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Electrocardiographic markers of successful fibrinolysis in patients with acute myocardial infarction
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Abstracts / Journal of Electrocardiology 44 (2011) e1–e64
Concentrations of 5-HT in the plasma of children with CHD showed an increase in PAH. Concentrations of 5-HIAA in the plasma of children with CHD having PAH increased and correlated with the degree of PAH and thus can serve as a marker for an estimation of efficiency of therapy for these patients. For children with CHD from 2 months to 17 years, the role of 5HT2R in atrium contraction is decreased, but the 5HT4R is active during all this period. Conclusion: Thus, these results may be important in relation to decreasing the high mortality in this group of sick children; 5-HT2 and 5-HT4 agonists and blockers, which may be very effective, are not currently used in the clinic. doi:10.1016/j.jelectrocard.2010.12.134
P55 New method of hemodynamic monitoring for determination of the best site for right ventricle lead during DDDR or cardiac resynchronization therapy device implantation Didenko Maxim, Bobrov Andrey, Tsyganov Alexey, Fedyainova Anastasiya, Khubulava Gennady, Shulenin Sergey, Bobrov Lev Military Medical Academy, St.Petersburg, Russia Background: One of the problems of modern pacing therapy is individualization of positioning of the ventricle lead. The existing methods can not evaluate hemodynamics response to the site of the ventricle lead during pacemaker implantation. We propose the new method to access cardiac function during the operation to evaluate the optimal site of ventricle lead. During the pacemaker implantation, it is necessary to position lead to several site. At the each position, stroke volume (SV) and cardiac output (CO) are calculated during overdrive pacing step by step from 80 until 150 beats/min with interval of 10 beats/min. The best position will be accompanied with the maximal increasing of CO at maximal heart rate. The aim of this study is to evaluate the optimal position of right ventricular (RV) lead in patients with DDDR pacemaker or cardiac resynchronization therapy (CRT) devices. Methods: We enrolled 10 patients, 5 of them underwent DDDR pacemaker implantation and 5 patients were treated by CRT device. After implantation of atrial and left ventricular leads, we studied 2 different sites of RV lead with temporal fixation: apex and interventricular septum (IVS) in middle part of right ventricular output tract region. At the each position, we measured SV and CO by 2 methods. The first was ultrasound Doppler (measuring of blood flow in the ascending aorta). The second was PiCCO technology (Pulse Contour Cardiac Output). Cardiac output was calculated at the rest and at the increased values of heart rate (HR): 80, 90, 100, 110, 120, 130, 140, and 150 beats/min. Results: Apex stimulation in patients with DDDR resulted to increasing of CO up to 29%, IVS stimulation up to 45%. Cardiac resynchronization therapy device apex stimulation resulted to 27% growth of CO at 137 beats/ min, Interventricular septum stimulation resulted to 25% growth of CO at 125 beats/min. In our cases, the best hemodynamic location of RV lead for DDDR device was IVS position. The best position of RV lead in patient with CRT device was apex. Conclusion: The new method of hemodynamic monitoring during the pacemaker implantation can show the best position of RV lead with maximal myocardial reserve. Furthermore, this method can provide individual approach for determination of the best site for permanent pacing for each patient. doi:10.1016/j.jelectrocard.2010.12.135
P56 Electrocardiographic markers of successful fibrinolysis in patients with acute myocardial infarction Leonid Berstein a, Alexander Vishnevsky b, Vladimir Novikov a, Yuri Grishkin a a Department of Cardiology, Medical Academy of Postgraduate Studies, St.Petersburg, Russia b Pokrovskaya Hospital, St.Petersburg, Russia
Background: In patients with ST-elevation myocardial infarction, prompt electrocardiographic assessment of fibrinolysis results helps the decision making on the rescue percutaneous coronary intervention and is valuable for prognosis. Methods: In 106 patients with ST-elevation myocardial infarction, with mean age of 59 ± 1 years, we analyzed electrocardiograms obtained before and 3 and 48 hours after fibrinolysis (electrocardiograms [ECGs] 1, 2, and 3). Separately for anterior and nonanterior infarctions (AMI and NAMI), the degrees of ST-segment resolution in the lead with its maximal baseline elevation (STmax) and total ST-segment resolution in leads with its elevation (STsum) were estimated from ECGs 1 and 2. The sums of T-wave amplitudes in leads with ST elevation for all 3 ECGs (sumT1, sumT2, sumT3) were measured, and the changes of these between baseline and succeeding ECGs (sum 2 − sum 1 and sum 3 − sum 1) were calculated. Echocardiographic left ventricular wall motion score index (WMSI) was obtained before fibrinolysis and on discharge (at 10 ± 3 days). The decrease in WMSI due to resolved stunning served as an integral marker of successful “myocardium-level” reperfusion. Results: Predictors of successful reperfusion along with their cutoff values providing the best differentiation of patients by the reperfusion result and sensitivities and specificities of the resultant variables are listed below (only those with P b.05). “Sum 3 − sum 1 b −28 mm”: sensitivity 68%, specificity 76%; “STsum AMI N 44%”—81% and 62%; “STsum NAMI N 59%”— 100% and 42%; “STmax NAMI N 67%”—83% and 53%; “STmax AMI N 33%”—81% and 54%; and “sum 2 − sum 1 b −28 mm”—39% and 86%. Conclusion: Total ST-segment resolution is more accurate in prediction of reperfusion results than ST-segment resolution in the “worse” lead, though the former is not specific in nonanterior infarctions. Successful reperfusion is marked by smaller ST-segment resolution in anterior than in nonanterior infarctions. Deep T-wave inversion 48 hours after fibrinolysis is indicative of successful reperfusion, whereas early T-wave analysis is lacking sensitivity. doi:10.1016/j.jelectrocard.2010.12.136
P57 Detection of cardiac arrhythmogenic sources using a time inversion reconstruction method Zohar Zafrir, Sharon Zlochiver Tel Aviv University, Tel Aviv, Israel Background: Nonpharmacologic therapy of atrial fibrillation involves the detection and ablation of suspected arrhythmogenic sources. The sources location is mostly speculated by means of dominant frequency maps or fractionated local electrograms. However, these techniques have not shown consistent results, and in many cases, the exact location of the arrhythmogenic source remains elusive. The purpose of this study is to establish a novel mathematical algorithm for the detection of atrial arrhythmogenic sources, based on extrapolation of electrical activity backwards in time from measurements taken in the present. Methods: As a proof of concept, we used a simple ionic model of an excitable cell action potential (AP) that incorporates 3 membrane currents and 4 state variables based on the classical Hodgkin-Huxley (HH) model of the squid giant axon. Although the neuron-specific ion-channel characteristics are considerably different than those of a cardiac myocyte, the biophysical principles by which an AP is developed in a single cardiac myocyte and in a single neural cell axon are similar. A 16-millisecond-long forward simulation of the AP was performed by numerically solving HH equations with time resolution of 25 microseconds. To elicit an AP, a 0.4-millisecond-long, 50mA rectangular stimulation was given. A modified, regularized NewtonRaphson optimization scheme was used, and backward time reconstructions were performed using 2 temporal resolutions of 0.5 and 1 millisecond. Results: Fig. 1 shows the reconstruction results for the 4 state variables, along with the true curves taken from the forward simulation. It can be seen that all reconstructions succeeded to reproduce the general temporal behavior of the state variables back to the time point when the stimulation was given. The backward reconstructions with the 1-millisecond resolution yielded smoother curves that better fitted the true curves from the forward simulation. Conclusion: The results suggest that it is feasible to reconstruct the membrane activity of a single cell with a reasonable accuracy. The shape of
Abstracts / Journal of Electrocardiology 44 (2011) e1–e64
Concentrations of 5-HT in the plasma of children with CHD showed an increase in PAH. Concentrations of 5-HIAA in the plasma of children with CHD having PAH increased and correlated with the degree of PAH and thus can serve as a marker for an estimation of efficiency of therapy for these patients. For children with CHD from 2 months to 17 years, the role of 5HT2R in atrium contraction is decreased, but the 5HT4R is active during all this period. Conclusion: Thus, these results may be important in relation to decreasing the high mortality in this group of sick children; 5-HT2 and 5-HT4 agonists and blockers, which may be very effective, are not currently used in the clinic. doi:10.1016/j.jelectrocard.2010.12.134
P55 New method of hemodynamic monitoring for determination of the best site for right ventricle lead during DDDR or cardiac resynchronization therapy device implantation Didenko Maxim, Bobrov Andrey, Tsyganov Alexey, Fedyainova Anastasiya, Khubulava Gennady, Shulenin Sergey, Bobrov Lev Military Medical Academy, St.Petersburg, Russia Background: One of the problems of modern pacing therapy is individualization of positioning of the ventricle lead. The existing methods can not evaluate hemodynamics response to the site of the ventricle lead during pacemaker implantation. We propose the new method to access cardiac function during the operation to evaluate the optimal site of ventricle lead. During the pacemaker implantation, it is necessary to position lead to several site. At the each position, stroke volume (SV) and cardiac output (CO) are calculated during overdrive pacing step by step from 80 until 150 beats/min with interval of 10 beats/min. The best position will be accompanied with the maximal increasing of CO at maximal heart rate. The aim of this study is to evaluate the optimal position of right ventricular (RV) lead in patients with DDDR pacemaker or cardiac resynchronization therapy (CRT) devices. Methods: We enrolled 10 patients, 5 of them underwent DDDR pacemaker implantation and 5 patients were treated by CRT device. After implantation of atrial and left ventricular leads, we studied 2 different sites of RV lead with temporal fixation: apex and interventricular septum (IVS) in middle part of right ventricular output tract region. At the each position, we measured SV and CO by 2 methods. The first was ultrasound Doppler (measuring of blood flow in the ascending aorta). The second was PiCCO technology (Pulse Contour Cardiac Output). Cardiac output was calculated at the rest and at the increased values of heart rate (HR): 80, 90, 100, 110, 120, 130, 140, and 150 beats/min. Results: Apex stimulation in patients with DDDR resulted to increasing of CO up to 29%, IVS stimulation up to 45%. Cardiac resynchronization therapy device apex stimulation resulted to 27% growth of CO at 137 beats/ min, Interventricular septum stimulation resulted to 25% growth of CO at 125 beats/min. In our cases, the best hemodynamic location of RV lead for DDDR device was IVS position. The best position of RV lead in patient with CRT device was apex. Conclusion: The new method of hemodynamic monitoring during the pacemaker implantation can show the best position of RV lead with maximal myocardial reserve. Furthermore, this method can provide individual approach for determination of the best site for permanent pacing for each patient. doi:10.1016/j.jelectrocard.2010.12.135
P56 Electrocardiographic markers of successful fibrinolysis in patients with acute myocardial infarction Leonid Berstein a, Alexander Vishnevsky b, Vladimir Novikov a, Yuri Grishkin a a Department of Cardiology, Medical Academy of Postgraduate Studies, St.Petersburg, Russia b Pokrovskaya Hospital, St.Petersburg, Russia
Background: In patients with ST-elevation myocardial infarction, prompt electrocardiographic assessment of fibrinolysis results helps the decision making on the rescue percutaneous coronary intervention and is valuable for prognosis. Methods: In 106 patients with ST-elevation myocardial infarction, with mean age of 59 ± 1 years, we analyzed electrocardiograms obtained before and 3 and 48 hours after fibrinolysis (electrocardiograms [ECGs] 1, 2, and 3). Separately for anterior and nonanterior infarctions (AMI and NAMI), the degrees of ST-segment resolution in the lead with its maximal baseline elevation (STmax) and total ST-segment resolution in leads with its elevation (STsum) were estimated from ECGs 1 and 2. The sums of T-wave amplitudes in leads with ST elevation for all 3 ECGs (sumT1, sumT2, sumT3) were measured, and the changes of these between baseline and succeeding ECGs (sum 2 − sum 1 and sum 3 − sum 1) were calculated. Echocardiographic left ventricular wall motion score index (WMSI) was obtained before fibrinolysis and on discharge (at 10 ± 3 days). The decrease in WMSI due to resolved stunning served as an integral marker of successful “myocardium-level” reperfusion. Results: Predictors of successful reperfusion along with their cutoff values providing the best differentiation of patients by the reperfusion result and sensitivities and specificities of the resultant variables are listed below (only those with P b.05). “Sum 3 − sum 1 b −28 mm”: sensitivity 68%, specificity 76%; “STsum AMI N 44%”—81% and 62%; “STsum NAMI N 59%”— 100% and 42%; “STmax NAMI N 67%”—83% and 53%; “STmax AMI N 33%”—81% and 54%; and “sum 2 − sum 1 b −28 mm”—39% and 86%. Conclusion: Total ST-segment resolution is more accurate in prediction of reperfusion results than ST-segment resolution in the “worse” lead, though the former is not specific in nonanterior infarctions. Successful reperfusion is marked by smaller ST-segment resolution in anterior than in nonanterior infarctions. Deep T-wave inversion 48 hours after fibrinolysis is indicative of successful reperfusion, whereas early T-wave analysis is lacking sensitivity. doi:10.1016/j.jelectrocard.2010.12.136
P57 Detection of cardiac arrhythmogenic sources using a time inversion reconstruction method Zohar Zafrir, Sharon Zlochiver Tel Aviv University, Tel Aviv, Israel Background: Nonpharmacologic therapy of atrial fibrillation involves the detection and ablation of suspected arrhythmogenic sources. The sources location is mostly speculated by means of dominant frequency maps or fractionated local electrograms. However, these techniques have not shown consistent results, and in many cases, the exact location of the arrhythmogenic source remains elusive. The purpose of this study is to establish a novel mathematical algorithm for the detection of atrial arrhythmogenic sources, based on extrapolation of electrical activity backwards in time from measurements taken in the present. Methods: As a proof of concept, we used a simple ionic model of an excitable cell action potential (AP) that incorporates 3 membrane currents and 4 state variables based on the classical Hodgkin-Huxley (HH) model of the squid giant axon. Although the neuron-specific ion-channel characteristics are considerably different than those of a cardiac myocyte, the biophysical principles by which an AP is developed in a single cardiac myocyte and in a single neural cell axon are similar. A 16-millisecond-long forward simulation of the AP was performed by numerically solving HH equations with time resolution of 25 microseconds. To elicit an AP, a 0.4-millisecond-long, 50mA rectangular stimulation was given. A modified, regularized NewtonRaphson optimization scheme was used, and backward time reconstructions were performed using 2 temporal resolutions of 0.5 and 1 millisecond. Results: Fig. 1 shows the reconstruction results for the 4 state variables, along with the true curves taken from the forward simulation. It can be seen that all reconstructions succeeded to reproduce the general temporal behavior of the state variables back to the time point when the stimulation was given. The backward reconstructions with the 1-millisecond resolution yielded smoother curves that better fitted the true curves from the forward simulation. Conclusion: The results suggest that it is feasible to reconstruct the membrane activity of a single cell with a reasonable accuracy. The shape of