ST-segment abnormalities are associated with long-term prognosis in non-ST-segment elevation acute coronary syndromes: The ERICO-ECG study.

INTRODUCTION: We aimed to identify whether ST-segment abnormalities, in the admission or during in-hospital stay, are associated with survival and/or new incident myocardial infarction (MI) in 623 non-ST-elevation acute coronary syndrome participants of the Strategy of Registry of Acute Coronary Syndrome (ERICO) study. MATERIALS AND METHODS: ERICO is conducted in a community-based hospital. ST-segment analysis was based on the Minnesota Code. We built Cox regression models to study whether ECG was an independent predictor for clinical outcomes. RESULTS: Median follow-up was 3years. We found higher risk of death due to MI in individuals with ST-segment abnormalities in the final ECG (adjusted hazard ratio: 2.68; 95% confidence interval: 1.14-6.28). Individuals with ST-segment abnormalities in any tracing had a non-significant trend toward a higher risk of fatal or new non-fatal MI (p=0.088). CONCLUSIONS: ST-segment abnormalities after the initial tracing added long-term prognostic information.

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.

Left atrium reverse remodeling in patients with mitral valve stenosis after percutaneous valvuloplasty: a 2- and 3-dimensional echocardiographic study.

INTRODUCTION AND OBJECTIVES: The left atrium is clinically relevant in patients with mitral valve stenosis. The objective of this study was to analyze the effects of percutaneous balloon valvuloplasty on left atrium volumes and the left atrium emptying fraction in symptomatic mitral valve stenosis patients using 2-dimensional and real-time 3 -dimensional transthoracic echocardiography. METHODS: We carried out a prospective study of 28 consecutive symptomatic mitral valve stenosis patients, aged 22-72 (39 [11.5]) years, 24/28 (85.6%) women, who underwent to percutaneous balloon valvuloplasty between March 2009 and May 2011. Patients underwent 2- and 3-dimensional transthoracic and transesophageal echocardiography (atrial fibrillation) and invasive mitral valve area measurement. Echocardiographic analysis was performed before, 72 h after and 12 months after percutaneous balloon valvuloplasty. The following parameters were analyzed: a) mitral valve area (2-dimensional planimetry, pressure half-time, 3-dimensional echocardiography, invasive hemodynamic measurement); b) indexed left atrium maximum and indexed minimum volumes, and c) left atrium emptying fraction. RESULTS: The 3-dimensional parameters of the mitral valve stenosis patients before and 72 h and 12 months after percutaneous balloon valvuloplasty were as follows: a) mitral valve area: 0.9 (0.1) cm(2); 1.8 (0.2) cm(2) (P<.001); 1.7 (0.2) cm(2) (P<.001); b) left atrium maximum volumes: 49.9 (12) mL/m(2); 42 (11.4) mL/m(2) (P<.001); 40.3 (10.2) mL/m(2) (P<.001), and c) left atrium emptying fraction: 30.1 (9.4%); 40.6 (7.4%) (P<.001); 44.1 (8%) (P<.001), respectively. CONCLUSIONS: In symptomatic mitral valve stenosis patients who underwent percutaneous balloon valvuloplasty analysis by 2- and 3-dimensional echocardiography, improvements in left atrium reverse remodeling and left atrium emptying fraction were observed 72 h and 12 months after the procedure.

Global and regional ventricular repolarization study by body surface potential mapping in patients with left bundle-branch block and heart failure undergoing cardiac resynchronization therapy.

BACKGROUND: The controversial effects promoted by cardiac resynchronization therapy (CRT) on the ventricular repolarization (VR) have motivated VR evaluation by body surface potential mapping (BSPM) in CRT patients. METHODS: Fifty-two CRT patients, mean age 58.8 ± 12.3 years, 31 male, LVEF 27.5 ± 9.2, NYHA III-IV heart failure with QRS181.5 ± 14.2 ms, underwent 87-lead BSPM in sinus rhythm (BASELINE) and biventricular pacing (BIV). Measurements of mean and corrected QT intervals and dispersion, mean and corrected T peak end intervals and their dispersion, and JT intervals characterized global and regional (RV, Intermediate, and LV regions) ventricular repolarization response. RESULTS: Global QTm (P < 0.001) and QTc(m) (P < 0.05) were decreased in BIV; QTm was similar across regions in both modes (P = ns); QTc(m) values were lower in RV/LV than in Intermediate region in BASELINE and BIV (P < 0.001); only RV/Septum showed a significant difference (P < 0.01) in the BIV mode. QTD values both of BASELINE (P < 0.01) and BIV (P < 0.001) were greater in the Intermediate than in the LV region. CRT effect significantly reduced global/regional QTm and QTc(m) values. QTD was globally decreased in RV/LV (Intermediate: P = ns). BIV mode significantly reduced global T peak end mean and corrected intervals and their dispersion. JT values were not significant. CONCLUSIONS: Ventricular repolarization parameters QTm, QTc(m), and QTD global/regional values, as assessed by BSPM, were reduced in patients under CRT with severe HF and LBBB. Greater recovery impairment in the Intermediate region was detected by the smaller variation of its dispersion.

Signal-averaged electrocardiogram in chronic Chagas' heart disease

The aim of the study was to register the prevalence of late potentials (LP) in patients with chronic Chagas' heart disease (CCD) and the relationship with sustained ventricular tachycardia (SVT). 192 patients (96 males), mean age 42.9 years, with CCD were studied through a Signal Averaged ECG using time domain analysis. According to presence or absence of bundle branch block (BBB) and SVT, four groups of patients were created: Group I (n = 72): without SVT (VT-) and without BBB (BBB-): Group II (n = 27): with SVT (VT+) and BBB-; Group Ill (n = 63): VT- and with BBB (BBB+); and Group IV (N = 30): VT+ and BBB+. The LP was admitted, with 40 Hz filter, in the groups without BBB using standard criteria of the method. In the group with BBB, the root-mean-square amplitude of the last 40 ms (RMS) < = 14 microV was considered as an indicator of LP. Results: In groups I and II, LP was present in 21 (78 percent) of the patients with SVT and in 22 (31 percent) of the patients without SVT (p < 0.001), with Sensitivity (S) 78 percent; Specificity (SP) 70 percent and Accuracy (Ac) 72 percent. LP was present in 30 (48 percent) of the patients without and 20 (67 percent) of the patients with SVT, in groups Ill and IV. p = 0.066, with S = 66 percent; SP = 52 percent; and Ac = 57 percent. In the follow-up, there were 4 deaths unrelated to arrhythmic events, all of them did not have LP. Eight (29,6 percent) of the patients from group II and 4 (13 percent) from group IV presented recurrence of SVT and 91,6 percent of these patients had LP. Conclusions: LP occurred in 77.7 percent of the patients with SVT and without BBB. In the groups with BBB, there was association of LP with SVT in 66,6 percent of the cases. The recurrence of SVT was present in 21 percent of the cases from which 91,6 percent had LP.

Eletrocardiograma de alta resoluçäo na cardiopatia chagásica crônica / The signal average ECG in patients with chronic Chagas' heart disease

Foram estudados, por meio de eletrocardiograma de alta resoluçäo, 192 pacientes com cardiopatia chagásica crônica, sendo 96 (50 por cento) do sexo masculino. A idade variou entre 17 e 75 anso (média de 42,93.). O estudo objetivou estudar a prevalência de potencial tardio em portadores de cardiopatia chagásica crônica e sua relaçäo com taquicardia ventricular sustentada. De acordo com a presença ou a ausência de bloqueio de ramo e taquicardia ventricular sustentada foram constituídos 4 grupos. Admitiu-se a presença de potencial tardio, com filtro de 40H2, nos grupos sem bloquio de ramo, quando a duraçäo do QRS filtrado era . 110 ms, a duraçäo do sinal abaixo de 40 uV maior-igual 35ms e voltagem da raiz quadrada dos últimos 40 ms (VM40) maior-igual 20uV. Nos grupos com bloqueio de ramo considerou-se o VM 40 maior-igual 14UV como indicativo de potencial tardio. Resultados: nos grupos sem bloqueio de ramo o potencial tardio esteve presente em 21 (78 por cento) dos pacientes com taquicardia ventricular sustentada e em 22 (31 por cento) dos sem taquicardia ventricular sustentada (p < 0,001), com sensibilidade (S) 78 por cento, especificidade (E) 70 por cento e acurácia (Ac) 77 por cento. O potencial tardio esteve presente em 30 (48 por cento) dos pacientes sem taquicardia ventricular sustentada e em 20 (67 por cento) com taquicardia ventricular sustentada nos grupos com bloqueio de ramo (p=0,066), com S, 66 por cento; E, 52 por cento; e Ac, 57 por cento. No seguimento 12 (21 por cento) pacientes apresentaram recorrência de taquicardia ventricular sustentada: 91,6 por cento desses pacientes tinham potencial tardio. Ocorreram quatro óbtios sem relaçäo com eventos arrítmicos todos pertencentes ao grupo com bloqueio de ramo e sem taquicardia ventricular sustentada, e com potencial tardio ausente. Conclusöes: potencial tardio ocorreu em 77,7 por cento dos pacientes com taquicardia ventricular sustentada e sem bloqueio de ramo. Na ausência de bloqueio de ramo o eletrocardiograma de alta resoluçäo diferenciou pacientes com e sem taquicardia ventricular sustentada. nos grupos sem bloqueio de ramo observou-se S=70por cento e Ac=77 por cento. Nos grupos com bloqueio de ramo, em 66,6 por cento dos casos houve associaçäo entre potencial tardio e taquicardia ventricular sustentada. A recorrência de taquicardia ventricular sustentada esteve presente em 21 por cento dos casos e, desses, 91,6 por cento tinham potencial tardio.