Conduction slowing is the major in vivo effect of sodium channel blocking drugs. Although this action may promote arrhythmia suppression, apparently paradoxical arrhythmia aggravation does occur. The latter outcome is most frequently seen during treatment with the class IC agents such as encainide or flecainide, which are potent depressors of conduction even at usual plasma concentrations and h...

Based on constraint database techniques, we present a new approach to software verification. This new approach has some similarity to abstract interpretation that uses various widening operators; therefore, we call the new approach l-u widening. We show that our l-u widening leads to a more precise over-approximation of the invariants in a program than comparable previously proposed widening op...

The electrocardiogram (ECG) shows the plot of the bio-potential generated by the activity of the heart and is used by physicians to predict and treat various cardio vascular diseases. The QRS detection is a very important step in ECG signal processing. The main parameters concerned with QRS detection are sensitivity, accuracy, positive prediction and detection error. The methods used to detect ...

BACKGROUND For patients with symptomatic New York Heart Association class III or IV, ejection fraction ≤ 35%, and QRS ≥ 130 ms, cardiac resynchronization therapy (CRT) has become an established treatment option. However, use of these implant criteria fails to result in clinical or echocardiographic improvement in 30% to 45% of CRT patients. METHODS AND RESULTS The Predictors of Response to CR...

Background—Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. We aimed to assess the impact of baseline QRS duration and morphology and the change in QRS duration with pacing on CRT outcomes in mild heart failure. Methods and Results—Resynchronization Reverses Remode...

The accuracy of the use of the maximal QRS vector difference to estimate myocardial infarct size irrespective of infarct location was compared with that of measurement of cumulative creatine kinase (CK) release. Sixty patients with acute myocardial infarction and a history of symptoms of less than 4 hr duration were followed for 24 to 72 hr with orthogonal vectorcardiography and CK release anal...

BACKGROUND The planar QRS-T angle can be easily obtained from standard 12-lead ECGs, but its predictive ability is not established. We sought to determine the predictive ability of the planar QRS-T angle in patients with nonischemic cardiomyopathy and to assess QRS-T angle behavior over time. METHODS AND RESULTS Baseline QRS-T angles from 455 patients in the Defibrillators in Nonischemic Card...