| 1. |
- Boehmer, John P, et al.
(författare)
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Adjudication of mortality events in a heart failure-arrhythmia trial by a multiparameter descriptive method: comparison with methods used in heart failure trials and methods used in arrhythmia trials.
- 2008
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Ingår i: Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing. - : Springer Science and Business Media LLC. - 1383-875X. ; 23:2, s. 101-10
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Mortality events in studies of cardiovascular disease are currently adjudicated using different methodologies depending on the investigators' preferences. Traditionally, deaths have been categorized by a single term, such as sudden, ischemic, or pump failure, a method that can be referred to as "categorical". In contrast, deaths may be categorized using several specific pieces of information about the event, a method that can be referred to as "multiparameter descriptive." Herein, we describe an adaptation of this descriptive method in a trial of patients with heart failure and arrhythmias. METHODS AND RESULTS: Case examples were selected from two clinical trials of an investigational implantable cardioverter-defibrillator (ICD)-biventricular pacing system in patients with symptomatic heart failure and a class I indication for ICD implantation, and the complete results for one of the trials are given. Deaths were classified according to the new descriptive method, and also according to published categorical methods for heart failure and arrhythmia trials. The descriptive method preserved traditional arrhythmia and heart failure trial single category classifications of death. Furthermore, there was agreement between the arrhythmia and heart failure category classifications in 126 of the 148 of the mortality events adjudicated (85%). CONCLUSION: A descriptive method for the classification of death retains more data and allows for comparison among trials using different classification schemes. This may allow greater mechanistic insight into study populations that have diverse and frequently multiple etiologies of death.
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| 2. |
- Liuba, Ioan, et al.
(författare)
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Activation mapping of focal atrial tachycardia : the impact of the method for estimating activation time
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer. - 1383-875X .- 1572-8595. ; 26:3, s. 169-180
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Tidskriftsartikel (refereegranskat)abstract
- PurposeDifferent methods can be used to estimate activation time during the mapping of focal atrial tachycardia. The present study aimed to compare activation maps generated by three widely used methods of determining activation time.MethodsFourteen patients (mean age 48 ± 17 years) with focal atrial tachycardia were investigated. Mapping was performed with the CARTO system. All patients underwent successful ablation. Local activation time was successively defined as the peak amplitude (Bi-peak), the steepest downslope (Bi-dslope), and the onset (Bi-on) of the bipolar electrograms.ResultsThe three methods of activation time determination were highly correlated with one another but generated foci with different locations. The distances between the foci generated by the different methods were 4.36 ± 4.91 mm (Bi-peak–Bi-dslope), 7.21 ± 5.11 mm (Bi-peak–Bi-on), and 7.21 ± 5.87 mm (Bi-dslope–Bi-on) (p = 0.26). Also, the three methods generated foci with different diameters: 3.13 ± 2.17 mm for Bi-peak, 2.81 ± 0.78 for Bi-dslope, and 2.54 ± 0.14 mm for Bi-on (p = 0.60). However, the foci tended to cluster within relatively wide regions of low-amplitude fractionated electrograms. The surface of these regions was 3.81 ± 2.34 cm2 (Bi-peak), 3.38 ± 2.12 cm2 (Bi-dslope), and 4.76 ± 3.01 cm2 (Bi-on) (p = 0.34).ConclusionThe three methods of activation time determination, although highly correlated with one another, may generate foci of different sizes and in different locations. However, the foci tend to cluster within relatively large areas of low-amplitude fractionated electrograms. These findings suggest a sizeable atrial region with particular electrophysiological proprieties and raise the possibility of an anatomical substrate of the tachycardia. During mapping, this region can be roughly delineated by all three methods of activation time estimation. However, details concerning the activation pattern within the region and the location of the focus vary among the methods.
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| 3. |
- Malmborg, Helena, et al.
(författare)
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A prospective randomised comparison of large-tip cryoablation and 8-mm-tip radiofrequency catheter ablation of atrial flutter
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1383-875X .- 1572-8595. ; 24:2, s. 127-31
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Although radiofrequency (RF) energy is routinely used for tricuspid isthmus (TI) ablation, it is often associated with discomfort. The paucity of studies comparing the feasibility and efficacy of cryo- versus RF energy for TI-ablation urged us to conduct a prospective, randomised trial. METHODS: Forty patients with atrial flutter (AFl) were randomised to RF- or cryoenergy for TI-ablation. Perceived pain was scored from 1 to 10 on a Visual Analogue Scale. RESULTS: Significantly lower pain scores were recorded for cryoablation versus RF ablation (0.96 +/- 0.73 versus 4.2 +/- 2.4, p = 0.00004). Cryoablation was associated with significantly longer procedure duration and ablation time (137 +/- 35 versus 111 +/- 29 min, p = 0.016 and 81 +/- 40 versus 48 +/- 30 min, p = 0.007) and lower acute success rate (56% versus 100%, p = 0.001) than RF ablation. The recurrence of AFl was 20% (cryo) versus 15% (RF; p = 0.45) after a mean of 15.1 months follow-up. CONCLUSION: Cryoablation results in significantly less pain and discomfort compared to RF ablation of AFl, which is offset by the significantly lower acute success rate.
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| 4. |
- Nault, Isabelle, et al.
(författare)
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Clinical value of fibrillatory wave amplitude on surface ECG in patients with persistent atrial fibrillation
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1572-8595 .- 1383-875X. ; 26:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- We postulated that amplitude of fibrillatory (F)-wave in patients with persistent AF would correlate with clinical characteristics and outcome in patients undergoing catheter ablation for AF. Maximal and mean amplitude of F-waves were measured in V1 and lead II in 90 patients prior to ablation for persistent AF. F-wave amplitudes were correlated to clinical, echocardiographic variables, and outcome. F-wave a parts per thousand yenaEuro parts per thousand 0.1 mV in lead II and V1was correlated with younger age and shorter AF history, and in lead II only was correlated with a smaller left atrium. Higher F-wave amplitude at baseline predicted AF termination during ablation. Maximal amplitude of a parts per thousand yenaEuro parts per thousand 0.07 mV predicted AF termination by ablation with 82%/79% sensitivity and 68%/73% specificity in V1/lead II respectively. An association between F-wave amplitude and AF recurrence was observed. Forty-three percent of patients with mean f wave amplitude < 0.05 in lead V1 had AF recurrence compared to 12% of those with F-wave a parts per thousand yenaEuro parts per thousand 0.05 (p = 0.004). Longer AF duration, older age and larger LA size are associated with fine AF amplitude. High F-wave amplitude predicts procedural termination of arrhyhmia in patients with persistent AF and freedom from AF upon follow-up.
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| 5. |
- ONeill, Mark D, et al.
(författare)
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The stepwise ablation approach for chronic atrial fibrillation - evidence for a cumulative effect
- 2006
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1383-875X .- 1572-8595. ; 16, s. 153-167
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Tidskriftsartikel (refereegranskat)abstract
- Treatment options for atrial fibrillation (AF) have evolved from simple, fluoroscopy-guided pulmonary vein isolation for those patients with paroxysmal AF to complex, multi-modality procedures targeting not only anatomic structures but also electrophysiologic phenomena including complex fractionated electrograms, sites of dominant frequency and local non-venous drivers in patients with persistent and permanent AF. The stepwise ablation approach is a novel technique whereby structures contributing to initiation and maintenance of AF are sequentially targeted by radiofrequency ablation. Broadly divided into pulmonary veins, left atrial (LA) roof, left atrium (incorporating all anatomic regions of the chamber), mitral isthmus and non-LA structures, each region is targeted in sequence and the impact of ablation upon the global fibrillatory process assessed by measurement of AF cycle length (AFCL) at a site remote from the ablation target. In addition to pulmonary vein electrical disconnection and demonstrable complete conduction block across the roof and mitral isthmus lines (when performed), ablation is performed at those sites displaying continuous electrical and complex fractionated activity, with the endpoint of local organization, as well as at sites displaying electrograms consistent with focal sources driving AF. Ablation is accompanied by a cumulative increase in the AFCL prior to termination of AF by conversion either directly to sinus rhythm or to an atrial tachycardia which is then mapped conventionally and ablated. There is a ceiling of ablation within the LA beyond which further ablation is unlikely to result in a clinical benefit and should prompt evaluation of the contribution of the right atrium to maintenance of AF. The stepwise approach benefits from the integration of anatomic and electrophysiologic information to achieve a high level of success in termination of chronic AF by catheter ablation.
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| 6. |
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| 7. |
- Sciaraffia, Elena, et al.
(författare)
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The use of impedance cardiography for optimizing the interventricular stimulation interval in cardiac resynchronization therapy-a comparison with left ventricular contractility
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1383-875X .- 1572-8595. ; 25:3, s. 223-228
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to assess whether impedance cardiography (IC) can correctly identify the optimal interventricular (VV) pacing interval in cardiac resynchronization therapy (CRT). Twenty four patients received a biventricular pacemaker and underwent IC for cardiac output (CO) measurements to identify the optimal VV interval. Invasive measurements of left ventricular (LV) dP/dt(max) were used as a reference. During optimization the VV interval was changed with 20 ms steps from +80 (LV pre-excitation) to-80 ms (RV pre-excitation). The optimal VV interval was defined as the one that resulted in the highest LV dP/dt(max) value and the highest CO obtained by IC, respectively. During simultaneous biventricular pacing both LV dP/dt(max) and CO increased (mean 16.6% and 16.2%, respectively) as compared to baseline. Biventricular pacing with optimized VV intervals resulted in a further absolute increase of LV dP/dt (max) and CO (5.6% and 41.3%, respectively). The average decrease in LV dP/dt(max) was 79.6 +/- 51.6 mmHg/s when the optimal VV interval was programmed according to the IC measurements. Cross spectral analysis showed no correlation between the optimal VV intervals identified by the two methods (p > 0.05) and identical optimal VV intervals were identified in only six of the 24 patients. When broader VV time intervals were compared the correlation between the two methods was statistically significant (p = 0,0166). In conclusion, the use of IC for VV interval optimization is questionable since these optimized time intervals do not seem to correlate well with those obtained by measuring LV dP/dt.
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| 8. |
- Tapanainen, Jari M., et al.
(författare)
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Interatrial right-to-left conduction in patients with paroxysmal atrial fibrillation
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1572-8595 .- 1383-875X. ; 25:2, s. 117-122
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Tidskriftsartikel (refereegranskat)abstract
- We wanted to illustrate the right-to-left impulse propagation routes during sinus in patients with paroxysmal atrial fibrillation (PAF), as alterations in conduction patterns have been linked to the pathogenesis of PAF, and as no large patient materials have been published. Patients underwent 3-D electroanatomical contact mapping prior to catheter ablation. The site of the earliest left atrial (LA) activation was determined. Three different interatrial routes were identified, either as solitary pathways (36/50 patients, 72%) or in their combinations (14/50). Bachmann's bundle (BB) was involved in the majority of the cases with solitary routes (25/36). More seldom, impulse propagation occurred near the oval fossa (FO) (7/36) or the coronary sinus ostium (4/36). In patients with combined routes, both the BB (10/14) and FO routes (11/14) were included in most cases. In PAF patients, LA can be activated during sinus rhythm through three distinct connections, either encompassing a single route or via any combination of these connections. In one third, the earliest LA activation occurs outside BB. The knowledge of the propagation patterns may give insight into the pathophysiology of PAF and into refining ablation therapy.
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