Length of the Mitral Isthmus But Not Anatomical Location of Ablation Line Predicts Bidirectional Mitral Isthmus Block in Patients Undergoing Catheter Ablation of Persistent Atrial Fibrillation: A Randomized Controlled Trial.

INTRODUCTION: Mitral isthmus (MI) ablation is an effective option in patients undergoing ablation for persistent atrial fibrillation (AF). Achieving bidirectional conduction block across the MI is challenging, and predictors of MI ablation success remain incompletely understood. We sought to determine the impact of anatomical location of the ablation line on the efficacy of MI ablation. METHODS AND RESULTS: A total of 40 consecutive patients (87% male; 54 ± 10 years) undergoing stepwise AF ablation were included. MI ablation was performed in sinus rhythm. MI ablation was performed from the left inferior PV to either the posterior (group 1) or the anterolateral (group 2) mitral annulus depending on randomization. The length of the MI line (measured with the 3D mapping system) and the amplitude of the EGMs at 3 positions on the MI were measured in each patient. MI block was achieved in 14/19 (74%) patients in group 1 and 15/21 (71%) patients in group 2 (P = NS). Total MI radiofrequency time (18 ± 7 min vs. 17 ± 8 min; P = NS) was similar between groups. Patients with incomplete MI block had a longer MI length (34 ± 6 mm vs. 24 ± 5 mm; P < 0.001), a higher bipolar voltage along the MI (1.75 ± 0.74 mV vs. 1.05 ± 0.69 mV; P < 0.01), and a longer history of continuous AF (19 ± 17 months vs. 10 ± 10 months; P < 0.05). In multivariate analysis, decreased length of the MI was an independent predictor of successful MI block (OR 1.5; 95% CI 1.1-2.1; P < 0.05). CONCLUSIONS: Increased length but not anatomical location of the MI predicts failure to achieve bidirectional MI block during ablation of persistent AF.

'Fast-implantable' aortic valve implantation and concomitant mitral procedures.

Concomitant aortic and mitral valve replacement or concomitant aortic valve replacement and mitral repair can be a challenge for the cardiac surgeon: in particular, because of their structure and design, two bioprosthetic heart valves or an aortic valve prosthesis and a rigid mitral ring can interfere at the level of the mitroaortic junction. Therefore, when a mitral bioprosthesis or a rigid mitral ring is already in place and a surgical aortic valve replacement becomes necessary, or when older high-risk patients require concomitant mitral and aortic procedures, the new 'fast-implantable' aortic valve system (Intuity valve, Edwards Lifesciences, Irvine, CA, USA) can represent a smart alternative to standard aortic bioprosthesis. Unfortunately, this is still controversial (risk of interference). However, transcatheter aortic valve replacements have been performed in patients with previously implanted mitral valves or mitral rings. Interestingly, we learned that there is no interference (or not significant interference) among the standard valve and the stent valve. Consequently, we can assume that a fast-implantable valve can also be safely placed next to a biological mitral valve or next to a rigid mitral ring without risks of distortion, malpositioning, high gradient or paravalvular leak. This paper describes two cases: a concomitant Intuity aortic valve and bioprosthetic mitral valve implantation and a concomitant Intuity aortic valve and mitral ring implantation.

Cardiac disease in systemic lupus erythematosus: prospective study of 70 patients.

A prospective two dimensional and Doppler echocardiographic study of 70 consecutive patients with systemic lupus erythematosus (SLE) and 40 controls was carried out. Forty patients (57%) were found to have echocardiographic disturbance. Valvular abnormalities were detected in 31 patients (44%) and in only two controls (5%). Mitral valve abnormalities were the most common findings (23/70 (33%)) with mild or moderate regurgitation the most frequent lesion (16% and 9% respectively). Three patients (4%) had a morphological echocardiographic pattern suggestive of non-infective verrucous vegetations affecting the mitral valve. No patient had haemodynamically significant clinical valve disease. Pericardial effusion was identified in 19 patients (27%), of whom 14 had mild and clinically silent disease. Myocardial abnormalities were found in 14 patients (20%), but clinical features of myocardial dysfunction were present in only one. Patients with antiphospholipid antibodies were found to have an increased prevalence of endocardial lesions, mainly valvular regurgitation. It is concluded that the inclusion of echocardiography in a study protocol of patients with SLE can identify an important subset of patients with cardiac abnormalities, many of which are clinically silent. In addition, the association of antiphospholipid antibodies with endocardial lesions suggests that these antibodies may have a prominent role in the pathogenetic mechanisms of heart valve disease in SLE.

Cardiac disease in systemic lupus erythematosus. Prospective study of 70 patients.

A prospective two dimensional and Doppler echocardiographic study of 70 consecutive patients with systemic lupus erythematosus (SLE) and 40 controls was carried out. Forty patients (57%) were found to have echocardiographic disturbance. Valvular abnormalities were detected in 31 patients (44%) and in only two controls (5%). Mitral valve abnormalities were the most common findings (23/70 (33%)) with mild or moderate regurgitation the most frequent lesion (16% and 9% respectively). Three patients (4%) had a morphological echocardiographic pattern suggestive of non-infective verrucous vegetations affecting the mitral valve. No patient had haemodynamically significant clinical valve disease. Pericardial effusion was identified in 19 patients (27%), of whom 14 had mild and clinically silent disease. Myocardial abnormalities were found in 14 patients (20%), but clinical features of myocardial dysfunction were present in only one. Patients with antiphospholipid antibodies were found to have an increased prevalence of endocardial lesions, mainly valvular regurgitation. It is concluded that the inclusion of echocardiography in a study protocol of patients with SLE can identify an important subset of patients with cardiac abnormalities, many of which are clinically silent. In addition, the association of antiphospholipid antibodies with endocardial lesions suggests that these antibodies may have a prominent role in the pathogenetic mechanisms of heart valve disease in SLE.

Avaliação da evolução da área das valvas mitral e tricúspide fetal com ultrassonografia tridimensional

OBJETIVO: avaliar as áreas das válvulas atrioventriculares (tricúspide e mitral) de fetos normais por meio da ultrassonografia tridimensional (US3D) utilizando o método STIC (spatiotemporal image correlation). MÉTODOS: realizou-se estudo de corte transversal com 141 mulheres entre a 18ª e a 33ª semana de gestação. As medidas dos volumes cardíacos foram obtidas por um transdutor volumétrico transabdominal acoplado ao aparelho Voluson 730 Expert. Utilizou-se como referência o plano de quatro câmaras com a ROI (região de interesse) posicionada a partir dos ventrículos, sendo a área das valvas delimitada manualmente. Para conhecer a correlação das áreas valvulares com a idade gestacional, foram construídos diagramas de dispersão e calculou-se o coeficiente de correlação de Pearson (r). Foram calculadas médias, medianas, desvios padrão (DP), valores máximo e mínimo. Para se determinar intervalos de referência das áreas valvulares em função da idade gestacional, seguiu-se o modelo de regressão linear simples, utilizando o método de Altman, com nível de significância de p<0,05. Para o cálculo da reprodutibilidade intraobservador, utilizou-se o coeficiente de correlação intraclasse (CCI) e o gráfico de Bland-Altman. RESULTADOS: as áreas valvulares tricúspide e mitral se correlacionaram com a idade gestacional (r=0,80 para a tricúspide e r=0,79 para a mitral), sendo que a média aumentou da válvula tricúspide e mitral, respectivamente, de 0,22±0,10 cm² e de 0,23±0,10 cm² na 18º semana para 0,92±0,29 cm² e para 1,08±0,41 cm² na 33º semana de gestação. A reprodutibilidade intraobservador resultou em CCI=0,993 (IC95% 0,987; 0,996), com diferença média de 0,01 cm² (DP±0,2 cm² e IC95%±0,4 cm²). CONCLUSÃO: intervalos de referência para a área das valvares mitral e tricúspide entre a 18ªe a 33ª semana de gestação foram determinados pela US3D e se mostraram altamente reprodutíveis.

Clinical evaluation of enalapril maleate and furosemide usage in dogs with degenerative myxomatous mitral valve, CHF functional class Ib

Degenerative myxomatous mitral valve (DMMV) is a heart disease of high incidence in small animal clinical medicine, affecting mainly older dogs and small breeds. Thus, a scientific investigation was performed in order to evaluate the clinical use of the medicines furosemide and enalapril maleate in dogs with this disease in CHF functional class Ib before and after the treatment was established. For this purpose 16 dogs with the given valve disease were used, separated into two groups: the first received furosemide (n=8) and the second received enalapril maleate (n=8) throughout 56 days. The dogs were evaluated in four stages (T0, T14, T28 and T56 day) in relation to clinical signs, hematological, biochemical and serum assessment, which included serum angiotensin converting enzyme (ACE) and aldosterone, as well as radiography, electrocardiography, Doppler-echocardiography and blood pressure. The results regarding the clinical, hematological and serum chemistry evaluations revealed no significant changes in both groups, but significant reductions in the values of ACE and aldosterone in the group receiving enalapril maleate were verified. The radiographic examination revealed reductions of VHS values and variable Pms wave of the electrocardiogram in both groups, but no changes in blood pressure values were identified. The echocardiogram showed a significant decrease of the variables LVDd/s in the studied groups and the FS% in animals that received only enalapril. Therefore, analysis of results showed that monotherapy based on enalapril maleate showed better efficiency of symptoms control in patients with CHF functional class Ib.

A pulsatile flow model for in vitro quantitative evaluation of prosthetic valve regurgitation

A pulsatile pressure-flow model was developed for in vitro quantitative color Doppler flow mapping studies of valvular regurgitation. The flow through the system was generated by a piston which was driven by stepper motors controlled by a computer. The piston was connected to acrylic chambers designed to simulate "ventricular" and "atrial" heart chambers. Inside the "ventricular" chamber, a prosthetic heart valve was placed at the inflow connection with the "atrial" chamber while another prosthetic valve was positioned at the outflow connection with flexible tubes, elastic balloons and a reservoir arranged to mimic the peripheral circulation. The flow model was filled with a 0.25% corn starch/water suspension to improve Doppler imaging. A continuous flow pump transferred the liquid from the peripheral reservoir to another one connected to the "atrial" chamber. The dimensions of the flow model were designed to permit adequate imaging by Doppler echocardiography. Acoustic windows allowed placement of transducers distal and perpendicular to the valves, so that the ultrasound beam could be positioned parallel to the valvular flow. Strain-gauge and electromagnetic transducers were used for measurements of pressure and flow in different segments of the system. The flow model was also designed to fit different sizes and types of prosthetic valves. This pulsatile flow model was able to generate pressure and flow in the physiological human range, with independent adjustment of pulse duration and rate as well as of stroke volume. This model mimics flow profiles observed in patients with regurgitant prosthetic valves.

Short-term follow-up of exercise training program and beta-blocker treatment on quality of life in dogs with naturally acquired chronic mitral valve disease

This study aimed to evaluate the effects of carvedilol treatment and a regimen of supervised aerobic exercise training on quality of life and other clinical, echocardiographic, and biochemical variables in a group of client-owned dogs with chronic mitral valve disease (CMVD). Ten healthy dogs (control) and 36 CMVD dogs were studied, with the latter group divided into 3 subgroups. In addition to conventional treatment (benazepril, 0.3-0.5 mg/kg once a day, and digoxin, 0.0055 mg/kg twice daily), 13 dogs received exercise training (subgroup I; 10.3±2.1 years), 10 dogs received carvedilol (0.3 mg/kg twice daily) and exercise training (subgroup II; 10.8±1.7 years), and 13 dogs received only carvedilol (subgroup III; 10.9±2.1 years). All drugs were administered orally. Clinical, laboratory, and Doppler echocardiographic variables were evaluated at baseline and after 3 and 6 months. Exercise training was conducted from months 3-6. The mean speed rate during training increased for both subgroups I and II (ANOVA, P>0.001), indicating improvement in physical conditioning at the end of the exercise period. Quality of life and functional class was improved for all subgroups at the end of the study. The N-terminal pro-brain natriuretic peptide (NT-proBNP) level increased in subgroup I from baseline to 3 months, but remained stable after training introduction (from 3 to 6 months). For subgroups II and III, NT-proBNP levels remained stable during the entire study. No difference was observed for the other variables between the three evaluation periods. The combination of carvedilol or exercise training with conventional treatment in CMVD dogs led to improvements in quality of life and functional class. Therefore, light walking in CMVD dogs must be encouraged.

Análisis de supervivencia en pacientes con prótesis valvular biológica, Fundación Cardioinfantil-Instituto de Cardiología, Colombia, 2005-2013

Introducción: A partir de la década de los cincuenta el manejo de la enfermedad valvular presenta cambios significativos cuando se incorporan los reemplazos valvulares tanto mecánicos como biológicos dentro de las opciones de tratamiento quirúrgico (1). Las válvulas biológicas se desarrollaron como una alternativa que buscaba evitar los problemas relacionados con la anticoagulación y con la idea de utilizar un tejido que se comportara hemodinámicamente como el nativo. Este estudio está enfocado en establecer la sobrevida global y la libertad de reoperación de la válvula de los pacientes sometidos a reemplazo valvular aórtico y mitral biológicos en la Fundación Cardioinfantil - IC a 1, 3, 5 y 10 años. Materiales y métodos: Estudio de cohorte retrospectiva de supervivencia de pacientes sometidos a reemplazo valvular aórtico y/o mitral biológico intervenidos en la Fundación Cardioinfantil entre 2005 y 2013. Resultados: Se obtuvieron 919 pacientes incluidos en el análisis general y 876 (95,3%) pacientes con seguimiento efectivo para el análisis de sobrevida. La edad promedio fue 64años. La sobrevida a 1, 3, 5 y 10 años fue 95%,90%,85% y 69% respectivamente. El seguimiento efectivo para el desenlace reoperación fue del 55% y se encontró una libertad de reoperación del 99%, 96%, 93% y 81% a los 1, 3, 5 y 10 años. No hubo diferencias significativas entre la localización de la válvula ni en el tipo de válvula aortica empleada. Conclusiones: La sobrevida de los pacientes que son llevados a reemplazo valvular biológico en este estudio es comparable a grandes cohortes internacionales. La sobrevida de los pacientes llevados a reemplazo valvular con prótesis biológicas en posición mitral y aortica fue similar a 1, 3, 5 y 10 años.

Clinical evaluation of enalapril maleate and furosemide usage in dogs with degenerative myxomatous mitral valve, CHF functional class Ib

A doença degenerativa mixomatosa da válvula mitral (DDMVM) é uma cardiopatia de alta incidência na clínica médica de pequenos animais, acometendo mormente cães idosos e raças de pequeno porte. Desta forma, foi realizada uma investigação científica objetivando avaliar clinicamente a utilização dos fármacos maleato de enalapril e furosemida em cães com a referida enfermidade na classe funcional Ib da ICC, antes e após a terapêutica implantada. Para isso, utilizaram-se 16 cães portadores da valvulopatia supracitada, distribuídos em dois grupos; com o primeiro recebendo furosemida (n=8) e o segundo maleato de enalapril (n=8), durante 56 dias. Os cães foram avaliados em quatro momentos (T0, T14, T28 e T56 dias) quanto aos sinais clínicos e parâmetros hematológicos e bioquímico-séricos, que incluíram concentrações séricas da enzima conversora da angiotensina (ECA) e aldosterona, como também avaliações radiográficas, eletrocardiográficas, ecodopplercardiográficas e da pressão arterial. Os resultados quanto aos parâmetros clínicos, avaliações hematológicas e bioquímicas séricas não revelaram alterações significativas em ambos os grupos, mas reduções significativas nos valores de ECA e aldosterona no grupo que recebeu o maleato de enalapril foram identificadas. Ao exame radiográfico observou-se reduções nos valores de VHS e na variável onda Pms do eletrocardiograma em ambos os grupos, mas sem alterações nos valores da pressão arterial. Por sua vez, o ecodopplercardiograma evidenciou diminuição significativa das variáveis DIVEd/s nos grupos estudados e na FEC% nos cães que receberam somente enalapril. Portanto, a análise dos resultados encontrados indicou que a monoterapia fundamentada no maleato de enalapril apresentou melhor eficiência no controle do quadro clínico em pacientes da classe funcional Ib da ICC.