Canadian Cardiovascular Society 2023 Guidelines on the Fitness to Drive.

Cardiovascular conditions are among the most frequent causes of impairment to drive, because they might induce unpredictable mental state alterations via diverse mechanisms like myocardial ischemia, cardiac arrhythmias, and vascular dysfunction. Accordingly, health professionals are often asked to assess patients' fitness to drive (FTD). The Canadian Cardiovascular Society previously published FTD guidelines in 2003-2004; herein, we present updated FTD guidelines. Because there are no randomized trials on FTD, observational studies were used to estimate the risk of driving impairment in each situation, and recommendations made on the basis of Canadian Cardiovascular Society Risk of Harm formula. More restrictive recommendations were made for commercial drivers, who spend longer average times behind the wheel, use larger vehicles, and might transport a larger number of passengers. We provide guidance for individuals with: (1) active coronary artery disease; (2) various forms of valvular heart disease; (3) heart failure, heart transplant, and left ventricular assist device situations; (4) arrhythmia syndromes; (5) implantable devices; (6) syncope history; and (7) congenital heart disease. We suggest appropriate waiting times after cardiac interventions or acute illnesses before driving resumption. When short-term driving cessation is recommended, recommendations are on the basis of expert consensus rather than the Risk of Harm formula because risk elevation is expected to be transient. These recommendations, although not a substitute for clinical judgement or governmental regulations, provide specialists, primary care providers, and allied health professionals with a comprehensive list of a wide range of cardiac conditions, with guidance provided on the basis of the level of risk of impairment, along with recommendations about ability to drive and the suggested duration of restrictions.

Integration of 3D nuclear imaging in 3D mapping system for ventricular tachycardia ablation in patients with implanted devices: Perfusion/voltage retrospective assessment of scar location.

Background: The identification of low-voltage proarrhythmic areas for catheter ablation of scar-mediated ventricular tachycardia (VT) remains challenging. Integration of myocardial perfusion imaging (single-photon emission computed tomography/computed tomography; SPECT/CT) and electroanatomical mapping (EAM) may improve delineation of the arrhythmogenic substrate. Objective: To assess the feasibility of SPECT/CT image integration with voltage maps using the EnSite Precision system (Abbott) in patients undergoing scar-mediated VT ablation. Methods: Patients underwent SPECT/CT imaging prior to left ventricular (LV) EAM with the EnSite Precision mapping system. The SPECT/CT, EAM data, and ablation lesions were retrospectively co-registered in the EnSite Precision system and exported for analysis. Segmental tissue viability scores were calculated based on SPECT/CT perfusion and electrogram bipolar voltage amplitude. Concordance, specificity, and sensitivity between the 2 modalities as well as the impact of SPECT/CT spatial resolution were evaluated. Results: Twenty subjects (95% male, 67 ± 7 years old, left ventricular ejection fraction 36% ± 11%) underwent EAM and SPECT/CT integration. A concordance of 70% was found between EAM and SPECT/CT for identification of cardiac segments as scar vs viable, with EAM showing a 68.5% sensitivity and 76.4% specificity when using SPECT/CT as a gold standard. Projection on low-resolution 3D geometries led to an average decrease of 38% ± 22% of the voltage points used. Conclusion: The study demonstrated the feasibility of integrating SPECT/CT with EAM performed retrospectively for characterization of anatomical substrates during VT ablation procedures.

Importance of genetic testing in unexplained cardiac arrest.

AIMS: Genetic testing is recommended in specific inherited heart diseases but its role remains unclear and it is not currently recommended in unexplained cardiac arrest (UCA). We sought to assess the yield and clinical utility of genetic testing in UCA using whole-exome sequencing (WES). METHODS AND RESULTS: Survivors of UCA requiring external defibrillation were included from the Cardiac Arrest Survivor with Preserved Ejection fraction Registry. Whole-exome sequencing was performed, followed by assessment of rare variants in previously reported cardiovascular disease genes. A total of 228 UCA survivors (mean age at arrest 39 ± 13 years) were included. The majority were males (66%) and of European ancestry (81%). Following advanced clinical testing at baseline, the likely aetiology of cardiac arrest was determined in 21/228 (9%) cases. Whole-exome sequencing identified a pathogenic or likely pathogenic (P/LP) variant in 23/228 (10%) of UCA survivors overall, increasing the proportion of 'explained' cases from 9% only following phenotyping to 18% when combining phenotyping with WES. Notably, 13 (57%) of the 23 P/LP variants identified were located in genes associated with cardiomyopathy, in the absence of a diagnosis of cardiomyopathy at the time of arrest. CONCLUSIONS: Genetic testing identifies a disease-causing variant in 10% of apparent UCA survivors. The majority of disease-causing variants was located in cardiomyopathy-associated genes, highlighting the arrhythmogenic potential of such variants in the absence of an overt cardiomyopathy diagnosis. The present study supports the use of genetic testing including assessment of arrhythmia and cardiomyopathy genes in survivors of UCA.

Canadian Heart Rhythm Society Task Force Report on Physician Training and Maintenance of Competency for Cardiovascular Implantable Electronic Device Therapies: Executive Summary.

Physicians engaged in cardiovascular implantable electronic device (CIED)-related practice come from diverse training backgrounds with variable degrees of CIED implant training. The objective of the Canadian Heart Rhythm Society Task Force on CIED Implant Training was to establish a common structure and content for training programs in CIED implantation, related activities and maintenance of competency. This executive summary presents the essence of the report with key recommendations included, with the complete version made available in a linked supplement. The goals are to ensure that future generations of CIED implanters are better prepared for continuously evolving CIED practice and quality care for all Canadians.

2021 Update on Safety of Magnetic Resonance Imaging: Joint Statement From Canadian Cardiovascular Society/Canadian Society for Cardiovascular Magnetic Resonance/Canadian Heart Rhythm Society.

Magnetic resonance imaging (MRI) is often considered the gold-standard test for characterizing cardiac as well as noncardiac structure and function. However, many patients with cardiac implantable electronic devices (CIEDs) and/or severe renal dysfunction are unable to undergo this test because of safety concerns. In the past 10 years, newer-generation CIEDs and gadolinium-based contrast agents (GBCAs) as well as coordinated care between imaging and heart rhythm device teams have mitigated risk to patients and improved access to MRI at many hospitals. The purpose of this statement is to review published data on safety of MRI in patients with conditional and nonconditional CIEDs in addition to patient risks from older and newer GBCAs. This statement was developed through multidisciplinary collaboration of pan-Canadian experts after a relevant and independent literature search by the Canadian Agency for Drugs and Technologies in Health. All recommendations align with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Key recommendations include: (1) the development of standardized protocols for patients with a CIED undergoing MRI; (2) patients with MRI nonconditional pacemakers and pacemaker dependency should be programmed to asynchronous mode and those with MRI nonconditional transvenous defibrillators should have tachycardia therapies turned off during the scan; and (3) macrocyclic or newer linear GBCAs should be used in preference to older GBCAs because of their better safety profile in patients at higher risk of nephrogenic systemic fibrosis.

Pulmonary Vein Stenosis After Atrial Fibrillation Ablation: Insights From the ADVICE Trial.

BACKGROUND: Pulmonary vein (PV) stenosis is a complication of atrial fibrillation (AF) ablation. The incidence of PV stenosis after routine post-ablation imaging remains unclear and is limited to single-centre studies. Our objective was to determine the incidence and predictors of PV stenosis following circumferential radiofrequency ablation in the multicentre Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) trial. METHODS: Patients with symptomatic AF underwent circumferential radiofrequency ablation in one of 13 trial centres. Computed tomographic (CTA) or magnetic resonance (MRA) angiography was performed before ablation and 90 days after ablation. Two blinded reviewers measured PV diameters and areas. PVs with stenosis were classified as severe (> 70%), moderate (50%-70%), or mild (< 50%). Predictors of PV stenosis were identified by means of multivariable logistic regression. RESULTS: A total of 197 patients (median age 59.5 years, 29.4% women) were included in this substudy. PV stenosis was identified in 41 patients (20.8%) and 47 (8.2%) of 573 ablated PVs. PV stenosis was classified as mild in 42 PVs (7.3%) and moderate in 5 PVs (0.9%). No PVs had severe stenosis. Both cross-sectional area and diameter yielded similar classifications for severity of PV stenosis. Diabetes was associated with a statistically significant increased risk of PV stenosis (OR 4.91, 95% CI 1.45-16.66). CONCLUSIONS: In the first systematic multicentre evaluation of post-ablation PV stenosis, no patient acquired severe PV stenosis. Although the results are encouraging for the safety of AF ablation, 20.8% of patients had mild or moderate PV stenosis, in which the long-term effects are unknown.

Infections Associated with Resterilized Pacemakers and Defibrillators.

BACKGROUND: Access to pacemakers and defibrillators is problematic in places with limited resources. Resterilization and reuse of implantable cardiac devices obtained post mortem from patients in wealthier nations have been undertaken, but uncertainty around the risk of infection is a concern. METHODS: A multinational program was initiated in 1983 to provide tested and resterilized pacemakers and defibrillators to underserved nations; a prospective registry was established in 2003. Patients who received reused devices in this program were matched in a 1:3 ratio with control patients who received new devices implanted in Canada. The primary outcome was infection or device-related death, with mortality from other causes modeled as a competing risk. RESULTS: Resterilized devices were implanted in 1051 patients (mean [±SD] age, 63.2±18.5 years; 43.6% women) in Mexico (36.0%), the Dominican Republic (28.1%), Guatemala (26.6%), and Honduras (9.3%). Overall, 85% received pacemakers and 15% received defibrillators, with one (55.5%), two (38.8%), or three (5.7%) leads. Baseline characteristics did not differ between these patients and the 3153 matched control patients. At 2 years of follow-up, infections had occurred in 21 patients (2.0%) with reused devices and in 38 (1.2%) with new devices (hazard ratio, 1.66; 95% confidence interval, 0.97 to 2.83; P = 0.06); there were no device-related deaths. The most common implicated pathogens were Staphylococcus aureus and S. epidermidis. CONCLUSIONS: Among patients in underserved countries who received a resterilized and reused pacemaker or defibrillator, the incidence of infection or device-related death at 2 years was 2.0%, an incidence that did not differ significantly from that seen among matched control patients with new devices in Canada.

Atrial fibrillation in young patients.

INTRODUCTION: Atrial fibrillation (AF) is the most frequent arrhythmia worldwide. While mostly seen in elderly, it can also affect young adults (≤ 45 years of age), older adolescent, and children. Areas covered: The aim of this review is to provide an overview of the current management of AF in young patients. Specific issues arise over diagnostic workup as well as antiarrhythmic and anticoagulation therapies. The future management and diagnostic strategies are also discussed. Expert commentary: Management of AF in the young adult is largely extrapolated from adult studies and guidelines. In this population, AF could reveal a genetic pathology (e.g. Brugada, Long QT or Short QT syndromes) or be the initial presentation of a cardiomyopathy. Therefore, thorough workup in the young population to eliminate potential malignant pathology.

Reducing radiation exposure during procedures performed in the electrophysiology laboratory.

INTRODUCTION: Expert societies recently published strong recommendations to reduce the exposure of patients and staff to ionizing radiation (IR) during interventional and electrophysiology (EP) procedures. However, adherence to these guidelines remains difficult and the impact of implementing such recommendations is poorly characterized. METHODS AND RESULTS: We conducted a single-center cohort study to quantify radiation exposure over time in three EP laboratories at the Montreal Heart Institute during 5,546 consecutive procedures from 2012 to 2015 by 11 primary operators. Overall, 2,618 (47.2%) procedures were catheter-based and 2,928 (52.8%) were device interventions. Interventions to reduce radiation exposure included educational initiatives to raise awareness (i.e., limiting cine acquisition, patient position, table height), slower frame rate, lower radiation dose per pulse, collimation, and integration with 3-D mapping systems and/or MediGuide technology. An 85% reduction in IR exposure was observed from 2012 to 2015, with the mean dose-area-product (DAP) decreasing from 7.65 ± 0.05 Gy·cm2 to 1.15 ± 0.04 Gy·cm2 (P < 0.001). This was true for catheter-based procedures (mean DAP 16.99 ± 0.08 to 2.00 ± 0.06 Gy·cm2 , P < 0.001) and device interventions (mean DAP 4.18 ± 0.06 to 0.64 ± 0.05 Gy·cm2 , P < 0.001). The median effective dose of IR recorded per quarter by 282 cervical dosimeters on EP staff decreased from 0.57 (IQR 0.18, 1.03) mSv in 2012 to 0.00 (IQR 0.00, 0.19) mSv in 2015, P < 0.001. CONCLUSION: Enforcing good clinical practices with simple measures and low-dose fluoroscopy settings are highly effective in reducing IR exposure in the EP lab. These promising results should encourage other EP labs to adopt similar protective measures.

Subclavian access using a three-dimensional electromagnetic cardiovascular navigation system: novel approach to access the venous system during device implant procedures.

We report a case in which a novel three-dimensional (3D) electromagnetic cardiovascular navigation system (MediGude™, St. Jude Medical, St. Paul, MN, USA) was used to create a 3D reconstruction of the axillary vein and its anatomic course to guide its successful puncture and cannulation. The MediGuide system's projection accuracy has proved to offer a level of precision that is sufficient to achieve axillary vein access. This highlights its enormous possibilities to obtain 3D venous system reconstruction with minimal fluoroscopic use when performing cardiac or even non-cardiac procedures.

Focal Transcatheter Cryoablation: Is a Four-Minute Application Still Required?

INTRODUCTION: The standard 4-minute application time for transcatheter cryoablation was determined in the 1990s when the system employed less potent chlorofluorocarbon refrigerants. The current refrigerant, nitrous oxide, generates substantially colder temperatures, with a faster cooling rate. METHODS AND RESULTS: We conducted a preclinical study on 32 mongrel dogs with stratified randomization of right atrial, right ventricular, and left ventricular chambers to 2-minute versus 4-minute application times using 8-mm electrode tip cryocatheters (Freezor Max, Medtronic CryoCath LP, Montreal, Canada). Animals were sacrificed one month after the procedure. Three-dimensional morphometric analyses were conducted in a blinded fashion. A total of 193 identified ablation lesions were processed for histological analyses, 102 with 2-minute applications and 91 with 4-minute applications. Ablation lesion surface area (167.8 ± 21.6 mm2 vs. 194.3 ± 22.6 mm2 , P = 0.40), maximum depth (4.4 ± 0.2 mm vs. 4.5 ± 0.2 mm, P = 0.71), and volume (125.7 ± 69.5 mm3 vs. 141.0 ± 83.5 mm3 , P = 0.25) were similar between groups. Overall, 90.2% of ablation lesions in the right atrium were transmural, 45.6% in the right ventricle, and 2.4% in the left ventricle, with no differences between 2-minute and 4-minute application times (P = 0.55). Thrombus was detected on the endocardial surface of 0.0% and 3.3% of ablation lesions created with 2-minute and 4-minute application times, respectively (P = 0.10). CONCLUSION: Single 2-minute and 4-minute application times result in catheter ablation lesions of similar size using the modern cryoablation system with nitrous oxide as a refrigerant. While these findings suggest the potential to reduce the standard 4-minute application time, further studies are required to compare clinical efficacy.

Decreased Mortality With Beta-Blockers in Patients With Heart Failure and Coexisting Atrial Fibrillation: An AF-CHF Substudy.

OBJECTIVES: The impact of beta-blockers on mortality and hospitalizations was assessed in the largest randomized trial of patients with both atrial fibrillation (AF) and heart failure with a reduced ejection fraction (HFrEF): the Atrial Fibrillation-Congestive Heart Failure trial. BACKGROUND: Although beta-blockers are the cornerstone of therapy for HFrEF, a recent patient-level meta-analysis cast doubt on their efficacy in patients with coexisting AF. METHODS: From a total of 1,376 subjects randomized in the AF-CHF trial, those without beta-blockers at baseline were propensity matched to a maximum of 2 exposed patients. All absolute standardized differences after matching were ≤10%. Primary analyses respected the intention-to-treat principle. In on-treatment sensitivity analyses, beta-blocker status was modeled as a time-dependent covariate. RESULTS: Baseline characteristics were comparable among the matched cohorts (mean age 70 ± 11 years, 81% male, and mean left ventricular ejection fraction 27 ± 6%). During a median follow-up of 37 months, beta-blockers were associated with significantly lower all-cause mortality (hazard ratio [HR]: 0.721, 95% confidence interval [CI]: 0.549 to 0.945; p = 0.0180) but not hospitalizations (HR: 0.886; 95% CI: 0.715 to 1.100; p = 0.2232). Similar results were obtained in sensitivity analyses that modeled beta-blockers as a time-dependent variable (HR: 0.668 for all-cause mortality; 95% CI: 0.511 to 0.874; p = 0.0032; HR: 0.814 for hospitalizations; 95% CI: 0.653 to 1.014; p = 0.0658). There were no significant interactions between beta-blockers and patterns (i.e., persistent vs. paroxysmal) or burden of AF with respect to mortality or hospitalizations. CONCLUSIONS: In propensity-matched analyses, beta-blockers were associated with significantly lower mortality but not hospitalizations in patients with HFrEF and AF, irrespective of the pattern or burden of AF. These results support current evidence-based recommendations for beta-blockers in patients with HFrEF, whether or not they have associated AF.

Contact-force-guided vs. contact-force-blinded catheter ablation of typical atrial flutter: a prospective study.

AIMS: It remains unknown whether contact force (CF) sensing technology is of value for cavotricuspid isthmus (CTI) ablation. We prospectively evaluated procedural parameters and outcomes of CF-guided vs. CF-blinded CTI ablation for typical atrial flutter (AFL). METHODS AND RESULTS: A total of 70 consecutive patients (62.5 ± 10.9 years) undergoing CTI ablation for AFL were prospectively enrolled, 35 in CF-blinded and 35 in CF-guided groups. A CF-sensing catheter (power 25-35 W) was used in all. In the CF-guided group, CF target range was 10-25 g, whereas in the CF-blinded group, the operator was blinded to CF. The isthmus was divided into anterior, middle, and posterior segments for region-specific CF analysis. The procedural endpoint of bidirectional isthmus block following a 20-min observation period was achieved in all. A trend towards lower fluoroscopy and procedure duration was observed when the CF-guided group was compared with the CF-blinded group. The total radiofrequency (RF) energy delivery time required to achieve bidirectional block was significantly lower in the CF-guided vs. CF-blinded group [10.0 min (IQR 8.3;15.1) vs. 15.9 min (IQR 9.6;24.7), P= 0.0020], with a significant inverse correlation between CF and total RF delivery time (r = -0.36; P= 0.0027). Mean CF measurements significantly increased from anterior to posterior anatomical zones of CTI in the CF-blinded group (ANOVA P= 0.0466). CONCLUSIONS: Catheter ablation of AFL guided by real-time CF assessment results in a significant reduction in total RF delivery time. Real-time CF measurements facilitate the maintenance of homogenous efficient contact all along the CTI, particularly in the anterior segment where CF is generally lower.

Redefining the Blanking Period After Catheter Ablation for Paroxysmal Atrial Fibrillation: Insights From the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) Trial.

BACKGROUND: Early recurrences (ERs) of atrial tachyarrhythmia are common after catheter ablation of atrial fibrillation. A 3-month blanking period is recommended by current guidelines. This study sought to investigate the significance of ER during the first 3 months post ablation in predicting late recurrences and determine whether it varies according to timing. METHODS AND RESULTS: A total of 401 patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation were followed for 12 months with transtelephonic monitoring in the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) trial. Patients with atrial tachyarrhythmia ≥30 s within the 3-month blanking period were stratified according to the timing of ER. A total of 179 patients (44.6%) experienced their last episode of ER during the first (n=53), second (n=44), or third (n=82) month of the 3-month blanking period. One-year freedom from symptomatic atrial tachyarrhythmia was 77.2% in patients without ER compared with 62.6%, 36.4%, and 7.8% in patients with ER 1, 2, and 3 months post ablation, respectively (P<0.0001). Receiver operating curve analyses revealed a strong correlation between the timing of ER and late recurrence (area under the curve 0.82, P<0.0001). Corresponding hazard ratios for ER during the first, second, and third months were 1.84, 4.45, and 9.64, respectively. CONCLUSIONS: This study validates the use of a blanking period after catheter ablation for paroxysmal atrial fibrillation but calls into question the 90-day cut-off value. In particular, >90% of patients with ER during the third month post ablation experience late recurrence by 1 year. However, pending further study, repeat ablation before 90 days cannot be routinely advocated. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01058980.

Reducing Radiation Exposure During CRT Implant Procedures: Single-Center Experience With Low-Dose Fluoroscopy Settings and a Sensor-Based Navigation System (MediGuide).

INTRODUCTION: Cardiac resynchronization therapy (CRT) implant procedures are often complex and prolonged, resulting in substantial ionizing radiation (IR) exposure to the patient and operator. We assessed the impact of lower-dose fluoroscopy settings and a sensor-based electromagnetic tracking system (MediGuide™, MDG) on reducing IR exposure during CRT implantation. METHODS: A single-center 2-group cohort study was conducted on 348 consecutive patients, age 66.4 ± 11.0 years, 80.4% male, with CRT implant procedures from 2013 to 2015. Patients were arbitrarily assigned to MDG (N = 239) versus no MDG (N = 109) guidance. Lower-dose fluoroscopy settings were adopted in January 2015 (3 instead of 6 fps; 23 instead of 40 nGy/pulse; N = 101). RESULTS: Overall, MDG was associated with an 82.1% reduction in IR exposure (393 µGray·m2 vs. 2191 µGray·m2 , P < 0.001). Lower-dose fluoroscopy resulted in a 59.5% reduction in IR-exposure without MDG (1055 µGray·m2 vs. 2608 µGray·m2 , P < 0.001) and 81.8% reduction with MDG (108 µGray·m2 vs. 595 µGray·m2 , P < 0.001). Low-dose fluoroscopy combined with MDG was associated with a 95.9% lower exposure to IR when compared to standard fluoroscopy without MDG (108 µGray·m2 vs. 2608 µGray·m2 , P < 0.001). Procedures with MDG were shorter (96 minutes vs. 123 minutes, P < 0.001) and associated with a trend towards a higher success rate (94.6% vs. 89.0%, P = 0.062), with fewer coronary sinus cannulation failures (2.1% vs. 6.4%, P = 0.040). CONCLUSION: Low-dose fluoroscopy settings are highly effective (>50%) in reducing IR exposure during CRT implant procedures. When combined with MDG, >95% reduction in IR exposure is achieved. Moreover, MDG shortens procedural duration and may improve acute procedural outcomes.

Predictors of Ventricular Arrhythmias and Sudden Death in a Québec Cohort With Brugada Syndrome.

BACKGROUND: Patients with Brugada syndrome (BrS) are at risk for ventricular arrhythmias (VAs) and sudden death. Identification of high-risk individuals beyond those with syncope or resuscitated sudden death remains a major challenge. METHODS: We assessed the value of clinical, electrophysiological, and electrocardiographic (ECG) features, including depolarization and repolarization metrics, in predicting arrhythmic events and sudden death in consecutive patients with BrS diagnosed between 2002 and 2013 in Quebec, Canada. Qualifying electrocardiograms with the highest type 1 ST-segment elevations were reviewed and analyzed by 2 electrophysiologists who were blinded to clinical history. Survival analyses were adjusted for Firth bias correction and left truncation. RESULTS: A total of 105 patients, 79.8% of whom were men, were diagnosed with BrS at a mean age of 46.2 ± 13.3 years and were followed for 59.6 ± 16.4 months. Ten (9.5%) had a history of cardiac arrest, 37 (35.2%) had syncope, and 7 (6.7%) experienced 20 arrhythmic events during follow-up, all consisting of appropriate ICD therapy (7 antitachycardia pacing; 13 shocks). In multivariate Cox regression analyses, a spontaneous type 1 electrocardiographic (ECG) pattern (hazard ratio [HR], 10.80; 95% confidence interval [CI], 1.03-113.87; P = 0.0476), maximal T peak-end (Tp-e) duration ≥ 100 ms (HR, 29.73; 95% CI, 1.33-666.37; P = 0.0325), and QRS duration in lead V6 > 110 ms (HR, 15.27; 95% CI, 1.07-217.42; P = 0.0443) were independently associated with VAs or aborted sudden cardiac death. CONCLUSIONS: In a multicentre cohort with BrS from Quebec, Canada, VAs and sudden death were independently associated with standard 12-lead ECG features, including a spontaneous type 1 pattern, depolarization (QRS in lead V6), and repolarization (maximal Tp-e duration) criteria.

The dream of near-zero X-rays ablation comes true.

While radiation exposure related to natural sources plays a minor role, medicine-related exposure, represents, to date, a major exposure source. Within this exposure interventional electrophysiology is a relevant contributor. Unfortunately, no safe dose in radioprotection exists, the negative acute and long-term effects of radiological exposure may emerge at any radiation exposure dose. For this reason, patients and physicians should be aware of the risk of radiation exposure and the benefits of the imaging/procedure balanced by the required radiation exposure. Given this, performing a near to zero X-rays transcatheter ablation procedure should therefore represent an aim for all electrophysiological lab. Fortunately, the introduction of electroanatomic mapping systems, have provided the possibility to perform simple and complex electrophysiological procedures avoiding, or at least, limiting the use of radiations. The present review summarizes state of the art of feasibility and safety of the near to zero approach for the main electrophysiological procedures, highlighting the potential health benefits.

ECG Features Associated With Adverse Cardiovascular Outcomes in Patients With Atrial Fibrillation: A Combined AFFIRM and AF-CHF Analysis.

BACKGROUND: The association between standard parameters from a simple 12-lead ECG (i.e., QRS duration and PR, JT, and QT intervals) and adverse cardiovascular outcomes (cardiovascular mortality, all-cause mortality, arrhythmic mortality, and hospitalizations) in patients with a history of atrial fibrillation (AF) has not been previously studied. METHODS AND RESULTS: A pooled analysis of patient-level data was conducted on 5,436 patients, age 68.2 ± 8.3 years, 34.8% female, with a history of non-permanent AF randomized in AFFIRM and AF-CHF trials. The predictive value of ECG parameters was assessed in AF and sinus rhythm in multivariate Cox regression models. During a follow-up of 40.8 ± 16.3 months, QRS duration >120 milliseconds was independently associated with all-cause mortality (hazard ratio [HR] 1.46, 95% confidence interval [CI; 1.21-1.76] in AF, P < 0.001), cardiovascular mortality (HR 1.75, 95% CI (1.15-2.65) in sinus rhythm, P = 0.009; HR 1.56, 95% CI [1.27-1.93] in AF, P < 0.001), arrhythmic mortality (HR 1.90, 95% CI [1.09-3.32] in sinus, P = 0.024; HR 1.84, 95% CI [1.35-2.51] in AF, P < 0.001), any hospitalization (HR 1.15, 95% CI [1.02-1.29] in AF, P = 0.027), and cardiovascular hospitalization (HR 1.21, 95% CI [1.06-1.37] in AF; P = 0.004). Increased PR interval (>200 milliseconds) was independently associated with cardiovascular (HR 1.56, 95% CI [1.11-2.21], P = 0.010) and arrhythmic (HR 1.91, 95% CI [1.14-3.18], P = 0.004) mortality. The JT and QTc intervals were not predictive of mortality. CONCLUSIONS: Simple parameters from standard ECGs are significantly and independently associated with adverse cardiovascular outcomes in patients with a history of AF.

Impact of revascularization in patients with sustained ventricular arrhythmias, prior myocardial infarction, and preserved left ventricular ejection fraction.

BACKGROUND: The impact of revascularization on recurrent ventricular arrhythmias (VAs) in patients with coronary artery disease and relatively preserved left ventricular ejection fraction (LVEF) is unknown. OBJECTIVE: The purpose of this study was to determine the impact of revascularization on recurrent VAs or death. METHODS: A cohort study was conducted on consecutive patients with prior myocardial infarction and LVEF ≥40% presenting with a first clinical sustained VA in the absence of an acute coronary syndrome. The impact of revascularization on recurrent VAs and all-cause mortality was assessed. RESULTS: A total of 274 patients (mean age 66.1 ± 9.7 years, 85.4% male, mean LVEF 48.3% ± 7.2%) were included in the study. Eight-eight patients (32.1%) underwent coronary revascularization. During mean follow-up of 6.2 ± 5.1 years, 140 (51.1%) died or had recurrent sustained VAs or appropriate implantable-cardioverter defibrillator therapy. Revascularization was not associated with a significantly lower rate of recurrent VAs or death (multivariable hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.60-1.24, P = .43) regardless of whether it was complete or incomplete (HR 0.65, 95% CI 0.25-1.69, P = .37) or was performed by percutaneous or surgical means (HR 1.02, 95% CI 0.53-1.94, P = .96). An implantable-cardioverter defibrillator was associated with a significant reduction in mortality (HR 0.23, 95% CI 0.09-0.55, P = .001). CONCLUSION: Patients with prior myocardial infarction and LVEF ≥40% who present with sustained VAs in the absence of an acute coronary syndrome remain at high risk for recurrent VAs and all-cause death. Coronary revascularization does not systemically mitigate this risk.

Heart rate and adverse outcomes in patients with atrial fibrillation: A combined AFFIRM and AF-CHF substudy.

BACKGROUND: An elevated resting heart rate has been associated with adverse cardiovascular outcomes. Its prognostic value has not specifically been examined in patients with atrial fibrillation. OBJECTIVE: The purpose of this study was to assess the relationship between resting heart rate measured in sinus rhythm and in atrial fibrillation and subsequent hospitalizations and death. METHODS: An analysis of individual patient-level data from subjects enrolled in the AFFIRM and AF-CHF trials was conducted to determine the impact of resting heart rate on hospitalizations and mortality. Separate analyses were performed in atrial fibrillation and sinus rhythm. A total of 7159 baseline ECGs (4848 in atrial fibrillation, 2311 in sinus rhythm) were analyzed in 5164 patients (34.8% female, age 68.2 ± 8.3 years). RESULTS: During mean follow-up of 40.8 ± 16.3 months, 1016 patients died (668 cardiovascular deaths), and 3150 required at least 1 hospitalization (2215 cardiovascular). An elevated baseline heart rate in sinus rhythm was associated with increased all-cause mortality [hazard ratio (HR) 1.24 per 10 bpm increase, 95% confidence interval (CI) 1.14-1.36, P < .0001]. In contrast, a baseline heart rate in atrial fibrillation was not associated with mortality. However, compared to heart rates 90-114 bpm in atrial fibrillation, a heart rate >114 bpm was independently associated with all-cause (HR 1.18, 95% CI 1.06-1.31, P = .0018) and cardiovascular (HR 1.25, 95% CI 1.10-1.42, P = .0005) hospitalizations. CONCLUSION: In patients with a history of atrial fibrillation, an elevated baseline heart rate in sinus rhythm is independently associated with mortality. In contrast, the baseline heart rate in atrial fibrillation is not associated with mortality but predicts hospitalizations.