No abstract

This study describes the Autonomic Nervous System (ANS) response before, during and after a percutaneous transluminal coronary angioplasty (PTCA). The study population consisted of 37 patients undergoing PTCA from Staff-3 Database. Classical Heart rate variability (HRV) parameters: RR mean, SD, rMSSD, LF, HF, LF/HF and LF/(HF+LF) were extracted and a multiple factorial analysis (MFA) was carried out. Preliminary results show that sympathetic activity increases during and after PTCA, and global HRV decreases during PTCA and increases after PTCA. These findings suggest that MFA provides a powerful tool allowing assessment of ANS's response during PTCA.

Predicting non-invasively the effectiveness of a shock on Internal Electrical Cardioversion (IECV) is clinically relevant to enhance step-up voltage protocols in the treatment of Persistent Atrial Fibrillation (PAF). The present study assess the ability of a non-linear index, such as sample entropy (SampEn), to follow-up noninvasively AF organization under successive attempts of IECV and to predict the effectiveness of every single shock. Results showed a SampEn significant difference just after the first attempt in successful vs. unsuccessful patients (0.0398 ± 0.0139) vs. (0.0608 ± 0.0221) p = 0.0094; indicating that probably first shock plays the most important role in the procedure.

This study describes total energy changes over eight regions of the QRS time-frequency (TF) plane, during percutaneous transluminal coronary angioplasty (PTCA IntroductionDuring ischemic events myocardial cells must abandon electric and mechanic coupling and stay into rest in order to survive [1]. This may result, mainly, in a deviation of final wave QRS amplitudes in the same direction of ST segment [2], more probably as a consequence of slow myocardium electric activation. Reversible ischemia was generally measured only during the repolarization process through ST segment deviation. Recent studies suggest that ischemic events can produce changes in highfrequency components of the QRS complex [3,4]. Because of its multi-resolution signal decomposition, wavelet analysis and specifically complex Morlet wavelet has been successfully used to characterize qualitatively patients prone to ventricular tachycardia (VT) [5,6] and short lasting events with the surface ECG before and after angioplasty [7]. Different studies have reported high frequency energy changes (HFEC) during acute coronary occlusion. Abboud et al. and Mor Avi et al [3,8] studied this phenomenon over human and animal models respectively; Petterson et al.[4] could find HFEC even without ST deviations and obtained better sensitivity and specificity than the ST criteria. These studies of HFEC have used the 150-250Hz bandwidth, however, others research have included the bands of 80-300Hz [9],, which shows that there is not a specific time-frequency region to evaluate HFEC. The purpose of this paper is searching high frequency bands within the QRS related with ischemia produced during percutaneous transluminal coronary angioplasty (PTCA). We focused on eight time-frequency regions over the QRS where ischemic events could produce HFEC caused by coronary occlusion. Rectangle regions were used in the time-frequency (t-f) plane, but our aim is finding a "fingerprint" of HFEC over the t-f plane.

No abstract