Browsing by Author "Radovanović, Nikola N. (56543116700)"

We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals) and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin), with sinus rhythm and ventricular extrasystoles (HF-VES), and with permanent atrial fibrillation (HF-AF). We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF) there is no coherence between signals (p < 0.01), while in HF-Sin it is reduced (p < 0.05), compared with control subjects. In all heart failure groups causality between signals is diminished, but with significantly stronger causality of RR signal in respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the presence of atrial/ventricular arrhythmias and it could be revealed by complementary methods of time series analysis. © 2018 Radovanović, Pavlović, Milašinović, Kirćanski and Platiša.

We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals) and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin), with sinus rhythm and ventricular extrasystoles (HF-VES), and with permanent atrial fibrillation (HF-AF). We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF) there is no coherence between signals (p < 0.01), while in HF-Sin it is reduced (p < 0.05), compared with control subjects. In all heart failure groups causality between signals is diminished, but with significantly stronger causality of RR signal in respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the presence of atrial/ventricular arrhythmias and it could be revealed by complementary methods of time series analysis. © 2018 Radovanović, Pavlović, Milašinović, Kirćanski and Platiša.

Background: The implantable loop recorder (ILR) is a small cardiac rhythm-monitoring device. Our aim was to determine ILR diagnostic value in patients with unexplained syncope, presyncope, or palpitations suggesting cardiac arrhythmias. Methods: This has been a retrospective, observational, single-center study. We included 181 patients in whom ILR was implanted at the Clinical Center of Serbia between January 2006 and July 2019. An event was marked as diagnostic if it led to a diagnosis and ILR was considered diagnostic if it verified or excluded an arrhythmia as the cause of syncope or palpitations. Results: The mean age was 51.8 ± 17.8 years and 94 (51.9%) were male. The mean follow-up period was 20.2 ± 15.8 months. ILR was diagnostic in 98 patients (54.1%). There was no significant difference in diagnostic value of ILR in regard to the baseline patients’ characteristics. The mean time to occurrence of the diagnostic event was 11.1 ± 9.6 months. The time to occurrence of a diagnostic event did not differ significantly between patients who underwent basic as compared to extended diagnostics before ILR implantation. Conclusions: ILR was able to achieve an etiological diagnosis in 54.1% of patients with unexplained syncope, presyncope, or palpitations suggesting cardiac arrhythmias. In a subgroup of patients with recurrent palpitations, ILR was significantly less diagnostic than in patients with syncope or presyncope. ILR should be implanted beforehand in syncope evaluation process. © 2021 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.

Heart failure (HF) is one of the most frequent heart diseases. It is usually characterized with structural and functional cardiac abnormalities followed by dysfunction of autonomic cardiac control. Current methods of heartbeat interval analysis are not capable to differentiate HF patients and some new differentiation of HF patients could be useful in the determination of the direction of their treatment. In this study, we examined potential of the ratio of the short-term and long-term scaling exponents (α1 and α2) to separate HF patients with similar level of reduced cardiac autonomic nervous system control and with no significant difference in age, left ventricular ejection fraction (LVEF) and NYHA class. Thirty-five healthy control subjects and 46 HF patients underwent 20 min of continuous supine resting ECG recording. The interbeat interval time series were analyzed using standardized power spectrum analysis, detrended fluctuation analysis method and standard Poincaré plot (PP) analysis with measures of asymmetry of the PP. Compared with healthy control group, in HF patients linear measures of autonomic cardiac control were statistically significantly reduced (p < 0.05), heart rate asymmetry was preserved (Cup > Cdown, p < 0.01), and long-term scaling exponent α2 was significantly higher. Cluster analysis of the ratio of short- and long-term scaling exponents showed capability of this parameter to separate four clusters of HF patients. Clusters were determined by interplay of presence of short-term and long-term correlations in interbeat intervals. Complementary measure, commonly accepted ratio of the PP descriptors, SD2/SD1, showed tendency toward statistical significance to separate HF patients in obtained clusters. Also, heart rate asymmetry was preserved only in two clusters. Finally, a multiple regression analysis showed that the ratio α1/α2 could be used as an integrated measure of cardiac dynamic with complex physiological background which, besides spectral components as measures of autonomic cardiac control, also involves breathing frequency and mechanical cardiac parameter, left ventricular ejection fraction. © 2019 Platiša, Radovanović, Kalauzi, Milašinović and Pavlović. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Heart failure (HF) is one of the most frequent heart diseases. It is usually characterized with structural and functional cardiac abnormalities followed by dysfunction of autonomic cardiac control. Current methods of heartbeat interval analysis are not capable to differentiate HF patients and some new differentiation of HF patients could be useful in the determination of the direction of their treatment. In this study, we examined potential of the ratio of the short-term and long-term scaling exponents (α1 and α2) to separate HF patients with similar level of reduced cardiac autonomic nervous system control and with no significant difference in age, left ventricular ejection fraction (LVEF) and NYHA class. Thirty-five healthy control subjects and 46 HF patients underwent 20 min of continuous supine resting ECG recording. The interbeat interval time series were analyzed using standardized power spectrum analysis, detrended fluctuation analysis method and standard Poincaré plot (PP) analysis with measures of asymmetry of the PP. Compared with healthy control group, in HF patients linear measures of autonomic cardiac control were statistically significantly reduced (p < 0.05), heart rate asymmetry was preserved (Cup > Cdown, p < 0.01), and long-term scaling exponent α2 was significantly higher. Cluster analysis of the ratio of short- and long-term scaling exponents showed capability of this parameter to separate four clusters of HF patients. Clusters were determined by interplay of presence of short-term and long-term correlations in interbeat intervals. Complementary measure, commonly accepted ratio of the PP descriptors, SD2/SD1, showed tendency toward statistical significance to separate HF patients in obtained clusters. Also, heart rate asymmetry was preserved only in two clusters. Finally, a multiple regression analysis showed that the ratio α1/α2 could be used as an integrated measure of cardiac dynamic with complex physiological background which, besides spectral components as measures of autonomic cardiac control, also involves breathing frequency and mechanical cardiac parameter, left ventricular ejection fraction. © 2019 Platiša, Radovanović, Kalauzi, Milašinović and Pavlović. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Introduction Vasovagal syncope is the most common type of reflex syncope. Efficacy of cardiac pacing in this indication has not been the subject of many studies and pacemaker therapy in patients with vasovagal syncope is still controversial. Objective This study aimed to assess the efficacy and safety of pacing therapy in treatment of patients with vasovagal syncope, to determine contribution of new therapeutic models in increasing its success, and to identify risk factors associated with a higher rate of symptoms after pacemaker implantation. Methods A retrospective study included 30 patients with pacemaker implanted due to vasovagal syncope in the Pacemaker Center, Clinical Center of Serbia, between November 2003 and June 2014. Head-up tilt test was performed to diagnose vasovagal syncope. Patients with cardioinhibitory and mixed type of disease were enrolled in the study. Results Mean age was 48.1 ± 11.1 years and 18 (60%) patients were men. Mean follow-up period was 5.9 ± 3.0 years. Primarily, implantable loop recorder was implanted in 10 (33.3%) patients. Twenty (66.7%) patients presented cardioinhibitory and 10 (33.3%) mixed type of vasovagal syncope. After pacemaker implantation, 11 (36.7%) patients had syncope. In multiple logistic regression analysis we showed that syncope is statistically more likely to occur after pacemaker implantation in patients with mixed type of vasovagal syncope (p = 0.018). There were two (6.7%) perioperative surgical complications. Conclusion Pacemaker therapy is a safe treatment for patients with vasovagal syncope, whose efficacy can be improved by strict selection of patients. We showed that symptoms occur statistically more often in patients with mixed type of disease after pacemaker implantation. ©2016, Serbia Medical Society. All rights reserved.

Introduction/Objective Persistent left superior vena cava (PLSVC) is the most common congenital malformation of the thoracic venous system and may often complicate cardiac implantable electronic device (CIED) lead implantation. The purpose of this study was to assess feasibility and safety of CIED lead implantation through PLSVC and its long-term efficacy. Methods This is a retrospective observational study performed in a tertiary center from July 2005 to July 2019 among patients with fully successful implantation of all intended CIED leads through PLSVC. Results CIED implantation was successfully completed with left-side approach in 26 of 32 (81.3%) patients with PLSVC. The average implantation time was 62, 73.5, 120, 74, 103.3, and 130 minutes and the average fluoroscopy time was 13.3, 20.8, 35.7, 17.1, 45.6, and 42.6 minutes for single and dual-chamber pacemakers, ICD-VR, ICD-DR, CRT-P, and CRT-D devices, respectively. The average follow-up period was 43.5 ± 29.9 months. During the follow-up period no CIED leads-related complications were noticed. Conclusion The results of our study showed that the presence of PLSVC is not an obstacle for CIED implantation. The long-term follow-up proved stability of CIED leads implanted through PLSVC. © 2024, Serbia Medical Society. All rights reserved.

Introduction/Objective Pneumothorax is one of the most common complications of cardiac rhythm management (CRM) devices implantation. We aimed to assess the incidence of pneumothorax after implantation of these devices and to determine risk factors for this complication. Methods A retrospective, observational study included patients in whom CRM devices were implanted, pacing system was upgraded, or lead revision was performed during 2012 at the Pacemaker Center, Clinical Center of Serbia. We determined the connection between different variables, including sex, age, type of implanted device, prior history of chronic obstructive pulmonary disease, operator experience, venous access, the use of intravenous contrast during procedure, and the development of pneumothorax as the procedure-related complication, using multiple logistic regression. Results A total of 999 patients were included in this study. The patients’ mean age was 68.1 ± 9.2 years; 665 (66.6%) patients were male. The incidence of pneumothorax was 1.8% and an invasive treatment of this complication was required in 13 (72.2%) patients. Pneumothorax was more frequent in women (B = -2.136, p = 0.015), in patients with age > 75 years (B = 4.315, p = 0.001), venous access with subclavian vein puncture (B = 2.672, p = 0.045), and use of intravenous contrast during procedure (B = 3.155, p = 0.007). Conclusion Pneumothorax is a relatively rare complication of CRM device implantation, and for reducing its incidence, cephalic vein cut-down should be preferred to subclavian or axillary vein puncture as venous access, axillary vein puncture should not be avoided when cephalic vein cannot be found or used, and in the case of difficult vein puncture, contrast venography should be done immediately, before risky punctures. © 2017, Serbia Medical Society. All rights reserved.

Introduction Chronic right ventricular pacing can deteriorate cardiac function. Consequently, pacemaker system upgrades are more frequently indicated. These interventions can be hindered by venous thrombosis. In literature, it is rarely described that this problem is resolved by implanting a new lead for left ventricle (LV) stimulation on the opposite side of the previously implanted pacemaker and then subcutaneously transferring it to the old pocket. Case outline A 75-year-old male patient was hospitalized due to a planned pacemaker upgrade in December 2015. A dual-chamber pacemaker had been implanted due to sinus node dysfunction in 2011. During the previous 18 months he had been complaining about symptoms of heart failure. An upgrade to the cardiac resynchronization therapy (CRT) with a new CRT-P device was indicated due to the LV dilatation with the ejection fraction decrease, clinical deterioration, and the presence of high percentage of ventricular pacing. In October 2015, the mentioned intervention was unsuccessful due to total left subclavian vein thrombosis on the side of the previously implanted pacemaker. Anticoagulation therapy was ordinated and the reevaluation was postponed. During this hospitalization, venography confirmed total left subclavian vein thrombosis despite the anticoagulation therapy. It was decided to implant a new LV lead on the right side and then subcutaneously shift it by pre-sternal tunneling to the previous left prepectoral pocket. The intervention was uneventful. The first controls have shown stable pacemaker parameters. Conclusion This case report confirms that contralateral lead placement and subcutaneous pre-sternal tunnelling of the lead is feasible and safe in patients with an implanted pacemaker, an indication for system upgrade and ipsilateral vein obstruction. © 2017, Serbia Medical Society. All rights reserved.