Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-31957087

RESUMO

INTRODUCTION: Ablation with second-generation cryoballoon technology evolves as an effective and safe alternative to radiofrequency for atrial fibrillation ablation procedures. Nevertheless, the optimal freezing strategy remains unknown. Our objective was to identify the procedural cryoablation parameters predicting successful peri-pulmonary vein (PV) lesions by directly analyzing Postablation gaps in late-gadolinium-enhanced cardiac magnetic resonance (LGE-CMR). METHODS AND RESULTS: Forty-nine consecutive patients (196 PVs) undergoing ablation with second-generation cryoballoon at our center were included. The number and duration of cryoballoon application to achieve PV isolation were left to operator discretion. Gap number and length were quantified in all patients with a LGE-CMR performed 3 months postablation. Application time (420 ± 217 seconds), number of applications (2.1 ± 1.2), application time after electrical isolation (311 ± 194 seconds) and minimum temperature (-45.8 ± 6.5°C) were similar in the 4 PVs. Gaps were observed in 148 PVs (76%), averaging 1.3 ± 1 gaps per vein. Gaps were longer and more frequent in the right PVs (91% vs 59% in left PVs, P < .001). Neither the number, total duration of applications, nor postisolation application time predicted relative length or number of gaps. CONCLUSIONS: After successful PV isolation was achieved in patients undergoing cryoablation, increasing the number of applications, the total application time or application time postisolation did not result in a reduction in the number or the relative length of gaps.

3.
Eur J Prev Cardiol ; : 2047487319891779, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801048

RESUMO

BACKGROUND: The mechanisms underlying the high interindividual variability demonstrated for right-ventricular (RV) adaptation to exercise have not yet been identified, but different pulmonary vascular adaptations among individuals could be involved. Pulmonary transit of agitated saline (PTAS) during exercise has been demonstrated to be a good estimator of vascular reserve. AIM: The aim of this study was to evaluate the presence of PTAS among endurance athletes (EAs) of both sexes and its influence on RV adaptation to exercise. METHODS: A total of 100 highly trained EAs performed a maximal cardiopulmonary exercise test. Bi-ventricular functional and structural characteristics as well as PTAS were evaluated at baseline and at peak exercise. Athletes were distributed between two groups based on the amount of PTAS during exercise as high (HTPAS; >12 bubbles) and low (LPTAS; ≤12 bubbles). RESULTS: Overall, 11 EAs exhibited an intra-cardiac shunt at rest and 1 met the criteria for chronic pulmonary disease and were excluded from the study. Among the remaining 88 EAs (51% women), 47 (53%) athletes were classified as HPTAS and 41 (47%) as LPTAS. HPTAS capability was associated with significantly larger RV contractile reserve, larger pulmonary vascular reserve and an enhanced maximal exercise capacity. On multivariate analysis, females were the only independent correlate of the HPTAS capability. CONCLUSION: In highly trained endurance athletes, a HPTAS capability during exercise corresponded to an increase in pulmonary vascular and RV contractile reserves as well as an enhanced maximal exercise capacity. The long-term clinical or performance implications of the absence or presence of pulmonary shunting, and the subsequent RV afterload increase while performing exercise, remains to be determined.

4.
Eur J Prev Cardiol ; : 2047487319868545, 2019 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-31423814

RESUMO

BACKGROUND: The cumulative effects of intensive endurance exercise may induce a broad spectrum of right ventricular remodelling. The mechanisms underlying these variable responses have been scarcely explored, but may involve differential pulmonary vasculature adaptation. Our aim was to evaluate right ventricular and pulmonary circulation in highly trained endurance athletes. METHODS: Ninety-three highly trained endurance athletes (>12 h training/week at least during the last five years; age: 36 ± 6 years; 52.7% male) and 72 age- and gender-matched controls underwent resting cardiovascular magnetic resonance imaging to assess cardiac dimensions and function, as well as pulmonary artery dimensions and flow. Pulmonary vascular resistance (PVR) was estimated based on left ventricular ejection fraction and pulmonary artery flow mean velocity. Resting and exercise Doppler echocardiography was also performed in athletes to estimate pulmonary artery pressure. RESULTS: Athletes showed larger biventricular and biatrial sizes, slightly reduced systolic biventricular function, increased pulmonary artery dimensions and reduced pulmonary artery flow velocity as compared with controls in both genders (p < 0.05), which resulted in significantly higher estimated PVR in athletes as compared with controls (2.4 ± 1.2 vs. 1.7 ± 1.1; p < 0.05). Substantially high estimated PVR values (>4.2 WU) were found in seven of the 93 (9.3%) athletes: those exhibiting an enlarged pulmonary artery (indexed area cm2/m2: 4.8 ± 0.6 vs. 3.9 ± 0.6, p < 0.05), a decreased pulmonary artery distensibility index (%: 43.0 ± 15.2 vs. 62.0 ± 17.4, p < 0.05) and a reduced right ventricular ejection fraction (%: 49.3 ± 4.5 vs. 53.6 ± 4.6, p < 0.05). CONCLUSIONS: Exercise-induced remodelling involves, besides the cardiac chambers, the pulmonary circulation and is associated with an increased estimated PVR. A small subset of athletes exhibited substantial increase of estimated PVR related to pronounced pulmonary circulation remodelling and reduced right ventricular systolic function.

5.
Europace ; 20(12): 1959-1965, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29860416

RESUMO

Aims: Left atrial (LA) fibrosis can be identified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) in patients with atrial fibrillation (AF). However, there is limited information about anatomical fibrosis distribution in the left atrium. The aim is to determine whether there is a preferential spatial distribution of fibrosis in the left atrium in patients with AF. Methods and results: A 3-Tesla LGE-CMR was performed in 113 consecutive patients referred for AF ablation. Images were post-processed and analysed using ADAS-AF software (Galgo Medical), which allows fibrosis identification in 3D colour-coded shells. A regional semiautomatic LA parcellation software was used to divide the atrial wall into 12 segments: 1-4, posterior wall; 5-6, floor; 7, septal wall; 8-11, anterior wall; 12, lateral wall. The presence and amount of fibrosis in each segment was obtained for analysis. After exclusions for artefacts and insufficient image quality, 76 LGE-MRI images (68%) were suitable for fibrosis analysis. Segments 3 and 5, closest to the left inferior pulmonary vein, had significantly higher fibrosis (40.42% ± 23.96 and 25.82% ± 21.24, respectively; P < 0.001), compared with other segments. Segments 8 and 10 in the anterior wall contained the lowest fibrosis (2.54% ± 5.78 and 3.82% ± 11.59, respectively; P < 0.001). Age >60 years was significantly associated with increased LA fibrosis [95% confidence interval (CI) 0.19-8.39, P = 0.04] and persistent AF approached significance (95% CI -0.19% to 7.83%, P = 0.08). Conclusion: In patients with AF, the fibrotic area is preferentially located at the posterior wall and floor around the antrum of the left inferior pulmonary vein. Age >60 years was associated with increased fibrosis.


Assuntos
Fibrilação Atrial/diagnóstico por imagem , Função do Átrio Esquerdo , Remodelamento Atrial , Meios de Contraste/administração & dosagem , Átrios do Coração/diagnóstico por imagem , Imagem por Ressonância Magnética , Compostos Organometálicos/administração & dosagem , Veias Pulmonares/diagnóstico por imagem , Fatores Etários , Idoso , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Feminino , Fibrose , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Veias Pulmonares/patologia , Veias Pulmonares/fisiopatologia , Fatores de Risco
6.
J Cardiovasc Electrophysiol ; 29(8): 1065-1072, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29722466

RESUMO

INTRODUCTION: The purpose of this study was to compare the anatomical characteristics of scar formation achieved by visual-guided laser balloon (Laser) and radiofrequency (RF) pulmonary vein isolation (PVI), using late-gadolinium-enhanced cardiac magnetic resonance imaging (LGE-CMR). METHODS AND RESULTS: We included 17 patients with paroxysmal or early persistent drug resistant AF who underwent Laser ablation; 2 were excluded due to procedure-related complications. The sample was matched with a historical group of 15 patients who underwent PVI using RF. LGE-CMR sequences were acquired before and 3 months post-PVI. Ablation gaps were defined as pulmonary vein (PV) perimeter sections showing no gadolinium enhancement. The number of ablation gaps was lower in Laser versus RF ablations (median 7 vs. 14, P  =  0.015). Complete anatomical PVI (circumferential scar around PV, without gaps) was more frequently achieved with Laser than with RF (39% vs. 19% of PVs, P  =  0.025). Fewer gaps were present at the superior and anterior left PV and posterior right PV antral regions in the Laser group, compared to RF. Scar extension into the PVs was similar in both groups, although RF produced more extensive ablation scar toward the LA body. AF recurrences at 1 year were similar in both groups (Laser 36% vs. RF 27%, P  =  1.00). CONCLUSIONS: Compared to RF, Laser ablation achieved more complete anatomical PVI, with less LA scar extension. However, AF recurrence appears to be similar after Laser compared to RF ablation. Further studies are needed to assess whether the anatomical advantages of Laser ablation translate into clinical benefit in patients with AF.


Assuntos
Gadolínio , Imagem Cinética por Ressonância Magnética/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Veias Pulmonares/diagnóstico por imagem , Ablação por Radiofrequência/tendências , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Terapia a Laser/efeitos adversos , Terapia a Laser/tendências , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Veias Pulmonares/cirurgia , Ablação por Radiofrequência/efeitos adversos
7.
Ann Cardiothorac Surg ; 6(4): 394-401, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28944181

RESUMO

Despite septal myectomy remaining the gold standard septal reduction therapy for hypertrophic obstructive cardiomyopathy (HOCM), there has been a disproportionate use of alcohol septal ablation (ASA) worldwide. Absolute resolution of left ventricular outflow tract (LVOT) obstruction with ASA is not achieved in a substantial proportion of patients. The mechanisms of failure from ASA are partially understood and described. Residual obstruction in hypertrophic cardiomyopathy is associated with worse clinical outcomes and mortality. There is a growing number of patients who present with significant residual gradients after ASA and require a rescue septal myectomy operation, which then carries an increased risk of perioperative complications and life-long sequelae. This contrasts with the excellent outcomes achieved by septal myectomy without previous percutaneous intervention. Despite complete resolution of obstruction in rescue myectomy, the outcomes remain compromised by the prior ASA.

10.
J Cardiovasc Magn Reson ; 18(1): 78, 2016 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-27814739

RESUMO

BACKGROUND: Chronic total occlusion percutaneous coronary intervention (CTO-PCI) can improve angina and left ventricular ejection fraction (LVEF). These benefits were not assessed in populations with heart failure with reduced ejection fraction (HFrEF). We studied the effect of CTO-PCI on left ventricular function and clinical parameters in patients with HFrEF. METHODS: Using cardiovascular magnetic resonance (CMR), we studied 29 patients with HFrEF and evidence of viability and/or ischemia in the territory supplied by a CTO who were successfully treated with CTO-PCI. In patients with multi-vessel disease, non-CTO PCI was also performed. Imaging parameters, clinical status, and brain natriuretic peptide (BNP) levels were evaluated before and 6 months after CTO-PCI. RESULTS: A decrease in left ventricular end-systolic volume (160 ± 54 ml vs. 143 ± 58 ml; p = 0.029) and an increase in LVEF (31.3 ± 7.4 % vs. 37.7 ± 8 %; p < 0.001) were observed. There were no differences in LVEF improvement between patients who underwent non-CTO PCI (n = 11) and those without this intervention (n = 18); (p = 0.73). The number of segments showing perfusion defects was significantly reduced (0.5 ± 1 vs. 0.2 ± 0.5; p = 0.043). Angina (p = 0.002) and NYHA functional class (p = 0.004) improved, and BNP levels decreased (p = 0.004) after CTO-PCI. CONCLUSIONS: In this group of patients with HFrEF showing CMR evidence of viability and/or ischemia within the territory supplied by the CTO, an improvement in ejection fraction, left ventricular end-systolic volume and ischemia burden was observed after CTO-PCI. Clinical and laboratory parameters also improved. TRIAL REGISTRATION: ClinicalTrials.gov NCT02570087 . Registered 6 October 2015.


Assuntos
Oclusão Coronária/terapia , Insuficiência Cardíaca/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Intervenção Coronária Percutânea , Volume Sistólico , Função Ventricular Esquerda , Idoso , Biomarcadores/sangue , Doença Crônica , Meios de Contraste/administração & dosagem , Angiografia Coronária , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/patologia , Oclusão Coronária/fisiopatologia , Feminino , Nível de Saúde , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Peptídeo Natriurético Encefálico/sangue , Compostos Organometálicos/administração & dosagem , Valor Preditivo dos Testes , Estudos Prospectivos , Recuperação de Função Fisiológica , Fatores de Tempo , Sobrevivência de Tecidos , Resultado do Tratamento
11.
Int J Cardiol ; 223: 458-464, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27544605

RESUMO

AIMS: ST-segment elevation myocardial infarction (STEMI) triggers remote extracellular matrix expansion. Myocardial extracellular volume fraction (ECV), determined by cardiovascular magnetic resonance, permits quantification of interstitial space expansion. Our aim was to determine the relationship between early serum fibrosis biomarkers and 180-day post-infarct remote myocardium remodeling using ECV. METHODS AND RESULTS: In 26 patients with STEMI, functional imaging, T1-mapping, and late-gadolinium-enhancement were performed on a 3-T CMR scanner at baseline (days 3 to 5) and 180days. Biomarkers were measured at days 1, 3, and 7 after STEMI. The mean initial and follow-up left ventricular ejection fraction (LVEF) were 48.3±18.1% and 52.6±12.3%, respectively. Initial infarct size was 11.6±16.8% of LV mass. ECV in the remote myocardium at 180days correlated with indexed end-systolic volume (r=0.4, p=0.045). A significant correlation was observed between galectin-3 at day 7 and ECV at 6months (r=0.428, p=0.037). A trend towards a direct correlation was found for BNP (r=0.380, p=0.059). Multivariate analysis revealed that BNP and galectin-3 were independent predictors of long-term changes in ECV and explained nearly 30% of the variance in this parameter (r2=0.34; p=0.01). A galectin-3 cutoff value of 10.15ng/mL was the most powerful predictor of high ECV values (≥28.5%) at follow-up. Galectin-3 at day 7 was an independent predictor of high ECV values at follow-up (OR=22.51; CI 95%: 2.1-240.72; p=0.01) with 0.76 AUC (CI: 0.574-0.964; p=0.03). CONCLUSIONS: Galectin-3 measured acutely after STEMI is an independent predictor of increased ECV at 6-month follow-up that might be useful for long-term risk stratification.


Assuntos
Matriz Extracelular/patologia , Galectina 3/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Função Ventricular Esquerda/fisiologia , Remodelação Ventricular/fisiologia , Biomarcadores/sangue , Feminino , Seguimentos , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Prognóstico , Estudos Prospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia
12.
J Cardiovasc Electrophysiol ; 27(7): 804-10, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27027899

RESUMO

BACKGROUND: Left atrial (LA) sphericity (LASP) is a new remodeling parameter based on LA shape analysis, with independent predictive value for recurrence after atrial fibrillation (AF) ablation. OBJECTIVES: To evaluate the association between LASP and thromboembolic events (TE) in patients with AF. METHODS: Twenty-nine AF patients and prior TE and 29 age- and gender-matched controls were included. LASP was calculated using a 3D-LA reconstruction. The LA appendage (LAA) volume and morphology were assessed. ROC curve analysis was performed for LASP, LA volume, LAA volume, and CHAD/CHA2 D-VASc scores (Stroke2 -the grouping variable-was excluded). RESULTS: Mean age of the study population was 61 ± 11 years (79.3% males, 53.4% hypertension, 8.6% diabetes). Patients with prior TE had higher LASP than those without (82.5 ± 3.3% vs. 80.2 ± 3.1%, P = 0.008); there were no differences in CHAD or CHA2 D-VASc scores, LA volume, LAA volume, or LAA morphology. The C-statistic was higher for LASP (0.71) than for other tested variables (CHAD score = 0.58, CHA2 D-VASc score = 0.59, LA volume = 0.50, LAA volume = 0.46; P < 0.01 for all vs. LASP). The best cutoff value for LASP was 83.6% (sensitivity 0.52, specificity 0.90). Logistic regression analysis showed predictive value for LASP (OR 1.26 per each 1% increase [1.85-52.20], P = 0.013), but not for clinical risk scores. The addition of LASP to the CHAD and CHA2 D-VASc scores increased the predictive value over the risk scores alone (P = 0.004), and reclassified 45.5% of patients with CHAD = 0 (no anticoagulation indicated) to moderate-risk (anticoagulation indicated). CONCLUSION: LA sphericity is associated with prior TE in AF patients and improves the performance of the CHAD and CHA2 D-VASc scores alone.


Assuntos
Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/diagnóstico por imagem , Função do Átrio Esquerdo , Remodelamento Atrial , Coagulação Sanguínea , Angiografia Coronária/métodos , Angiografia por Ressonância Magnética , Acidente Vascular Cerebral/etiologia , Tromboembolia/etiologia , Idoso , Área Sob a Curva , Apêndice Atrial/fisiopatologia , Fibrilação Atrial/complicações , Fibrilação Atrial/fisiopatologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imagem Tridimensional , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Espanha , Acidente Vascular Cerebral/diagnóstico , Tromboembolia/sangue , Tromboembolia/diagnóstico , Utah
13.
J Heart Valve Dis ; 25(1): 1-7, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-29505225

RESUMO

BACKGROUND AIM OF THE STUDY: The real burden of valvular heart disease (VHD) is scarcely known, as several factors may potentially lead to its increased prevalence. The study aim was to assess the prevalence of VHD and its treatment in the authors' environment to plan the healthcare requisites for optimal management of the condition. METHODS: A retrospective analysis was conducted of data acquired from patients who had been assessed at different consultation levels for cardiovascular disorders during a six-month period between January and June 2014 in public health referral area of 500,00 inhabitants. Patients included were those admitted to hospital cardiology, cardiac surgery and geriatric care units (n = 1,083), as well as ambulatory patients attending cardiology-specific outpatient clinics at the authors' hospital or at two ascribed primary care centers (n = 852). Data were registered regarding the epidemiology, etiology, echocardiography and treatment of patients in whom VHD was detected. RESULTS: Among a total of 1,935 adult patients, moderate or severe valve disease was identified in 453 cases (23.4%) who were evaluated for cardiovascular disease. The prevalence of VHD increased with age. Multivalvular moderate-severe dysfunction was present in two valves in 33% and in three valves in 5.7% of patients. Significant mitral valve disease was present in 39% and aortic valve disease in 48% of patients. The etiology of the valvular lesions was degenerative in 60%, functional in 15.5%, rheumatic in almost 10%, congenital in 6%, due to endocarditis in only 3%. Patients with VHD represented up to 24.2% of the in-hospital admissions. An interventional treatment was required in 55% of the patients (mostly surgical valve procedures). CONCLUSION: The present study results showed that VHD is a frequent occurrence and is increasingly prevalent with age, constituting up to one-fourth of all in-hospital admissions for cardiovascular disease. VHD is a growing public health problem that should be addressed with appropriate resources to improve research into its nature, diagnosis and treatment.


Assuntos
Serviço Hospitalar de Cardiologia/estatística & dados numéricos , Geriatria/estatística & dados numéricos , Doenças das Valvas Cardíacas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Insuficiência da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/epidemiologia , Feminino , Doenças das Valvas Cardíacas/diagnóstico , Doenças das Valvas Cardíacas/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/epidemiologia , Estenose da Valva Mitral/epidemiologia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Espanha/epidemiologia
14.
Heart Rhythm ; 13(1): 37-45, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26272524

RESUMO

BACKGROUND: Catheter contact force (CF) has a strong correlation with lesion formation during radiofrequency ablation. Delayed-enhancement cardiac magnetic resonance (DE-CMR) provides lesion information in patients with prior atrial fibrillation (AF) ablation. OBJECTIVE: The aim of this study was to determine the CF threshold to create permanent lesions detected by DE-CMR. METHODS: A total of 36 patients referred for AF ablation were included. A CF catheter was used during the ablation procedure, and DE-CMR was performed 3 months after the ablation procedure. Eighteen pulmonary vein (PV) segments were defined, and 3-dimensional (3D) reconstructions of the left atrium (LA) derived from the DE-CMR images were obtained. One observer evaluated the presence of any discontinuity of previous ablation lesions (gap) in the 3D reconstructions of the LA, and another observer (blinded to the gap findings) determined the minimum CF value in each PV segment. RESULTS: The PV segments where a gap was observed had a lower maximal CF value than did the segments without gap in the 3D LA reconstructions (6.7 ± 4.4 g vs 12.2 ± 4.7 g; P < .001). In receiver operating characteristic analysis, a CF threshold of >8 g provided 73% sensitivity and 81% specificity in the prediction of a complete PV lesion (positive predictive value [PPV] 84%). A CF threshold of >12 g had a specificity of 94% and increased the PPV to 91% in creating a complete lesion in the LA wall (area under the curve 0.834). CONCLUSION: A CF threshold of >12 g H5H20 predicts a complete lesion with high specificity and PPV when a dragging ablation strategy is used in AF ablation.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Cicatriz/diagnóstico , Átrios do Coração , Imagem por Ressonância Magnética , Complicações Pós-Operatórias , Veias Pulmonares/cirurgia , Idoso , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Fontes de Energia Elétrica/normas , Feminino , Átrios do Coração/patologia , Átrios do Coração/cirurgia , Humanos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/instrumentação , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Prevenção Secundária/métodos , Fatores de Tempo
15.
Europace ; 17(6): 938-45, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25616406

RESUMO

AIMS: Non-invasive depiction of conducting channels (CCs) is gaining interest for its usefulness in ventricular tachycardia (VT) ablation. The best imaging approach has not been determined. We compared characterization of myocardial scar with late-gadolinium enhancement cardiac magnetic resonance using a navigator-gated 3D sequence (3D-GRE) and conventional 2D imaging using either a single shot inversion recovery steady-state-free-precession (2D-SSFP) or inversion-recovery gradient echo (2D-GRE) sequence. METHODS AND RESULTS: We included 30 consecutive patients with structural heart disease referred for VT ablation. Preprocedural myocardial characterization was conducted in a 3 T-scanner using 2D-GRE, 2D-SSFP and 3D-GRE sequences, yielding a spatial resolution of 1.4 × 1.4 × 5 mm, 2 × 2 × 5 mm, and 1.4 × 1.4 × 1.4 mm, respectively. The core and border zone (BZ) scar components were quantified using the 60% and 40% threshold of maximum pixel intensity, respectively. A 3D scar reconstruction was obtained for each sequence. An electrophysiologist identified potential CC and compared them with results obtained with the electroanatomic map (EAM). We found no significant differences in the scar core mass between the 2D-GRE, 2D-SSFP, and 3D-GRE sequences (mean 7.48 ± 6.68 vs. 8.26 ± 5.69 and 6.26 ± 4.37 g, respectively, P = 0.084). However, the BZ mass was smaller in the 2D-GRE and 2D-SSFP than in the 3D-GRE sequence (9.22 ± 5.97 and 9.39 ± 6.33 vs. 10.92 ± 5.98 g, respectively; P = 0.042). The matching between the CC observed in the EAM and in 3D-GRE was 79.2%; when comparing the EAM and the 2D-GRE and the 2D-SSFP sequence, the matching decreased to 61.8% and 37.7%, respectively. CONCLUSION: 3D scar reconstruction using images from 3D-GRE sequence improves the overall delineation of CC prior to VT ablation.


Assuntos
Cardiomiopatias/patologia , Cicatriz/patologia , Imagem por Ressonância Magnética/métodos , Infarto do Miocárdio/patologia , Miocárdio/patologia , Taquicardia Ventricular/cirurgia , Idoso , Cardiomiopatias/complicações , Ablação por Cateter/métodos , Cicatriz/etiologia , Estudos de Coortes , Meios de Contraste , Feminino , Fibrose , Gadolínio DTPA , Humanos , Imagem Tridimensional , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Isquemia Miocárdica/complicações , Isquemia Miocárdica/patologia , Cirurgia Assistida por Computador , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/patologia
16.
Insights Imaging ; 6(2): 189-202, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25424598

RESUMO

UNLABELLED: Myocardial fibrosis is always present in end-stage heart failure and is a major independent predictor of adverse cardiac outcome. Cardiac magnetic resonance (CMR) is an imaging method that permits a non-invasive assessment of the heart and has been established as the "gold standard" for the evaluation of cardiac anatomy and function, as well as for quantifying focal myocardial fibrosis in both ischaemic and non-ischaemic heart disease. However, cardiac pathologies characterised by diffuse myocardial fibrosis cannot be evaluated by late gadolinium enhancement (LGE) imaging, as there are no reference regions of normal myocardium. Recent improvements in CMR imaging techniques have enabled parametric mapping of relaxation properties (T1, T2 and T2*) clinically feasible within a single breath-hold. T1 mapping techniques performed both with and without contrast enable the quantification of diffuse myocardial fibrosis and myocardial infiltration. This article reviews current imaging techniques, emerging applications and the future potential and limitations of CMR for T1 mapping. TEACHING POINTS: • Myocardial fibrosis is a common endpoint in a variety of cardiac diseases. • Myocardial fibrosis results in myocardial stiffness, heart failure, arrhythmia and sudden death. • T1-mapping CMR techniques enable the quantification of diffuse myocardial fibrosis. • Native T1 reflects myocardial disease involving the myocyte and interstitium. • The use of gadolinium allows measurement of the extracellular volume fraction, reflecting interstitial space.

17.
Eur Heart J ; 35(20): 1316-26, 2014 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-24394378

RESUMO

AIMS: The endocardial vs. epicardial origin of ventricular arrhythmia (VA) can be inferred from detailed electrocardiogram (ECG) analysis. However, despite its clinical usefulness, ECG has limitations. Alternatively, scarred tissue sustaining VAs can be identified by contrast-enhanced cardiac magnetic resonance (ce-CMR). The objective of this study was to determine the clinical value of analysing the presence and distribution pattern of scarred tissue in the ventricles to identify the VA site of origin and the ablation approach required. METHODS AND RESULTS: A ce-CMR study was carried out before the index ablation procedure in a cohort of 80 patients with non-idiopathic VA. Hyper-enhancement (HE) in each ventricular segment was coded as absent, subendocardial, transmural, mid-myocardial, or epicardial. The endocardial or epicardial VA site of origin was also assigned according to the approach needed for ablation. The clinical VA was successfully ablated in 77 (96.3%) patients, all of them showing HE on ce-CMR. In segments with successful ablation of the clinical ventricular tachycardia, HE was absent in 3 (3.9%) patients, subendocardial in 19 (24.7%), transmural in 36 (46.7%), mid-myocardial in 8 (10.4%), and subepicardial in 11 (14.3%) patients. Epicardial ablation of the index VA was necessary in 3 (6.1%) ischaemic and 12 (42.9%) non-ischaemic patients. The presence of subepicardial HE in the successful ablation segment had 84.6% sensitivity and 100% specificity in predicting an epicardial origin of the VA. CONCLUSION: Contrast-enhanced cardiac magnetic resonance is helpful to localize the target ablation substrate of non-idiopathic VA and also to plan the approach needed, especially in non-ischaemic patients.


Assuntos
Arritmias Cardíacas/diagnóstico , Ablação por Cateter/métodos , Arritmias Cardíacas/cirurgia , Meios de Contraste , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas/métodos , Feminino , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
19.
Int J Cardiol ; 153(3): 256-61, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-20864196

RESUMO

BACKGROUND: The structural secuelae of acute myocardial infarction (AMI) is mostly dictated by left ventricular (LV) remodelling, leading to heart failure. Monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a critical role in LV remodelling. ß-blockers are first line therapy for AMI and heart failure; however, the mechanisms responsible for their benefits remain poorly understood. Different ß-blocker agents have been shown to exert beneficial activities both in AMI and heart failure, however, their role in early remodelling after ischemia/reperfusion is to be fully elucidated. We sought to compare the effect of 2 of the most prescribed ß-blocker agents in early markers of LV remodelling after AMI. METHODS: A reperfused AMI was induced in Yorshire pigs, being randomized to early intravenous carvedilol, metoprolol or placebo. Twenty-four hours after reperfusion markers of early remodelling were addressed in the LV. RESULTS: The early administration of both ß-blockers is able to significantly reduce macrophage infiltration as well as the expression and activity of MCP-1 and MMP-2 compared to placebo. The effects of carvedilol were much stronger than those of metoprolol. Conversely, carvedilol upregulated the expression TIMP-2 to a greater extent than metoprolol. CONCLUSIONS: In an AMI model closely mimicking human pathophysiology, the early administration of carvedilol reduced the expression of markers associated with early LV remodelling to greater extent than metoprolol. These findings may explain the superior clinical benefits exerted by carvedilol in heart failure.


Assuntos
Carbazóis/uso terapêutico , Regulação para Baixo/efeitos dos fármacos , Metoprolol/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Propanolaminas/uso terapêutico , Remodelação Ventricular/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Carbazóis/farmacologia , Carvedilol , Metoprolol/farmacologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Propanolaminas/farmacologia , Distribuição Aleatória , Suínos , Remodelação Ventricular/fisiologia
20.
Int J Cardiol ; 147(3): 428-32, 2011 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-19913314

RESUMO

BACKGROUND: Myocardial infarct size is a strong predictor of cardiovascular events. Intravenous metoprolol before coronary reperfusion has been shown to reduce infarct size; however, it is unknown whether oral metoprolol initiated early after reperfusion, as clinical guidelines recommend, is similarly cardioprotective. We compared the extent of myocardial salvage associated with intravenous pre-reperfusion-metoprolol administration in comparison with oral post-reperfusion-metoprolol or placebo. We also studied the effect on suspected markers of reperfusion injury. METHODS: Thirty Yorkshire-pigs underwent a reperfused myocardial infarction, being randomized to pre-reperfusion-metoprolol, post-reperfusion-metoprolol or placebo. Cardiac magnetic resonance imaging was performed in eighteen pigs at day 3 for the quantification of salvaged myocardium. The amounts of at-risk and infarcted myocardium were quantified using T2-weighted and post-contrast delayed enhancement imaging, respectively. Twelve animals were sacrificed after 24h for reperfusion injury analysis. RESULTS: The pre-reperfusion-metoprolol group had significantly larger salvaged myocardium than the post-reperfusion-metoprolol or the placebo groups (31 ± 4%, 13 ± 6%, and 7 ± 3% of myocardium at-risk respectively). Post-mortem analyses suggest lesser myocardial reperfusion injury in the pre-reperfusion-metoprolol in comparison with the other 2 groups (lower neutrophil infiltration, decreased myocardial apoptosis, and higher activation of the salvage-kinase phospho-Akt). Salvaged myocardium and reperfusion injury pair wise comparisons proved there were significant differences between the pre-reperfusion-metoprolol and the other 2 groups, but not among the latter two. CONCLUSIONS: The intravenous administration of metoprolol before coronary reperfusion results in larger myocardial salvage than its oral administration initiated early after reperfusion. If confirmed in the clinical setting, the timing and route of ß-blocker initiation could be revisited.


Assuntos
Cardiotônicos/administração & dosagem , Cardiotônicos/uso terapêutico , Metoprolol/administração & dosagem , Metoprolol/uso terapêutico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Reperfusão Miocárdica/métodos , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Masculino , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Distribuição Aleatória , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA