Predictors of ventricular tachyarrhythmia in patients with implantable cardioverter-defibrillator and non-ischemic systolic heart failure.

BACKGROUND: The benefit derived from implantable cardioverter-defibrillators (ICD) in subjects with non-ischemic systolic HF (NICM) is less well-established. AIM: The study aimed to determine the incidence, predictors, and prognostic impact of ventricular arrhythmias in patients with ICD and NICM. METHODS: The study sample included 377 consecutive patients with ICD or cardiac resynchronization cardioverter-defibrillators (CRT-D, 74% of patients) and NICM implanted and monitored remotely in a university hospital. RESULTS: During the median (interquartile range [IQR]) follow-up of 1645 (960-2675) days, sustained ventricular arrhythmia occurred in 92 patients (24.4%). Of those, ventricular fibrillation (VF), ventricular tachycardia (VT), and both VT and VF occurred in 10 (10.9%), 72 (78.3%), and 10 (10.9%) patients, respectively. Patients with vs. those without ventricular arrhythmia differed concerning sex, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), post-inflammatory etiology, atrial fibrillation/flutter occurrence, and supraventricular arrhythmia (SVT) other than AF/AFL during follow-up. In multivariable Cox regression, LVEDD (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.003-1.09; P = 0.03), AF/AFL (HR, 1.86; 95% CI, 1.21-2.85; P = 0.004), and SVT (HR, 1.77; 95% CI, 1.10-2.87; P = 0.02) were independent predictors of sustained VT, while AF/AFL (HR, 1.65; 95% CI, 1.07-2.56; P = 0.02) was independent predictor of VF. All-cause mortality in patients with VT/VF was significantly higher than in subjects without sustained ventricular arrhythmias (35.9% vs. 22.4%; P = 0.01). CONCLUSIONS: Ventricular arrhythmia occurred in every fourth patient with NICM and ICD during 4.5 years of observation and was associated with significantly worse prognosis than in subjects free of VT/VF. Higher LVEDD, atrial fibrillation/atrial flutter, and supraventricular tachycardia flag patients at risk of ventricular arrhythmia.

Does the origin of ablated premature ventricular contractions determine the level of left ventricular function improvement?

BACKGROUND: Premature ventricular contractions (PVCs) are associated with tachycardiomyopathy and high mortality rate. The treatment depends on the engaged ventricle. For PVCs originating from the right outflow tract (OT), radiofrequency catheter ablation (RFCA) is recommended (class IB­R recommendation) in preference to pharmacotherapy. In those originating from the left ventricle, ablation is a class IIa B­NR recommendation. AIMS: The aim of the study was to assess the success of RFCA of PVCs based on arrhythmia origin. METHODS: A total of 110 consecutive patients with monomorphic PVCs referred for ablation were enrolled and divided according to the site of ablation to the OT group and the ventricles (VENT) group. Holter electrocardiography and echocardiography were performed before the procedure and at 6­month follow­up. RESULTS: Long­term RFCA success was achieved in 93 (85%) patients (89% in the OT group and 82% in the VENT group; P = 0.39). The PVC reduction was similar in both groups (median [interquartile range] 99.55% [14] and 99.88% [6], respectively; P = 0.56). The OT group presented greater left ventricle (LV) recovery than the VENT group (odds ratio, 2.01; 95% CI, 1.15-10.75; P = 0.015). The procedure in the VENT group was longer, required additional access, the complication rate was similar, and 1 serious adverse event (aortic dissection) was observed in a patient with arrhytmia originating in the LV outflow tract. CONCLUSIONS: The origin of PVCs does not determine the success of arrhythmia elimination. The OT origin may predict LV improvement. The duration of RFCA in the VENT group was longer. The outflow tract origin may predict reversal of LV deterioration.

Contrast-induced acute kidney injury in patients undergoing cardiac resynchronization therapy-incidence and prognostic importance. Sub-analysis of data from randomized TRUST CRT trial.

INTRODUCTION: Because data on contrast-induced acute kidney injury (CI-AKI) in patients undergoing cardiac resynchronization therapy (CRT-D) are scarce, we aimed to assess the incidence, natural course and prognostic importance of this syndrome in CRT recipients. METHODS: Study population consisted of 100 consecutive patients enrolled into the Triple Site Versus Standard Cardiac Resynchronization (TRUST CRT) trial, who were treated with CRT-D. Two patients were excluded up to 3 months after randomization and not analysed further. CI-AKI was defined as a rise in serum creatinine of at least 26.5 µmol/L (0.3 mg/dL) within 48 h after contrast exposure, or at least 50% increase from the baseline value during index hospital stay with CRT-D implantation according to KDIGO Clinical Practice Guideline for Acute Kidney Injury. RESULTS: Among 98 subjects of TRUST CRT trial, 10 patients (10.2%) developed CI-AKI after CRT-D implantation. In patients with glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) on admission, the incidence of CI-AKI was almost twofold (15.4%) higher than in subjects with GFR ≥60 (8.3%). CRT-D recipients with CI-AKI had significantly higher mortality rate (50.0%) compared to those without CI-AKI (17.0%) during 30 months of follow-up (logrank p = 0.012). Multivariate Cox regression analysis showed CI-AKI as significant and independent risk factor for death in CRT-D recipients (hazard ratio 5.71; 95% CI 5.16-6.26; p = 0.001). CONCLUSIONS: Contrast-induced acute kidney injury is a serious and frequent procedural complication of CRT-D implantation with a significant negative influence on long-term survival. The results suggest that clinical evaluation regarding renal function should be considered in CRT-D recipients, both before and after device implantation.

The incidence and risk factors of stroke in patients with acute myocardial infarction treated invasively and concomitant impaired renal function.

BACKGROUND: Impaired renal function is a marker of poor prognosis in patients with acute myocardial infarction (AMI). The aim of the study was to assess the incidence and independent predictors of stroke in population of patients with AMI treated invasively and concomitant impaired renal function (IRF). METHODS: We analyzed 2,520 consecutive AMI patients admitted to our Center between 2003 and 2007 and treated with percutaneous coronary intervention. The whole population was divided into patients with IRF, defined as glomerular filtration rate < 60 mL/min/1.73 m(2) or contrast induced nephropathy (IRF group, n = 933; 37.02%) and patients without IRF (control group, n = 1587; 62.98%). The IRF group was subjected to further analysis. Data on long-term follow-up were screened to identify the patients who experienced stroke. RESULTS: During median of 25.5 months of follow-up 52 (2.07%) the patients experienced stroke - 33 (3.54%) in the IRF group and 19 (1.2%) patients in the control group. The risk of major adverse cardiovascular events in the IRF group, including repeated AMI (68.8 vs.14.9%, p < 0.001) and death (45.5 vs. 25.1%, p < 0.05) was significantly higher in patients with stroke. Previous stroke (HR 6.85), female gender (HR 3.13), as well as STEMI anterior (HR 2.55) were independent risk factors of stroke in this population. CONCLUSIONS: Patients with AMI treated invasively and concomitant IRF were at higher risk of stroke occurrence in the future. Stroke was associated with poor outcome in the studied population. Independent predictors of stroke in patients with IRF and AMI treated invasively were different from commonly recognized stroke predictors.

Evaluation of factors affecting persistence of atrial fibrillation in patients with concomitant atrial flutter treated with percutaneous radiofrequency current ablation of the right atrial cavotricuspid isthmus.

BACKGROUND: Atrial fibrillation (AF) and atrial flutter (AFL) often coexist. In some patients, AF remission is seen after successful percutaneous radiofrequency current ablation of the cavotricuspid isthmus (CTI). AIM: To evaluate factors affecting AF remission in patients with typical AFL and concomitant AF who underwent CTI ablation. METHODS: The study included consecutive 69 patients with typical AFL and concomitant clinically documented AF who underwent successful CTI ablation in 2003-2010. Based on the follow-up data from medical records and telephone interviews, the patients were divided into two groups: with persistent AF (group A) and with remission of AF (group B). This distinction was based on arrhythmia symptoms reported by the patient, such as palpitation or irregular heartbeat, and confirmed electrocardiographically (12-lead ECG or Holter monitoring). RESULTS: Group A included 47 patients, and group B included 22 patients. The two groups did not differ significantly in regard to the New York Heart Association (NYHA) functional class and concomitant diseases including diabetes, ischaemic heart disease, previous myocardial infarction and arterial hypertension. The two groups also did not differ by echocardiographically determined mean left ventricular ejection fraction (LVEF) and left atrial dimension (43.5 ± 9.27 vs. 39.27 ± 5.76, p = 0.075). Multivariate logistic regression did not identify any independent risk factors of AF persistence after CTI ablation. Univariate logistic regression also did not show arterial hypertension, type 2 diabetes, previous myocardial infarction, LVEF, left ventricular dimension or age to affect AF persistence after successful ablation. CONCLUSIONS: Based on the results of our study, we were unable to identify factors determining remission of AF coexisting with AFL in patients after percutaneous CTI ablation. These findings may indicate the need for complex ablation procedure (involving both CTI and pulmonary venous ostia ablation) in patients in whom these two arrhythmias coexist.

Many response criteria are poor predictors of outcomes after cardiac resynchronization therapy: validation using data from the randomized trial.

AIMS: The aim of the study was to assess the predictive value for outcomes of various response criteria currently used in patients undergoing cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Data from TRUST CRT randomized trial in patients with New York Heart Association (NYHA) III-IV class, QRS ≥ 120 ms, ejection fraction ≤ 35%, and mechanical dyssynchrony was analysed. Ninety-seven subjects who survived 6 months after implantation of CRT-defibrillator were classified as responders or non-responders depending on 15 criteria used in most of the previous trials. Blindly adjudicated data on major adverse cardiac events (MACEs) within 1 year after classification were used to calculate the predictive value of response criteria. After adjustment for baseline confounding variables only eight criteria were significantly predictive for future MACEs. Sensitivity and specificity ranged substantially for clinical (32-94% and 26-63%) and echocardiographic criteria (40-93% and 22-70%, respectively). The most powerful clinical predictor was >a NYHA class reduction ≥ 1 [adjusted relative risk (RR) 4.41 for non-responders; 95% confidence interval (CI) 1.75-11.04, P = 0.002], while the strongest echocardiographic predictor was a reduction in the left ventricular end-systolic index by > 15% (RR 3.49; 95% CI 1.59-7.64, P = 0.002). A combination of these two criteria did not improve the predictive value of a single parameter. Both criteria showed multiple significant interactions with baseline patients' characteristics. CONCLUSION: Only some of the commonly used response criteria predict outcome in patients undergoing CRT. The predictive value varies substantially across different criteria, with a higher sensitivity observed for the clinical parameters and a higher specificity observed for echocardiographic parameters. Combining various criteria adds little to their prognostic value. The predictive accuracy of various criteria can be different in various subgroups due to multiple interactions with baseline characteristics. CLINICALTRIALS. GOV IDENTIFIER: NCT00814840.

The prognostic value of different glucose abnormalities in patients with acute myocardial infarction treated invasively.

BACKGROUND: Diabetes (DM) deteriorates the prognosis in patients with coronary heart disease. However, the prognostic value of different glucose abnormalities (GA) other than DM in subjects with acute myocardial infarction (AMI) treated invasively remains unclear. AIMS: To assess the incidence and impact of GA on clinical outcomes in AMI patients treated with percutaneous coronary intervention (PCI). METHODS: A single-center, prospective registry encompassed 2733 consecutive AMI subjects treated with PCI. In all in-hospital survivors (n = 2527, 92.5%) without the history of DM diagnosed before or during index hospitalization standard oral glucose tolerance test (OGTT) was performed during stable condition before hospital discharge and interpreted according to WHO criteria. The mean follow-up period was 37.5 months. RESULTS: The incidence of GA was as follows: impaired fasting glycaemia - IFG (n = 376, 15%); impaired glucose tolerance - IGT (n = 560, 22%); DM (n = 425, 17%); new onset DM (n = 384, 15%); and normal glucose tolerance - NGT (n = 782, 31%). During the long-term follow-up, death rate events for previously known DM, new onset DM and IGT were significantly more frequent than those for IFG and NGT (12.3; 9.6 and 9.4 vs. 5.6 and 6.4%, respectively, P < 0.05). The strongest and common independent predictors of death in GA patients were glomerular filtration rate < 60 ml/min/1,73 m^2 (HR 2.0 and 2.8) and left ventricle ejection fraction < 35% (HR 2.5 and 1.8, all P < 0.05) respectively. CONCLUSIONS: Glucose abnormalities are very common in AMI patients. DM, new onset DM and IGT increase remote mortality. Impaired glucose tolerance bears similar long-term prognosis as diabetes.

Implantation feasibility, procedure-related adverse events and lead performance during 1-year follow-up in patients undergoing triple-site cardiac resynchronization therapy: a substudy of TRUST CRT randomized trial.

INTRODUCTION: This substudy was to assess implantation feasibility and long-term safety of triple-site resynchronization therapy (CRT) in a series of consecutive patients included in a randomized trial. METHODS AND RESULTS: One hundred consecutive patients enrolled into Triple-Site Versus Standard Cardiac Resynchronization Therapy Randomized Trial were analyzed. Eligibility criteria included NYHA class III-IV, sinus rhythm, QRS ≥ 120 milliseconds, left ventricular ejection fraction ≤35%, and significant mechanical dyssynchrony. Patients were randomized in a 1:1 ratio to conventional or triple-site CRT with defibrillator-cardioverter. After 12 months of resynchronization 30% of patients with conventional resynchronization and 12.5% with triple-site CRT were in NYHA functional class III or IV (P < 0.05). Implantation of triple-site systems was significantly longer (median 125 minutes vs 96 minutes; P < 0.001), with higher fluoroscopic exposure, especially in patients with very enlarged left ventricle or pulmonary hypertension. Implantation success-rate was similar in the triple-site and conventional group (94% vs 98%; P = NS); however, additional techniques had to be used in a greater proportion of the triple-site patients (33.3% vs 16%; P < 0.05). Long-term lead performance tests revealed significantly higher pacing threshold and lower impedance in the triple-site group. The 1-year incidence of serious, CRT-related adverse events was similar in triple-site and conventional group (20.8% vs 30%; P = NS). CONCLUSIONS: Triple-site CRT is associated with more pronounced functional improvement than standard resynchronization. This form of pacing is equally safe and feasible as the conventional CRT. However, triple-site procedure is more time-consuming, associated with higher radiation exposure and the need to use additional techniques. Triple-site resynchronization is associated with less favorable electrical lead characteristics.

The risk of stroke in patients with acute myocardial infarction treated invasively.

BACKGROUND: To assess the incidence, clinical significance, and independent risk factors of stroke in patients with acute myocardial infarction (AMI) treated invasively. MATERIALS AND METHODS: We analyzed 2520 consecutive patients with AMI admitted between 2003 and 2007. Data on long-term follow-up were screened to identify patients who had stroke. RESULTS: During a median of 25.5 months, 52 patients (2.07%) had stroke. The cumulative risk of stroke was the highest during the first year (1.23%) and particularly within the first month after AMI (0.28%). Patients with stroke were at a significantly higher risk of developing major adverse cardiovascular events, including repeated AMI (26.9 vs. 14.6%, P<0.05) and death (40.4 vs. 13.6%, P<0.001). Previous stroke [hazard ratio (HR) 5.89], female sex (HR 2.60), glomerular filtration rate <60 ml/min/1.73 m (HR 1.92), and contrast nephropathy (HR 1.87, all P<0.05) were independent predictors of stroke. The receiver-operating curve calculated for the Contrast nephropathy, renal Insufficiency, Female, prior Stroke (CIFS) risk scale demonstrated a significant predictive value of this scale (area under curve 0.73, P<0.001). Patients with the lowest, median, and highest risk scores (<4, 4-5, ≥6 points, respectively) differed significantly with regard to stroke incidence (2.1 vs. 7.9 vs. 14.0%, respectively, P<0.05). CONCLUSION: The risk of stroke is the highest within the first month after AMI. Stroke is a marker of unfavorable outcome in this population. Independent risk factors for stroke after invasive treatment of AMI are different from those commonly perceived as stroke predictors. A risk scale based on sex, stroke history, and renal impairment is useful in risk stratification.

Effect of cardiac resynchronization on gradient reduction in patients with obstructive hypertrophic cardiomyopathy: preliminary study.

BACKGROUND: The purpose of this study was to assess the effectiveness of cardiac resynchronization therapy (CRT) in terms of outflow tract gradient reduction and functional improvement in symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) requiring implantable cardioverter-defibrillator (ICD) implantation. METHODS: Eleven consecutive symptomatic HOCM patients with a significant (≥40 mmHg) gradient and indications for ICD, but without indications for resynchronization, underwent CRT-D implantation. Nine of them (four female, median age of 50 years) in whom the procedure succeeded were screened for New York Heart Association (NYHA) class, outflow gradient, mechanical dyssynchrony, QRS-width change, and 6-minute walking distance (6MWD) and peak oxygen consumption (VO(2)peak) improvement after 6 months and remotely. RESULTS: After 6 months of pacing, NYHA class decreased (median 1 vs 2, respectively); peak (33 vs 84 mmHg) and mean (13 vs 38 mmHg) outflow tract gradients were reduced; and QRS width (143 vs 105 ms), intraventricular dyssynchrony (35 vs 55 ms), and VO(2)peak (19.5 vs 14.2 mL/kg/min) increased significantly (all P < 0.05) compared to baseline. In six of nine patients (67%), the peak gradient was reduced >50% and reached <40 mmHg. After a median of 36 months, the outflow gradient decreased even more (8 mmHg) and was significantly (P < 0.05) lower than after 6 months of CRT. CONCLUSIONS: These preliminary data suggest that CRT seems to be an effective method of reducing the outflow tract gradient and improving the functional status of symptomatic HOCM patients requiring ICD implantation. Our findings need to be confirmed by more extensive studies.

The impact of unsuccessful percutaneous coronary intervention on short- and long-term prognosis in STEMI and NSTEMI.

OBJECTIVES: To compare the impact of the efficacy of percutaneous coronary intervention (PCI) on prognosis in ST and non-ST elevation myocardial infarction (STEMI and NSTEMI) patients with respect to infarct-related artery (IRA). BACKGROUND: The significance of the efficacy of PCI in STEMI and NSTEMI depending on the type of IRA has yet to be clarified. METHODS: Study population consisted of 2,179 STEMI and 554 NSTEMI consecutive patients treated with urgent PCI. The efficacy of PCI (TIMI [thrombolysis in myocardial infarction] 3 vs. TIMI < 3) was assessed with regard to the type of IRA (left anterior descending artery, circumflex artery [Cx] or right coronary artery). The mean follow-up was 37.5 months. RESULTS: The rate of unsuccessful PCI was similar in STEMI and NSTEMI irrespectively of IRA (14.1 vs. 17.7%; P = 0.062). In STEMI, unsuccessful PCI was associated with significantly higher early (23.1 vs. 5.6%; P < 0.001) and late (29.9 vs. 12.8%; P < 0.001) mortality regardless of IRA. In NSTEMI, the inefficacious PCI significantly increased early (19.0% vs. 0.9%; P < 0.001) and late (27.3% vs. 6.3%; P < 0.001) mortality only in patients with Cx-related infarction. Unsuccessful PCI of IRA was an independent risk factor for death in STEMI (HR 1.64; P < 0.05), but not in NSTEMI (P = 0.64). Further analysis showed that whilst unsuccessful PCI of any vessel in STEMI is an independent risk factor for death, in NSTEMI this applies to unsuccessful PCI of Cx only. CONCLUSIONS: The significance of unsuccessful PCI of IRA seems to be different in STEMI and NSTEMI. Unsuccessful PCI is an independent risk factor for death in STEMI regardless of IRA and in NSTEMI with the involvement of Cx.

Transseptal versus transaortic approach for radiofrequency ablation in patients with cardioverter-defibrillator and electrical storm.

PURPOSE: Radiofrequency current ablation (RFCA) of ventricular tachycardia (VT) is usually performed using a retrograde transaortic approach. We compared the mapping accuracy, procedural course, safety, and results of VT ablation using transseptal and transaortic route. METHODS: Twenty-one consecutive patients with ischemic cardiomyopathy and history of electrical storm underwent RFCA with electro-anatomic mapping system. In six patients, ablation was performed with transseptal approach (transseptal group); in 15, retrograde approach to the left ventricle was used (retrograde group). RESULTS: The endocardial surface of the left ventricle was similarly accessible in both methods. Less detailed maps of interventricular septum were constructed with the use of transseptal approach. The RFCA success rate was similar in the transseptal and retrograde groups (83 vs. 80%, p = NS). The median procedural time was 112 min in transseptal vs. 145 min in the retrograde group; radiation exposure was 200 vs. 67 mGy, respectively (both p < 0.05), and fluoroscopy time was 22 vs.16 min (p = NS). During the 3-month follow-up, VT recurrence occurred in one patient in the transseptal group and in three patients in the retrograde group (p = NS). CONCLUSIONS: Transseptal approach is an accurate, safe, feasible, and effective method of RF ablation in patients with malignant, recurrent ventricular arrhythmias. However, limited access to the septal regions with the use of this method has to be remembered. Transseptal approach may be considered as an alternative to the transaortic route in patients with contraindication to the latter.

Triple-site versus standard cardiac resynchronization therapy study (TRUST CRT): clinical rationale, design, and implementation.

BACKGROUND: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with heart failure (HF), lowered LV ejection fraction, and wide QRS. However, many patients (< or =40%) do not respond to this form of pacing. TRUST CRT is a prospective, single-center, randomized, single-blind, parallel, and controlled study that has been designed to treat patients with moderate to severe HF (NYHA III-IV), QRS > or =120 ms, sinus rhythm, LV dysfunction (EF < or = 35%), and signs of mechanical dyssynchrony. OBJECTIVE: The primary objective will evaluate the 6-month's combined endpoint of alive status, freedom from hospitalization for HF or heart transplantation, relative > or =10% increase in LV ejection fraction, > or =10% in peak oxygen consumption, and > or =10% in 6-minute walking distance. METHODS: Patients with HF receiving optimal pharmacotherapy, with LV dysfunction, mechanical dyssynchrony, wide QRS and sinus rhythm will be randomized in a 1: 1 fashion to standard or triple-site CRT-D. Patients will be followed for 1 week, 1, 3, and 6 months during a blind phase, then every 6 months until study completion. One hundred patients will be enrolled by the study center. CONCLUSIONS: TRUST CRT is a randomized, clinical trial in CRT candidates to evaluate the effectiveness of triple-site pacing versus standard resynchronization in patients with HF.

[Radiofrequency catheter ablation in the treatment of arrhythmias in children--efficacy, safety of the method, predictors of the procedural course and acute success]. / Ablacja pradem o czestotliwosci radiowej w leczeniu arytmii u dzieci-skutecznosc, bezpieczenstwo metody i czynniki warunkujace jej przebieg i sukces bezposredni.

BACKGROUND: Radiofrequency current ablation (RFCA) is a safe and efficient method of treatment in adult patients with symptomatic arrhythmias. Recently RFCA is being also used in the treatment of children with cardiac arrhythmias, however its value in this set of patients is poorly documented. Aims of our study were to assess the feasibility and safety of RFCA procedures in children with symptomatic supraventricular and ventricular arrhythmias, and to identify the parameters which influence the probability of acute success and RFCA course. METHODS: Consecutive 110 patients aged less than 18, who underwent RFCA due to the symptomatic arrhythmias at our center were included into a retrospective analysis. The patients presented mainly with the preexcitation syndrome (57%), 13.6% had ectopic ventricular arrhythmias, in 17.3% nodal reentrant tachycardia, in 8.2% intraatrial reentry tachycardia (IART), whereas in 5.4% ectopic atrial tachycardia (EAT) was diagnosed. Three patients had multiple arrhythmias. In ten subjects congenital heart defect was diagnosed in the past, which was treated surgically in 8. Analyzed parameters included: RFCA success-rate, procedure duration, fluoroscopy-time, perioperative complications and arrhythmia recurrence-rate during 6 months follow-up. RESULTS: Ablation was successful in 101 (91.8%) patients and abolished 104 out of 113 (92%) treated arrhythmias. Out of 9 patients with unsuccessful RFCA, three had congenital heart defect. Two complications occurred intra-operatively in two patients: in one patient pneumothorax was observed following jugular vein puncture, which resolved spontaneously without the need of drainage, in the second patient transient atrioventricular conduction block occurred during radiofrequency current application. Mean procedure duration in the studied population was 118.9 +/- 46 min, fluoroscopy exposure equaled 22.3 +/- 17min. In twelve patients (10.9%) arrhythmia recurred during the follow-up period. The longest procedure duration was observed in patients with EAT and IART, the longest fluoroscopy-time in subjects with IART, whereas the shortest fluoroscopy was observed in patients with the ventricular ectopic arrhythmias. Success-rates, complications, and recurrence-rates did not differ irrespectively from arrhythmia treated. The only independent predictor of unsuccessful RFCA was the presence of congenital cardiac defect (adjusted OR 0.15, p<0.05). The presence of cardiac defect, procedure performed without electroanatomic mapping system and less experienced operators were the parameters associated with longer fluoroscopic exposure. CONCLUSIONS: Radiofrequency current ablation is a safe and efficient method of treatment in children with arrhythmias. The presence of congenital heart defect was a factor influencing unfavorably the probability of successful RFCA. Procedural course was related to the experience of electrophysiology team, the use of advanced mapping systems and presence of cardiac defect.

Sleep apnoea as a predictor of mid- and long-term outcome in patients undergoing cardiac resynchronization therapy.

AIMS: To assess the impact of baseline apnoea-hypopnoea index (AHI) on mid-term outcome and its change after 6 months of cardiac resynchronization therapy (CRT) on remote outcome. METHODS AND RESULTS: In 71 patients with CRT devices, Holter-derived AHI was assessed before and 6 months after the procedure. Baseline AHI >20 was considered abnormal. After 6 months of CRT, a 50% decrease of baseline AHI was considered significant and stratified patients into AHI dippers and non-dippers, except those who preserved normal AHI. Prognostic value of baseline AHI and its change were assessed in relation to mortality and major cardiac events (MACE). More patients with an abnormal AHI died during 6 months follow-up (P = 0.02), especially due to sudden cardiac death. MACE-rate was insignificantly higher in abnormal AHI patients. Significantly higher mortality (P = 0.001), especially due to heart failure progression and higher MACE-rate (P < 0.001) during further observation were observed in AHI non-dippers. In multivariate analysis, the absence of AHI reduction was an independent predictor of mortality [hazard ratio (HR) 6.56, P = 0.015)] and MACE (HR 6.05, P = 0.002). CONCLUSIONS: Abnormal baseline AHI identifies patients prone to death during mid-term observation. Lack of AHI reduction after 6 months of CRT is an independent risk factor of death and MACE during further follow-up.

Mid-term outcomes of triple-site vs. conventional cardiac resynchronization therapy: a preliminary study.

BACKGROUND: The primary objectives of this study were to compare the implantation course of triple-site (double left-single right) and conventional cardiac resynchronization devices. The secondary target was to assess mid-term outcomes of both types of cardiac resynchronization therapy (CRT). METHODS: Fifty-four patients with NYHA classes III-IV, left ventricular EFor=120 ms were included; 27 received triple-site pacemakers (TRIV group), 27 conventional CRT devices (BIV group). Procedural course, clinical data, QRS duration, echocardiographic parameters, peak oxygen consumption (VO2max) and 6-minute walking distance (6MWD) were screened for inter-group differences. RESULTS: Procedure duration was higher in TRIV than in BIV group (197.6 vs. 137.6 min, P<0.001), fluoroscopy exposure and complication-rates were similar. After 3 months of CRT, triple-site pacing was associated with a more significant (P<0.05) NYHA class reduction (by 1.4 vs. 1.0 class, respectively), increase in VO(2) max (2.9 vs. 1.1 mL/kg/min) and 6MWD (98.7 vs. 51.6 m) than conventional CRT. A higher EF and more improved intraventricular synchrony were observed in the TRIV than in the BIV group. The response rate in the TRIV group was 96.3% vs. 62.9% in the conventional group (P=0.002). Triple-site stimulation was an independent predictor of response to CRT (adjusted odds ratio 26.4, P=0.01). CONCLUSIONS: Triple-site resynchronization appears to be more beneficial than conventional CRT. Upgrade to triple-site CRT may be considered in non-responders to standard resynchronization.

Radiofrequency catheter ablation in children and adolescents with preexcitation syndrome.

BACKGROUND: Atrioventricular reentrant tachycardia (AVRT) is the most common tachycardia, accounting for 70% of regular narrow-QRS arrhythmias in children. Because of the potential disadvantages of a life-long drug therapy and relatively favourable results from radiofrequency catheter ablation (RFCA) therapy in adults, the indications for ablation therapy in children with preexcitation syndrome (PS) need to be considered. AIM: To assess efficacy and safety of RFCA in children and adolescents with PS. METHODS: The study population consisted of 302 consecutive, symptomatic, drug-refractory patients with PS undergoing RFCA. Two age groups were selected: 52 patients younger than 19 years (24 females, age 15.38+/-2.53 years); and 250 adults (115 females, age 38.67+/-13.1 years). In all study patients electrophysiological study and radiofrequency catheter ablation were performed. Comparative analysis between groups was performed with respect to procedure duration, fluoroscopy exposure time, location of accessory pathways (AP), success rate, recurrences and complications. RESULTS: No significant differences between the groups were noted with respect to procedure duration and exposure time. Success and recurrence rates did not differ between the two-age groups. The mean procedure time for children was 124.12+/-43.48 min (range 45-285) and for adults - 126.3+/-61.49 min (range 25-330) (NS). The mean fluoroscopy time for children was 27.95+/-16.86 min (range 4-75) and for adults - 31.27+/-25.51 min (range 1-131) (NS). The initial RF ablation procedure was successful in 48 (92.31%) children and in 233 (93.2%) adults (NS). Recurrence rate was 12.5% (6 patients) in children vs. 8.58% (20 patients) in adults (NS). In one child (1.92%) and in two adult patients (0.8%) serious complication occurred (NS). Electrophysiological study revealed significantly more frequent presence of the right free wall and right antero-septal AP in children than in adults (21.15 vs. 7.6%, and 17.31 vs. 5.2%, respectively, p <0.01). In adults more frequent left antero-lateral AP was detected: 32.4 vs. 7.69%, p <0.01. CONCLUSIONS: Radiofrequency catheter ablation is a safe and efficient procedure in paediatric patients with preexcitation syndrome. Effectiveness, safety, recurrence rate and RFCA procedural aspects, including total procedure time and fluoroscopy time, are comparable in paediatric patients with PS and in adults.

Triple-site biventricular pacing in patients undergoing cardiac resynchronization therapy: a feasibility study.

AIMS: To evaluate implantation safety and efficiency of triple-site (double left-single right) cardiac resynchronization therapy (CRT) and to assess the outcome of this procedure. METHODS AND RESULTS: Twenty-six patients with New York Heart Association (NYHA) class III-IV, left ventricular ejection fraction (EF) < or = 35%, and QRS > or = 120 ms underwent triple-site CRT. Procedural course and complications were analysed. NYHA class, QRS duration, echocardiographic parameters, peak oxygen consumption (VO(2)max), and 6 min walking distance (6MWD) were assessed at baseline and after 3 months. Responders were defined by survival, by no re-hospitalization for heart failure, and by >10% EF, VO(2)max, and 6MWD increase. Implantation was successful in 22 patients (84.6%). Procedure duration (199.1 min) and fluoroscopy time (38.7 min) were higher than in standard procedures. Two clinically silent coronary sinus dissections occurred intra-operatively; one phrenic nerve stimulation and one pocket infection were observed during follow-up. After 3 months of CRT, a significant reduction (P < 0.05) of NYHA class, increment of VO(2)max, 6MWD, EF, and improvement of indices of dyssynchrony were observed. Response rate in the studied group was 95.4%. CONCLUSION: Triple-site resynchronization appears to be a safe and efficient treatment method, with high response rate. Further studies are needed to evaluate the role of this pacing mode in CRT.

Triple site biventricular pacing in a patient with congestive heart failure and severe mechanical dyssynchrony.

We report on a case of a 62-year-old patient with symptomatic heart failure and severe ventricular electrical and mechanical dyssynchrony, who was implanted percutaneously with a triple site (dual-left single-right) resynchronization device. At 3-months follow-up, the patient's functional status improved significantly as shown by subjective and objective tests. Furthermore, this mode of pacing has allowed nearly complete inter- and intraventricular mechanical resynchronization.