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1.
Artigo em Inglês | MEDLINE | ID: mdl-32634027

RESUMO

Background - Endocardial-epicardial dissociation (EED) and focal breakthroughs in humans with atrial fibrillation (AF) have been recently demonstrated using activation mapping of short 10-second AF segments. In the current study we used simultaneous endo-epi phase mapping to characterise endo-epi activation patterns on long segments of human persistent AF (PeAF). Methods - Simultaneous intra-operative mapping of endo- and epicardial lateral RA wall was performed in patients with PeAF using two high-density grid catheters (16 electrodes, 3mm spacing). Filtered unipolar and bipolar electrograms (EGM's) of continuous 2-min AF recordings and electrodes locations were exported for phase analyses. We defined EED as phase difference of ≥20ms between paired endo-epi electrodes. Wavefronts (WF) were classified as rotations, single WF (SWF), focal waves or disorganised activity as per standard criteria. Endo-Epi WF patterns were simultaneously compared on dynamic phase maps. Complex fractionated EGM's were defined as bipolar EGM's with ≥5 directional changes occupying at least 70% of sample duration. Results - Fourteen patients with PeAF undergoing cardiac surgery were included. EED was seen in 50.3% of phase maps with significant temporal heterogeneity. Disorganised activity (Endo:41.3% vs Epi:46.8%, p=0.0194) and SWF (Endo:31.3% vs Epi:28.1%, p=0.129) were the dominant patterns. Transient rotations (Endo:22% vs Epi:19.2%, p=0.169; mean duration: 590±140ms) and non-sustained focal waves (Endo:1.2% vs Epi:1.6%, p=0.669) were also observed. Apparent transmural migration of rotational activations (n=6) from the epi- to the endocardium was seen in 2 patients. EGM fractionation was significantly higher in the epicardium than endocardium (61.2% vs 51.6%, p<0.0001). Conclusions - Simultaneous endo-epi phase mapping of prolonged human PeAF recordings shows significant EED marked temporal heterogeneity, discordant and transitioning WF patterns and complex fractionations. No sustained focal activity was observed. Such complex 3D-interactions provide insight into why endocardial mapping alone may not fully characterise the AF mechanism and why endocardial ablation may not be sufficient.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32506159

RESUMO

PURPOSE: Prior studies reporting efficacy of radiofrequency catheter ablation for complex ventricular ectopy in mitral valve prolapse (MVP) are limited by selective inclusion of bileaflet MVP, papillary muscle only ablation, or short-term follow-up. We sought to evaluate the long-term incidence of hemodynamically significant ventricular tachycardia (VT) or fibrillation (VF) in patients with MVP after initial ablation. METHODS: We studied consecutive patients with MVP undergoing ablation for complex ventricular ectopy between 2013 and 2017 at our institution. Of 580 patients with MVP, we included 15 (2.6%, 10 women; mean age 50 ± 14 years, 53% bileaflet) with complex ventricular ectopy treated with initial ablation. RESULTS: Over a median follow-up of 3406 (1875-6551) days or 9 years, 5 of 15 (33%) patients developed hemodynamically significant VT/VF after their initial ablation and underwent placement of an implantable cardioverter defibrillator (ICD). Three of 5 also underwent repeat ablations. Sustained VT was inducible prior to index ablation in all 5 who developed VT/VF, compared to none of the 10 patients who did not develop VT/VF after index ablation (p = 0.002). Complex ventricular ectopy at index ablation was multifocal in all 5 patients who underwent repeat intervention versus 4 of 10 patients (40%) who did not (p = 0.04). All 3 patients with subsequent VT/VF who underwent repeat ablation had a new clinically dominant focus of ventricular arrhythmia and 3 of the patients with ICD had appropriate VT/VF therapies. CONCLUSIONS: In the long term, a subset of MVP patients treated with ablation for ventricular arrhythmias, all with multifocal ectopy on initial EP study, develop hemodynamically significant VT/VF. Our findings suggest the progressive nature of ventricular arrhythmias in patients with MVP and multifocal ectopy.

4.
JACC Clin Electrophysiol ; 6(5): 484-490, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32276868

RESUMO

OBJECTIVES: The goal of this study was to report a multicenter series of left-sided catheter ablations performed by using intravenous direct thrombin inhibitors (DTIs) as an alternative to heparin. BACKGROUND: Amidst a looming worldwide shortage of heparin, there are insufficient data to guide nonheparin-based peri-procedural anticoagulation in patients undergoing catheter ablation. METHODS: This study reviewed all catheter ablations at 6 institutions between 2006 and 2019 to assess the safety and efficacy of DTIs for left-sided radiofrequency catheter ablation of atrial fibrillation and ventricular tachycardia. RESULTS: In total, 53 patients (age 63.0 ± 9.3 years, 68% male, CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score 2.8 ± 1.6, left ventricular ejection fraction 46 ± 15%) underwent ablation with DTIs (75% bivalirudin, 25% argatroban) due to heparin contraindication(s) (72% heparin-induced thrombocytopenia, 21% heparin allergy, 4% protamine reaction, and 4% religious reasons). The patient's usual oral anticoagulant was continued without interruption in 69%. Procedures were performed for atrial fibrillation (64%) or ventricular tachycardia/premature ventricular contractions (36%). Transseptal puncture was undertaken in 81%, and a contact force-sensing catheter was used in 70%. Vascular ultrasound was used in 71%, and femoral arterial access was gained in 36%. A bolus followed by infusion was used in all but 4 cases, and activated clotting time was monitored peri-procedurally in 72%, with 32% receiving additional boluses. Procedure duration was 216 ± 116 min, and ablation time was 51 ± 22 min. No major bleeding or embolic complications were observed. Four patients had minor self-limiting bleeding complications, including a small pericardial effusion (<1 cm), a small groin hematoma, and hematuria. CONCLUSIONS: In this multicenter series, intravenous DTIs were safely used as an alternative to heparin for left-sided catheter ablation.

6.
Heart Rhythm ; 17(7): 1066-1074, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32109563

RESUMO

BACKGROUND: No independently validated score currently exists for risk stratification of patients with frequent premature ventricular complexes (PVCs). OBJECTIVES: The purpose of this study was to develop a risk score to predict adverse events in patients with frequent PVCs. METHODS: We analyzed consecutive patients between 2012 and 2017 undergoing 14-day continuous monitoring with frequent PVCs (>5%) and concurrent echocardiography. We performed binary logistic regression to determine multivariate predictors of adverse left ventricular remodeling (left ventricular ejection fraction [LVEF] <45% or left ventricular end-diastolic volume index >75 mL/m2). A risk score was created using the log(odds ratio (OR)) of these predictors and validated prospectively to determine the risk of future adverse events in those with baseline LVEF >45%. An adverse event was defined as LVEF decline by 10%, heart failure hospitalization, or cardiovascular mortality. Two validation cohorts were used: follow-up from the original derivation cohort (cohort 1) and an independent Korean PVC registry (cohort 2). RESULTS: The derivation cohort comprised 206 patients with a mean PVC burden of 11.6% ± 6.2% and considerable daily fluctuation (minimum burden 7.3% ± 6.2% vs maximum 17.9% ± 8.0%). Independent predictors of adverse remodeling were as follows: superiorly directed PVC axis (OR 2.7; 1 point), PVC burden 10%-20% (OR 3.5; 2 points) and >20% (OR 4.4; 3 points), PVC coupling interval >500 ms (OR 4.7; 4 points), nonsustained ventricular tachycardia (OR 5.3; 4 points), which form the ABC-VT risk score. This score predicted future adverse events in both validation cohorts: cohort 1, hazard ratio 1.43; 95% confidence interval 1.19-1.73; P < .001 and cohort 2, hazard ratio 1.22; 95% confidence interval 1.05-1.42; P = .01. CONCLUSION: The ABC-VT score is a simple tool that predicts adverse left ventricular remodeling and future clinical deterioration in patients with frequent PVCs.

7.
Heart Rhythm ; 17(3): 476-484, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31606463

RESUMO

BACKGROUND: Ventricular bipolar voltage values <0.5 and <1.0/1.5 mV (epi- and endocardium) correlating with dense scar and border zone, respectively, were established using a 3.5-mm tip catheter. Novel microelectrode catheters promise improved mapping resolution; however, whether standard voltage criteria apply to catheters with smaller electrode size and interelectrode distance remains unclear. OBJECTIVE: The purpose of this study was to determine whether traditional bipolar voltage criteria for scar apply during substrate mapping with a microelectrode catheter. METHODS: Paired bipolar and microbipolar voltage values were acquired from control swine (n = 2) using the microelectrode catheter and assessed for systemic differences. In a postinfarction swine model (n = 6), scar characteristics were compared between the bipolar maps and microbipolar maps using both standard and adjusted voltage criteria derived from the control animals. RESULTS: In control swine, although 5th percentile values for bipolar and microbipolar voltage were similar (1.12 vs 1.22 mV [left ventricular (LV) endo]; 0.88 mV vs 0.98 mV [epi]), median values were significantly greater when acquired by microbipolar electrodes (3.60 vs 6.76 mV, P = .002 [LV endo]; 2.61 vs 2.72 mV, P = .02 [epi]). Microbipolar values were systematically larger by 2.0× and 1.4× in the LV endocardium and epicardium, respectively. Application of standard voltage values to microbipolar maps in postinfarct swine underestimated scar area by approximately 41% in the LV endocardium (13.7 vs 33.4 cm2, P = .004). CONCLUSION: Bipolar voltage values acquired from microelectrodes are systemically larger than those acquired from standard catheters. New reference values should be established for these novel catheters.

9.
J Am Heart Assoc ; 8(18): e010952, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31538835

RESUMO

Background Long-term corticosteroid therapy is the standard of care for treatment of cardiac sarcoidosis (CS). The efficacy of long-term corticosteroid-sparing immunosuppression in CS is unknown. The goal of this study was to assess the efficacy of methotrexate with or without adalimumab for long-term disease suppression in CS, and to assess recurrence and adverse event rates after immunosuppression discontinuation. Methods and Results Retrospective chart review identified treatment-naive CS patients at a single academic medical center who received corticosteroid-sparing maintenance therapy. Demographics, cardiac uptake of 18-fluorodeoxyglucose, and adverse cardiac events were compared before and during treatment and between those with persistent or interrupted immunosuppression. Twenty-eight CS patients were followed for a mean 4.1 (SD 1.5) years. Twenty-five patients received 4 to 8 weeks of high-dose prednisone (>30 mg/day), followed by taper and maintenance therapy with methotrexate±low-dose prednisone (low-dose prednisone, <10 mg/day). Adalimumab was added in 19 patients with persistently active CS or in those with intolerance to methotrexate. Methotrexate±low-dose prednisone resulted in initial reduction (88%) or elimination (60%) of 18-fluorodeoxyglucose uptake, and patients receiving adalimumab-containing regimens experienced improved (84%) or resolved (63%) 18-fluorodeoxyglucose uptake. Radiologic relapse occurred in 8 of 9 patients after immunosuppression cessation, 4 patients on methotrexate-containing regimens, and in no patients on adalimumab-containing regimens. Conclusions Corticosteroid-sparing regimens containing methotrexate with or without adalimumab is an effective maintenance therapy in patients after an initial response is confirmed. Disease recurrence in patients on and off immunosuppression support need for ongoing radiologic surveillance regardless of immunosuppression regimen.

10.
Circ Arrhythm Electrophysiol ; 12(9): e007337, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505948

RESUMO

BACKGROUND: Nodofascicular and nodoventricular (NFV) accessory pathways connect the atrioventricular node and the Purkinje system or ventricular myocardium, respectively. Concealed NFV pathways participate as the retrograde limb of supraventricular tachycardia (SVT). Manifest NFV pathways can comprise the anterograde limb of wide-complex SVT but are quite rare. The purpose of this report is to highlight the electrophysiological properties and sites of ablation for manifest NFV pathways. METHODS: Eight patients underwent electrophysiology studies for wide-complex tachycardia (3), for narrow-complex tachycardia (1), and preexcitation (4). RESULTS: NFV was an integral part of the SVT circuit in 3 patients. Cases 1 to 2 were wide-complex tachycardia because of manifest NFV SVT. Case 3 was a bidirectional NFV that conducted retrograde during concealed NFV SVT and anterograde causing preexcitation during atrial pacing. NFV was a bystander during atrioventricular node re-entrant tachycardia, atrial fibrillation, atrial flutter, and orthodromic atrioventricular re-entrant tachycardia in 4 cases and caused only preexcitation in 1. Successful NFV ablation was achieved empirically in the slow pathway region in 1 case. In 5 cases, the ventricular insertion was mapped to the slow pathway region (2 cases) or septal right ventricle (3 cases). The NFV was not mapped in cases 5 and 7 because of its bystander role. QRS morphology of preexcitation predicted the right ventricle insertion sites in 4 of the 5 cases in which it was mapped. During follow-up, 1 patient noted recurrent palpitations but no documented SVT. CONCLUSIONS: Manifest NFV may be critical for wide-complex tachycardia/manifest NFV SVT, act as the retrograde limb for narrow-complex tachycardia/concealed NFV SVT, or cause bystander preexcitation. Ablation should initially target the slow pathway region, with mapping of the right ventricle insertion site if slow pathway ablation is not successful. The QRS morphology of maximal preexcitation may be helpful in predicting successful right ventricle ablation site.


Assuntos
Feixe Acessório Atrioventricular/fisiopatologia , Nó Atrioventricular/fisiopatologia , Fascículo Atrioventricular/fisiopatologia , Ablação por Cateter/métodos , Síndromes de Pré-Excitação/cirurgia , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Feixe Acessório Atrioventricular/cirurgia , Adulto , Idoso , Nó Atrioventricular/cirurgia , Fascículo Atrioventricular/cirurgia , Criança , Eletrocardiografia , Feminino , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/fisiopatologia , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologia , Adulto Jovem
11.
Circulation ; 140(8): 624-626, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31424993
12.
J Cardiovasc Electrophysiol ; 30(10): 1801-1810, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310380

RESUMO

INTRODUCTION: The clinical role of atrial arrhythmias (AA) in arrhythmogenic right ventricular cardiomyopathy (ARVC) and the echocardiographic variables that predict them are not well defined. We describe the prevalence, types, echocardiographic predictors, and management of AA in patients with ARVC. METHODS: We retrospectively evaluated medical records of 117 patients with definite ARVC (2010 Task Force Criteria) from two tertiary care centers. We identified those patients with sustained AA (>30 seconds), including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT). We collected demographic, genetic, and clinical data. The median follow-up was 3.4 years (interquartile range = 2.0-5.7). RESULTS: Total 26 patients (22%) had one or more types of AA: AF (n = 19), AFL (n = 9), and AT (n = 8). We performed genetic testing on 84 patients with ARVC (71.8%). Two patients with AA (8%) had peripheral emboli, and one patient (4%) suffered inappropriate implantable cardioverter-defibrillator shock. We performed catheter ablation of AA in eight patients (31%), with no procedural complications. Right atrial area and left atrial volume index were independently associated with increased odds of AA; odds ratio (OR), 1.1 (95% confidence interval [CI]:1.02-1.16) (P = .01) and OR, 1.1 (95% CI:1.03-1.15) (P = .003), respectively. An increase in tricuspid annular plane peak systolic excursion was independently associated with reduced odds; OR, 0.3 (95% CI: 0.1-0.94) (P = .003). CONCLUSIONS: Atrial arrhythmias (AA) are common in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Inappropriate shocks and systemic emboli may be associated with AA. Atrial size and right ventricular dysfunction may help identify patients with ARVC at increased odds of AA.

13.
Europace ; 21(6): 879-885, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30982849

RESUMO

AIMS: To describe heparin dosing requirements in patients who underwent catheter ablation of atrial fibrillation with uninterrupted anticoagulation using dabigatran etexilate (dabigatran) or warfarin to attain therapeutic activated clotting time (ACT) in the RE-CIRCUIT® study. The RE-CIRCUIT study showed significantly fewer major bleeding events in the dabigatran vs. warfarin treatment group. Unfractionated heparin was administered during the procedure to maintain ACT >300 s. METHODS AND RESULTS: Patients were randomly assigned to dabigatran 150 mg bid or international normalized ratio-adjusted warfarin. Ablation was performed with uninterrupted anticoagulation and continued for 8 weeks after the procedure. Heparin was administered after placement of femoral sheaths before or immediately after transseptal puncture. Ablation was performed in 635 patients (dabigatran, 317; warfarin, 318); data were available from 396 patients administered heparin (dabigatran, 191; warfarin, 205). Most frequent time window from last dose of study drug to septal puncture was 0 to <4 h in the dabigatran (41.3%) and 16 to <24 h in the warfarin arms (44.7%). Overall mean (standard deviation) heparin dose was similar between the dabigatran and warfarin groups [12 402 (10 721) vs. 11 910 (8359) IU, respectively]. Heparin dosing requirement to reach therapeutic ACT was lowest when time from last dose of dabigatran to septal puncture was 0 to <4 h. CONCLUSION: Patients treated with dabigatran required a similar amount of unfractionated heparin as those treated with warfarin to achieve an ACT of >300 s during ablation. More heparin units were required when the time from the last dose of dabigatran to septal puncture increased.

14.
15.
J Interv Card Electrophysiol ; 55(2): 145-152, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30758702

RESUMO

PURPOSE: To describe regional differences in patient characteristics, ablation procedures, and bleeding events in the RE-CIRCUIT study. RE-CIRCUIT was a prospective, multicenter study that captured data from different regions, providing an opportunity to understand the practices followed in various regions. The incidence of major bleeding events (MBEs) was significantly lower with uninterrupted dabigatran versus uninterrupted warfarin. METHODS: Patients were randomized to receive dabigatran 150 mg twice daily or warfarin. Ablation was performed with uninterrupted anticoagulation for 8 weeks after the procedure. Regions were Western Europe, Eastern Europe, North America, and Asia. RESULTS: Of 704 patients screened across 104 sites, 635 underwent catheter ablation (dabigatran, 317; warfarin, 318). Patient characteristics were different across various regions. Patients from North America had the highest prevalence of atrial flutter (33%), coronary artery disease (29%), diabetes mellitus (18%), and previous myocardial infarction (9%). Hypertension was most prevalent in Eastern Europe (75%), as was congestive heart failure (40% vs 2% in Western Europe). Pulmonary vein isolation alone was the preferred technique used in most patients (86% in North America and 75-83% elsewhere) and radio frequency was the preferred energy source. The major outcome measure, incidence of MBEs during and up to 2 months after the procedure, was consistently lower with uninterrupted dabigatran versus warfarin, irrespective of regions and their procedural differences, and different ablation techniques utilized. CONCLUSIONS: This analysis shows that the benefits of dabigatran over a vitamin K antagonist in patients undergoing atrial fibrillation ablation are consistent across all geographic regions studied. TRIAL REGISTRATION: NCT02348723 (https://clinicaltrials.gov/ct2/show/NCT02348723).


Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Dabigatrana/administração & dosagem , Varfarina/administração & dosagem , Idoso , Ásia , Comorbidade , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , América do Norte , Estudos Prospectivos
16.
Heart Rhythm ; 16(6): 846-852, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30593868

RESUMO

BACKGROUND: An increasing number of adults with congenital heart disease (CHD) are undergoing catheter ablation for atrial fibrillation (AF). Data on ablation strategy and outcomes in CHD are limited. Rhythm control is often believed to be of greater importance among patients with complex CHD. OBJECTIVE: The purpose of this study was to examine the safety and efficacy of AF ablation in adult patients with CHD. METHODS: A multicenter retrospective analysis was performed of CHD patients undergoing AF ablation. Clinical data were collected, including AF and CHD type, procedural data, and outcomes. Patients were divided into 3 groups (simple, moderate, and severe) based on CHD complexity, as defined by the 2014 PACES/HRS (Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society) consensus statement. One-year procedural success was defined as freedom from recurrent AF, off antiarrhythmic drugs (complete) or off/on previously failed antiarrhythmic drugs (partial). RESULTS: Overall, 84 CHD patients (mean age 51.5 ± 12.1 years; 65.5% male; 45.2% with paroxysmal AF) undergoing AF ablation (51 simple, 22 moderate, 11 severe complexity) were included. Pulmonary vein isolation was performed in 80 (95.2%), of whom 30 (35.7%) underwent pulmonary vein isolation alone. Overall, complete and complete/partial freedom was achieved at 1 year in 53.1% and 71.6%, respectively, with no significant differences between those with simple, moderate, or severe complexity. There were no major complications and 7 minor complications, and 2 patients died during follow-up. CONCLUSION: There are dramatic differences in the degree of CHD complexity among patients referred for AF ablation. When performed at experienced centers, AF ablation is safe and effective even among patients with the most complex forms of CHD.

17.
Clin Cardiol ; 42(1): 198-205, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30460702

RESUMO

Catheter ablation has been established as a rhythm control strategy in selected patients with atrial fibrillation (AF) who have failed or wish to avoid anti-arrhythmic drugs. Uninterrupted oral anticoagulation with vitamin K antagonists (VKAs) peri-ablation is associated with a lower risk of thromboembolic and bleeding complications as compared to interrupted oral anticoagulation and bridging heparin. However, a substantial portion of patients with AF are treated with non-vitamin K antagonist oral anticoagulants (NOACs). Herein, we perform an in-depth review and comparison of three recent randomized trials of uninterrupted oral anticoagulation with NOACs vs VKAs in patients undergoing AF catheter ablation. Furthermore, we report pooled results of these randomized trials. The pooled incidence of major bleeding was significantly lower with NOACs as compared to VKAs (2% vs 4.9%, respectively; odds ratio [OR] 0.40; 95% confidence intervals [CI] 0.16-0.99). Similarly, cardiac tamponade was also reduced in the NOAC group (0.4% vs 1.5%; OR 0.27; 95% CI 0.07-0.97). Thromboembolic complications were not significantly different between groups. Overall, these findings support the 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement's class I recommendation for uninterrupted NOAC use in patients undergoing AF catheter ablation.


Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/terapia , Ablação por Cateter/métodos , Tromboembolia/prevenção & controle , Administração Oral , Fibrilação Atrial/complicações , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Tromboembolia/etiologia , Vitamina K/antagonistas & inibidores
18.
Heart Lung Circ ; 28(1): 178-190, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30322758

RESUMO

Frequent ventricular ectopy is a common clinical presentation in patients suffering idiopathic ventricular outflow tract arrhythmias. These are focal arrhythmias that generally occur in patients without structural heart disease and share a predilection for characteristic anatomic sites of origin. Mechanistically, they are generally due to cyclic adenosine monophosphate (cAMP)-mediated triggered activity. As a result, there is typically an exercise or catecholamine related mode of induction and often a sensitivity to suppression with adenosine. Treatment options include clinical surveillance, medical therapy with anti-arrhythmic agents or catheter ablation. Medical therapy may offer symptomatic benefit but may have side-effects and usually results in burden reduction rather than eradication of ectopy. Catheter ablation using contemporary mapping techniques, whilst associated with some inherent procedural risk, is a potentially curative and safe option in most patients. Although usually associated with a good prognosis, some patients may develop an ectopy-mediated cardiomyopathy or, rarely, ectopy-induced polymorphic ventricular arrhythmias; catheter ablation is the treatment of choice in those patients.


Assuntos
Ablação por Cateter , Eletrocardiografia , Ventrículos do Coração/fisiopatologia , Complexos Ventriculares Prematuros , Saúde Global , Humanos , Incidência , Complexos Ventriculares Prematuros/epidemiologia , Complexos Ventriculares Prematuros/fisiopatologia , Complexos Ventriculares Prematuros/cirurgia
20.
J Am Coll Cardiol ; 72(23 Pt A): 2870-2882, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30522650

RESUMO

BACKGROUND: The pathophysiology of cardiomyopathy associated with premature ventricular contractions (PVCs) remains unclear. OBJECTIVES: This study prospectively explored cardiomyopathy development in a swine model of paced ectopic beats. METHODS: A total of 35 swine underwent pacemaker implantation. A group exposed to paced bigeminy from the right ventricular apex (RVA) for 14 weeks (RVA PVC) (n = 10) were compared with a group exposed to regular pacing from the RVA at 140 beats/min (RV-140) (n = 5) and a control group (n = 5). To test the role of ectopic beat dyssynchrony, further groups were exposed for 12 weeks to bigeminy from the right ventricular free wall (RVFW PVC) (n = 5), the left ventricular epicardium (LV Epi PVC) (n = 5) or the right atrium (premature atrial complex) (n = 5). RESULTS: After 14 weeks, the mean left ventricular ejection fraction (LVEF) was significantly lower in the RVA PVC group than in the RV-140 or control groups (p < 0.05). LVEF declined significantly in the LV Epi PVC (65.2 ± 2.4% to 39.7 ± 3.0%; p < 0.01) and RVFW PVC (66.1 ± 2.6% to 48.6 ± 2.7%; p < 0.01) groups, with final LVEF significantly lower and ventricular fibrosis significantly higher in the LV Epi PVC group compared with all others (p < 0.05). Protein levels of pRyR2, NCX-1, CaMKII-α, and PLN were up-regulated and levels of SERCA2a were down-regulated in the LV Epi PVC group compared with the control group (p < 0.05). Longer ectopic beat QRS duration and greater LV dyssynchrony were significantly associated with larger declines in LV systolic function. CONCLUSIONS: In a swine model of paced ectopic beats, PVC-induced cardiomyopathy is phenotypically distinct from a tachycardia-induced cardiomyopathy. Cardiomyopathy severity is strongly associated with severity of the hemodynamic derangement associated with the paced ectopic beats, particularly the extent of LV dyssynchrony.


Assuntos
Cardiomiopatias/diagnóstico , Cardiomiopatias/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/fisiopatologia , Animais , Valor Preditivo dos Testes , Suínos , Porco Miniatura
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