Fibrillation atriale (de la physiopathologie aux traitements actuels)

La fibrillation atriale (FA) est le trouble du rythme cardiaque le plus fréquent et dont la prévalence est en constante augmentation. Les extrasystoles déclenchant cette arythmie naissent le plus souvent des veines pulmonaires. Ainsi l ablation des veines pulmonaires est devenue un traitement important de cette arythmie, surtout quand elle est paroxystique. Cependant le maintien de la FA est assuré par du substrat atrial pathologique.Le traitement endocavitaire de ce substrat comprend essentiellement l ablation de potentielsfragmentés enregistrés en FA.Nous avons démontré que ces potentiels fragmentés existent aussi en rythme sinusal etqu une partie de ces potentiels pouvait être générée par une activation vagale myocardiquelocale.Par ailleurs cette ablation de FA présente de nombresuses complications dont certaines sont potentiellement graves comme par exemple la tamponnade.Nous avons montré que la ponction transseptale nécessaire pour réaliser cette intervention pouvait être effectuée de manière sure en utilisant un monitorage du septum interatrial parechocardiographie endovasculaire utilisée par voie oesophagienne, diminuant ainsi le risque de tamponnade.Nous avons aussi montré que la présence d une récidive d arythmie précoce (21 mois et une amplitude de l onde fibrillatoire < 0.07 mV étaient des facteurs importants d échec d ablation de FA persistante.Pas de résumé anglaisPARIS-EST-Université (770839901) / SudocPARIS12-Bib. électronique (940280011) / SudocSudocFranceF

C-Reactive Protein in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy and Relationship with Ventricular Tachycardia

Background. The relationship between C-reactive protein (CRP) elevation and ventricular tachycardia (VT) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is unclear. Methods and Results. In 91 consecutive patients with either ARVD/C with or without VT (cases) or idiopathic right ventricular outflow tract (RVOT) tachycardia (controls), blood sampling were taken to determine CRP levels. In ARVD/C patients with VT, we analyzed the association between VT occurrences and CRP level. Sixty patients had ARVD/C, and 31 had idiopathic RVOT VT. Patients with ARVD/C had a significant higher level of CRP compared to those with RVOT VT (3.5 ± 4.9 versus 1.1 ± 1.2 mg/l, P = .0004). In ARVD/C group, 77%, (n = 46) patients experienced VT. Of these, 37% (n = 17) underwent blood testing for CRP within 24 h after the onset of VT and the remaining 63% (n = 29) after 24 h of VT reduction. CRP level was similar in ARVD/C patients with or without documented VT (3.6 ± 5.1 mg/l versus 3.1 ± 4.1 mg/l, P = .372). However, in patients with ARVD/C and documented VT, CRP was significantly higher when measured within 24 hours following VT in comparison to that level when measured after 24 h (4.9 ± 6.2 mg/l versus 3.0 ± 4.4 mg/l, P = .049). Conclusion. Inflammatory state is an active process in patients with ARVD/C. Moreover, there is a higher level of CRP in patients soon after ventricular tachycardia, and this probably tends to decrease after the event

A Randomized Comparison of High Clopidogrel Loading Doses in Patients With Non–ST-Segment Elevation Acute Coronary Syndromes The ALBION (Assessment of the Best Loading Dose of Clopidogrel to Blunt Platelet Activation, Inflammation and Ongoing Necrosis) Trial

ObjectivesWe sought to compare the antiplatelet effects of three clopidogrel loading doses (LDs).BackgroundAdministration of a 300-mg clopidogrel LD is beneficial in situations requiring rapid platelet inhibition. Whether higher LDs can provide further benefits remains unknown.MethodsPatients (n = 103) with non–ST-segment elevation acute coronary syndromes were randomized to receive a 300-mg, 600-mg, or 900-mg clopidogrel LD, given on top of other standard therapy (including acetylsalicylic acid). The main outcome measure was inhibition of adenosine diphosphate-induced inhibition of platelet aggregation (IPA); inhibition of platelet activation, inflammatory markers, troponin I release, and major adverse cardiac events also were evaluated; all measures were blindly evaluated.ResultsCompared with the 300-mg LD, greater doses were associated with significantly greater platelet inhibition, with dose-effect relationships observed for onset of action, maximal plateau, 24-h areas under the curves of IPA, and rates of low IPA (<10% at 6 h), using 20 μmol/l major adverse cardiac events. A significant dose-response was also observed for the vasodilator-stimulated phosphoprotein index, a measure of P2Y12receptor inhibition. Similar but nonsignificant trends were observed for troponin release and major adverse cardiac events. Bleeding rates were similar in each group.ConclusionsIn low-to-moderate risk patients with non–ST-elevation acute coronary syndromes, clopidogrel LDs >300 mg provide a faster onset of action, a higher IPA plateau, and greater reductions in platelet activation during the first 24 h. A 900-mg LD may induce a greater antiplatelet effect than 600 mg, when compared with the standard 300-mg regimen. These findings require further clinical confirmation

Combined epicardial and endocardial ablation for atrial fibrillation:Best practices and guide to hybrid convergent procedures

The absence of strategies to consistently and effectively address nonparoxysmal atrial fibrillation by nonpharmacological interventions has represented a long-standing treatment gap. A combined epicardial/endocardial ablation strategy, the hybrid Convergent procedure, was developed in response to this clinical need. A subxiphoid incision is used to access the pericardial space facilitating an epicardial ablation directed at isolation of the posterior wall of the left atrium. This is followed by an endocardial ablation to complete isolation of the pulmonary veins and for additional ablation as needed. Experience gained with the hybrid Convergent procedure during the last decade has led to the development and adoption of strategies to optimize the technique and mitigate risks. Additionally, a surgical and electrophysiology "team" approach including comprehensive training is believed critical to successfully develop the hybrid Convergent program. A recently completed randomized clinical trial indicated that this ablation strategy is superior to an endocardial-only approach for patients with persistent atrial fibrillation. In this review, we propose and describe best practice guidelines for hybrid Convergent ablation on the basis of a combination of published data, author consensus, and expert opinion. A summary of clinical outcomes, emerging evidence, and future perspectives is also given

Impact of cardiac resynchronization therapy optimization inside a heart failure programme : a real‐world experience

Aims: This study sought to describe and evaluate the impact of a routine in‐hospital cardiac resynchronization therapy (CRT) programme, including comprehensive heart failure (HF) evaluation and systematic echo‐guided CRT optimization. Methods and results: CRT implanted patients were referred for optimization programme at 3 to 12 months from implantation. The program included clinical and biological status, standardized screening for potential cause of CRT non‐response and systematic echo‐guided atrioventricular and interventricular delays (AVd and VVd) optimization. Initial CRT‐response and improvement at 6 months post‐optimization were assessed with a clinical composite score (CCS). Major HF events were tracked during 1 year after optimization. A total of 227 patients were referred for CRT optimization and enrolled (71 ± 11 years old, 77% male, LVEF 30.6 ± 7.9%), of whom 111 (48.9%) were classified as initial non‐responders. Left ventricular lead dislodgement was noted in 4 patients (1.8%), and loss or ≤90% biventricular capture in 22 (9.7%), mostly due to arrhythmias. Of the 196 patients (86%) who could undergo echo‐guided CRT optimization, 71 (36.2%) required VVd modification and 50/144 (34.7%) AVd modification. At 6 months post‐optimization, 34.3% of the initial non‐responders were improved according to the CCS, but neither AVd nor VVd echo‐guided modification was significantly associated with CCS‐improvement. After one‐year follow‐up, initial non‐responders maintained a higher rate of major HF events than initial responders, with no significant difference between AVd/VVd modified or not. Conclusions: Our study supports the necessity of a close, comprehensive and multidisciplinary follow‐up of CRT patients, without arguing for routine use of echo‐guided CRT optimization

Initial experience of temperature-controlled irrigated radiofrequency ablation for ischaemic cardiomyopathy ventricular tachycardia ablation

Background The DiamondTemp ablation (DTA) catheter system delivers high power, open-irrigated, temperature-controlled radiofrequency (RF) ablation. This novel ablation system has not been previously used for ventricular tachycardia (VT) ablation. Objective Feasibility of using the DTA catheter system for VT ablation in ischaemic cardiomyopathy (ICM) patients. Method Ten ICM patients with optimal anti-arrhythmic drug therapy and implantable cardiac defibrillators (ICD) were recruited. VT inducibility testing was performed at the end of the procedure. ICD data for device detected VT episodes and device treated VT episodes were collected for 6-months pre- and post-ablation. Results Substrate analysis demonstrated reductions in the borderzone area of 4.4 cm2 (p = 0.026) and late potential area of 3.5 cm2 (p = 0.0449) post-ablation, with reductions in the mean bipolar and unipolar voltages of the ablation target areas (0.14 mV (p = 0.0007); 0.59 mV (p = 0.0072) respectively). Complete procedural success was achieved in 9 procedures. Post-ablation VT inducibility testing was not performed in 1 procedure due to a steam pop complication resulting in pericardial tamponade requiring drainage. Mean follow-up of 214 ± 33 days revealed an 88% reduction in total VT episodes (n = 266 median 16 [IQR 3–57] to n = 33 median 0; p = 0.0164) and 77% reduction in ICD therapies (n = 128 median 5 [IQR 2–15] to n = 30 median 0; p = 0.0181). Conclusion The DTA system resulted in adequate lesion characteristics with effective substrate modification, acute procedural success and improved outcomes at intermediate-term follow-up. Randomised controlled trials are required to compare the performance of the DTA system against conventional ablation catheters