Resumo A cardiomiopatia/displasia arritmogênica do ventrículo direito (C/DAVD) foi inicialmente reconhecida como uma entidade clínica por Fontaine e Marcus que avaliaram um grupo de pacientes com taquiarritmia ventricular proveniente de um ventrículo direito (VD) estruturalmente comprometido. Desde então, houve avanços significativos na compreensão da fisiopatologia, manifestação e evolução clínica e prognóstico da patologia. A identificação de mutações genéticas comprometendo os desmossomos cardíacos levou a inclusão desta entidade na classificação das cardiomiopatias. Classicamente, a C/DAVD é uma doença hereditária que se caracteriza por arritmias ventriculares, disfunção ventricular direita e/ou esquerda; e substituição fibro-gordurosa dos cardiomiócitos; cuja identificação pode ser muitas vezes desafiadora, devido à apresentação clínica heterogênea, expressividade intra- e inter-familiar altamente variável e penetrância incompleta. Na falta de um padrão-ouro que permita o diagnóstico da C/DAVD, várias categorias diagnósticas foram combinadas e, recentemente revisadas buscando uma maior sensibilidade diagnóstica, sem comprometer a especificidade. A descoberta de que as anormalidades elétricas, particularmente as arritmias ventriculares, geralmente precedem anormalidades estruturais é extremamente importante para a estratificação de risco em membros genéticos positivos. Entre os exames complementares, a ressonância magnética cardíaca (RMC) possibilita o diagnóstico precoce de comprometimento ventricular esquerdo, mesmo antes das anormalidades morfofuncionais. A estratificação de risco continua a ser um grande desafio clínico e medicamentos antiarrítmicos, ablação de cateter e desfibrilador cardioversor implantável são as ferramentas terapêuticas atualmente disponíveis. A desqualificação do esporte previne casos de morte súbita uma vez que o esforço pode desencadear não só a instabilidade elétrica, mas também deflagrar o início e a progressão da doença.

Abstract Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) was initially recognized as a clinical entity by Fontaine and Marcus, who evaluated a group of patients with ventricular tachyarrhythmia from a structurally impaired right ventricle (RV). Since then, there have been significant advances in the understanding of the pathophysiology, manifestation and clinical progression, and prognosis of the pathology. The identification of genetic mutations impairing cardiac desmosomes led to the inclusion of this entity in the classification of cardiomyopathies. Classically, ARVC/D is an inherited disease characterized by ventricular arrhythmias, right and / or left ventricular dysfunction; and fibro-fatty substitution of cardiomyocytes; its identification can often be challenging, due to heterogeneous clinical presentation, highly variable intra- and inter-family expressiveness, and incomplete penetrance. In the absence of a gold standard that allows the diagnosis of ARVC/D, several diagnostic categories were combined and recently reviewed for a higher diagnostic sensitivity, without compromising the specificity. The finding that electrical abnormalities, particularly ventricular arrhythmias, usually precede structural abnormalities is extremely important for risk stratification in positive genetic members. Among the complementary exams, cardiac magnetic resonance imaging (CMR) allows the early diagnosis of left ventricular impairment, even before morpho-functional abnormalities. Risk stratification remains a major clinical challenge, and antiarrhythmic drugs, catheter ablation and implantable cardioverter defibrillator are the currently available therapeutic tools. The disqualification of the sport prevents cases of sudden death because the effort can trigger not only the electrical instability, but also the onset and progression of the disease.

BACKGROUND: Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Simultaneous blood pressure control has been advocated for the same purpose, but findings reported from individual studies have supported varying conclusions regarding the ocular benefit of interventions on blood pressure.OBJECTIVES: The primary aim of this review was to summarize the existing evidence regarding the effect of interventions to control or reduce blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs. A secondary aim was to compare classes of anti-hypertensive medications with respect to the same outcomes.METHODS:Search methods: We searched a number of electronic databases including CENTRAL as well as ongoing trial registries. We last searched the electronic databases on 25 April 2014. We also reviewed reference lists of review articles and trial reports selected for inclusion. In addition, we contacted investigators of trials with potentially pertinent data. Selection criteria: We included in this review randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to intense versus less intense blood pressure control, to blood pressure control versus usual care or no intervention on blood pressure, or to different classes of anti-hypertensive agents versus placebo. Data collection and analysis: Pairs of review authors independently reviewed titles and abstracts from electronic and manual searches and the full text of any document that appeared to be relevant. We assessed included trials independently for risk of bias with respect to outcomes reported in this review. We extracted data regarding trial characteristics, incidence and progression of retinopathy, visual acuity, quality of life, and cost-effectiveness at annual intervals after study entry whenever provided in published reports and other documents available from included trials.MAIN RESULTS: We included 15 RCTs, conducted primarily in North America and Europe, that had enrolled 4157 type 1 and 9512 type 2 diabetic participants, ranging from 16 to 2130 participants in individual trials. In 10 of the 15 RCTs, one group of participants was assigned to one or more anti-hypertensive agents and the control group received placebo. In three trials, intense blood pressure control was compared to less intense blood pressure control. In the remaining two trials, blood pressure control was compared with usual care. Five of the 15 trials enrolled type 1 diabetics, and 10 trials enrolled type 2 diabetics. Six trials were sponsored entirely by pharmaceutical companies, seven trials received partial support from pharmaceutical companies, and two studies received support from government-sponsored grants and institutional support. Study designs, populations, interventions, and lengths of follow-up (range one to nine years) varied among the included trials. Overall, the quality of the evidence for individual outcomes was low to moderate. For the primary outcomes, incidence and progression of retinopathy, the quality of evidence was downgraded due to inconsistency and imprecision of estimates from individual studies and differing characteristics of participants. For primary outcomes among type 1 diabetics, one of the five trials reported incidence of retinopathy and one trial reported progression of retinopathy after 4 to 5 years of treatment and follow-up; four of the five trials reported a combined outcome of incidence and progression over the same time interval. Among type 2 diabetics, 5 of the 10 trials reported incidence of diabetic retinopathy and 3 trials reported progression of retinopathy; one of the 10 trials reported a combined outcome of incidence and progression during a 4- to 5-year follow-up period. One trial in which type 2 diabetics participated had reported no primary (or secondary) outcome targeted for this review. The evidence from these trials supported a benefit of more intensive blood pressure control intervention with respect to 4- to 5-year incidence of diabetic retinopathy (estimated risk ratio (RR) 0.80; 95% confidence interval (CI) 0.71 to 0.92) and the combined outcome of incidence and progression (estimated RR 0.78; 95% CI 0.63 to 0.97). The available evidence provided less support for a benefit with respect to 4- to 5-year progression of diabetic retinopathy (point estimate was closer to 1 than point estimates for incidence and combined incidence and progression, and the CI overlapped 1; estimated RR 0.88; 95% CI 0.73 to 1.05). The available evidence regarding progression to proliferative diabetic retinopathy or clinically significant macular edema or moderate to severe loss of best-corrected visual acuity did not support a benefit of intervention on blood pressure: estimated RRs and 95% CIs 0.95 (0.83 to 1.09) and 1.06 (0.85 to 1.33), respectively, after 4 to 5 years of follow-up. Findings within subgroups of trial participants (type 1 and type 2 diabetics; participants with normal blood pressure levels at baseline and those with elevated levels) were similar to overall findings. The adverse event reported most often (7 of 15 trials) was death, yielding an estimated RR 0.86 (95% CI 0.64 to 1.14). Hypotension was reported from three trials; the estimated RR was 2.08 (95% CI 1.68 to 2.57). Other adverse ocular events were reported from single trials.AUTHORS' CONCLUSIONS: Hypertension is a well-known risk factor for several chronic conditions in which lowering blood pressure has proven to be beneficial. The available evidence supports a beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to 4 to 5 years. However, the lack of evidence to support such intervention to slow progression of diabetic retinopathy or to prevent other outcomes considered in this review, along with the relatively modest support for the beneficial effect on incidence, weakens the conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy.

Several studies have shown the role of focal triggers in the pulmonary veins initiating episodes of atrial fibrillation. Radiofrequency catheter ablation of this foci is a curative therapy for paroxysmal atrial fibrillation. We report a case of idiopathic paroxysmal atrial fibrillation triggered by abnormal electrical activity in a single pulmonary vein. Mapping was performed during sinus rhythm with a 4F decapolar catheter (Spiral Supreme, Daig, St. Jude Medical) positioned near the ostium by a transseptal approach. Pulmonary vein potentials were only identified in the left superior pulmonary vein. Segmental ostial ablation (30 W) performed during left atrial pacing resulted in complete cesation of conduction in the pulmonary vein. There were no complications. The clinical response (suppression of the paroxysms of atrial fibrillation in a 9-month follow-up) observed in this patient imply that atrial fibrillation was triggered by this pulmonary vein. This case report illustrates several aspects of catheter-based ablation of pulmonary vein foci for the treatment of paroxysmal atrial fibrillation and demonstrates its efficacy. (Arch Cardiol Mex 2003; 73:124-128).

El conocimiento de que la génesis y el mantenimiento de la fibrilación atrial idiopática se debe en ciertos casos a actividad eléctrica anormal en las venas pulmonares, ha constituido un avance fundamental y ha permitido utilizar la ablación por radiofrecuencia como un procedimiento terapéutico exitoso. Se informa el resultado de la ablación segmentaria del ostium de la vena pulmonar superior izquierda en un paciente con fibrilación atrial paroxística idiopática. Para el mapeo de actividad eléctrica en las venas pulmonares se realizó un abordaje transeptal y se utilizó un catéter decapolar 4F. Sólo se registraron potenciales eléctricos en la vena pulmonar superior izquierda. La aplicación secuencial de radiofrecuencia en el ostium se acompañó de eliminación gradual de la actividad eléctrica anormal de la vena pulmonar hasta conseguir su completa desaparición. No hubo complicaciones. En un seguimiento a 9 meses no hubo recurrencia de los paroxismos de fibrilación atrial, lo que implica que esta arritmia era generada por la actividad eléctrica de la vena pulmonar tratada. El presente caso ilustra varios aspectos de la ablación con catéter de la actividad generada en las venas pulmonares en el tratamiento de la fibrilación atrial paroxística y demuestra la eficacia del procedimiento.