ≥ 70.1 Hounsfield unit (HU). The remaining 173 patients (76% male) had CAD-RADS 2 to 3 and were divided into patients with at least one low attenuation plaque (LAP) and patients without LAPs (n-LAP). Compared to n-LAP, patients with LAPs had higher pFAI (p = 0.005) and had more plaques than patients with n-LAP. Presence of LAPs was significantly higher in elderly (p < 0.001), males (p < 0.001) and patients with traditional risk factors (hypertension p = 0.0001, hyperlipemia p = 0.0003, smoking p = 0.0003, diabetes p = <0.0001, familiarity p = 0.0007). Among patients with CAD-RADS 0 to 1, the ones with pFAI ≥ 70.1 HU were more often hyperlipidemic (p = 0.05) and smokers (p = 0.007). Follow-up (25,4 months, range: 17.6−39.2 months) demonstrated that LAP and pFAI ≥ 70.1 significantly and independently (p = 0.04) predisposed to outcomes (overall mortality and interventional procedures). There is an added value of CCTA-derived features in stratifying cardiovascular risk in low- to intermediate-risk patients with non-severe, non-calcified coronary plaques. This is of utmost clinical relevance as it is possible to identify a subset of patients with increased risk who need strengthening in therapeutic management and closer follow-up even in the absence of severe CAD. Further studies are needed to evaluate the effect of medical treatments on pericoronary inflammation and plaque composition.

Thyroid dysfunction on the heart: clinical effects, prognostic impact and management strategies.

Thyroid hormones have a considerable influence on cardiac function and structure. There are direct and indirect effects of thyroid hormone on the cardiovascular system, which are prominent in both hypothyroidism and hyperthyroidism. In this review, we discuss how thyroid dysfunction impacts cardiovascular pathophysiology and the underlying molecular mechanisms.

The valuable interaction among cardiac surgeon and electrophysiologist for transvenous rotational mechanical lead extraction.

BACKGROUND: Recent studies have shown that Evolution RL bidirectional rotational mechanical sheath (Cook Medical, USA) is an effective and safe technique for transvenous lead extraction (TLE). We reported our experience with the bidirectional rotational mechanical tools using a multidisciplinary approach highlighting the value of a joint cardiac surgeon and electrophysiologist collaboration. METHODS: The study population comprised 84 patients (77% male; mean age 65 ± 18 years) undergoing TLE. After a multidisciplinary evaluation, a combined procedure was considered. RESULTS: The main indication for TLE was infection in 54 cases (64%). Overall, 152 leads were extracted with a mean implant duration of 94 ± 63 months (range 12-421). Complete procedural success rate, clinical success rate, and lead removal with clinical success rate were 91.6% (77/84), 97.6% (82/84), and 98.6% (150/152), respectively. Eighteen combined procedures were performed in 12 patients (14%), such as "hybrid approach" (n = 2) or TLE concomitant to: 1) transcatheter aspiration procedure for large vegetation (n = 8); 2) left ventricular assistance device implantation as bridge to cardiac transplantation (n = 1); 3) permanent pacing with epicardial leads (n = 6); 4) tricuspid valve replacement (n = 1). One major complication (1.2%) and 11 (13%) minor complications were encountered. No injury to the superior vena cava occurred and no procedure-related deaths were reported. During a mean time follow-up of 21 ± 18 months, 17 patients (20%) died. They were more often diabetics (p = .02), and they underwent TLE more often for infection (p = .004). CONCLUSIONS: Our results support the finding that excellent outcomes can be achieved in performing TLE of chronically implanted leads by using the Evolution RL bidirectional rotational mechanical sheath and a multidisciplinary team approach involving both electrophysiologist and cardiac surgeon as first line operators.

Surgical management of failing Fontan circulation: results from 30 cases with 285 patient-years follow-up.

OBJECTIVES: Fontan patients are known to suffer from clinical attrition over the years, which has been characterized as Fontan failure. We sought to evaluate the clinical outcomes of such Fontan patients undergoing surgical management in a 25-year, single-centre experience. METHODS: A retrospective single-centre analysis of patients undergoing surgical treatment for failing Fontan between 1995 and 2020, including any reoperations when ventricular function was preserved, or a heart transplant (HTx), when ventricular contractility was impaired. We analysed survival, indications for surgery and early and late complication rates. RESULTS: We collected 30 patients (mean age 24.7 years) who required surgery after a mean time of 19.3 years from the original Fontan procedure: Fontan conversion in 21 (70%, extracardiac conduit in 19, lateral tunnel in 2), a HTx in 4 (13.3%) and other reoperations in 5 (16.7%). The most common indications for surgery were tachyarrhythmias (63.3%) and severe right atrial dilatation (63.3%). Overall survival at the 1-, 5-, 10- and 20-year follow-up examinations were 75.9% [95% confidence interval (CI): 91.4-60.4%], 75.9% (95% CI: 91.4-60.4%), 70% (95% CI: 78-52%) and 70% (95% CI: 78-52%), respectively. The most frequent complications were postoperative tachyarrhythmias (50%) and late Fontan-associated liver disease (56.5%). HTx and Fontan conversion provided comparably good outcomes compared to other reoperations (P = 0.022). CONCLUSIONS: Surgery for failing Fontan can be performed effectively with overall good long-term survival. However, early and late morbidities are still a significant burden. Because other reoperations performed when patients presented with contraindications for a HTx have carried high mortality, close clinical follow-up is mandatory, and an earlier indication for Fontan conversion or a HTx is advisable to optimize outcomes.

Feasibility and Role of Right Ventricular Stress Echocardiography in Adult Patients.

BACKGROUND: The great technological advancements in the field of echocardiography have led to applications of stress echocardiography (SE) in almost all diagnostic fields of cardiology, from ischemic heart disease to valvular heart disease and diastolic function. However, the assessment of the right ventricle (RV) in general, and in particular in regard to the contractile reserve of the RV, is an area that has not been previously explored. We, therefore, propose a study to investigate the potential use of SE for the assessment of RV function in adult patients. AIMS AND OBJECTIVES: The primary aim is to evaluate the feasibility of right ventricular SE. The secondary aim is to assess right ventricular contractile reserve. MATHERIALS AND METHODS: Eighty-one patients undergoing a physical or dobutamine stress echocardiogram for cardiovascular risk stratification or chest pain were the subject of the study. An exercise leg cycle using a standard WHO protocol was used to simultaneously assess the right and left ventricular global and regional function as well as acquiring Doppler data. Whereas the patient had limitations in mobility, a dobutamine SE was be performed. We evaluated the average values of tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), S-wave, systolic pulmonary artery pressure (sPAP), and right ventricle global longitudinal (free wall) strain (RVGLS) during baseline and at the peak of the effort. RV contractile reserve was defined as the change in RVGLS from rest to peak exercise. We also assessed the reproducibility of these measurements between two different expert operators (blind analysis). RESULTS: At least 3 over 5 RV function parameters were measurable both during baseline and at the peak of the effort in 95% of patients, while all 5 parameters in 65% of our population, demonstrating an excellent feasibility. All RV-studied variables showed a statistically significant increase (P < 0.001) at peak compared to the baseline. The average percentage increases at peak were 31.1% for TAPSE, 24.8% for FAC, 50.6% for S-wave, 55.2% for PAPS, and 39.8% for RV strain. The reproducibility between operators at baseline and peak was excellent. Our study demonstrates that TAPSE, FAC, and S-wave are highly feasible at rest and at peak, while TAPSE, S-wave, and sPAP are the most reliable measurements during RV stress echo. CONCLUSION: RVGLS is useful in the assessment of RV contractile reserve in patients with good acoustic window. Further studies are needed to evaluate the impact of contrast echocardiography in improving RV contractile reserve assessment during SE.

Italian Cardiological Guidelines (COCIS) for Competitive Sport Eligibility in athletes with heart disease: update 2020.

Since 1989, SIC Sport and a FMSI, in partnership with leading Italian Cardiological Scientific Associations (ANCE, ANMCO and SIC) have produced Cardiological Guidelines for Completive Sports Eligibility for athletes with heart disease (COCIS -- 1989, 1995, 2003, 2009 and 2017). The English version of the Italian Cardiological Guidelines for Competitive Sports Eligibility for athletes with heart disease was published in 2013 in this Journal. This publication is an update with respect to the document previously published in English in 2013. It includes the principal innovations that have emerged over recent years, and is divided into five main chapters: arrhythmias, ion channel disorders, congenital heart diseases, acquired valve diseases, cardiomyopathies, myocarditis and pericarditis and ischemic heart disease. Wherever no new data have been introduced with respect to the 2013 publication, please refer to the previous version. This document is intended to complement recent European and American guidelines but an important difference should be noted. The European and American guidelines indicate good practice for people engaging in physical activity at various levels, not only at the competitive level. In contrast, the COCIS guidelines refer specifically to competitive athletes in various sports including those with high cardiovascular stress. This explains why Italian guidelines are more restrictive than European and USA ones. COCIS guidelines address 'sports doctors' who, in Italy, must certify fitness to participate in competitive sports. In Italy, this certificate is essential for participating in any competition.

Atrial fibrillation after orthotopic heart transplantatation: Pathophysiology and clinical impact.

BACKGROUND: Atrial fibrillation (AF) is a well-established post-cardiac surgery complication. Orthotopic heart transplantation (OHT) represents a peculiar condition where surgical thoracic veins isolation and autonomic denervation occur. This study aims at investigating AF incidence in OHT in order to define its risk factors and to evaluate its prognostic impact. METHODS: 278 patients affected by OHT were recruited in our Cardiac Surgery Unit and retrospectively analyzed, using clinical, surgical and instrumental data. RESULTS: The patients cohort showed 45 post-operative (16.5%) and 20 late AF cases (7.2%). Only paroxysmal AF episodes were observed. Elderly donors and acute rejection resulted as risk factors in patients with post-operative AF episodes, who presented higher all-cause mortality at 11 years post-OHT (p < 0.001, Kaplan Meier analysis). The majority of late AF episodes occurred during hospitalization, due to renal failure or infections and more frequently in male patients; no significant correlation was observed with acute or chronic rejection or other characteristics. CONCLUSION: Pulmonary vein isolation and vagal denervation lead to low AF incidence in OHT recipients. Acute rejection and graft status are the main risk factors for post-operative AF episodes, while other systemic conditions act as late AF triggers. The occurrence of AF episodes is associated with poor outcome and AF should be considered as a marker of clinical frailty.

'Hot phase' clinical presentation in arrhythmogenic cardiomyopathy.

AIMS: The aim of this study is to evaluate the clinical features of patients affected by arrhythmogenic cardiomyopathy (AC), presenting with chest pain and myocardial enzyme release in the setting of normal coronary arteries ('hot phase'). METHODS AND RESULTS: We collected detailed anamnestic, clinical, instrumental, genetic, and histopathological findings as well as follow-up data in a series of AC patients who experienced a hot phase. A total of 23 subjects (12 males, mean age at the first episode 27 ± 16 years) were identified among 560 AC probands and family members (5%). At first episode, 10 patients (43%) already fulfilled AC diagnostic criteria. Twelve-lead electrocardiogram recorded during symptoms showed ST-segment elevation in 11 patients (48%). Endomyocardial biopsy was performed in 11 patients, 8 of them during the acute phase showing histologic evidence of virus-negative myocarditis in 88%. Cardiac magnetic resonance was performed in 21 patients, 12 of them during the acute phase; oedema and/or hyperaemia were detected in 7 (58%) and late gadolinium enhancement in 11 (92%). At the end of follow-up (mean 17 years, range 1-32), 12 additional patients achieved an AC diagnosis. Genetic testing was positive in 77% of cases and pathogenic mutations in desmoplakin gene were the most frequent. No patient complained of sustained ventricular arrhythmias or died suddenly during the 'hot phase'. CONCLUSION: 'Hot phase' represents an uncommon clinical presentation of AC, which often occurs in paediatric patients and carriers of desmoplakin gene mutations. Tissue characterization, family history, and genetic test represent fundamental diagnostic tools for differential diagnosis.

Anatomical Predictors of Pacemaker Dependency After Transcatheter Aortic Valve Replacement.

BACKGROUND: Conduction disturbances after transcatheter aortic valve replacement (TAVR) are often transient. Limited data exist on anatomic factors predisposing to pacemaker dependency after TAVR. We sought to assess the rate and the possible predictors of pacemaker dependency after TAVR. METHODS: Consecutive patients undergoing pacemaker implantation up to 30 days after TAVR between May 2014 and September 2019 were included. Baseline electrocardiographic, computed tomography, and procedural characteristics were collected, including valve implantation depth and membranous septum length, an anatomic surrogate of the distance between the aortic annulus and the His bundle. Pacemaker dependency at 30 days and 1 year and all-cause mortality during follow-up were evaluated. RESULTS: Of 728 TAVR patients, 112 (53.5% men; median age, 81 years) underwent pacemaker implantation after TAVR. Of these, 44.6% (50 of 112) were pacemaker dependent at 30 days and 46.7% (36 of 77) at 1 year. By multivariate analysis, independent predictors of 30-day pacemaker dependency included left ventricular outflow tract calcifications under the left coronary cusp (odds ratio, 5.69 [95% CI, 1.45-22.31]; P=0.013) and a difference between membranous septum length and implantation depth (ΔMSID) ≥3 mm (odds ratio, 7.58 [95% CI, 2.07-27.78]; P=0.002). Conversely, membranous septum length and implantation depth alone were not associated with pacemaker dependency (odds ratio, 0.79 [95% CI, 0.60-1.05]; P=0.11 and odds ratio, 1.11 [95% CI, 0.99-1.24]; P=0.08). At a median follow-up of 28.1 (11.7-48.6) months, pacemaker-dependent patients did not show a worse survival (P=0.26). CONCLUSIONS: Less than half of the patients undergoing pacemaker implantation after TAVR are pacemaker-dependent at midterm follow-up. ΔMSID ≥3 mm and the presence of left ventricular outflow tract calcifications under the left coronary cusp, but not membranous septum length nor implantation depth alone, are predictive of long-term pacemaker dependency after TAVR, thus influencing device selection and programming.

Evaluation of mexiletine effect on conduction delay and bradyarrhythmic complications in patients with myotonic dystrophy type 1 over long-term follow-up.

BACKGROUND: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized by progressive cardiac conduction impairment, arrhythmias, and sudden death. Mexiletine is a sodium channel blocker drug used by patients with DM1 for treatment of myotonia, even though definitive proof of its safety over long-term follow-up is lacking. OBJECTIVE: The purpose of this study was to assess the impact of mexiletine for treatment of neurological symptoms on the composite endpoint of significant electrocardiogram modification (new onset or worsening of atrioventricular [AV] or intraventricular conduction delay) and bradyarrhythmic complications requiring pacemaker (PM) implantation (advanced AV block, symptomatic sinus pause >3 seconds). METHODS: This retrospective longitudinal study included a series of consecutive patients with genetically confirmed DM1 evaluated at our neurology and cardiology clinics from January 1, 2011, to January 1, 2020, who received mexiletine 200 mg twice daily. Patients with a PM, implantable cardioverter-defibrillator, or severe conduction abnormality (PQ interval ≥230 ms, complete bundle branch block, or atrial fibrillation) at enrollment were excluded. RESULTS: The study comprised 18 mexiletine-treated patients and 68 mexiletine-free controls. Over median follow-up of 53 months, the endpoint was reached by 4 (22%) mexiletine-treated patients and 23 (33%) non-mexiletine-treated patients (log-rank P = .45). In 3 non-mexiletine-treated patients, bradyarrhythmic complications requiring PM implantation were observed. At univariable analysis, only the presence of mild conduction delay (first-degree AV block with PQ interval <230 ms or left anterior fascicular block) at baseline predicted the endpoint (hazard ratio 2.22; 95% confidence interval 1.04-4.76). CONCLUSION: Mexiletine 200 mg twice daily is safe in patients with DM1 and no severe conduction abnormality.

Clinical predictors of pocket hematoma after cardiac device implantation and replacement.

AIMS: Pocket hematoma is a common complication of cardiac implantable electronic device (CIED) procedures. the aim of the study was to research the clinical factors associated with pocket hematoma formation after CIED implantation or replacement and to identify the best perioperative antithrombotic management. METHODS: We retrospectively analyzed 500 consecutive patients who underwent to CIED implantation or replacement at our center from November 2014. RESULTS: Among our population, 206 patients (41.2%) were on anticoagulant therapy at the time of the intervention: 68 (13.6%) on ongoing Warfarin; 111 (22.2%) on low-molecular-weight heparin (LMWH); and 27 (5.4%) on ongoing direct oral anticoagulants. Antiplatelet therapy was present in 262 (52.4%) patients: in particular, 50 (10%) were on dual antiplatelet therapy, 64 (12.8%) were on single antiplatelet therapy and anticoagulant therapy, whereas 12 (2.4%) were on anticoagulant with dual antiplatelet therapy.Incidence of pocket hematoma after CIEDs implantation was of 4.6%. Considering the different perioperative anticoagulant strategies, patients on LMWH presented the higher hematoma rate [11/100 patients (11.0%), P < 0.001]. At the multivariate analysis, anticoagulant with dual antiplatelet therapy (P = 0.021, OR 6.3, IC 1.3-30.8), left ventricular ejection fraction (LVEF) less than 30% (P < 0.001, OR 7.4, IC 2.7-20.4), and use of LMWH (P = 0.008, OR 3.8, IC 1.4-10.6) resulted the strongest predictors of pocket hematoma (Hosmer test = 0.899).Considering replacement procedures, incidence of pocket hematoma was of 4.4%. The incidence was higher after ICD/CRT-D replacement. The majority of pocket hematoma occurred in patients with mechanical valve prosthesis (3/4 cases, 75%, P < 0.001). CONCLUSION: The use of LMWH and a low LVEF expose patients to a higher risk of pocket hematoma after CIED procedures. Anticoagulant with dual antiplatelet therapy and LMWH should be avoided.

First-degree atrioventricular block on basal electrocardiogram predicts future arrhythmic events in patients with Brugada syndrome: a long-term follow-up study from the Veneto region of Northeastern Italy.

AIMS: This study was designed to assess the prognostic value of clinical and electrocardiographic parameters in Brugada syndrome (BrS). METHODS AND RESULTS: The study population included 272 consecutive patients (82% males; mean age 43 ± 12 years), with either a spontaneous (n = 137, 50%) or drug-induced (n = 135, 50%) Type 1 Brugada electrocardiogram (ECG) pattern. The study combined endpoint included sudden cardiac death (SCD), cardiac arrest, and appropriate intervention of implantable cardioverter-defibrillator (ICD). A first-degree atrioventricular (AV) block (PR = 219 ± 17 ms) was documented at basal ECG in 45 patients (16.5%); 27 of these underwent an electrophysiological study with recording in 21 (78%) of an HV interval ≥55 ms (mean 61 ± 3 ms). Patients with first-degree AV block had a wider QRS complex (median 110 ms vs. 95 ms; P = 0.04) and more often showed a left anterior hemiblock pattern (n = 13, 29% vs. n = 35, 16%; P = 0.056). During a mean follow-up of 85 ± 55 months, 17 patients (6.3%) experienced ≥1 major arrhythmic events (appropriate ICD intervention, n = 13 and SCD, n = 4). At univariate analysis, the occurrence of major arrhythmic events was significantly associated with a history of syncope or cardiac arrest (P < 0.001), Type 1 ECG pattern (P = 0.04), and first-degree AV block (P < 0.001). Univariate and multivariable predictors of events included a history of syncope or cardiac arrest [hazard ratio (HR) 5.8, 95% confidence interval (95% CI) 2.04-16.5; P < 0.001; and HR 6.68, 95% CI 2.34-19.1; P < 0.001; respectively], a spontaneous Type 1 ECG pattern (HR 1.56, 95% CI 1.03-4.24; P = 0.033; and HR 1.84, 95% CI 1.01-4.29; P = 0.044; respectively) and a first-degree AV block at baseline ECG (HR 3.84, 95% CI 1.47-9.99; P = 0.006; and HR 4.65, 95% CI 2.34-19.1; P = 0.002; respectively). CONCLUSION: Besides a history of cardiac arrest or syncope, first-degree AV block on basal ECG is an independent predictor of malignant arrhythmic events and a stronger marker of arrhythmic risk than a spontaneous 'coved-type' ECG pattern in patients with BrS.

Is the time between first diagnosis of paroxysmal atrial fibrillation and cryoballoon ablation a predictor of efficacy?

AIMS: Cryoablation is an indicated therapy for the treatment of recurrent atrial fibrillation through pulmonary vein isolation; however, the optimal time between first diagnosis of atrial fibrillation and cryoablation is still unknown. We aimed to assess the clinical efficacy and safety of early versus later treatment of patients with paroxysmal atrial fibrillation by cryoablation. METHODS: Five hundred and ten patients underwent atrial fibrillation cryoablation and were prospectively followed for at least 6 months in 43 Italian cardiology centers. The population was divided into two groups according to the time since the first diagnosis of atrial fibrillation until the index cryoablation procedure. An early-treatment group had an elapsed time of 15 months or less from atrial fibrillation diagnosis until cryoablation, and the late-treatment group had an elapsed time of greater than 15 months. During the evaluation, clinical efficacy was defined as atrial fibrillation recurrence outside a landmark 90-day blanking period, and safety was defined as the reporting of all procedure-related complications. RESULTS: In the total cohort, cryoablation was performed after a median of 36 months from the point of the patient diagnosis with drug refractory symptomatic recurrent atrial fibrillation. The early-treatment group was composed of 130 (25%) patients, whereas the late-treatment group had 380 (75%) patients. Both cohorts had similar baseline clinical characteristics. Of 510 patients, 22 had a complication related to the procedure with no difference between the two groups. Multivariable analysis showed that the risk of atrial fibrillation recurrence was significantly higher in the late-treatment group (hazard ratio: 1.77; 95% confidence interval 1.00-3.13) CONCLUSION: In our multicenter observational examination, cryoablation was well tolerated and effective in the treatment of patients with drug refractory symptomatic paroxysmal atrial fibrillation. Reducing the time between diagnosis and ablation brought about a treatment that had a lower risk of atrial fibrillation recurrence with no change in safety.(Italian ClinicalService Project: NCT01007474).