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The purpose of this study was to evaluate the safety and efficacy of radiofrequency (RF) ablation of typical atrial flutter by using an 8-mm electrode catheter and a 100-W RF power generator. A limitation of previous trials of catheter ablation of atrial flutter is that the data were not collected as part of a prospective multicenter clinical trial. The study results associated catheter ablation of typical atrial flutter in a cohort of 150 patients with an 88% acute efficacy rate. At 6-month follow-up, recurrent typical atrial flutter was observed in 13% of patients. Of the 12 patients with typical atrial flutter recurrence, 4 were symptomatic and 8 were asymptomatic. Procedure duration was a significant predictor of typical atrial flutter recurrence. The 12-month rate for development of atrial fibrillation was 30%. Catheter ablation of atrial flutter was associated with significant improvements in 5 of 8 domains of the Short Form 36 Survey (quality of life) and significant decreases in 13 of the 16 symptoms of the Symptom Checklist. The device- or procedure-related complication rate was 2.7%. Skin burns occurred at the dispersive pad site due to stronger RF power in 3 patients. Use of a dual dispersive pad system mitigated this problem. Thus, the results of this study associated catheter ablation of atrial flutter with high acute efficacy, a small risk of recurrent atrial flutter, and an important risk of atrial fibrillation during follow-up. [Copyright &y& Elsevier]

Vasovagal syncope is a common disorder of autonomic cardiovascular regulation. Many pharmacologic agents have been proposed as effective in the management of this condition based on nonrandomized clinical trials. Notably, only 3 agents--atenolol, midodrine, and paroxetine--have demonstrated efficacy in the treatment of vasovagal syncope in at least 1 prospective, randomized, placebo-controlled clinical trial. Other therapies commonly used in treating syncope include increased salt and fluid intake and fludrocortisone. In this review, we provide a summary of currently available data that support or question the use of various pharmacologic agents for treatment of vasovagal syncope. [ABSTRACT FROM AUTHOR]

Increased attention is now being focused on developing new technologies to cure atrial fibrillation using catheter ablation techniques. The performance of a MAZE-type procedure using standard catheter ablation technologies is arduous and is associated with an unacceptable risk of complications. The Guidant Heart Rhythm Technologies Linear Ablation System was developed to create long transmural linear lesions. Unique features of this system include the availability of different preshaped multi-electrode steerable ablation catheters, the use of phased radiofrequency (RF) energy, and the control of RF output by varying the duty cycle. A prospective multicenter clinical trial to evaluate the safety and efficacy of a right atrial ablation procedure using this technology to treat atrial fibrillation is currently underway. To date, 15 patients have been enrolled and the procedure was acutely effective in 14 of 15 patients with no complications. Atrial fibrillation has recurred during short-term follow-up in 12 of 15 patients, a not surprising result, because this initial phase of testing involved only right-sided ablation. The early results of the phase I clinical trial confirm the findings of others that successful ablation of chronic atrial fibrillation is likely to require a left atrial approach. This clinical trial, as well as others that are currently underway, will be invaluable in the continuing development of catheter ablation of atrial fibrillation and, ultimately, in determining if the routine use of this therapeutic tool can become a reality. [ABSTRACT FROM AUTHOR]

A letter to the editor in response to the article Dabigatran in catheter ablation of atrial fibrillation : a call for a randomized control trial" by A.A. Bin Abdulhak and others in a 2014 issue is presented.

The purpose of this study was to perform a systematic review and meta-analysis to evaluate the safety and efficacy of radiofrequency ablation (RFA) of typical atrial flutter (AFL) and atrioventricular node–dependent supraventricular tachycardia (SVT) in adult patients. Medline and EMBASE were searched (1990 to 2007) for all study design trials of RFA. Data relating to single- and multiple-procedure success, arrhythmia recurrence, repeat ablation, adverse events, and death were extracted. For RFA in AFL, 18 primary studies with 22 treatment arms and 1,323 patients were identified. Single-procedure success for AFL was 91.7% (95% confidence interval [CI] 88.4% to 94.9%). Multiple-procedure success was 97.0% (95% CI 94.7% to 99.4%). Postablation arrhythmia was noted in 13.2% of patients (95% CI 7.5% to 18.9%), while repeat ablation was reported in 8% (95% CI 4.5% to 11.4%). For RFA of SVT, 39 primary studies with 49 treatment arms in 7,693 patients with accessory pathways and atrioventricular nodal reentrant tachycardia were identified. Single-procedure success for SVT was 93.2% (95% CI 90.8% to 95.5%). Multiple-procedure success was 94.6% (95% CI 92.4% to 96.9). Postablation arrhythmia was noted in 5.6% patients (95% CI 4.1% to 7.2%). Repeat ablation occurred in 6.5% (95% CI 4.7% to 8.3%). For AFL studies, all-cause mortality was 0.6%, and adverse events were reported in 0.5% of patients. For SVT studies, all-cause mortality was 0.1%, and adverse events were reported in 2.9% of patients. In conclusion, studies of RFA for the treatment of patients with AFL and SVT report high efficacy rates and low rates of complications. [Copyright &y& Elsevier]

Infection remains a feared complication after cardiac device implantation. Whether early postprocedural leukocytosis, a recognized marker of infection, is an indicator of impending infection is unclear and was the focus of this study. A retrospective chart review of consecutive patients who underwent implantable cardioverter defibrillator or pacemaker implantation was performed. The association between change in white blood cell (WBC) count and development of infection after device implantation was assessed. Infection was defined as pocket or lead infection or as bacteremia or sepsis <60 days after implantation. Pre- and postprocedural WBC counts were obtained within 48 hours of the procedure. Significant leukocytosis was defined as a ≥50% increase in WBC count; 1,245 device implantations met inclusion criteria. Device-related infections occurred in 8 cases (0.6%). A modest 17.6 ± 30.2% increase in WBC count was observed for the entire cohort. Cases resulting in infection demonstrated minimal change in WBC count (mean+5.5 ± 26.5%). No infections occurred in patients with ≥50% increases in WBC count or postprocedural WBC counts >15,000/μl. Subjects with significant leukocytosis were younger (mean age 61.9 ± 16.5 vs 65.6 ± 15.1 years, p <0.01), had longer procedure times (mean 198 ± 97 vs 170 ± 77 minutes, p <0.001), and received biventricular implantable cardioverter-defibrillators (25% vs 13.9%, p <0.001). In conclusion, after device implantation, a ≥50% increase in WBC count occurred in about 10% to 15% of patients. Age, race, type of device, and procedure time influenced the development of significant leukocytosis. Elevation in WBC count after cardiac device implantation was not associated with an increased risk for early infection. [ABSTRACT FROM AUTHOR]

The success of catheter ablation of atrial fibrillation (AF) is highly dependent on a preprocedural assessment of the size and shape of the left atrium. The most precise method to determine left atrial (LA) volume using computed tomography requires manually tracing the LA area of each cross-sectional image. This is a labor-intensive and time-consuming technique. The purpose of this study was to compare LA volume derived using the “gold-standard” multiple-slice technique with LA volume estimated using 3 orthogonal LA dimensions in patients with AF. The patient population was composed of 100 patients referred for catheter ablation of AF (87 men, mean age 57 ± 12 years). AF was paroxysmal in 49 patients and persistent in 51. Each patient underwent computed tomography before catheter ablation, and LA volume was measured using the 2 methods. The mean LA volume measured using the multiple-slice technique was 136 ± 46 ml. According to the simpler estimation approach, the mean LA volume was 112 ± 41 ml. A close correlation was noted between atrial volumes determined using the 2 methods (r = 0.91, p <0.001). There was a mean underestimation of LA volume by the estimation technique of 17 ± 13%. In conclusion, the results of this study reveal that LA volume determined using an estimation approach correlates closely with true LA volume as determined using the gold-standard multiple-slice approach. This estimation approach underestimates true LA volume by approximately 20%. [Copyright &y& Elsevier]

Arrhythmogenic right ventricular dysplasia (ARVD) is a heritable cardiomyopathy characterized by the fibrofatty replacement of right ventricular (RV) myocardium leading to RV failure and arrhythmias. This study evaluated the potential utility of tissue Doppler echocardiography (TDE) and strain echocardiography (SE) to quantitatively assess RV function and their potential role in diagnosing ARVD. Images of 30 patients with ARVD (diagnosed by task force criteria) and 36 healthy controls were obtained. Peak systolic velocity, early diastolic velocity, displacement, strain rate, strain, outflow tract diameter, and fractional RV area change were measured in all subjects. Peak RV systolic velocity (6.4 ± 2.2 vs 9 ± 1.6 cm/s, p <0.0001), early diastolic velocity (−6.7 ± 2.7 vs −9.4 ± 2 cm/s, p <0.0001), displacement (13.7 ± 5.8 vs 18.7 ± 3.5 mm, p <0.0003), strain rate (−1 ± 0.7 vs −2 ± 1 s−1, p = 0.002), and strain (−10 ± 6% vs −28 ± 11%, p = 0.001) were significantly lower in patients with ARVD compared with controls, respectively. Sensitivity and specificity, respectively, were 67% and 89% for systolic velocity, 77% and 71% for displacement, 73% and 87% for strain, 50% and 96% for strain rate, 53% and 93% for outflow tract diameter, and 47% and 83% for fractional area change. RV systolic velocity and displacement were significantly lower than in controls, even in the subset of patients with ARVD with apparently normal right ventricles by conventional echocardiography. Inter- and intraobserver agreement was high. In conclusion, TDE and SE enable the detection of ARVD via the quantification of RV function and may have potential clinical value in the assessment of patients with suspected ARVD. Peak RV systolic velocity <7.5 cm/s and peak RV strain <18% best identify patients with ARVD. [Copyright &y& Elsevier]

The purpose of this study was to report 1 center’s experience with multidetector computed tomography (MDCT) in the evaluation of patients suspected to have arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C). RV dilatation/dysfunction is 1 of the most important criteria for establishing the diagnosis of ARVD/C. Cardiac magnetic resonance imaging (MRI) is the most preferred imaging modality for the diagnosis of ARVD/C. However, many patients with suspected ARVD/C have implantable cardioverter-defibrillators, prohibiting the use of MRI. Thirty-one patients (19 men; mean age 41 ± 12 years) referred for evaluation of known or suspected ARVD/C had a complete reevaluation including contrast-enhanced cardiac MDCT at the center. Two patients underwent both cardiac MRI and MDCT. Seventeen of 31 patients met Task Force criteria for ARVD/C and were confirmed to have ARVD/C. Multidetector computed tomographic images were analyzed for qualitative and quantitative characteristic findings of ARVD/C. Increased RV trabeculation (p <0.001), RV intramyocardial fat (p <0.001), and scalloping (p <0.001) were significantly associated with the final diagnosis of ARVD/C. RV volumes, RV inlet dimensions, and RV outflow tract surface area were increased in patients with ARVD/C compared with patients who did not meet the criteria. RV and left ventricular functional analysis was performed in 2 patients. In conclusion, cardiac MDCT has a strong potential to detect many qualitative and quantitative abnormalities of the right ventricle in patients with ARVD/C. Limitations include implantable cardioverter-defibrillators and motion artifacts, along with well-known radiation and contrast-induced reaction. [Copyright &y& Elsevier]

Each of the main approaches to catheter ablation of atrial fibrillation (AF, segmental and circumferential) is associated with limited efficacy in patients with permanent AF. The objective is to report outcomes of circumferential ablation with pulmonary vein (PV) isolation, determined using a circular mapping catheter, in patients with permanent AF and determine relations between the duration of permanent AF and efficacy. The patient population was composed of 41 consecutive patients (34 men; age 58 ± 11 years) with permanent AF who underwent radiofrequency catheter ablation through circumferential ablation with PV isolation. They were in permanent AF for 2.3 ± 3.6 years, and 3.4 ± 2.2 cardioversion procedures and 1.9 ± 0.8 class I/III antiarrhythmic drugs had failed. After a follow-up of 11 ± 2 months, the single-procedure success rate was 36% (n = 15) with an additional 12% (n = 5) showing improvement. With repeat procedures in 19%, the success rate was 54% (n = 22) with an additional 12% (n = 5) showing improvement. All patients who underwent repeat ablations had recovered PV conduction. Single-procedure success was higher in patients who were in permanent AF for ≤1 year compared with those in permanent AF for >1 year (50% vs 20%, respectively, p = 0.05). A major complication occurred in 4 patients (8%), including 3 patients with vascular complications and 1 with stroke. In conclusion, study results suggest that circumferential ablation with PV isolation has moderate efficacy in patients with permanent AF. Efficacy is limited in those in continuous AF for >12 months. [Copyright &y& Elsevier]

The purpose of this study was to establish reference ranges for magnetic resonance imaging (MRI) measurements of the adult right ventricle stratified by gender. Cardiovascular MRI is increasingly used for evaluating the right ventricle in congenital and acquired heart disease, but gender-specific normative values are currently unavailable. Study participants included 500 subjects free of clinical cardiovascular disease who were participants in the Multi-Ethnic Study of Atherosclerosis (MESA). All subjects underwent MRI according to a standard protocol. The endocardial margins of the right ventricle were manually contoured on short-axis images, and right ventricular (RV) volumes were calculated using a summation-of-disks method. RV dimensions were measured on 4-chamber gradient-echo images and in the short-axis plane. Except for the ejection fraction, all unadjusted RV parameters were significantly greater in men than in women (p <0.001). In the entire study population, RV volumes and linear dimensions each correlated significantly with height (r = 0.38 to 0.64, p = 0.001 for all) and body surface area (r = 0.41 to 0.64, p = 0.001 for all). Gender differences persisted after adjustment for subject height. After adjustment for body surface area, volumetric variables remained significantly greater (p = 0.001) in men than in women. Even after adjusting for body surface area and height, Chinese participants had significantly lower RV volumes compared with Caucasians. In conclusion, gender-specific normal values for the adult right ventricle by MRI are presented. Cardiovascular MRI measures of RV volumes and linear dimensions differ significantly according to gender and body size. These values will be useful to differentiate RV health from diseases that result in abnormal RV structure and function. [Copyright &y& Elsevier]

Arrhythmogenic right ventricular dysplasia (ARVD/C) is a genetic cardiomyopathy characterized by fibrous fatty replacement of the right ventricular (RV) myocardium, leading to progressive RV failure and ventricular arrhythmias in young athletes. This study evaluated whether transthoracic, real-time, 3-dimensional echocardiography (3DE) can adequately assess RV morphology and function in ARVD/C by comparing 3DE with cardiac magnetic resonance (CMR), the current reference standard. Three-dimensional echocardiography was prospectively performed in 58 patients (23 with ARVD/C, 20 first-degree relatives with no ARVD/C, 8 with idiopathic ventricular tachycardia with no ARVD/C, and 7 healthy volunteers). All patients, except 15 patients with ARVD/C with implanted defibrillators, also underwent CMR. Three-dimensional echocardiography and CMR-derived RV volumes and ejection fractions were obtained by offline data analysis by blinded, independent observers. The mean age of the study group was 37 ± 11 years (30 men). The feasibility of 3DE was high, and analyzable images were obtained in all subjects. Three-dimensional echocardiography revealed a wide variety of RV morphologic abnormalities in ARVD/C. There was a good correlation between 3DE and CMR for RV end-systolic volume (r = 0.72, p = 0.0001), RV end-diastolic volume (r = 0.50, p = 0.0001), and the RV ejection fraction (r = 0.88, p = 0.001). We found high intraobserver and moderate interobserver correlations for 3DE estimations of volumes and ejection fractions. In conclusion, 3DE measurements of RV volumes and ejection fractions closely correlate with CMR values and may be useful in the follow-up of patients with ARVD/C. [Copyright &y& Elsevier]

Thirty-five patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy underwent serial electrocardiographic (ECG) testing and were evaluated for evidence of ECG progression. Over a median of 43 months, 89% of the patients had evidence of progression, with S-wave prolongation being the most prevalent marker of ECG progression. [Copyright &y& Elsevier]

Global and regional biventricular functions were analyzed in 14 patients diagnosed with arrhythmogenic right ventricular dysplasia/cardiomyopathy using cine magnetic resonance imaging and compared with similar data from 18 age-matched controls. In this study, we report results of quantitative evaluation of biventricular global and regional function using peak ejection rate and peak filling rate as measures of systolic and diastolic function, respectively (volumetric method). [Copyright &y& Elsevier]

We evaluated 20 patients with idiopathic ventricular tachycardia for structural abnormalities using magnetic resonance imaging (MRI) and compared them with 20 controls. Two experienced observers interpreted the MRIs. There were no differences in incidence of qualitative MRI findings in patients compared with controls. These findings do not favor an association between anatomic abnormalities and arrhythmia in these patients. [Copyright &y& Elsevier]

Neurocardiogenic syncope is the most common cause of acute loss of consciousness in adults. The present study attempted to identify neuroendocrine and hemodynamic changes before syncope that could therefore play a pathophysiologic role. Twenty-five patients referred for chronic orthostatic intolerance had plasma catecholamines measured serially; 21 patients during tilt-table testing (evoking syncope in 13) and 4 others with spontaneous syncope while supine. Forearm blood flow was measured by impedance plethysmography. All 12 patients with blood sampled before tilt-induced syncope had progressive, marked increases in plasma epinephrine levels (mean 11 times baseline, p <0.0001) before syncope. Simultaneously obtained norepinephrine levels increased to a much smaller extent than did epinephrine levels ("sympathoadrenal imbalance"). In the same patients, forearm vascular resistance decreased by 21% before syncope. Proportionate changes in forearm vascular resistance before syncope correlated negatively with those in the epinephrine:norepinephrine ratio (r = -0.75, p = 0.005). Patients without syncope had forearm vasoconstriction and no sympathoadrenal imbalance during tilt. Patients with syncope while supine also had sympathoadrenal imbalance before loss of consciousness. Sympathoadrenal imbalance precedes tilt-evoked and spontaneous neurocardiogenic syncope and correlates with concurrent skeletal muscle vasodilation. Sympathoadrenal imbalance may contribute to hemodynamic derangements precipitating neurocardiogenic syncope. [ABSTRACT FROM AUTHOR]

Identifies factors that predict fluoroscopy duration and radiation exposure during catheter ablation procedures. Patient population studied; Requirement of longer duration of fluoroscopy exposure in men than women; Dose needed to cause radiation skin injury; Overall mean effective absorbed dose from catheter ablation procedures.

Atrial fibrillation (AF) and flutter (AFL) are the most common clinically significant arrhythmias in older adults with an increasing disease burden due to an aging population. However, up-to-date trends in disease burden and regional variation remain unknown. In an observational study utilizing the Global Burden of Disease (GBD) database, age-standardized mortality and incidence rates for AF overall and for each state in the United States (US) from 1990 to 2017 were determined. All analyses were stratified by gender. The relative change in age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) over the observation period were determined. Trends were analyzed using Joinpoint regression analysis. The mean ASIR per 100,000 population for men was 92 (+/-8) and for women was 62 (+/-5) in the US in 2017. The mean ASDR per 100,000 population for men was 5.8 (+/-0.3) and for women was 4.4 (+/-0.4). There were progressive increases in ASIR and ASDR in all but 1 state. The states with the greatest percentage change in incidence were New Hampshire (+13.5%) and Idaho (+16.0%) for men and women, respectively. The greatest change regarding mortality was seen in Mississippi (+26.3%) for men and Oregon (+53.8%) for women. In conclusion these findings provide updated evidence of increasing AF and/or AFL incidence and mortality on a national and regional level in the US, with women experiencing greater increases in incidence and mortality rates. This study demonstrates that the public health burden related to AF in the United States is progressively worsening but disproportionately across states and among women., Competing Interests: Declaration of Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Inc.)

Patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) classically initially present with ventricular arrhythmias or, less commonly, heart failure. Myocardial inflammation has been implicated in pathogenesis, but clinical myocarditis in ARVC is less described. We therefore studied clinical myocarditis as an initial ARVC presentation, and hypothesized that these patients have distinct clinical and genetic characteristics. Using the Johns Hopkins ARVC Registry, we identified 12 patients (all female, median age 20) referred between 2014 and 2019 diagnosed with myocarditis at presentation who were subsequently diagnosed with ARVC by Task Force Criteria. Majority presented with chest pain (n = 7, 58%) or ventricular arrhythmia (n = 3, 25%). All patients had troponin elevations and left ventricular (LV) function was reduced in 5 (42%). Magnetic resonance imaging demonstrated LV delayed gadolinium enhancement and/or pericardial enhancement in 10 (83%); only 3 (25%) patients had right ventricular abnormalities. Pathogenic genetic variants were identified in 11 (92%) patients: 10 desmoplakin (DSP) and 1 desmoglein-2 (DSG2). Thus, nearly 1/3 (10/32, 31%) of overall DSP ARVC patients were originally diagnosed with myocarditis. Patients were diagnosed with ARVC 1.8 years (IQR 2.7 years) after presentation and 8 (75%) patients did not meet Task Force Criteria without genetic testing. ARVC diagnosis led to an additional 5 (42%) patients referred for implantable cardiac defibrillator and 17 family member diagnoses. In conclusion, ARVC may initially present as myocarditis and these patients have distinct characteristics including female gender, LV involvement and DSP gene variants. Genetic testing is key to ARVC diagnosis and should be considered in select myocarditis patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Abnormalities on cardiac magnetic resonance imaging (CMR) and positron emission tomography (PET) predict ventricular arrhythmias (VA) in patients with cardiac sarcoidosis (CS). Little is known whether concurrent abnormalities on CMR and PET increases the risk of developing VA. Our aim was to compare the additive utility of CMR and PET in predicting VA in patients with CS. We included all patients treated at our institution from 2000 to 2018 who (1) had probable or definite CS and (2) had undergone both CMR and PET. The primary endpoint was VA at follow up, which was defined as sustained ventricular tachycardia, sudden cardiac death, or any appropriate device tachytherapy. Fifty patients were included, 88% of whom had a left ventricular ejection fraction >35%. During a mean follow-up 4.1 years, 7/50 (14%) patients had VA. The negative predictive value of LGE for VA was 100% and the negative predictive value of FDG for VA was 79%. Among groups, VA occurred in 4/21 (19%) subjects in the LGE+/FDG+ group, 3/14 (21%) in the LGE+/FDG- group, and 0/15 (0%) in the FDG+/LGE- group. There were no LGE-/FDG- patients. In conclusion, CMR may be the preferred initial clinical risk stratification tool in patients with CS. FDG uptake without LGE on initial imaging may not add additional prognostic information regarding VA risk., (Copyright © 2020. Published by Elsevier Inc.)

Although atrial fibrillation (AF) is strongly associated with stroke, previous studies have shown suboptimal use of anticoagulation (AC). In particular, there is a lack of data on the long-term use of AC after AF catheter ablation. We followed up patients 1 to 5 years out from catheter ablation at the Johns Hopkins Hospital (JHH) to assess their long-term use of AC. We sent a survey to patients from the JHH AF database who underwent an AF catheter ablation between 01/01/2014 and 03/31/2018. Patients were asked whether they were still on AC, if they thought the ablation was successful in controlling AF symptoms and whether they had follow-up rhythm monitoring. Replies were compared with risk scores and demographic data from the electronic medical record. We sent the survey to 628 patients in the database meeting our inclusion criteria, and we received 289 responses. The average age of patients was 67 ± 10 with a median CHA 2 DS 2 -VASc of 2 and a median follow-up of 3.6 years. Overall, 81.6% of patients with a CHA 2 DS 2 -VASc >2 reported taking AC. Use of AC was positively correlated with a higher CHA 2 DS 2 -VASc score (p = 0.012) and older age (p = 0.028), but negatively correlated with a successful ablation (p = 0.040). The most common reason (50.0%) for not being on AC was that doctors were recommending stopping it after a successful ablation. In general, higher risk patients (older, higher CHA 2 DS 2 -VASC score) were more likely to remain on AC. However, patients who self-reported a successful ablation were less likely to remain on AC. There may be many patients who can tolerate AC, but are recommended to stop due to a successful ablation. It is still debated how successful AF ablation affects stroke risk. In conclusion, there is considerable variation in the long-term management of AC after an ablation, but for the present, it seems prudent to continue AC based on stroke risk scores until more definite data are available., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Atrial flutter (AFL) is a common form of arrhythmia recurrence after atrial fibrillation (AF) ablation. We aimed to define (1) the incidence of AFL and (2) the clinical factors associated with cavo-tricuspid isthmus dependent (typical) and atypical AFL, after AF ablation. The retrospective cohort consisted of 1,029 patients that underwent initial radiofrequency AF ablation from May 2005 to December 2013 at a single academic center. Patients with missing follow-up data, history of AFL ablation, and those with undocumented AFL were excluded. Atrial volumes were measured using three-dimensional cardiac computed tomography or magnetic resonance imaging. A total of 607 patients were included in the final cohort (age 59.2 ± 10.6 years, 76.0% men, 58.7% paroxysmal AF). During a median follow-up of 845 days (interquartile range 389 to 1,597 days), 122 (20.1%) patients developed AFL. Of these, 17 had typical AFL, 98 had atypical AFL, and 7 patients had both circuits. In the multivariable Cox regression analysis, only right atrial volume index (hazard ratio [HR] 1.25 per 10 ml/m 2 , confidence interval [CI] 95% 1.10 to 1.42) was associated with incident typical AFL; whereas persistent AF (HR 1.59, CI 95% 1.06 to 2.40), linear lesions (HR 1.58, CI 95% 1.02 to 2.46) and left atrial volume index (HR 1.17 per 10 ml/m 2 , CI 95% 1.07 to 1.27) were associated with incident atypical AFL. In conclusion, noninvasive measures of right and left atrial remodeling are strongly associated with incident AFL after AF ablation. Strategies to prevent incident AFL using these measures after index ablation warrant further investigation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The P-wave terminal force in lead V 1 (PTFV 1 ) on the 12-lead electrocardiogram (ECG) quantifies left atrial (LA) structural and electrophysiologic abnormalities. We aimed to evaluate the association between PTFV 1 and cerebrovascular accident (CVA) as well as LA structure and function in patients with atrial fibrillation (AF). We conducted a cross-sectional study of 229 patients with AF (60 ± 10years, 72% men) with (n = 21) and without (n = 208) a history of CVA, who underwent preablation ECG and cardiac magnetic resonance in sinus rhythm. PTFV 1 was defined as the duration (in milliseconds) of the downward deflection of the P wave in lead V 1 multiplied by the absolute value of its amplitude (in microvolts) on ECG. PTFV 1 is associated with LA minimum volume (V min ) and left ventricular ejection fraction but not associated with the extent of LA fibrosis quantified by cardiac magnetic resonance late gadolinium enhancement. In addition, PTFV 1 is associated with CVA independent of the CHA 2 DS 2 -VASc score and LA V min (odds ratio 1.23; 95% confidence interval 1.08 to 1.40; p = 0.002). Furthermore, PTFV 1 has an incremental value over the CHA 2 DS 2 -VASc score as a marker of CVA (p <0.001). In conclusion, ECG-defined PTFV 1 is independent marker of stroke in patients with AF and reflects the underlying LA remodeling. Our findings suggest that evaluation of PTFV 1 can improve the current risk stratification of stroke., (Copyright © 2018. Published by Elsevier Inc.)

The evidence on the association between resting heart rate (HR) and incident atrial fibrillation (AF) is conflicting. Whether change in resting HR is associated with incident AF is unknown. We evaluated 11,545 participants (mean [±standard deviation] age: 57 ± 5.7 years) free of AF at baseline (1990 to 1992). Resting HR was obtained from 10-second electrocardiograms at baseline and 3 years later. AF diagnosis was ascertained from visit electrocardiograms, hospital discharge records, and death certificates through 2013. High and low resting HR were defined as ≥80 and <55 beats/min, respectively. Increase and decrease in HR were defined as a 3-year HR difference >15 and <-15 beats/min, respectively. Over a median follow-up of 22.5 years, 1,746 (15%) participants developed AF. Both baseline high resting HR and increase in HR were independently associated with incident AF (hazard ratio = 1.2, 95% confidence interval = 1.0 to 1.5 and hazard ratio = 1.4, 95% confidence interval = 1.1 to 1.9). Increase in HR was no longer associated with incident AF after additional adjustment for incident heart failure. In stratified analyses, increase in HR was associated only with AF in participants <60 years, with bachelor's degree or above, without diabetes, and without hypertension (p values for interaction ≤0.05). In conclusion, in a middle-aged population, high resting HR is associated with higher AF risk. Increase in resting HR is also associated with higher AF risk, especially in individuals without traditional AF risk factors. Whether interventions to decrease HR can prevent AF remain to be examined., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Once arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is diagnosed, the incidence of sudden cardiac death (SCD) is rare and prognosis is favorable, highlighting the value of early disease recognition. To inform strategies to diagnose ARVD/C before SCD, we sought to characterize clinical, genetic, and family history features of ARVD/C cases first recognized after SCD or resuscitated SCD (sudden cardiac arrest [SCA]). We identified 66 ARVD/C cases submitted to the Johns Hopkins ARVD/C Registry in whom disease was first recognized after SCD (n = 45) or SCA (n = 21) and compared their clinical, genetic, and demographic features with 352 patients (227 probands) diagnosed with ARVD/C by 2010 Task Force Criteria before any arrest. SCD/SCA cases were 65% men and experienced their arrest at 29.3 ± 13.8 years. Exertion precipitated 72% of arrests. Family history was recognized before arrest in 11 cases (17%), and 24 cases (41%) had reported cardiac symptoms before arrest. The SCD/SCA cohort was disproportionately men (65% SCD/SCA vs 50% living, p = 0.03) and younger at both first reported symptom (27.7 ± 13.5 years SCD/SCA vs 33.0 ± 13.6 years living, p = 0.01) and first sustained ventricular arrhythmia (VA) (29.3 ± 13.8 years SCD/SCA vs 35.6 ± 12.9 years living, p <0.001). In addition, survival from first symptom to VA was significantly shorter in SCD/SCA cases (p <0.001). These results suggest that the natural history of ARVD/C may be accelerated in SCD/SCA cases. In conclusion, although symptoms or family history provide a window of opportunity for diagnosis before death, time to intervene after symptom onset is limited., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Biomarkers are important prognostic tools in various cardiovascular conditions, including coronary artery disease and heart failure. Although their utility in cardiac electrophysiology (EP) is less established, biomarkers may guide EP clinical practice by identifying patients at risk for developing arrhythmias and their complications, in addition to augmenting therapeutic decisions by targeting appropriate pharmacologic and interventional therapies to patients who may benefit most. In this review, we focus on the prognostic role of high-sensitivity cardiac troponin (hs-cTn) assays-which detect subclinical cardiac myocyte damage-in cardiac arrhythmias and their sequelae. We review the current literature on hs-cTn and its impact on various arrhythmia disease states and also provide suggestions for future research in this field. In conclusion, although the utility of hs-cTn assays remains at an investigational stage in cardiac EP, studies to date have suggested value as a prognostic biomarker in atrial fibrillation and as a screening marker for patients at high risk of sudden cardiac death (both in the general population and among those with hypertrophic cardiomyopathy)., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The purpose of this study was to perform a systematic review and meta-analysis to evaluate the safety and efficacy of radiofrequency ablation (RFA) of typical atrial flutter (AFL) and atrioventricular node-dependent supraventricular tachycardia (SVT) in adult patients. Medline and EMBASE were searched (1990 to 2007) for all study design trials of RFA. Data relating to single- and multiple-procedure success, arrhythmia recurrence, repeat ablation, adverse events, and death were extracted. For RFA in AFL, 18 primary studies with 22 treatment arms and 1,323 patients were identified. Single-procedure success for AFL was 91.7% (95% confidence interval [CI] 88.4% to 94.9%). Multiple-procedure success was 97.0% (95% CI 94.7% to 99.4%). Postablation arrhythmia was noted in 13.2% of patients (95% CI 7.5% to 18.9%), while repeat ablation was reported in 8% (95% CI 4.5% to 11.4%). For RFA of SVT, 39 primary studies with 49 treatment arms in 7,693 patients with accessory pathways and atrioventricular nodal reentrant tachycardia were identified. Single-procedure success for SVT was 93.2% (95% CI 90.8% to 95.5%). Multiple-procedure success was 94.6% (95% CI 92.4% to 96.9). Postablation arrhythmia was noted in 5.6% patients (95% CI 4.1% to 7.2%). Repeat ablation occurred in 6.5% (95% CI 4.7% to 8.3%). For AFL studies, all-cause mortality was 0.6%, and adverse events were reported in 0.5% of patients. For SVT studies, all-cause mortality was 0.1%, and adverse events were reported in 2.9% of patients. In conclusion, studies of RFA for the treatment of patients with AFL and SVT report high efficacy rates and low rates of complications.