Automated detection of atrial fibrillation based on vocal features analysis.

INTRODUCTION: Early detection of atrial fibrillation (AF) is desirable but challenging due to the often-asymptomatic nature of AF. Known screening methods are limited and most of them depend of electrocardiography or other techniques with direct contact with the skin. Analysis of voice signals from natural speech has been reported for several applications in medicine. The study goal was to evaluate the usefulness of vocal features analysis for the detection of AF. METHODS: This prospective study was performed in two medical centers. Patients with persistent AF admitted for cardioversion were enrolled. The patients pronounced the vowels "Ahh" and "Ohh" were recorded synchronously with an ECG tracing. An algorithm was developed to provide an "AF indicator" for detection of AF from the speech signal. RESULTS: A total of 158 patients were recruited. The final analysis of "Ahh" and "Ohh" syllables was performed on 143 and 142 patients, respectively. The mean age was 71.4 ± 9.3 and 43% of patients were females. The developed AF indicator was reliable. Its numerical value decreased significantly in sinus rhythm (SR) after the cardioversion ("Ahh": from 13.98 ± 3.10 to 7.49 ± 1.58; "Ohh": from 11.39 ± 2.99 to 2.99 ± 1.61). The values at SR were significantly more homogenous compared to AF as indicated by a lower standard deviation. The area under the receiver operating characteristic curve was >0.98 and >0.89 ("Ahh" and "Ohh," respectively, p < .001). The AF indicator sensitivity is 95% with 82% specificity. CONCLUSION: This study is the first report to demonstrate feasibility and reliability of the identification of AF episodes using voice analysis with acceptable accuracy, within the identified limitations of our study methods. The developed AF indicator has higher accuracy using the "Ahh" syllable versus "Ohh."

Radial strain imaging-guided lead placement for improving response to cardiac resynchronization therapy in patients with ischaemic cardiomyopathy: the Raise CRT trial.

AIMS: To evaluate the benefit of speckle tracking radial strain imaging (STRSI)-guided left ventricular (LV) lead (LVL) positioning in cardiac resynchronization therapy (CRT) in patients (pts) with ischaemic cardiomyopathy with CRT indication. METHODS AND RESULTS: We conducted a prospective randomized controlled trial. Patients were enrolled in nine centres with 2:1 randomization into two groups (guided vs. control). Patients underwent STRSI to identify the optimal LV position from six LV segments at midventricular level. Implantation via STRSI was attempted for recommended segment in the guided group only. Follow-up included echocardiography (6 months) and clinical evaluation (6 and 12 months). The primary endpoint was comparison % reduction in LV end-systolic volume at 6 months with baseline. Secondary endpoints included hospitalizations for heart failure and death, and improvement in additional echocardiographic measurements and quality of life score. A total of 172 patients (115 guided vs. 57 control) were enrolled. In the guided group, 60% of the implanted LV leads were adjudicated to be successfully located at the recommended segment, whereas in the control group 44% reached the best STRSI determined segment. There was no difference between the groups in any of the primary or secondary endpoints at 6 and 12 months. CONCLUSION: Our findings suggest that echo-guided implantation of an LV lead using STRSI does not improve the clinical or echocardiographic response compared with conventional implantation.

Arrhythmic Events in Brugada Syndrome: A Nationwide Israeli Survey of the Clinical Characteristics, Treatment; and Long-Term Follow-up (ISRABRU-VF).

BACKGROUND: Limited information exists about detailed clinical characteristics and management of the small subset of Brugada syndrome (BrS) patients who had an arrhythmic event (AE). OBJECTIVES: To conduct the first nationwide survey focused on BrS patients with documented AE. METHODS: Israeli electrophysiology units participated if they had treated BrS patients who had cardiac arrest (CA) (lethal/aborted; group 1) or experienced appropriate therapy for tachyarrhythmias after prophylactic implantable cardioverter defibrillator (ICD) implantation (group 2). RESULTS: The cohort comprised 31 patients: 25 in group 1, 6 in group 2. Group 1: 96% male, mean CA age 38 years (range 13-84). Nine patients (36%) presented with arrhythmic storm and three had a lethal outcome; 17 (68%) had spontaneous type 1 Brugada electrocardiography (ECG). An electrophysiology study (EPS) was performed on 11 patients with inducible ventricular fibrillation (VF) in 10, which was prevented by quinidine in 9/10 patients. During follow-up (143 ± 119 months) eight patients experienced appropriate shocks, none while on quinidine. Group 2: all male, age 30-53 years; 4/6 patients had familial history of sudden death age < 50 years. Five patients had spontaneous type 1 Brugada ECG and four were asymptomatic at ICD implantation. EPS was performed in four patients with inducible VF in three. During long-term follow-up, five patients received ≥ 1 appropriate shocks, one had ATP for sustained VT (none taking quinidine). No AE recurred in patients subsequently treated with quinidine. CONCLUSIONS: CA from BrS is apparently a rare occurrence on a national scale and no AE occurred in any patient treated with quinidine.

Characteristics and outcomes of diabetic patients with an implantable cardioverter defibrillator in a real world setting: results from the Israeli ICD registry.

AIMS: There are limited data regarding the effect of diabetes mellitus (DM) on the risks of both appropriate and inappropriate implantable cardioverter defibrillator (ICD) therapy. The present study was designed to compare the outcome of appropriate and inappropriate ICD therapy in patients with or without DM. METHODS AND RESULTS: The risk of a first appropriate ICD therapy for ventricular tachyarrhythmias (including anti tachycardia pacing and shock) was compared between 764 DM and 1346 non-DM patients enrolled in the national Israeli ICD registry. We also compared the risks of inappropriate ICD therapy, and death or cardiac hospitalization between diabetic and non-diabetic patients. Diabetic patients were older, were more likely to have ischemic cardiomyopathy, lower ejection fraction, atrial fibrillation, and other co-morbidities. The 3-year cumulative incidence of appropriate ICD therapy was similar in the DM and non-DM groups (12 and 13%, respectively, p = 0.983). Multivariate analysis showed that DM did not affect the risk of appropriate ICD therapy (HR = 1.07, 95% CI 0.78-1.47, p = 0.694) or inappropriate therapy (HR = 0.72, 95% CI 0.42-1.23, p = 0.232). However, DM was associated with a 31% increased risk for death or cardiac hospitalization (p = 0.005). Results were similar in subgroup analyses including ICD and defibrillators with cardiac resynchronization therapy function recipients, primary or secondary prevention indication for an ICD. CONCLUSIONS: Despite a significant excess of cardiac hospitalizations and mortality in the diabetic population, there was no difference in the rate of ICD treatments, suggesting that the outcome difference is not related to arrhythmias.

Torsades de pointes after adenosine administration.

Adenosine can produce arrhythmias, which are generally short living. It may induce PACs and PVCs, sinus bradycardia, and atrial fibrillation. There have been reports of transient polymorphic VT (torsades de pointes) in patients with LQTS and others in people with normal QT interval. We report a case of a long episode of polymorphic VT induced by adenosine. A 27 year old woman received 6 mg adenosine for PSVT, which terminated and torsades de pointes developed, persisting for 17 seconds and terminated spontaneously. This is the longest described duration of the torsades after adenosine administration in patients with normal QT interval.

The effect of ICD programming on inappropriate and appropriate ICD Therapies in ischemic and nonischemic cardiomyopathy: the MADIT-RIT trial.

INTRODUCTION: The MADIT-RIT trial demonstrated reduction of inappropriate and appropriate ICD therapies and mortality by high-rate cut-off and 60-second-delayed VT therapy ICD programming in patients with a primary prophylactic ICD indication. The aim of this analysis was to study effects of MADIT-RIT ICD programming in patients with ischemic and nonischemic cardiomyopathy. METHODS AND RESULTS: First and total occurrences of both inappropriate and appropriate ICD therapies were analyzed by multivariate Cox models in 791 (53%) patients with ischemic and 707 (47%) patients with nonischemic cardiomyopathy. Patients with ischemic and nonischemic cardiomyopathy had similar incidence of first inappropriate (9% and 11%, P = 0.21) and first appropriate ICD therapy (11.6% and 14.1%, P = 0.15). Patients with ischemic cardiomyopathy had higher mortality rate (6.1% vs. 3.3%, P = 0.01). MADIT-RIT high-rate cut-off (arm B) and delayed VT therapy ICD programming (arm C) compared with conventional (arm A) ICD programming were associated with a significant risk reduction of first inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy (HR range 0.11-0.34, P < 0.001 for all comparisons). Occurrence of total inappropriate and appropriate ICD therapies was significantly reduced by high-rate cut-off ICD programming and delayed VT therapy ICD programming in both ischemic and nonischemic cardiomyopathy patients. CONCLUSION: High-rate cut-off and delayed VT therapy ICD programming are associated with significant reduction in first and total inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy.

Atrial Fibrillation Ablation Success Rate - A Retrospective Multicenter Study.

Atrial fibrillation (AF) has become a major health and economic burden. Pulmonary veins isolation (PVI) based ablation for rhythm control of AF is well established. Furthermore, recent studies show its superiority over anti-arrhythmic therapy. However, most of these studies were performed in highly experienced centers, that may not necessarily reflect real world outcomes. We evaluated the outcome (success rate and complications) of 300 consecutive procedures, performed on 291 patients (during 2014-2015) of a major HMO. All had undergone PVI for AF by experienced electrophysiologists in 8 medical centers (85% RF technique). Data were retrospectively collected using computerized medical records. Variables included demographic and clinical characteristics, acute procedural success and complications, long term success rate based on multiple ECGs and Holter monitoring. The average age was 63 years, 61% were male, 79% had paroxysmal AF. Sinus rhythm at 2 years was considered success. The overall success rate of maintaining sinus rhythm at 2 years was 56%. Success rate correlated significantly with age and standard risk factors. Those patients in whom the index procedure was the first ablation, success rate was 78%. Sixty-one patients underwent a second ablation with success rate of 64%, 32 underwent a 3rd/4th procedure with success rate of 56%. The probability to be in sinus rhythm after 2 years regardless of the number of ablations was 78%. Thirty-five percent of the patients were still on anti-arrhythmic therapy at 2 years post procedure. Complication rate was 6.6% (2.5% serious), among them 2 deaths, 1 procedure related. PVI in a real-world large unselected population is a valid therapeutic option for AF with an overall 2-year success rate of 56%. In our group higher complication rate was observed compared to the reported rate in the literature. The use of cryo-ablation for PVI and further improvements in both technique and experience may improve both efficacy and safety profile.

The Additive Effect of Left Ventricular Filling Pressure and Renal Function on Long-Term Prognosis of High-Risk Patients Undergoing Coronary Angiography.

INTRODUCTION: Impaired relaxation is the earliest manifestation of ischemic cascade. Risk factors and renal function abnormalities are associated with coronary disease and diastolic dysfunction as well. We aimed to study the association of noninvasive assessment of left ventricular filling pressures and renal function with mortality in high-risk patients undergoing coronary angiography. PATIENTS AND METHODS: An observational prospective study of 564 consecutive patients undergoing coronary angiography was conducted. The median follow-up was 2,293 days. Patients were categorized into 2 groups according to presence of significant diastolic dysfunction: group 1, 382 patients, with normal and group 2, 182 patients, with elevated filling pressure. Renal insufficiency was determined as calculated glomerular filtration rate <60 mL/min. Patients demographic, clinical, echocardiography, laboratory, and angiographic data were prospectively collected. RESULTS: Fifty-three percent of patients underwent angiography due to acute coronary syndrome (ACS), 85.5% had coronary artery disease, 53.4% had reduced (<50%) left ventricular ejection fraction (LVEF), and 47.4% had abnormal renal function. The mortality during the follow-up period was 30.0%. Patients with elevated filling pressure had significantly higher mortality (50.5% vs. 20.2%, p < 0.0001). Impaired renal failure as well, was associated with higher mortality (48% vs. 15%, p < 0.001). The association remained significant in subgroups of patients with and without ACS and reduced and preserved LVEF. In Cox regression model which combined elevated filling pressure, renal insufficiency, age, diabetes mellitus, hypertension, presence of atrial fibrillation, LVEF, and anemia, elevated filling pressure and renal function impairment were independently associated with higher mortality (HR: 3.717, CI: 1.623-8.475, p < 0.0001 and HR: 0.972, CI: 0.958-0.985, p = 0.0001, respectively). There was an incremental prognostic value of elevated filling pressures and renal function impairment on mortality. CONCLUSIONS: Advanced diastolic dysfunction and impaired renal function are signals toward worse outcomes and are associated with mortality in high-risk patients undergoing coronary angiography.

The CHA2DS2-VASC Score Predicts Mortality in Patients Undergoing Coronary Angiography.

BACKGROUND: The CHA2DS2-VASC score is used to predict the risk of thromboembolic complications in patients with atrial fibrillation (AF). We hypothesized that the CHA2DS2-VASC score can be used to predict mortality in patients undergoing coronary angiography. METHODS AND RESULTS: This was a prospective study of 990 patients undergoing coronary angiography. The median follow-up was 2294 days. The patients were categorized into two groups according to their CHA2DS2-VASC score: group I had scores <4 and group II had scores ≥4 (527 (53.2%) and 463 (46.8%), respectively). A Kaplan-Meier analysis demonstrated a significant association between the CHA2DS2-VASC score and mortality (69/527 (13.1%) vs. 179/463 (38.7%) for group I vs. group II, respectively, p < 0.0001). The association remained significant in patients with and without AF, reduced and preserved LVEF, normal and reduced kidney function, and with and without ACS (p < 0.009 to p < 0.0001 for all). In the Cox regression model, which combined the CHA2DS2-VASC score, the presence of AF, LVEF, anemia, and renal insufficiency, an elevated CHA2DS2-VASC score of ≥4 was independently associated with higher mortality (HR 2.12, CI 1.29-3.25, p = 0.001). CONCLUSIONS: The CHA2DS2VASC score is a simple and reliable mortality predictor in patients undergoing coronary angiography and should be used for the initial screening for such patients.

Catheter ablation of left-sided accessory pathways in small children.

BACKGROUND: Accessory pathways (APs) are a common reason for supraventricular tachycardia in small children. Trans-septal puncture (TSP) approach is commonly used for the ablation of left-sided APs, however it may be challenging in small children. The aim of this study was to assess the efficacy and safety of trans-septal approach radiofrequency (RF) ablation of left-sided APs in children weighing up to 30 kg. METHODS: Of the 658 children who underwent catheter ablation of APs since 06/2002, 86 children had left-sided AP and weighed less than 30 kg. TSP approach guided with TEE and fluoroscopy was used for left atrium access. RESULTS: The mean age, height, and body weight were 7.6 ± 1.9 years, 122.4 ± 9.3 cm and 24.0 ± 4.2 kg, respectively. Forty-three children (50%) were male, 46 of 86 (53%) had manifest AP, 17 of 86 (20%) weighed less than 20 kg and in 24 of 86 children (28%) a three-dimensional system (3DS) was used to reduce fluoroscopy time. The acute success rate was 98.8% (85/86), with a recurrence rate of 2.4% (2/85) in a mean follow-up of 66.2 ± 42.7 (9.1-184.2) months. The mean procedure time and fluoroscopy time were significantly lower for the 3DS group compared to the standard fluoroscopy group 131 ± 41 (55-262) and 2.4 ± 1.5 (1-6) minutes vs 164 ± 51 (62-249) and 27 ± 13 (8-77) minutes, P < 0.01 and P < 0.0001, respectively. There were no ablation-related complications. CONCLUSIONS: RF ablation of left-sided APs using TSP approach in small children had an excellent efficacy and safety profile. The use of 3DS significantly reduces the procedure and fluoroscopy time.

Head-up tilt table testing in syncope: safety and efficiency of isosorbide versus isoproterenol in pediatric population.

BACKGROUND: The aim of this study was to compare the diagnostic value and safety of sublingual isosorbid dinitrate (ISDN) with intravenous isoproterenol (ISOP) during head-up tilt table testing (HUTT) in pediatric patients with suspected neurocardiogenic syncope. METHODS: One hundred thirty-six consecutive pediatric patients complaining of presyncope or syncope were submitted to HUTT for the first time. Those who did not develop syncope or presyncope during passive HUTT for 20 minutes underwent repeated HUTT with either 1.25 to 2.5 mg sublingual ISDN or intravenous ISOP (1-3 mug/min) for 20 minutes. There were 54 boys and 82 girls, aged 10 to 18 years with an average of 15.5 +/- 2.4 years and a median of 16 years. Among the patients with cardioinhibition or mixed responses, the severity of the bradyarrhythmia was scored 1 to 3 (restoration of effective rhythm within 10 seconds, 10-20 seconds, and >20 seconds while back to supine position, respectively). RESULTS: During the passive period, 24 (17.6%) of 136 patients had a positive response to HUTT. Syncope was observed in another 44 patients during either ISDN or ISOP period (14/58 [24.1%] and 30/54 [55.5%] with ISDN vs ISOP, respectively, P < .05). The time to symptoms was shorter with both ISDN and ISOP compared with passive period (6.5 +/- 2.9, 6.3 +/- 5.9, and 10.3 +/- 4.4, minutes, respectively, P < .05). The severity score for cardioinhibition response was significantly higher with ISDN compared with the passive period and ISOP (2 +/- 0.8, 1.25 +/- 0.45, and 1.26 +/- 0.45, respectively, P < .01). CONCLUSIONS: Sublingual ISDN is less sensitive and less safe compared to intravenous ISOP in assessing pediatric age patients with suspected neurocardiogenic syncope and with a negative result in tilt test without provocation. The simplicity of ISDN use should be weighed against the risk of longer symptoms with ISDN.

Atrial sympathetic and parasympathetic nerve sprouting and hyperinnervation induced by subthreshold electrical stimulation of the left stellate ganglion in normal dogs.

BACKGROUND: Subthreshold electrical stimulation of the left stellate ganglion (LSG) can induce nerve sprouting and sympathetic hyperinnervation in canine ventricles. It is unclear whether a similar neural plasticity involving both sympathetic and parasympathetic innervation also exists in the atria. METHODS AND RESULTS: We applied subthreshold electrical stimulation at 20 Hz (0.45 ms pulse width) or 5 Hz (1.9 ms pulse width) to the LSG in 6 normal mongrel dogs. After 41+/-9 days, the hearts were harvested and the right and left atrium stained for synaptophysin (SYN), growth-associated protein 43 (GAP43), sympathetic nerve markers tyrosine hydroxylase (TH), and parasympathetic marker choline acetyltransferase (ChAT). Tissues from 6 additional healthy dogs were used as controls. The hearts from dogs with LSG electrical stimulation had a higher density of nerve structures immunopositive to the SYN, GAP43, TH, and ChAT (P<.01) in both right and left atria. Nerve density was equal in right and left atria. There were more TH-positive nerve structures than ChAT-positive nerve structures (P<.01) for both right and left atria. No atrial arrhythmia was observed at the second surgery. CONCLUSIONS: Continuous subthreshold electrical stimulation to the LSG induces both sympathetic and parasympathetic hyperinnervation in both right and left atria in normal dogs.

Outcome after implantation of cardioverter defibrillator [corrected] in patients with Brugada syndrome: a multicenter Israeli study (ISRABRU).

BACKGROUND: Many electrophysiologists recommend implantable cardioverter defibrillators for patients with Brugada syndrome who are cardiac arrest survivors or presumed at high risk of sudden death (patients with syncope or a familial history of sudden death or those with inducible ventricular fibrillation at electrophysiologic study). OBJECTIVES: To assess the efficacy and complications of ICD therapy in patients with Brugada syndrome. METHODS: The indications, efficacy and complications of ICD therapy in all patients with Brugada syndrome who underwent ICD implantation in 12 Israeli centers between 1994 and 2007 were analyzed. RESULTS: There were 59 patients (53 males, 89.8%) with a mean age of 44.1 years. At diagnosis 42 patients (71.2%) were symptomatic while 17 (28.8%) were asymptomatic. The indications for ICD implantation were: a history of cardiac arrest (n = 11, 18.6%), syncope (n = 31, 52.5%), inducible VF in asymptomatic patients (n = 14, 23.7%), and a family history of sudden death (n = 3, 0.5%). The overall inducibility rates of VF were 89.2% and 93.3% among the symptomatic and asymptomatic patients, respectively (P = NS). During a follow-up of 4-160 (45 +/- 35) months, all patients (except one who died from cancer) are alive. Five patients (8.4%), all with a history of cardiac arrest, had appropriate ICD discharge. Conversely, none of the patients without prior cardiac arrest had appropriate device therapy during a 39 +/- 30 month follow-up. Complications were encountered in 19 patients (32%). Inappropriate shocks occurred in 16 (27.1%) due to lead failure/dislodgment (n = 5), T wave oversensing (n = 2), device failure (n = 1), sinus tachycardia (n = 4), and supraventricular tachycardia (n = 4). One patient suffered a pneumothorax and another a brachial plexus injury during the implant procedure. One patient suffered a late (2 months) perforation of the right ventricle by the implanted lead. Eleven patients (18.6%) required a reintervention either for infection (n = 1) or lead problems (n = 10). Eight patients (13.5%) required psychiatric assistance due to complications related to the ICD (mostly inappropriate shocks in 7 patients). CONCLUSIONS: In this Israeli population with Brugada syndrome treated with ICD, appropriate device therapy was limited to cardiac arrest survivors while none of the other patients including those with syncope and/or inducible VF suffered an arrhythmic event. The overall complication rate was high.

Improvement in cardiac dysfunction with a novel circuit training method combining simultaneous aerobic-resistance exercises. A randomized trial.

INTRODUCTION: Exercise is considered a valuable nonpharmacological intervention modality in cardiac rehabilitation (CR) programs in patients with ischemic heart disease. The effect of aerobic interval exercise combined with alternating sets of resistance training (super-circuit training, SCT) on cardiac patients' with reduced left ventricular function, post-myocardial infarction (MI) has not been thoroughly investigated. AIM OF STUDY: to improve cardiac function with a novel method of combined aerobic-resistance circuit training in a randomized control trial by way of comparing the effectiveness of continuous aerobic training (CAT) to SCT on mechanical cardiac function. Secondary to compare their effect on aerobic fitness, manual strength, and quality of life in men post MI. Finally, to evaluate the safety and feasibility of SCT. METHODS: 29 men post-MI participants were randomly assigned to either 12-weeks of CAT (n = 15) or SCT (n = 14). Both groups, CAT and SCT exercised at 60%-70% and 75-85% of their heart rate reserve, respectively. The SCT group also engaged in intermittently combined resistance training. Primary outcome measure was echocardiography. Secondary outcome measures were aerobic fitness, strength, and quality of life (QoL). The effectiveness of the two training programs was examined via paired t-tests and Cohen's d effect size (ES). RESULTS: Post-training, only the SCT group presented significant changes in echocardiography (a reduction in E/e' and an increase in ejection fraction, P<0.05). Similarly, only the SCT group presented significant changes in aerobic fitness (an increase in maximal metabolic equivalent, P<0.05). In addition, SCT improvement in the physical component of QoL was greater than this observed in the CAT group. In both training programs, no adverse events were observed. CONCLUSION: Men post-MI stand to benefit from both CAT and SCT. However, in comparison to CAT, as assessed by echocardiography, SCT may yield greater benefits to the left ventricle mechanical function as well as to the patient's aerobic fitness and physical QoL. Moreover, the SCT program was found to be feasible as well as safe.

Correction: Improvement in cardiac dysfunction with a novel circuit training method combining simultaneous aerobic-resistance exercises. A randomized trial.

[This corrects the article DOI: 10.1371/journal.pone.0188551.].

Intensive Exercise Training Improves Cardiac Electrical Stability in Myocardial-Infarcted Rats.

BACKGROUND: Moderate exercise training has been shown to decrease sudden cardiac death post myocardial infarction. However, the effects of intensive exercise are still controversial. METHODS AND RESULTS: Fourteen myocardial-infarcted rats were divided into sedentary (n=8) and intensive training groups (n=6) and 18 sham control rats to sedentary (n=10) and intensive training groups (n=8). Heart rate variability was obtained at weeks 1 and 8. The inducibility of ventricular tachycardia/fibrillation was assessed in a Langendorff system. Fast Fourier transforms were applied on the recorded ventricular tachycardia/fibrillations. Training reduces low to high frequency ratio of heart rate variability at week 8 compared with that at week 1 (P<0.05). In isolated hearts, the probability for ventricular tachycardia/fibrillation was decreased from 4.5±0.8% in sedentary controls to 1.56±0.2% in intensive training controls (P<0.05) and from 13.5±2.1% in the sedentary group to 5.4±1.2% in the intensive training group (P<0.01). Moreover, the pacing current required for ventricular fibrillation induction in the trained groups was increased following exercise (P<0.05). Fast Fourier transform analysis of ECG findings revealed an exercise-induced ventricular fibrillation transition from a narrow, single-peak spectrum at 17 Hz in sedentary controls to a broader range of peaks ranging from 13 to 22 Hz in the intensive training controls. CONCLUSIONS: Intensive exercise in infarcted rats leads to reduced ventricular fibrillation propensity and is associated with normalization of refractoriness and intrinsic spatiotemporal electrical variations.

Limited fluoroscopy catheter ablation of accessory pathways in children.

BACKGROUND: Limited fluoroscopy ablation using 3D electro-anatomical system (3DS) has been used for arrhythmias in children, however it is not a common practice. We aimed to facilitate a fluoroscopy limited approach for ablation of accessory pathways (AP) in children. METHODS: Following electrophysiologic (EP) catheter placement a single dual-plane fluoroscopic image (right anterior oblique-30° and left anterior oblique-60° views) was acquired and the 3DS views were rotated to be a perfect match to the fluoroscopy. Ninety-four consecutive pediatric patients [mean age 11.8±4.1 (4.2-18) years, 61.7% males] with Wolf-Parkinson-White syndrome underwent ablation of an AP. Fifty-seven had manifest AP, 54 had left-sided AP (LSAP) and 40 had right-sided AP (RSAP). RESULTS: The acute success rate was 95.7% (90/94), with a recurrence rate of 1.1% (1/90) at a mean follow-up of 13±5.5 (4.4-22.9) months. Mean procedure and fluoroscopy times were 144±45 (55-262)min and 1.8±1.4 (0.1-5.6)min, respectively. Comparison of the first 20 procedures to the next 74 procedures demonstrated an extended procedure time (171±53min vs 135±38min, p<0.005), however the fluoroscopy time, the number of long applications, the time to effect, and the acute success rate were similar. There were no permanent ablation-related complications. CONCLUSIONS: A limited fluoroscopy approach for ablation of AP in children using 3DS is easily acquired, adapted, reduces the fluoroscopy time, and has an excellent efficacy and safety profile.