Differential diagnosis of wide QRS tachycardias: comparison of two electrocardiographic algorithms.

AIMS: This study's aim is to compare the ability of two ECG criteria to differentiate ventricular (VT) from supraventricular tachycardia (SVT): Brugada et al. [horizontal plane (HP) leads] and Vereckei et al. [frontal plane (FP), specifically aVR lead], having electrophysiological study (EPS) as gold standard. After comparing, suggestions for better diagnosis of wide QRS-complex tachycardia (WCT) in emergency situations were made. METHODS AND RESULTS: Fifty-one consecutive patients with 12-lead ECG registered during EPS-induced regular WCT were selected. Each ECG was split into two parts: HP (V1-V6) and FP (D1-D3, aVR, aVL, and aVF), randomly distributed to three observers, blinded for EPS diagnosis and complementary ECG plane, resulting in total 306 ECG analyses. Observers followed the four steps of both algorithms, counting time-to-diagnosis. Global sensitivity, specificity, percentage of incorrect diagnoses, and step-by-step positive/negative likelihood ratios (+LR and -LR) were calculated. Kaplan-Meier curve was plotted for final time-to-diagnosis. Inter-observer agreement was assessed with kappa-statistic. Global sensitivity was similarly high in FP and HP algorithms (89.2 vs. 90.1%), and incorrect classifications were 27.4 vs. 24.7%. Forty-eight correct analyses by Vereckei criteria took 9.13 s to diagnose VT in the first step, showing that first step was fast, with high +LR, generating nearly conclusive pre- (72.6%) to post-test (98.0%) changes for VT probability. CONCLUSION: Both algorithms as a whole are similar for diagnosis of WTC; however, the first step of Vereckei (initial R in aVR) is a simple, reproducible, accurate, and fast tool to use. The negativity of this step requires a 'holistic' approach to distinguish VT from SVT.

Additive effects of plant sterols supplementation in addition to different lipid-lowering regimens.

OBJECTIVE: Plant sterol (PS) supplementation has been widely used alone or combined with lipid-lowering therapies (LLTs) to reduce low-density lipoprotein (LDL) cholesterol. The effects of PS added to high-intensity LLT are less reported, especially regarding the effects on cholesterol synthesis and absorption. METHODS: A prospective, randomized, open-label study, with parallel arms and blinded end points was designed to evaluate the effects of addition of PS to LLT on LDL cholesterol, markers of cholesterol synthesis, and absorption. Eighty-six patients of both genders were submitted to a 4-wk run-in period with atorvastatin 10 mg (baseline). Following, subjects received atorvastatin 40 mg, ezetimibe 10 mg, or combination of both drugs for another 4-wk period (phase I). In phase II, capsules containing 2.0 g of PSs were added to previous assigned treatments for 4 wk. Lipids, apolipoproteins, plasma campesterol, ß-sitosterol, and desmosterol levels were assayed at all time points. Within and between-group analyses were performed. RESULTS: Compared with baseline, atorvastatin 40 mg reduced total and LDL cholesterol (3% and 22%, respectively, P < .05), increased ß-sitosterol, campesterol/cholesterol, and ß-sitosterol/cholesterol ratios (39%, 47%, and 32%, respectively, P < .05); ezetimibe 10 mg reduced campesterol and campesterol/cholesterol ratio (67% and 70%, respectively, P < .05), and the combined therapy decreased total and LDL cholesterol (22% and 38%, respectively, P < .05), campesterol, ß-sitosterol, and campesterol/cholesterol ratio (54%, 40%, and 27%, P < .05). Addition of PS further reduced total and LDL cholesterol by ∼ 7.7 and 6.5%, respectively, in the atorvastatin therapy group and 5.0 and 4.0% in the combined therapy group (P < .05, for all), with no further effects in absorption or synthesis markers. CONCLUSIONS: PS added to LLT can further improve lipid profile, without additional effects on intestinal sterol absorption or synthesis.

Contribuiçäo do monitor de eventos no diagnóstico de sintomas / The contribution of the loop memory ECG recorder to the diagnosis of symptoms

OBJETIVO: A avaliar o poder de contribuiçäo do monitor de enventos sintomáticos no esclarecimento de sintomas. MÉTODOS: Foram estudados 64 pacientes encaminhados para esclarecimento de sintomas e que já haviam sido submetidos à gravaçäo com Holter. Foram monitorizados, durante 15 dias, com gravador com memória circular com capacidade de registrar uma derivaçäo do ECG (CM5), antes e após ativado pelo paciente. Na vigência de sintomas, o paciente acionava um comando do gravador que provocava a retençäo do sinal do ECG, que era, posteriormente, transmitido a uma central via telefone. Resultados: Em dois pacientes näo foi possível a realizaçäo completa da monitorizaçäo, nos restantes, sintomas que motivaram a indicaçäo do exame foram: palpitaçöes ( 67,7 "por cento"), tonturas (32,3 "por cento"), síncopes(29 "por cento") e outros (30,6 "por cento"). Em 85,5 "por cento" dos pacientes houve relato de sintomas, sendo que em 62,2 "por cento" houve registros de alteraçöes eletrocardiográficas, relacionadas aos sintomas: taquicardia sinusal, 45,5 "por cento"; extra-sístoles, 30,3 "por cento"; taquicardia supraventricualar, 21,2 "por cento"; 21,2 "por cento" taquicadia ventricular, 3 "por cento" e bloqueio atrioventricular, 3 "por cento". A primeira transmissäo motivada por sintomas ocorreu: 35,5 "por cento" no 1 primeiro dia, 33,9 "por cento" do 2 "segundo" ao 5 "quinto", 12,9 "por cento" do 6 "sexto" ao 10 "decimo" e 3,2 "por cento" 11"décimo primeiro" ao 15 "décimo quinto". Nos pacientes onde a gravaçäo com Holter näo permitiu esclarecimentos, o gravador de eventos registrou sintomas em 35,5 "por cento". CONCLUSÄO: Trata-se de métodos bem aceito pelos pacientes e capaz de produzir aumento sgificativo no esclarecimento de síntomas em relaçäo ao Holer.