Showing papers in "Europace in 2006"

ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death

Abstract: It is important that the medical profession plays a significant role in critically evaluating the use of diagnostic procedures and therapies as they are introduced and tested in the detection, management, or prevention of disease states. Rigorous and expert analysis of the available data documenting absolute and relative benefits and risks of those procedures and therapies can produce helpful guidelines that improve the effectiveness of care, optimize patient outcomes, and favorably affect the overall cost of care by focusing resources on the most effective strategies. The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) have jointly engaged in the production of such guidelines in the area of cardiovascular disease since 1980. The ACC/AHA Task Force on Practice Guidelines, whose charge is to develop, update, or revise practice guidelines for important cardiovascular diseases and procedures, directs this effort. The Task Force is pleased to have this guideline developed in conjunction with the European Society of Cardiology (ESC). Writing committees are charged with the task of performing an assessment of the evidence and acting as an independent group of authors to develop or update written recommendations for clinical practice. Experts in the subject under consideration have been selected from all 3 organizations to examine subject-specific data and write guidelines. The process includes additional representatives from other medical practitioner and specialty groups when appropriate. Writing committees are specifically charged to perform a formal literature review, weigh the strength of evidence for or against a particular treatment or procedure, and include estimates of expected health outcomes where data exist. Patient-specific modifiers, comorbidities, and issues of patient preference that might influence the choice of particular tests or therapies are considered as well as frequency of follow-up and cost effectiveness. When available, information from studies on cost will be considered; however, review …

Analysis of surface electrocardiograms in atrial fibrillation: techniques, research, and clinical applications

Abstract: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Neither the natural history of AF nor its response to therapy is sufficiently predictable by clinical and echocardiographic parameters. The purpose of this article is to describe technical aspects of novel electrocardiogram (ECG) analysis techniques and to present research and clinical applications of these methods for characterization of both the fibrillatory process and the ventricular response during AF. Atrial fibrillatory frequency (or rate) can reliably be assessed from the surface ECG using digital signal processing (extraction of atrial signals and spectral analysis). This measurement shows large inter-individual variability and correlates well with intra-atrial cycle length, a parameter which appears to have primary importance in AF maintenance and response to therapy. AF with a low fibrillatory rate is more likely to terminate spontaneously and responds better to antiarrhythmic drugs or cardioversion, whereas high-rate AF is more often persistent and refractory to therapy. Ventricular responses during AF can be characterized by a variety of methods, which include analysis of heart rate variability, RR-interval histograms, Lorenz plots, and non-linear dynamics. These methods have all shown a certain degree of usefulness, either in scientific explorations of atrioventricular (AV) nodal function or in selected clinical questions such as predicting response to drugs, cardioversion, or AV nodal modification. The role of the autonomic nervous system for AF sustenance and termination, as well as for ventricular rate responses, can be explored by different ECG analysis methods. In conclusion, non-invasive characterization of atrial fibrillatory activity and ventricular response can be performed from the surface ECG in AF patients. Different signal processing techniques have been suggested for identification of underlying AF pathomechanisms and prediction of therapy efficacy.

Standardized-care pathway vs. usual management of syncope patients presenting as emergencies at general hospitals

Abstract: Aims The study hypothesis was that a decision-making approach improves diagnostic yield and reduces resource consumption for patients with syncope who present as emergencies at general hospitals. Methods and results This was a prospective, controlled, multi-centre study. Patients referred from 5 November to 7 December 2001 were managed according to usual practice, whereas those referred from 4 October to 5 November 2004 were managed according to a standardized-care pathway in strict adherence to the recommendations of the guidelines of the European Society of Cardiology. In order to maximize its application, a decision-making guideline-based software was used and trained core medical personnel were designated—both locally in each hospital and centrally—to verify adherence to the diagnostic pathway and give advice on its correct application. The ‘usual-care’ group comprised 929 patients and the ‘standardized-care’ group 745 patients. The baseline characteristics of the two study populations were similar. At the end of the evaluation, the standardized-care group was seen to have a lower hospitalization rate (39 vs. 47%, P =0.001), shorter in-hospital stay (7.2±5.7 vs. 8.1±5.9 days, P =0.04), and fewer tests performed per patient (median 2.6 vs. 3.4, P =0.001) than the usual-care group. More standardized-care patients had a diagnosis of neurally mediated (65 vs. 46%, P =0.001) and orthostatic syncope (10 vs. 6%, P =0.002), whereas fewer had a diagnosis of pseudo-syncope (6 vs. 13%, P =0.001) or unexplained syncope (5 vs. 20%, P =0.001). The mean cost per patient and the mean cost per diagnosis were 19 and 29% lower in the standardized-care group ( P =0.001). Conclusion A standardized-care pathway significantly improved diagnostic yield and reduced hospital admissions, resource consumption, and overall costs.

Left atrial tachycardia after circumferential pulmonary vein ablation for atrial fibrillation: incidence, electrophysiological characteristics, and results of radiofrequency ablation.

Abstract: Aims To investigate the incidence, electrophysiological properties, and ablation results for left atrial (LA) tachycardia as a sequel to the circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF). Methods and results Sixty-seven patients with AF underwent CPVA. Sustained LA tachycardia developed in 21/67 (31%) patients and in 16/21 symptomatic patients 55 LA tachycardias (3.4±2.4 per patient) were mapped: 18 (33%) tachycardias were related to macro-re-entry around the mitral valve (7) or pulmonary vein(s) (11). In 20 tachycardias (36%), a ‘small-loop’ LA re-entrant tachycardia (LART) was identified; gaps in prior ablation lines (7 LART) or an area of extremely slow conduction adjacent to the CPVA lesions (13 LART) were crucial for these re-entries. Seventeen tachycardias (31%) were too unstable for complete mapping. Ablation was a primary success in 34 of 38 (89%) mapped LART, but in eight of 21 procedures, cardioversion was necessary to achieve sinus rhythm. Conclusion LART develops in a high percentage of patients after CPVA. Small-loop re-entry, which is difficult to map, may arise and patients suffer from several and/or unstable variants of LART. Thus, mapping and ablation of these LART is challenging and the overall success is yet not satisfactory.

Heart rate variability in an ageing population and its association with lifestyle and cardiovascular risk factors: results of the SAPALDIA study

Abstract: Aims (i) To report associations between cardiovascular risk factors and heart rate variability (HRV) in a general population and (ii) to provide normal values for various HRV measurements in a healthy European general population sample aged ≥50. Methods and results Twenty-four-hour electrocardiograms were recorded in 1742 randomly selected SAPALDIA (Swiss cohort study on Air Pollution and Lung Diseases in Adults) participants aged ≥50. In multivariate regression analyses, women ( n =895) had a 6.1% lower standard deviation of all normal RR (NN) intervals (SDNN), a 11.4% lower total power (TP), and a 27.2% lower low-frequency (LF) power than men ( n =847). Per unit increase in BMI, SDNN decreased by 0.7% and TP decreased by 1.2%. Persons with high blood pressure had a 9.2% lower LF than normotensive persons and current smokers a 15.5% lower LF than never smokers. Each hour of heavy physical exercise was associated with a 2.0% increase in SDNN, a 3.6% increase in the high frequency (HF) range power and a 4.2% increase in LF power. Higher levels of uric acid, high-sensitive C-reactive protein and non-HDL-cholesterol were associated with lower TP, HF and LF. Percentiles of TP and LF/HF as a function of age were calculated for an asymptomatic subsample of participants ( n =499) free of cardioactive medications. Conclusion Heart rate variability in a general population sample shows expected associations with all known cardiovascular risk factors, although not identically for all HRV domains. Together with our percentile estimates for HRV as a function of age, these findings could assist scientists in interpreting 24 h HRV values and factors influencing them in an ageing population.

Does intensity of rate-control influence outcome in atrial fibrillation? An analysis of pooled data from the RACE and AFFIRM studies

Abstract: Aims The AFFIRM and RACE studies showed that rate control is an acceptable treatment strategy for atrial fibrillation (AF). We examined whether strict rate control offers benefit over more lenient rate control. Methods and Results We compared the outcome of patients enrolled in the rate-control arms of AFFIRM and RACE, using data from patients who met a composite of overlapping inclusion and exclusion criteria. We evaluated 1091 patients, 874 from AFFIRM and 217 from RACE. In AFFIRM, the rate-control strategy aimed for a resting heart rate � 80 bpm and heart rate during daily activity of � 110 bpm. In RACE, a more lenient approach was taken: resting heart rate ,100 bpm. Primary endpoint was a composite of mortality, cardiovascular hospitalization, and myocardial infarction. Mean heart rate across all follow-up visits for patients in AF was lower in AFFIRM (76.1 vs. 83.4 bpm). Event-free survival for the occurrence of the primary endpoint did not differ (64% in AFFIRM vs. 66% in RACE). Patients with mean heart rates during AF within the AFFIRM (� 80) or RACE (,100) criteria had a better outcome than patients with heart rates � 100 (hazard ratios 0.69 and 0.58, respectively, for � 80 and ,100 compared with � 100 bpm). Conclusion Stringency of the approach to rate control, based on the comparison of the AFFIRM and RACE studies, was not associated with an important difference in clinical events.

Electrical isolation of pulmonary veins in patients with atrial fibrillation: reduction of fluoroscopy exposure and procedure duration by the use of a non-fluoroscopic navigation system (NavX).

Abstract: Aims The aim of the study was to investigate the feasibility of performing segmental pulmonary vein (PV) isolation guided by the NavX®(Endocardial Solutions, St Jude Medical, Inc., St Paul, MN, USA) system without the three-dimensional (3D) geometric reconstruction option and whether the use of NavX system will reduce the radiation exposure and procedure duration. Methods and results The study included 64 patients with symptomatic paroxysmal or permanent atrial fibrillation, in whom PV isolation was performed using fluoroscopic guidance ( n =32) or the NavX system ( n =32). Pulmonary vein mapping with a circular mapping catheter allowed the identification and localization of myocardial connections between the PV and the left atrium. PV isolation was performed by radiofrequency ablation of these connections at the atrial aspect of the PV ostium. Primary success rate for isolated PVs did not differ significantly in patients ablated under fluoroscopic guidance vs. those ablated under guidance of NavX system [100/107 PVs (93.5%) vs. 120/124 PV (96.8%; P =n.s.)]. Compared with fluoroscopy guided procedures, NavX-guided procedures showed a significant reduction in the fluoroscopy time (75.8±24.5 vs. 38.9±19.3 min, P <0.05), total X-ray exposure (93.2±51.6 vs. 56.6±37.9 Gy cm2, P =0.03), and total procedural time (237.7±65.4 vs. 188.6±62.7 min, P =0.01). The mean follow-up was 9.5±3.0 months. One patient in each group was lost to follow-up. Seven-day Holter monitoring showed that 23 of 31 patients (74.2%) in the NavX-guided group and 21 of 31 patients (67.7%) in the fluoroscopy-guided group were in sinus rhythm ( P =0.57). Conclusion The 3D visualization of the catheters by NavX system allows a rapid and precise visualization of the mapping and ablation catheters at the PV ostia and markedly reduces fluoroscopy time, total X-ray exposure, and procedural duration during PV isolation compared with ablation performed under fluoroscopy guidance.

Biventricular stimulation to prevent cardiac desynchronization: rationale, design, and endpoints of the 'Biventricular Pacing for Atrioventricular Block to Prevent Cardiac Desynchronization (BioPace)' study

Abstract: Despite the deleterious effects of cardiac dyssynchrony and the positive effects of cardiac resynchronization therapy, patients with high-degree atrioventricular block continue to receive desynchronizing right ventricular (RV) pacing systems. Although it is unclear whether the negative effects of RV pacing and left bundle branch block (LBBB) are comparable, and whether they depend on the presence and the degree of structural heart disease, one may hypothesize that RV pacing may have similar effects to LBBB. In the BioPace trial, the long-term effects of RV pacing vs. biventricular pacing will be prospectively compared in 1200 pacemaker patients with high likelihood of mostly paced ventricular events, regardless of whether in sinus rhythm or in atrial fibrillation (AF). After echocardiographic examination of left ventricular (LV) function, patients will be randomly assigned to the implantation of an RV vs. a biventricular pacing system and followed for up to 5 years. Primary study endpoints are survival, quality of life (QoL), and the distance covered in a 6-min hall walk (6-MHW) at 24 months after implantation. Secondary endpoints are QoL and the 6-MHW result at 12 months after implantation, hospitalization rate, LV dimensions, LV ejection fraction, and the development of chronic AF and other adverse events.

Twenty years of paediatric cardiac pacing: 515 pacemakers and 480 leads implanted in 292 patients

Abstract: Aims The aim of this study was to evaluate long-term outcome of pacemakers (PMs) in paediatric patients. Methods and results Patients’ data were retrospectively reviewed. We recorded the techniques and systems used, any complication, and outcome. Endocardial leads were inserted by transcutaneous puncture of subclavian vein and fixed with a non-absorbable ligature, and epicardial leads by standard surgical technique. Lead survival was calculated and plotted with the product limit method of Kaplan– Meier. Between 1982 and 2002, 292 patients, aged 8+7 years (range 1 day–18 years), underwent PM implantation: the first PM had endocardial leads in 165 patients and epicardial in 127 patients. Structural heart disease (HD) was present in 239 patients. Follow-up was 5+4 (range 0.1–18) years. There were no pacing-related deaths. In total, 211 endocardial implantation procedures with 90 atrial and 165 ventricular leads and 145 epicardial procedures with 103 atrial and 123 ventricular leads were performed. Early (,3 months) complications: haemothorax occurred in 3.5% of endocardial leads and dislodgement was not significantly different for atrial and ventricular endocardial leads. Late complications: 63 leads failed (48 epicardial), with the worst outcome for conventional epicardial leads (31 vs. 9% endocardial, P , 0.05; steroid eluting 8% epicardial vs. 5% endocardial, P ¼ NS). Endocardial atrial leads failed (7%) in operated HD and ventricular leads failed (6%) after body growth, without difference in estimated mean survival time (11 years). Early and late PM infection/erosion was 2% in all patients. Conclusion Pacing in children shows good results, but complications are frequent and related to leads. Endocardial pacing showed better long-term outcome.

Determination of optimal atrioventricular delay for cardiac resynchronization therapy using acute non-invasive blood pressure.

Abstract: Aims In this study, we apply non-invasive blood pressure (BP) monitoring, by continuous finger photoplethysmography (Finometer), to detect directly haemodynamic responses during adjustment of the atrioventricular (AV) delay of cardiac resynchronization therapy (CRT), at different heart rates. Methods and results Twelve patients were studied with six re-attending for reproducibility assessment. At each AV delay, systolic BP relative to a reference AV delay of 120 ms (SBPrel) was calculated. We found that at higher heart rates, altering the AV delay had a more pronounced effect on BP (average range of SBPrel ¼ 17.4 mmHg) compared with resting rates (average range of SBPrel ¼ 6.5 mmHg), P , 0.0001. Secondly, peak AV delay differed between patients (minimum 120 ms, maximum 200 ms). Thirdly, small changes in AV delay had significant BP effects: programming AV delay 40 ms below the peak AV delay reduced SBPrel by 4.9 mmHg (P , 0.003); having it 40 ms above the peak decreased SBPrel by 4.4 mmHg (P , 0.0005). Finally, the peak AV delay is highly reproducible both on the same day and at 3 months (Bland–Altman difference: 3+ 8 ms). Conclusions Continuous non-invasive arterial pressure monitoring demonstrates that even small changes in AV delay from its haemodynamic peak value have a significant effect on BP. This peak varies between individuals, is highly reproducible, and is more pronounced at higher heart rates than resting rates.

Cardiac resynchronization therapy for adult congenital heart disease patients with a systemic right ventricle: analysis of feasibility and review of early experience.

Abstract: Aims Patients with a systemic right ventricle (RV) frequently develop heart failure and may benefit from cardiac resynchronization therapy (CRT). We aimed to assess the proportion of unselected patients with a systemic RV eligible for CRT and to review available data on the effect of CRT in congenital heart disease patients. Methods and results Adhering to criteria derived from landmark CRT trials, we determined the eligibility of patients with a systemic RV for CRT. Seventy-five transposition of the great arteries (TGA) patients (age 29.5+/-10.2 years) and 49 patients with congenitally corrected (cc) TGA (age 36.2+/-12.8 years) were studied. Full criteria for CRT were met in 4.0% of the TGA patients and 4.1% of the ccTGA patients. Including New York Heart Association class 2 patients, 9.3% of TGA and 6.1% of ccTGA patients were eligible for CRT. Conclusion Four to 9% of unselected patients with a systemic RV appear to be potential candidates for CRT. Although large clinical studies are currently lacking, available data consistently demonstrate that CRT improves haemodynamics in congenital heart disease patients and warrants further investigation.

Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation

Abstract: Aims For ablation of ventricular tachycardia (VT) in patients after myocardial infarction, a threedimensional mapping system is often used. We report on our overall success rate of VT ablation using CARTO in 47 patients, with a subgroup analysis comparing VT mapping with the results of mapping that had to be performed during sinus rhythm or pacing (substrate mapping). Methods and results A CARTO map was performed and VT ablation attempted using two strategies: Patients in the VT-mapping group had incessant VT (four patients) or inducible stable VT (18 patients) such that the circuit of the clinical VT could be reconstructed using CARTO. During VT, the critical area of slow conduction was identified using diastolic potentials and conventional concealed entrainment pacing. In contrast, patients in the substrate-mapping group had initially inducible VT. However, a complete VT map was not possible because of catheter-induced mechanical block (six patients) or because haemodynamics deteriorated during the ongoing VT (19 patients). Therefore, pathological myocardium was identified by fragmented, late- and/or low-amplitude (,1.5 mV) bipolar potentials during sinus rhythm or pacing, and the ablation site was primarily determined by pace mapping inside or at the border of this pathological myocardium. Acute ablation success in all patients with regard to noninducibility of the clinical VT or any slower VT was 79% after a single ablation procedure, but increased to 95% after a mean of 1.2 ablation procedures. However, chronic success was 75%, when it was defined as freedom from any ventricular tachyarrhythmia (VT or VF) during a follow-up of 25+ 13 months. In the subgroup analysis, patients in the VT-mapping group were not significantly different from patients in the substrate-mapping group with regard to age (65+7 vs. 65+9 years), ejection fraction (30+7 vs. 30+ 8%), VT cycle length (448+ 81 vs. 429+ 82 ms), number of radiofrequency applications (17+9 vs. 14+6 applications), use of an irrigated tip catheter (23 vs. 32%), and ablation results. Conclusion When using a CARTO-guided approach for VT ablation in patients with coronary artery disease, the freedom from any ventricular arrhythmia is high (75%), but leaves the patient at a 23% risk of developing fast VT/VF during follow-up. Mapping during sinus rhythm or pacing is as successful as mapping during VT.

Patient and staff radiation dosimetry during cardiac electrophysiology studies and catheter ablation procedures: a comprehensive analysis.

Abstract: Aims To perform a comprehensive analysis of all aspects of patient and in-room personnel radiation dosimetry in interventional electrophysiology. Methods and results Measurements were performed during 19 diagnostic electrophysiology studies and 24 catheter ablations. Kerma-area product and exposure time values were 48.7 (6.4–230) Gy cm2 and 25.5 (4.4–79.2) min for ablation, and 12.5 (4.5–117.2) Gy cm2 and 4.5 (1.2–31) min for diagnostic studies, respectively. Patient effective doses were 15.2 (2.1–59.6) mSv for ablation and 3.2 (1.3–23.9) mSv for diagnostic procedures. Radiation risk to the patient was estimated to be up to eight cases of fatal cancer in 10 000 procedures. The risk of development of fatal cancer was less than 3×10−6 per procedure to the primary operator. The risk for the nurse and technician was much lower. The dose per procedure for the primary operator was 7.1 µGy at the eyes, 0.79 µGy at the chest under the lead apron, 13.68 µGy at the chest over the apron, 3.82 µGy at the thyroid, 17.76 µGy at the left hand, and 12.11 µGy at the left knee. Conclusion As far as radiation exposure is concerned, electrophysiology studies followed by radiofrequency ablation are safe procedures for both patient and personnel when performed in catheterization laboratories with modern equipment, experienced operators, and standard safety precautions.

Upgrade to biventricular pacing in patients with conventional pacemakers and heart failure: a double-blind, randomized crossover study

Abstract: Aims To investigate whether patients with previously implanted conventional pacemakers and severe heart failure benefit from an upgrade to a biventricular system. Methods and results Study inclusion criteria were New York Heart Association (NYHA) classes III and IV, dominant paced rhythm, and no left bundle branch block in the pre-pacing ECG. Ten patients with pacemakers (four VVIR due to slow atrial fibrillation and six DDDR, of which four were due to high-degree atrioventricular block and two to sinus node disease) were upgraded to a biventricular pacing (BVP) system. The median duration of pacing before the upgrade was 5.7 years. Assessments of 6-min walk test, symptom score, brain natriuretic peptide (pro-BNP), and echocardiography were made pre-operatively. After a run-in period of 1 month in BVP following the upgrade, the patients were randomized to a 2-month period in either BVP or right ventricular pacing (RVP), followed by 2 months in the other mode, in a double-blind crossover fashion. After each period, the pre-operative measurements were repeated. After study completion, patients were asked to select their preferred period. The median 6-min walking distance was significantly longer in BVP (400 m) vs. RVP (315 m), P =0.02. The symptom score was also significantly better in BVP ( P =0.005). Median pro-BNP was significantly lower in BVP than in RVP, 3030 vs. 5064 ng/L ( P =0.005). Six patients demanded an early crossover in RVP but none in BVP ( P =0.015), and all patients except one expressed a preference for BVP. However, echo parameters did not show any significant differences between BVP and RVP. Conclusion Pacemaker patients with heart failure and dominant paced heart rhythm benefit substantially from an upgrade to BVP, in terms of physical performance and symptoms. The upgrade resulted in significantly improved cardiac function as reflected by reduced levels of pro-BNP.

Predictors of VT/VF-occurrence in ICD patients: results from the PROFIT-Study.

Abstract: Aims Identification of risk factors for ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence in patients with implantable cardioverter-defibrillators (ICD) is reasonable, because ICD patients with multiple risk factors might benefit from more aggressive anti-arrhythmic therapy for the prevention of arrhythmic events. Furthermore, in the era of prophylactic ICD therapy and limited healthcare resources, additional markers are needed for improved patient selection. Methods and results Thus, in Prospective Analysis of Risk Factor for Appropriate ICD Therapy (PROFIT), we prospectively analyzed the role of ejection fraction (EF), N-terminal probrain natriuretic peptide (NT-proBNP), New York Heart Association (NYHA) class, atrial fibrillation, and QRS-duration as independent predictors for VT/VF occurrence in 250 ICD patients. Kaplan–Meier analysis showed that EF , 40% (log-rank P ¼ 0.001), NT-proBNP levels higher than median (� 405 ng/L; log-rank P ¼ 0.04), QRS-duration � 150 ms (log-rank P ¼ 0.016), permanent atrial fibrillation (log-rank P ¼ 0.008), and higher NYHA class (log-rank P ¼ 0.029) were associated with VT/VF occurrence. By multivariate Cox regression analysis EF, QRS-duration and atrial fibrillation remained significantly associated with appropriate VT/VF therapy, whereas there was no relationship among NT-proBNP, NYHA class, and VT/VF occurrence. Stratifying patients according to the number of their independent risk factors (EF , 40%, AF, QRS-width � 150 ms) showed that patients with greater than or equal to two risk factors had a 100% 2-year risk of VT/VF occurrence, whereas patients with no or one risk factor had a 19.3 and 25% 2-year risk, respectively. Conclusions EF , 40%, permanent atrial fibrillation, and QRS � 150 ms are independent predictors for VT/VF occurrence in predominantly secondary prophylactic ICD patients. Combining all independent predictors, we developed a risk score for VT/VF occurrence identifying a subgroup of patients with two or more risk factors who had a 100% 2-year risk. Future studies will reveal if this risk score helps to identify ICD patients suitable for empirical anti-arrhythmic therapy and to improve patient selection for prophylactic ICD therapy.

Thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy

Abstract: Aims Incidence and clinical presentation of thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) were analysed. In reports on ARVD/C, thromboembolism is rarely mentioned. The possible risk factors are: right ventricle (RV) dilatation, aneurysms, and wall motion abnormalities. Methods and results A group of 126 patients (89 male, 37 female, aged 43.6+ 14.3) with ARVD/C was retrospectively analysed for the presence of thromboembolic complications. The mean follow-up period was 99+ 64 months. Thromboembolic complications, i.e. pulmonary embolism (n ¼ 2), RV outflow tract thrombosis with severe RV failure (n ¼ 1), and cerebrovascular accident associated with atrial fibrillation (n ¼ 2) were observed in 4% of the patients. Spontaneous echogenic contrast was observed in seven patients with severe damage to RV. In four of them supraventricular arrhythmias resulting in heart failure were reported. Annual incidence of thromboembolic complications was 0.5/100 patients. Conclusions (i) ARVD/C may be complicated by thrombosis. Annual incidence of such complications is significantly lower than reported for left ventricle failure. (ii) Anticoagulation should be used in ARVD/C patients with large, hypokinetic RV and slow blood flow. (iii) Patients with severe forms of ARVD/C, thrombus formation in the RV and/or spontaneous echocardiographic contrast are at higher risk of a poor outcome.

Onset mechanism of paroxysmal atrial fibrillation detected by ambulatory Holter monitoring

Abstract: Aims The aim of this study was to evaluate the mechanisms of induction of paroxysmal atrial fibrillation (PAF) by analysis of its onset recorded on Holter monitoring (HM) Methods and results One hundred and seven HM were evaluated in 90 patients (mean age 677, cardiac disease in 311%), with one or more self-terminating episodes of PAF, lasting � 30 s Two hundred and thirty-three episodes of PAF were detected A triggering premature atrial complex (PAC) was present in 222/233 episodes (953%); 118/233 episodes were preceded by a bradyarrhythmic event (BE) or a post-extrasystolic pause (506%) According to the polarity of the ectopic P-wave, triggering PACs were left atrial origin in 743%, right atrial in 153%, not determined in 104% of cases Coupling interval (CI) of triggering PACs was shorter in episodes preceded by BEs; it was shorter than that of non-triggering PACs Frequency of PACs was significantly higher in the hour preceding the onset of PAF During the day, three periods of higher frequency of PAF onsets were found from noon to 2 pm, 6 pm to 2 am, and 4 am to 6 am Heart rate variability analysis showed a vagal prevalence in the 5 min preceding the onset of arrhythmia, both in the time and in the frequency domain Conclusion Paroxysmal atrial fibrillation is generally triggered by a PAC, with left atrial origin in twothirds of cases: CI and neuroendocrine balance are factors affecting the induction of the arrhythmia

Post-operative use of heparin increases morbidity of pacemaker implantation

Abstract: Aims The objective of this study is to characterize the incidence of peri-operative severe adverse events (AEs) related to the post-operative use of heparin in patients undergoing pacemaker surgery. Methods and results We retrospectively compared the outcome of 38 patients with mechanical valves (MVs) and 76 patients with atrial fibrillation (AF) with control cases matched for gender, age, and surgical details. Heparin was systematically used post-operatively in MV patients, but left to clinical judgment in AF patients. The relative risk for severe haemorrhagic AEs was 11 (CI 1.5–81.1, P , 0.01) in the MV group when compared with matched controls and 8 (CI 1.0–62.5, P , 0.05) in the AF group. Overall, the relative risk of heparin use in the post-operative period was 14 (CI 1.88–104, P ¼ 0.0006) and the post-operative stay was prolonged from 7 days in this group when compared with control cases (P , 0.0001).The variables associated with haemorrhage were the delay to restart heparin after surgery and the presence of an MV. Conclusion Post-operative use of heparin increases morbidity of pacemaker implantation. A different approach to management of these patients is possible.

Fluoxetine vs. propranolol in the treatment of vasovagal syncope: a prospective, randomized, placebo-controlled study

Abstract: Aims To compare the therapeutic efficacy of placebo, propranolol, and fluoxetine in patients with vasovagal syncope (VVS). Methods and results Ninety-six consecutive patients with VVS were randomized to treatment with placebo, propranolol, or fluoxetine and followed-up for 6 months. Before and during treatment, they reported their syncopal and presyncopal episodes and graded their well-being, expressed as the general evaluation of life, general activities, and everyday activities (each scaled from 1 ¼ very good to 5 ¼ very bad). Two patients refused follow-up. Among the remaining 94, no difference between groups was observed regarding the distribution of time of vasovagal events (syncopes or presyncopes) during follow-up (log-rank test). No difference was also observed when syncopes and presyncopes were assessed separately. Eighteen patients discontinued therapy. Among the remaining 76 (‘ontreatment’ analysis), the mean time to a vasovagal episode (syncope or presyncope) was significantly longer in the fluoxetine group when compared with the two other groups (log-rank test, P , 0.05). A significant difference in favour of fluoxetine was also observed regarding presyncopes. The difference between groups regarding the syncope-free period was not significant. During therapy, patients’ well-being was improved (decreased) only in the fluoxetine-group (13.4+ 0.7 vs. 15.4+ 0.9 before treatment, P , 0.01). Conclusion Fluoxetine seems to be equivalent to propranolol and placebo in the treatment of VVS. However, it improves patients’ well-being and might be more effective in reducing presyncopes and total vasovagal events in some patients with recurrent VVS.

Cryoablation compared with radiofrequency ablation for atrioventricular nodal re-entrant tachycardia: analysis of factors contributing to acute and follow-up outcome.

Abstract: Aims The efficacy of transvenous Cryoablation (Cryo), for the treatment of atrioventricular nodal re-entry tachycardia (AVNRT), when compared with radiofrequency (RF) ablation, requires further investigation. Methods and results We sought to compare the acute- and follow-up results of 71 cases each of Cryo and RF for AVNRT using a retrospective matched case–control study design and aimed at identifying patient and procedural factors that may predict success with each strategy. Primary failure of Cryo (thus necessitating RF at the same sitting) was seen in 11 (15.4%) cases, whereas there were two (2.8%) primary failures with RF (P , 0.01). Patients in the Cryo group had significantly higher arrhythmia recurrence [14 (19.8%)] when compared with the RF group [4 (5.6%)] (P , 0.01). The incidence of recurrence following Cryo was significantly higher if an echo beat was still inducible after ablation than if complete slow pathway block was achieved (7/19, vs. 4/46, P , 0.001). The median number of Cryo lesions was significantly lower in patients who had recurrence compared with those who did not (1.5 vs. 3.0, P ¼ 0.02). Conclusion We have observed a much higher primary failure and recurrence rate with Cryo when compared with RF for AVNRT. It may be possible to decrease this high recurrence rate by aiming to achieve complete slow pathway block and by increasing the number of Cryo lesions.

Decrease in the heart rate complexity prior to the onset of atrial fibrillation

Abstract: Aims To assess heart rate complexity changes prior to the onset of atrial fibrillation (AF) using sample entropy. It has been proposed that the autonomic nervous system might have a role in the initiation of AF. Methods and results The study included 25 patients with lone AF. Each record set contained two 30 min records from 25 subjects. Each patient had 30 min records containing the ECG immediately preceding an episode of AF (pre-AF) and 30 min of ECG during a period distant from any episode of AF (AFd). Sample entropy was used for complexity analysis. The sample entropy of R–R intervals was significantly reduced in the pre-AF period compared with the AFd period (0.45+ 0.25 vs. 0.78+ 0.46, P ¼ 0.003). The pre-AF periods were divided into three successive 10 min segments. There was a significant decreasing trend in entropy towards the onset of AF with linear mixed models (P ¼ 0.002). Conclusions The heart rate complexity is reduced with a significant decreasing trend as assessed by R–R interval entropy prior to the onset of AF. There is a need for well-defined studies with larger patient groups in order to assess the entropy changes further and to look for possible changes, which might predict impending AF episodes.

The effectiveness of a high output/short duration radiofrequency current application technique in segmental pulmonary vein isolation for atrial fibrillation.

Abstract: AIMS: Segmental pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation has become a curative therapy for atrial fibrillation (AF). However, the long procedure time limits the wide application of this procedure. The aim of the current study was to compare a novel ablation technique with a high power output and short application time vs. a conventional technique using a low power output and long application time. METHODS AND RESULTS: The study included 90 consecutive patients (age 53+/-10 years; 66 men). Segmental PV isolation was performed by irrigated RF catheter ablation in both groups. In the conventional group (Group 1, 45 patients), the power output was limited to 30 W with a target temperature of 50 degrees C and an RF preset duration of 120 s. In the novel group (Group 2, 45 patients), the maximum power output was preset to 45 W, with a target temperature of 55 degrees C and duration of 20 s. In Group 2, a significant reduction in the PV isolation time (127+/-57 vs. 94+/-33 min, P<0.02), mean fluoroscopy time (73+/-23 vs. 55+/-16 min, P<0.001), and radiation dose was observed. According to the application time and number, Group 2 showed a reduction in RF application time, but a higher number of RF applications were required for creation of complete PV isolation. During a mean follow-up of 15+/-7 months, a total of 74% of patients in Group 1 and 76% of patients in Group 2 demonstrated stable SR. CONCLUSION: Segmental PV isolation using a high power output and short application time is safe and effective in PV isolation in patients with AF. This technique can significantly reduce the procedure and fluoroscopy time compared with a low-power output technique.

The progressive nature of atrial fibrillation: a rationale for early restoration and maintenance of sinus rhythm

Abstract: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting young as well as elderly patients and presenting a major therapeutic challenge for clinical cardiologists. Recent research has elucidated the progressive nature of AF, including the structural and electrical remodelling that may become manifest if normal sinus rhythm is not restored, and the serious morbidities associated with long-term disease. The controversy over the merits of ventricular rate control vs. the restoration and maintenance of normal sinus rhythm in the treatment of AF has been explored in a number of large-scale, randomized clinical trials. The results of these trials suggest that whereas the two strategies may be equivalent for some patient populations, with both approaches requiring accompanying anticoagulation therapy, the restoration and maintenance of sinus rhythm provide important haemodynamic as well as subjective benefits not afforded by rate control. Although early intervention to limit the progression of this arrhythmia is hindered by the limitations of existing anti-arrhythmic therapies, it is nevertheless a critical goal.

Natriuretic peptides in patients with atrial fibrillation and advanced chronic heart failure: determinants and prognostic value of (NT-)ANP and (NT-pro)BNP.

Abstract: Aims To study the determinants of natriuretic peptides in advanced chronic heart failure (CHF) patients with and without atrial fibrillation (AF) and to evaluate the prognostic value of natriuretic peptides in AF compared with sinus rhythm patients with advanced CHF, Methods and results The study group comprised 354 advanced CHIF patients (all New York Heart Association (NYHA) III/IV], including 76 AF patients. AF patients were older (70 +/- 7 vs. 67 +/- 8; P = 0.01), and non-ischaemic CHF was more common (42 vs. 19%; P = 0.002) than in sinus rhythm patients, but left-ventricular ejection fraction was comparable (0.23 +/- 0.08 vs. 0.24 +/- 0.07; P = ns). At baseline, (NT-)ANP and NT-proBNP levels were significantly higher in AF patients, compared with those in sinus rhythm. By multivariate regression analysis, AF was identified as independent determinant of (NT-)ANP, but not of (NT-pro)BNP levels. After a mean follow-up of 3.2 +/- 0.9 (range 0.4 +/- 5.4) years, cardiovascular mortality was comparable (55 vs. 47%; P = ns). In both groups, AF and sinus rhythm, NT-proBNP [AF: adjusted HR 5.8 (1.3 - 25.4), P = 0.02; sinus rhythm: adjusted HR 3.1 (1.7 - 5.7), P <0.001] was an independent risk indicator of cardiovascular mortality. Conclusion In advanced CHF patients, AF affects (NT-)ANP levels, but not (NT-pro)BNP levels. NT-proBNP is an independent determinant of prognosis in advanced CHF, irrespective of the rhythm, AF or sinus rhythm.

Classification and differential diagnosis of atrioventricular nodal re-entrant tachycardia

Abstract: Recent evidence on atrioventricular nodal re-entrant tachycardia has identified several types of this common arrhythmia, with potential therapeutic implications. This article reviews the relevant new information, discusses the differential diagnosis of atrioventricular nodal re-entrant tachycardia, and summarizes the electrophysiological criteria for classification of the various forms of the arrhythmia.

Long-term continuous external electrocardiographic recording: a review.

Abstract: Ambulatory electrocardiographic (AECG) monitoring is an essential tool in the diagnostic evaluation of patients with cardiac arrhythmias. Recent advances in solid-state technology have improved the quality of the ECG signals and new dedicated algorithms have expanded the clinical application of software-based AECG analysis systems. These advances, in addition to the availability of inexpensive large storage capacities, and very long-term continuous high-quality AECG monitoring, have opened new potential uses for AECG. New digital recorders have the capability of multichannel simultaneous recordings (from 3 to 12 leads) and for telemetred signal transduction. These possibilities will expand the traditional uses of AECG for arrhythmia detection, as arrhythmia monitoring to assess drug and device efficacies has been further defined by new studies. The analysis of transient ST-segment deviation still remains controversial, but considerably more data are now available, especially about the prognostic value of detecting asymptomatic ischaemia. Heart rate variability analysis has shown promise for predicting mortality rates in cardiac patients at high risk. We review recent advances in this field of non-invasive cardiac testing.

Health-related quality of life of patients with implantable cardioverter defibrillators compared with that of pacemaker recipients

Abstract: Aims Studies indicate a poorer quality of life (QoL) for implantable cardioverter defibrillator (ICD) patients than for the general population. However, studies comparing the QoL of ICD patients with that of patients with other implantable cardiac devices are scarce. We hypothesized that ICD patients had a poorer QoL than pacemaker patients. Methods and results All ICD patients living in Iceland at the beginning of 2002 (44 subjects), and a comparison group of 81 randomly selected patients with pacemakers were invited to participate. The Icelandic Quality of Life Questionnaire (IQL), the General Health Questionnaire (GHQ), the Beck Anxiety Inventory (BAI), and the Beck Depression Inventory (BDI) were submitted to measure QoL, psychiatric distress, and symptoms of anxiety and depression. The ICD and pacemaker groups did not differ on IQL, BAI, BDI, or GHQ scores. ICD patients were as a group more fearful of death ( P =0.056) and showed more concerns about returning to work ( P =0.072), although these items fell just short of statistical significance. Conclusion Contrary to our expectations, ICD patients had a comparable QoL with pacemaker recipients and were not more likely to suffer from anxiety, depression, or general psychiatric distress. These findings are encouraging in view of expanding ICD indications.

The role of psychological factors in response to treatment in neurocardiogenic (vasovagal) syncope.

Abstract: Aims Studies have established a link between vasovagal syncope (VVS) and anxiety, depression, and functional impairment. This study examines the prevalence of psychological problems in patients with VVS and whether non-responders are psychologically different from those whose symptoms respond to conservative treatment. Methods and results Subjects with tilt-confirmed VVS completed the hospital anxiety and depression scale (HADS) (measures current levels of anxiety and depression) and the syncope functional status questionnaire (SFSQ) (syncope-specific quality-of-life measure) and participated in a semi-structured interview to ascertain potential triggers, thought content, and coping strategies. In this study, 41 subjects participated. There was no difference in gender and age duration of symptoms between responders ( n =21) and non-responders ( n =20). Non-responders were significantly more anxious ( P =0.003) and depressed ( P =0.003) and had a higher level of state ( P =0.008) and trait ( P =0.004) anxiety than responders. Non-responders reported more fear/worry ( P =0.02), a significantly higher degree of impairment owing to syncope ( P =0.01), and a greater number of perceived triggers ( P =0.039); on average, participants reported eight negative thoughts about the consequences of VVS, with particular emphasis on threats of physical harm or death. Non-responders had higher levels of avoidance/protection coping and rumination. Conclusion This study has confirmed that patients with VVS have a significant degree of psychological distress, which is worthy of consideration in its own right, out with management purely aimed at reducing syncopal or pre-syncopal symptoms. Further, this distress may actually influence the natural history of what is a chronic relapsing condition and may in fact be more relevant to the patient than the number of syncopal episodes that they are experiencing.