THE TERM "peri-infarction block" was suggested by First, Bayley, and Bedford1 in 1950 to describe a type of intraventricular conduction defect that develops following myocardial infarction. They described alteration in the direction of the early portion of the QRS complex (initial QRS forces) that produced definite manifestations of myocardial infarction (i.e., Q waves) and slurring and prolong...

BACKGROUND AND OBJECTIVES Heart failure (HF) patients display more varied QRS duration. We investigated whether QRS variability during hospitalization for acute decompensated HF is associated with poor clinical outcomes after discharge. SUBJECTS AND METHODS One hundred seventy three patients (64% males; age 60±13 years) admitted for acute decompensated HF with severe left ventricular (LV) dys...

A 42-year-old woman was referred for radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine. Baseline twelve-lead ECG was normal during sinus rhythm and transthoracic echocardiography demonstrated no evidence of structural heart disease. The electrophysiological study showed a normal AH interval of 114 ms and HV interval of 37 ms during sinus r...

An electrocardiographic atlas of ventricular tachycardias was produced by pacing 27 epicardial sections of the heart and the mitral papillary muscles to simulate focal ventricular arrhythmias and simultaneously recording their 12 lead electrocardiographic appearances. One hundred and twenty nine patients undergoing cardiac surgery were studied. In five patients all 27 epicardial sites were pace...

AIMS The prognostic implications of QRS duration and morphology in heart failure patients treated with cardiac resynchronization therapy (CRT) remains debated. The present evaluation investigated the association between QRS duration (<150 vs. ≥150 ms) and QRS morphology (left bundle brand block [LBBB] vs. non-LBBB) and long-term prognosis of a large cohort of unselected heart failure patients t...

BACKGROUND Has been reported that patients exhibiting prolonged paced QRS duration tend to have more serious heart disease, and the paced QRS duration can be an effective indicator of impaired left ventricular function. However, the acute and chronic hemodynamic effects of paced QRS duration and pacing sites during right ventricular (RV) pacing remain unknown. METHODS A total of 14 patients w...

OBJECTIVE Despite progresses in surgical correction of Tetralogy of Fallot, pulmonary insufficiency and progressive dysfunction of the right ventricle impress its long-term prognosis. In this study we examined the correlations between QRS duration, pulmonary insufficiency and right ventricular performance index. METHODS We enrolled 57 repaired Tetralogy of Fallot patients. QRS duration on ele...

IMPORTANCE The benefits of cardiac resynchronization therapy (CRT) in clinical trials were greater among patients with left bundle-branch block (LBBB) or longer QRS duration. OBJECTIVE To measure associations between QRS duration and morphology and outcomes among patients receiving a CRT defibrillator (CRT-D) in clinical practice. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study...

The QRS is the most prominent feature in ECG signal, that correspond to the ventricular contraction ,the time of its occurrence as well as its shape provide much information about the current state of heart. There are many technique to delineation of QRS complex. This paper discusses various method for proposed earlier for delineation of QRS Complex. This paper provide also depth study of QRS d...

BackgroundPulmonary hypertension (PH) in congenital heart disease (CHD) affects the patient prognosis. QRS and QTC intervals prolongation in ECG may exaggerate life-threatening dysrhythmia in these patients. We aimed to investigate the correlation between QRS, QTC and JTC intervals prolongation in ECG with PH in CHD children. Materials and MethodsIn a cross-sectional study tha...