Multiple LVP configurations were clinically useful in a significant number of patients undergoing CRT system implantation by helping to overcome high LVP thresholds and PNS, and by providing more flexibility in placing the LV lead.

analysis of instantaneous heart rate: a study of autonomic control during thrombolysis. Am J Physiol Regul Integr Comp Physiol 284: R1079-R1091, 2003. First published November 27, 2002 10.1152/ajpregu.00287.2002 is known to elicit activation of the autonomic nervous system. Reperfusion, induced by thrombolysis, is thus expected to bring about a shift in the balance between the sympathetic and vagal systems, according to the infarct location. In this study, we explored the correlation between reperfusion and the spectral components of heart rate (HR) variability (HRV), which are associated with autonomic cardiac control. We analyzed the HR of patients during thrombolysis: nine anterior wall MI (AW-MI) and eight inferoposterior wall MI (IW-MI). Reperfusion was determined from changes in ST levels and reported pain. Reocclusion was detected in four patients. HRV was analyzed using a modified continuous wavelet transform, which provided time-dependent versions of the typically used low-frequency (LF) and high-frequency (HF) peaks and of their ratio, LF/HF. Marked alterations in at least one of the HRV parameters was found in all 18 reperfusion events. Patterns of HRV, compatible with a shift toward relative sympathetic enhancement, were found in all of the nine reperfusion events in IW-MI patients and in three AW-MI patients. Patterns of HRV compatible with relative vagal enhancement were found in six AW-MI patients (P Ͻ 0.001). Significant changes in HRV parameters were also found after reocclusion. Time-dependent spectral analysis of HRV using the wavelet transform was found to be valuable for explaining the patterns of cardiac rate control during reperfusion. In addition, examination of the entire record revealed epochs of markedly diminished HRV in two patients, which we attribute to vagal saturation. wavelet transform; myocardial infarction; spectral analysis; heart rate variability IN ACUTE MYOCARDIAL INFARCTION (AMI) patients, thrombolysis using streptokinase or recombinant tissue plasminogen activator (rtPA) is a widely used procedure. The occurrence and timing of reperfusion have crucial clinical implications, both for prognosis and for subsequent treatment. Reperfusion is typically determined by examining the changes in the ST segment and in the pain as reported by the patient. The principal aim of this study was characterizing the patterns of heart rate (HR) fluctuations, which appear in synchrony with reperfusion. Such characterization would reveal the behavior of the autonomic nervous system (ANS) during AMI and may lay the basis for a HR-based marker of reperfusion, which would be independent of current markers.The basic concept that underlies this study is the activation of cardiovascular reflexes by altered myocardial blood supply. It has been shown in animal models that myocardial ischemia induces strong autonomic reflexes: left anterior wall ischemia tends to induce sympathetic activation (43, 54), whereas ischemia of the inferoposterior wall tends to induce parasympathetic activation (23, 54). T...

Absence of LA contraction and LA volume index ≥33 ml/m(2) result in a significant increase in the risk for thromboembolic stroke after the Maze procedure for patients in sinus rhythm.

SVT-VT combined discriminators strongly influence dual-chamber SVT-VT discrimination performance. In our study, optimal programming is morphology only in the V=A branch and morphology or interval stability (ANY) in the V