Nancy M. M. de Oliveira Tobias

Diretriz de interpretação de eletrocardiograma de repouso

Jose Alves Pinho (BA), Mario Sergio de Carvalho Bacellar (BA),Demostenes G. Lima Ribeiro (CE), Rubens Nassar Darwich (MG),Antonio Luiz Pinho Ribeiro (MG), Marcelo Marcos Eloy Dunda (PB),Helio Germiniani (PR), Francisco Faustino Franca (PE),Laurindo Saraiva (PE), Clebia Maria Rios Ribeiro (PE),Paulo Ginefra (RJ), Iseu Gus (RS), Eney Fernandes (SC),Andres Riera (SC), Anisio Pedrosa (SP),Antonio Americo Friedman (SP), Antonio Carlos Firmiani (SP),Cesar Grupi (SP), Claudio Pinho (SP),Eduardo Vilaca Lima (SP), Elisabeth Kaiser (SP),Fabio Sandoli Brito (SP), Gilberto Luiz Castro Vinhas (SP),Helio Schwartz (SP), Jose Grindler (SP), Jose Luiz Aziz (SP),Marcio Figueiredo (SP), Marcos S. Molina (SP),Martino Martinelli (SP), Nancy Tobias (SP),Paulo Cesar R. Sanches (SP), Paulo Jorge Moffa (SP),Severino Attanes Neto (SP), Silvana Nishioka (SP)

Ativação elétrica ventricular na ressincronização cardíaca caracterizada pelo mapeamento eletrocardiográfico de superfície

OBJECTIVES: To assess cardiac electrical activation by using body surface potential mapping (BSPM), in patients with congestive heart failure (CHF) and left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT) with biventricular pacemaker (BIV-PM) implantation. METHODS: Mean cardiac electrical activation times were analyzed in the right ventricle (RV) (mean RV activation time = mRV), anteroseptal area (mAS), and left ventricle (mLV) of 28 patients (mean age 61.2 ± 9.5 years; NYHA class III-IV CHF; ejection fraction <40%; LBBB of mean QRS 181.2±19.4ms, SÂQRS -8.5o±68.6o), as shown in their BSPM isochronous maps, before and after implantation of atriobiventricular pacemaker, comparing those with values obtained from a control group of normal individuals [CG], in three situations: (1) native LBBB; (2) RV pacing; and (3) atriobiventricular pacing. RESULTS: Situation (1): mRV and mAS values were similar (41.0±11.8ms x 43.6±13.4ms), with delayed mLV (81.0±12.5ms, p<0.01) and asynchronous with RV and AS areas; situation (2): mRV was greater than in CG (86.8±22.9ms, p<0.001), with greater difference between mAS and mLV (63.4±20.7ms vs. 102.7±20.3ms; p<0,001); situation (3): mLV and mRV were similar (72.0±32.0ms vs. 71.6±32.3ms), mRV was greater than in CG and native LBBB (71.6±32.3ms vs. 35.1±10.9ms and 41.0±11.8ms; p<0.001), and mAS was close to CG and native LBBB values (51.3±32.8ms vs. 50.1±11.4ms and 43.6±13.4ms). CONCLUSION: The body surface potential mapping showed that RV and LV activation times which are similar, and are close to those of the AS area, suggest patterns of synchronized ventricular activation in patients with CHF and LBBB during atriobiventricular pacing.

O eletrocardiograma de alta resolução da ativação atrial em pacientes com ou sem fibrilação atrial paroxística

OBJECTIVE: To analyze the parameters of the time domain P-wave signal-averaged electrocardiogram (P-SAECG) and compare them with the P-wave duration on the conventional electrocardiogram (P on ECG) as well as the left atrium diameter (LAD) and left ventricular ejection fraction (EF) obtained on the echocardiogram in order to evaluate patients with paroxysmal atrial fibrillation (PAF). METHODS: One hundred and eighty-one patients were included in the study: 117 with confirmed PAF and 64 without PAF. The P-SAECG parameters used were: the filtered P-wave duration (FPD), the root mean square (RMS) voltages in the last 40, 30 and 20 ms of the filtered P-wave (RMS 40, RMS 30 and RMS 20), the root mean square voltage of the filtered P-wave potentials (RMS P), the integral of the potentials during the filtered P-wave (Integral P) and the filtered P-wave late potential durations below 3 µV (PL<3). RESULTS: The parameters that presented significant statistical differences between the groups were: FPD, RMS 40, 30 and 20, PL<3, P on ECG and LAD. The ROC curve calculations demonstrated the best cut-off points and performance estimates for each parameter: sensitivity, specificity, area under the curve and p-value (p). CONCLUSION: The time domain P-SAECG proved to be a superior method to identify patients with paroxysmal atrial fibrillation than the conventional electrocardiogram and echocardiogram.

Time Domain Analysis of the Signal Averaged Electrocardiogram to Detect Late Potentials in Heart Failure Patients with Different Etiologies

OBJECTIVE To evaluate the frequency, clinical correlations and prognosis influence of late potentials on the of heart failure patients with different etiologies using the signal averaged electrocardiogram. METHODS A 42 month study of the signal averaged electrocardiograms of 288 heart failure patients with different etiologies was conducted. The group of patients included 215 males (74.65%) and 73 females (25.35%) between the ages of 16 and 70 (mean 51.5, standard deviation 11.24). The heart failure etiologies were: hypertensive heart disease (78 patients, 27.1%); idiopathic dilated cardiomyopathy (73 patients, 25.4%); ischemic cardiomyopathy (65 patients, 22.6%); Chagas disease (42 patients, 14.6%); alcoholic cardiomyopathy (9 patients, 3.1%); peripartum cardiomyopathy (6 patients, 2.1%); valvular heart disease (2 patients, 4.2%) and viral myocarditis (3 patients, 1.04%). The variables included the duration of the standard QRS complex, duration of the filtered QRS complex, duration of the signal below 40 microV and the root mean square of the last 40 ms which were analyzed in regard to age, gender, etiology and mortality as well as the findings of the 12-lead electrocardiogram at rest, echocardiogram and ambulatory electrocardiogram. The statistical analysis tests used were: the Fisher exact probability test, Students t-test, Mann Whitney test, variance analysis, Log-Hank and the Kaplan-Meyer method. RESULTS Late potentials were diagnosed in 90 patients (31.3%) and there was no association with the etiologies. The presence of this condition is associated with: a lower maximum oxygen uptake during the ergospirometry (p=0.001); sustained and non-sustained ventricular tachycardia during Holter monitoring (p=0.001), sudden death and mortality (p<0.05). Patients that did not present late potentials had a higher overlife rate. CONCLUSION The presence of late potentials was not associated with the etiologies and proved to be an indication of a worse prognosis.

QT Interval Dispersion Analysis in Patients Undergoing Left Partial Ventriculectomy (Batista Operation)

Background: QT interval dispersion (QTd) has been valued as a marker of increased vulnerability for cardiac arrhythmias. QTd was analyzed in patients undergoing the left partial ventriculectomy (LPV) or Batista operation, a palliative surgery for patients in the line for heart transplantation, which is associated with complex arrhythmia and death from sustained ventricular tachyarrhythmia (SVT).

Computer-aided systematized approach to pediatric ECG analysis.

Background: In pediatric electrocardiography (ECG), the correct classification of segments in the medical record is subjected to various components. A conventional analysis based either on the cardiologists skills or a quick reference to a standard normality table may lead to mistakes and to an incorrect final medical diagnosis. In this study, the evaluation of 12 specific ECG segments (ES) is defined as segmental analysis (SA). We hypothesized that a computer‐aided SA can provide better results for a correct classification of pediatric ECGs, compared to the conventional analysis. This study aims to evaluate the accuracy of a computer‐aided SA ECG diagnosis of pediatric patients by cardiologists.