Information-Theoretic Analysis of Cardio-Respiratory Interactions in Heart Failure Patients: Effects of Arrhythmias and Cardiac Resynchronization Therapy.

The properties of cardio-respiratory coupling (CRC) are affected by various pathological conditions related to the cardiovascular and/or respiratory systems. In heart failure, one of the most common cardiac pathological conditions, the degree of CRC changes primarily depend on the type of heart-rhythm alterations. In this work, we investigated CRC in heart-failure patients, applying measures from information theory, i.

Effects of Cardiac Resynchronization Therapy on Cardio-Respiratory Coupling.

In this study, the effect of cardiac resynchronization therapy (CRT) on the relationship between the cardiovascular and respiratory systems in heart failure subjects was examined for the first time. We hypothesized that alterations in cardio-respiratory interactions, after CRT implantation, quantified by signal complexity, could be a marker of a favorable CRT response. Sample entropy and scaling exponents were calculated from synchronously recorded cardiac and respiratory signals 20 min in duration, collected in 47 heart failure patients at rest, before and 9 months after CRT implantation.

Diagnostic value of implantable loop recorders in patients with unexplained syncope or palpitations.

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.

Multiscale Entropy Analysis: Application to Cardio-Respiratory Coupling.

It is known that in pathological conditions, physiological systems develop changes in the multiscale properties of physiological signals. However, in real life, little is known about how changes in the function of one of the two coupled physiological systems induce changes in function of the other one, especially on their multiscale behavior. Hence, in this work we aimed to examine the complexity of cardio-respiratory coupled systems control using multiscale entropy (MSE) analysis of cardiac intervals MSE (RR), respiratory time series MSE (Resp), and synchrony of these rhythms by cross multiscale entropy (CMSE) analysis, in the heart failure (HF) patients and healthy subjects.

Differentiation of Heart Failure Patients by the Ratio of the Scaling Exponents of Cardiac Interbeat Intervals.

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.

Heart failure in cardiomyopathies: a position paper from the Heart Failure Association of the European Society of Cardiology.

Cardiomyopathies are a heterogeneous group of heart muscle diseases and an important cause of heart failure (HF). Current knowledge on incidence, pathophysiology and natural history of HF in cardiomyopathies is limited, and distinct features of their therapeutic responses have not been systematically addressed. Therefore, this position paper focuses on epidemiology, pathophysiology, natural history and latest developments in treatment of HF in patients with dilated (DCM), hypertrophic (HCM) and restrictive (RCM) cardiomyopathies.

Bidirectional Cardio-Respiratory Interactions in Heart Failure.

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.

Left atrial phasic function and heart rate variability in patients with systemic sclerosis: A new part of the old puzzle.

Objective: We aimed to research left atrial (LA) phasic function and heart rate variability (HRV), as well as their relationship, in subjects with uncomplicated systemic sclerosis (SSc).

Methods: The investigation involved 44 SSc patients and 33 age-matched healthy controls. All participants underwent clinical examination, serological tests, 24-hours Holter monitoring, and echocardiographic examination including strain analysis.

The Relationship of Myocardial Collagen Metabolism and Reverse Remodeling after Cardiac Resynchronization Therapy.

Background: In the majority of patients with a wide QRS complex and heart failure resistant to optimal medical therapy, cardiac resynchronization therapy (CRT) leads to reverse ventricular remodeling and possibly to changes in cardiac collagen synthesis and degradation. We investigated the relationship of biomarkers of myocardial collagen metabolism and volumetric response to CRT.

Methods: We prospectively studied 46 heart failure patients (mean age 61±9 years, 87% male) who underwent CRT implantation.

Uncoupling of cardiac and respiratory rhythm in atrial fibrillation.

Rearranged origin of heart rhythm in patients with atrial fibrillation (AF) influences the regulation of the heart and consequently the respiratory rhythm, and the bidirectional interaction of these rhythms not documented. Hence, we examined coupling of the RR interval and the respiration (Resp) signal by coherence, Granger causality and the cross-sample entropy method of time series analysis in patients with AF and a healthy control group. In healthy subjects, the influence of respiration on cardiac rhythm was found as increased coherence at the breathing frequency (BF) range, significantly stronger interaction and synchrony from Resp to RR than from RR to Resp.

Is pacemaker therapy the right key to patients with vasovagal syncope?

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.

Treatment strategies for carotid artery aneurysms.

Background: The aim of this paper was to present single centre experience in the treatment of extra cranial carotid artery aneurysms (ECCA) and to analyze results discussing different treatment modalities.

Methods: The study analyzed 60 patients with 62 ECCA treated surgically at the Clinic for vascular and endovascular surgery, Serbian Clinical Center (Belgrade) in the period between 1985 and 2013. Treatment strategy was individually selected and demographic, morphologic, intraoperative and postoperative data were collected.

Generalized Poincaré Plots-A New Method for Evaluation of Regimes in Cardiac Neural Control in Atrial Fibrillation and Healthy Subjects.

Classical Poincaré plot is a standard way to measure nonlinear regulation of cardiovascular control. In our work we propose a generalized form of Poincaré plot where we track correlation between the duration of j preceding and k next RR intervals. The investigation was done in healthy subjects and patients with atrial fibrillation, by varying j,k ≤ 100.

The interaction between blood pressure variability, obesity, and left ventricular mechanics: findings from the hypertensive population.

Objective: The aim of this study was to determine the relationship between blood pressure (BP) variability and left ventricular (LV) mechanical function in untreated normal-weight, overweight, and obese hypertensive patients.

Methods: This cross-sectional study included 144 untreated hypertensive study participants who underwent 24-h ambulatory BP monitoring and complete two (2DE) and three-dimensional echocardiography (3DE). All the patients were divided into three groups according to their BMI: normal-weight patients (BMI < 25 kg/m), overweight patients (25 ≤ BMI < 30 kg/m), and obese patients (BMI ≥ 30 kg/m).

[Approach to the Treatment of Atrial Fibrillation in Patients with Cardiovascular Risk Profile: Multicentric International Study].

Introduction: Atrial fibrillation (AF), the most common arrhythmia that requires treatment, does not come out of the focus of researchers. Monitoring its prevalence and effects of therapy is a good guideline approach to the growing population of patients in which this arrhythmia occurs.

Objective: The aim of the study was to evaluate the efficacy of treatment of AF and cardiovascular profiles in the observed population.

Association between left ventricular mechanics and heart rate variability in untreated hypertensive patients.

The authors sought to investigate left ventricular (LV) mechanics and heart rate variability (HRV), and their relationship, in untreated hypertensive patients. A total of 63 untreated hypertensive patients and 45 healthy patients were included. All patients underwent 24-hour Holter monitoring and echocardiographic examination (two- and three-dimensional).

[Brain natriuretic peptide as a predictor of heart failure in patients with permanent pacemaker].

Introduction: Brain natriuretic peptide (BNP) has a role in control of cardiovascular and renal functions.

Objective: The objective was to assess the predictive value of BNP levels for development of heart failure in patients with permanent pacemakers.

Method: In patients with implanted DDD pacemakers, BNP levels were measured at rest and after exercise testing, on DDD and VVI modes.

[Implantable "loop recorder"--a new diagnostic tool for syncope of unknown cause].

Introduction: The implantable loop recorder (ILR) is a new diagnostic tool in cardiology for establishing the causes of unexplained syncope in patients where standard conventional tests, invasive tests included, have failed. The device is a diagnostic "pacemaker," surgically implanted underneath the skin of the chest, with leads attached to the case of the device, not requiring endovenous lead implantation. Heart rhythm is monitored continuously on the basis of an endless loop, up to a maximum period of 14 months.

[Resynchronisation therapy in patients with heart failure: our results].

Introduction: Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treating patients with systolic heart failure, with echocardiograph signs of ventricular asynchrony and a prolonged QRS of longer than 120 milliseconds. This method has been accepted in most medical centres around the world and was instigated in our Pacemaker Centre in December 2001, 3 months after FDA approval for human use.

Objective: The aim of the study was to present this new procedure and the results obtained from our own group of patients.

Fracture of the subcutaneous patch electrode in a patient with an implanted cardioverter-defibrillator.

There are more than 20 years of experience with implantation of defibrillator devices in humans and the procedure is an important therapeutic option for patients at high risk of life-threatening ventricular arrhythmias. The incidence of new defibrillator implantation has gradually increased, being used even in children, (1) although pediatric use is associated with several complications, especially with epicardial systems,(2) including fracture of the subcutaneous patch,(3-5) mainly because of growth.(3) We present a case of subcutaneous patch electrode fracture in the left axillary pectoral region of a patient who needed the patch for effective defibrillation, and we discuss the methods of treatment.

[Reconstruction of the supra-aortic branches].

The authors present surgical techniques and distant results of the operative treatment in patients with occlusive lesions of the supraaortic branches. The study included 29 men (55.8%) and 23 women (44.

[Lifetime achievements of Milan H. Djordjević. 1933-1993].

Professor Dr. Sci. Milan Djordjevitsh was an excellent cardiovascular surgeon and results of his professional and research work were well known to professional public in the country and over the world.