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Introduction. Cardiac resynchronization therapy (CRT) reduces mortality and hospitalization in patients with symptomatic heart failure and left bundle branch block (LBBB) on optimal drug therapy. Among all, the reasons for ?non-response? to CRT pacemaker could be the failure to achieve optimal left ventricular (LV) lead position due to severe curve or stenosis/occlusion of the target vein. Case report. We presented a 79-old-male patient, New York Heart Association (NYHA) class III, with atrial fibrillation, chronic coronary syndrome (CCS), and prior myocardial infarction. The patient underwent coronary artery bypass surgery and mechanical prosthetic aortic valve implantation. He was indicated for CRT. The patient?s venogram revealed ostial/proximal severe curve and stenosis of the posterolateral vein, the only vein of coronary sinus that led to anatomically optimal LV segment for stimulation. After the balloon angioplasty of the curved and stenotic portion of the target vein with compliant balloon 4.0 ? 30 mm, a satisfactory and stable position of quadripolar LV lead was achieved. Conclusion. Compliant balloon angioplasty could be a safe and efficient way to override severe coronary vein stenosis in some CRT cases.

Background: Based on the known relationship between the human emotion and standard surface electrocardiogram (ECG), we explored the relationship between features extracted from standard ECG recorded during relaxation and seven personality traits (Honesty/humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, Openness, and Disintegration) by using the machine learning (ML) approach which learns from the ECG-based features and predicts the appropriate personality trait by adopting an automated software algorithm. Methods: A total of 71 healthy university students participated in the study. For quantification of 62 ECG-based parameters (heart rate variability, as well as temporal and amplitude-based parameters) for each ECG record, we used computation procedures together with publicly available data and code. Among 62 parameters, 34 were segregated into separate features according to their diagnostic relevance in clinical practice. To examine the feature influence on personality trait classification and to perform classification, we used random forest ML algorithm. Results: Classification accuracy when clinically relevant ECG features were employed was high for Disintegration (81.3%) and Honesty/humility (75.0%) and moderate to high for Openness (73.3%) and Conscientiousness (70%), while it was low for Agreeableness (56.3%), eXtraversion (47.1%), and Emotionality (43.8%). When all calculated features were used, the classification accuracies were the same or lower, except for the eXtraversion (52.9%). Correlation analysis for selected features is presented. Conclusions: Results indicate that clinically relevant features might be applicable for personality traits prediction, although no remarkable differences were found among selected groups of parameters. Physiological associations of established relationships should be further explored. Ministry of Education, Science, and Technological Development, Republic of Serbia, Grant/Award Number: 179018 and TR33020; Abbott Laboratories

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. Further, cross-sample entropy between these signals was calculated. After CRT, all patients had lower heart rate and CRT responders had reduced breathing frequency. Results revealed that higher cardiac rhythm complexity in CRT non-responders was associated with weak correlations of cardiac rhythm at baseline measurement over long scales and over short scales at follow-up recording. Unlike CRT responders, in non-responders, a significant difference in respiratory rhythm complexity between measurements could be consequence of divergent changes in correlation properties of the respiratory signal over short and long scales. Asynchrony between cardiac and respiratory rhythm increased significantly in CRT non-responders during follow-up. Quantification of complexity and synchrony between cardiac and respiratory signals shows significant associations between CRT success and stability of cardio-respiratory coupling.

Cardiac resynchronization therapy (CRT) is a well-established therapy for symptomatic patients with heart failure and reduced left ventricular ejection fraction. It is known that patients with heart failure have altered cardio-respiratory interactions, but it has not been examined whether resynchronization therapy leads to changes in coupling of cardiac and respiratory rhythm, and whether the success of this therapy leads to restoring of cardio-respiratory interactions. In these patients, in addition to sinus rhythm, different types of arrhythmias usually appear, which limits the application of linear methods in analysis of interbeat interval time series. Therefore they should be analyzed with non-linear techniques and we applied the sample entropy approach. Twenty minutes of ECG (RR intervals) and respiratory signal were recorded simultaneously in 47 patients with heart failure and CRT indication. The interbeat interval time series in patients with sinus rhythm, sinus rhythm with ventricular extrasystoles and with atrial fibrillation were analyzed. Sample entropy values were calculated from RR interval time series (SampEnRR) and respiratory signal time series (SampEnResp) to assess their complexity/regularity as well as cross sample entropy (CrossSampEn) to estimate their asynchrony. Measurements were performed before (baseline) and approximately 9 months after CRT implantation (follow-up). After follow-up, patients were divided into two groups, responders and non-responders, in relation to the response to CRT, which was assessed according to changes in certain clinical parameters. In both groups, there was no difference in SampEnRR between baseline and follow-up. However, in the non-responders group, a significant increase was obtained in SampEnResp and CrossSampEn (p < 0.05). Responders to CRT showed significant decrease in heart rate and breathing frequency, while non-responders showed only a significant decrease in heart rate. Our results indicate that in non-responders to CRT, respiratory rhythm is not adapting to changes in cardiac dynamics, which resulted in loss of their synchrony.

Funding Acknowledgements Type of funding sources: None. Background The European Society of Cardiology’s (ESC) risk calculator for sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathies (HCM) is currently a tool that facilitates the decision to implant a cardioverter defibrillator (ICD) in primary prevention, but doubts still exist in everyday clinical practice. Purpose We aimed to determine the incidence of life-threatening ventricular arrhythmias during long-term follow-up in patients with different ESC HCM risk scores for SCD calculated on ICD implantation in primary prevention. Methods This retrospective, observational study was conducted in a tertiary center among adult patients with HCM and ICD devices (ICD-VR, ICD-DR and CRT-ICD) implanted in primary prevention from January 2008 to December 2019. The patients followed up for less than one year were excluded from the analysis. Study group was divided into three subgroups, according to the ESC 5 years risk score of SCD and based on it the estimated need for ICD implantation: group A with risk < 4%, where ICD is generally not indicated; group B with risk 4-6%, where ICD may be considered; group C with risk ≥6%, where ICD should be considered. Regularly, ICD was interrogated twice a year, while emergency controls were performed after delivering of ICD therapy. Follow-up data including information about sustained ventricular tachicardia (VT) and ventricular fibrillation (VF) episodes were collected from patients medical records. Results In the observed period, ICD devices were implanted in 60 adult patients with HCM. Ten of them had history of sustained ventricular arrhythmias and 3 were lost to follow-up. Therefore, we analysed 47 patients (55.3% male, mean age 51.0 ± 15.7 years), 13 from group A, 12 from group B and 22 from group C. Mean follow-up period was 80.6 ± 37.9 months. During the follow-up period ventricular tachyarrhythmias (VT and VF, either in monitoring or therapy zone) were recorded in one patient from group A (7.7%), in two patients from group B (16.7%) and in 7 patients from group C (31.8%). Using Kruskal-Wallis analysis of variance, we did not find a statistically significant difference in the occurrence of ventricular tachyarrhythmias among the observed groups (p = 0.225). Conclusions Patients with HCM and a 5-year risk of SCD ≥ 6% calculated on ICD implantation had more frequent life-threatening ventricular arrhythmias during long-term follow-up, but not statistically significant. There should be an individual approach when deciding on the need for device implantation in all patients with HCM.

Funding Acknowledgements Type of funding sources: None. Introduction Cardiac implantable electronic devices (CIEDs) are being implanted worldwide in increasing numbers, so the incidence of hospitalizations due to their infections is also increasing. Purpose The aim of this study was to analyze the incidence of pocket infection related to the CIED procedure, as well as clinical presentation, diagnostic approach and methods of treatment during long-term follow- up on large cohort of patients. Methods: This was a retrospective, observational, single-center study. We enrolled patients who underwent CIED procedure between January 2011 and December 2015. The CIED procedure included implantation and replacement of the device. Pocket infection is defined as an infection limited to the generator pocket and can be presented from redness, swelling, pain to the skin erosion with exposure of the generator and/or leads. It may also be associated with lead infections and systemic CIED infections and/or infective endocarditis. All patients with CIED infection underwent the same diagnostics: complete blood count and inflammatory markers, pocket swab, three sets of blood cultures and echocardiography. Results: During the observed period 5 969 CIED procedures were performed (anti-bradycardia pacemakers 68.6%; ICD 21.4%; CRT-P/D 10.0%; CIED replacement 26.1%). CIED infection was registered in 41 patients (0.68%), most often after the ICD procedure (59.0%). In 22 patients (53.6%) the infection occurred after primo-implantation. The average time from intervention to infection was 17 ± 7.3 months. The mean follow-up was 52.2 ± 13.4 months. The most common manifestations of infection were redness (68.1%) and swelling (56.0%), then the protrusion of the generator or electrode (41.5%). Pacemaker pocket swabs and wound swabs were positive in 61.1% of samples and coagulase negative staphylococcus was found to be the most prevalent cause of infection (64.2%). The hemoculture test was positive in 10 patients, and the isolated causative agent matched the swab finding. The valvular vegetation was found in 4 patients. Pacemaker removal and surgical wound treatment were performed in all patients. Complete removal of all leads was achieved in 32 patients. In all pacemaker dependent patients and patients with ICD implanted in the secondary prevention of sudden cardiac death, reimplantation of the new device was performed in the same hospitalization on the opposite side. The remaining patients were operated on 3 to 4 weeks after the end of treatment. Conclusions: It has been shown that the risk of pocket infection was low in a large number of patients, during long-term follow-up. The risk was higher in patients with ICD devices, and slightly higher after primo-implantation.

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.

Heart rate (HR) asymmetry is a dynamic phenomenon related to the interplay of dominant regulatory mechanisms of cardiovascular system which operate over different scales of observation. The aim of this work is to examine asymmetry phenomenon in heart failure (HF) patients with sinus rhythm. We computed Guzik's index of heart rate asymmetry related to HR deceleration $(C_{d})$ from the Poincare plot (Pp) analysis extended up to 20th order. In the control group asymmetry is maintained over all orders of the Pp. In HF patients with asymmetric properties, $C_{d}$ is reduced in the range between 2ndand 5th order of the Pp analysis, compared the control subjects. More, this method revealed two clusters of HF patients. In conclusion, proposed new approach can be applied to reveal alterations in the behavior of the cardiovascular control mechanisms in pathological conditions.

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.

Background Heart failure (HF) is increasing in prevalence and is a major cause of morbidity and mortality despite advances in medical and device therapy. Autonomic imbalance, with excess sympathetic activation and decreased vagal tone, is an integral component of the pathophysiology of HF. Objectives The INOVATE-HF (Increase of Vagal Tone in Heart Failure) trial assessed the safety and efficacy of vagal nerve stimulation (VNS) among patients with HF and a reduced ejection fraction. Methods INOVATE-HF was a multinational, randomized trial involving 85 centers including patients with chronic HF, New York Heart Association functional class III symptoms and ejection fraction ≤40%. Patients were assigned to device implantation to provide VNS (active) or continued medical therapy (control) in a 3:2 ratio. The primary efficacy endpoint was composite of death from any cause or first event for worsening HF. Results Patients (n = 707) were randomized and followed up for a mean of 16 months. The primary efficacy outcome occurred in 132 of 436 patients in the VNS group, compared to 70 of 271 in the control group (30.3% vs. 25.8%; hazard ratio: 1.14; 95% confidence interval: 0.86 to 1.53; p = 0.37). During the trial, the estimated annual mortality rates were 9.3% and 7.1%, respectively (p = 0.19). Quality of life, New York Heart Association functional class, and 6-min walking distance were favorably affected by VNS (p Conclusions VNS does not reduce the rate of death or HF events in chronic HF patients. (INcrease Of VAgal TonE in CHF [INOVATE-HF]; NCT01303718 )

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.

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.We prospectively studied 46 heart failure patients (mean age 61±9 years, 87% male) who underwent CRT implantation. Plasma concentrations of amino-terminal propeptide type I (PINP), a marker of collagen synthesis, and carboxy-terminal collagen telopeptide (CITP), a marker of collagen degradation, were measured before and 6 months after CRT. Response to CRT was defined as 15% or greater reduction in left ventricular end-systolic volume at 6-month follow-up.Baseline PINP levels showed a negative correlation with both left ventricular end-diastolic volume (r=-0.51; p=0.032), and end-systolic diameter (r=-0.47; p=0.049). After 6 months of device implantation, 28 patients (61%) responded to CRT. No significant differences in the baseline levels of PINP and CITP between responders and nonresponders were observed (p0.05 for both). During follow-up, responders demonstrated a significant increase in serum PINP level from 31.37±18.40 to 39.2±19.19 μg/L (p=0.049), whereas in non-responders serum PINP levels did not significantly change (from 28.12±21.55 to 34.47± 18.64 μg/L; p=0.125). There were no significant changes in CITP levels in both responders and non-responders (p0.05).Left ventricular reverse remodeling induced by CRT is associated with an increased collagen synthesis in the first 6 months of CRT implantation.Kod većine pacijenata sa širokim QRS kompleksom i srčanim oboljenjima rezistentnim na optimalnu medicinsku terapiju, srčana resinhronizaciona terapija (CRT) dovodi do reverznog remodelovanja leve komore i potencijalno do promena u sintezi i degradaciji srčanog kolagena. Istraživali smo odnos između biomarkera metabolizma miokardijalnog kolagena i volumetrijskog odgovora na SRT.Prospektivno smo proučavali 46 pacijenata sa srčanim oboljenjima (prosečne starosti 61±9 godina, 87% muškog pola) koji su podvrgnuti implantaciji SRT. Koncentracije amino-terminalnog propeptida tipa I (PINP) u plazmi, markera sinteze kolagena, kao i karboksi-terminalnog telopeptida kolagena (CIPT), markera degradacije kolagena, izmereni su pre i 6 meseci posle početka SRT. Odgovor na SRT definisan je kao smanjenje od 15% ili više end-sistolnog volumena leve komore prilikom pregleda posle 6 meseci.Početni nivoi PINP pokazali su negativnu korelaciju sa end-diastolnim volumenom leve komore (r=-0,51; p=0,032) kao i end-sistolnim prečnikom (r=-0,47; p=0,049). Šest meseci nakon ugradnje uređaja, 28 pacijenata (61%) dalo je odgovor na SRT. Između početnih nivoa PINP i CITP kod pacijenata koji su odgovorili i onih koji nisu odgovorili na terapiju nisu uočene značajne razlike (p0,05 za oba). Tokom praćenja pacijenata, oni koji su pokazali odgovor na terapiju imali su i značajan porast nivoa PINP u serumu sa 31,37±18,40 na 39,2±19,19 μg/L (p=0,049), dok se kod pacijenata kod kojih nije bilo odgovora nivoi PINP u serumu nisu značajno promenili (sa 28,12±21,55 na 34,47±18,64 μg/L; p=0,125). Nije bilo značajnih promena u nivoima CITP ni u jednoj grupi pacijenata (p0,05).Reverzno remodelovanje leve komore izazvano srčanom resinhronizacionom terapijom povezano je s povećanom sintezom kolagena u prvih šest meseci posle implantacije SRT.

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.

Introduction. Carotid sinus syndrome is characterized by a hypersensitive carotid sinus and syncope. Although we have clear guidelines for the diagnosis and treatment of carotid sinus syndrome, the efficacy of pacing therapy with this indication has not been the subject of many studies. Objective. This study aimed to assess the efficacy and safety of pacing therapy in the treatment of patients with carotid sinus syndrome and to determine the factors contributing to symptoms recurrence after pacemaker implantation. Methods. This study was retrospective and included 32 patients in whom a pacemaker was implanted due to carotid sinus syndrome at the Pacemaker Center, Clinical Center of Serbia, between April 2005 and April 2012. Carotid sinus massage and head-up tilt test (HUTT) were performed to select patients with cardioinhibitory and mixed type carotid sinus syndrome, who were enrolled to the study. Results. The mean age of patients was 65.6?11.5 years and 20 (62.5%) were men. The mean follow-up period was 4.3?1.9 years. HUTT was performed in 3 (9.4%) patients. Twenty-seven (84.4%) patients presented with cardioinhibitory and 5 (15.6%) with mixed type of carotid sinus syndrome. After pacemaker implantation, 22 (68.7%) patients had no further symptoms, 8 (25.0%) had syncope and 2 (6.3%) presyncope. The mixed type of the disease (HR 3.1; 95% CI 1.4-5.1; p=0.021) and implantation of pacemaker in VVI mode (HR 1.8; 95%CI 1.1-3.2; p=0.034) were independent predictors of symptoms recurrence. There were 3 (9.4%) perioperative surgical complications. Conclusion. Pacemaker therapy is an effective and safe treatment for patients with carotid sinus syndrome. As predictors of symptoms persistence after pacemaker implantation in our population, we identified the implantation of pacemaker in VVI mode and the mixed type of carotid sinus syndrome.

Aims Selection of patients who are viable candidates for cardiac resynchronization therapy (CRT), prediction of the response to CRT as well as an optimal definition of a favorable response, all require further exploration. The purpose of this study was to evaluate the interplay between the prediction of the response to CRT and the definition of a favorable outcome. Methods Seventy patients who received CRT were included. All patients met current guideline criteria for CRT. Forty-three echocardiographic parameters were evaluated before CRT and at 1, 3, 6, and 12 months. M-mode, 2D echocardiography, and Doppler imaging were used to quantify left ventricular (LV) systolic and diastolic function, mitral regurgitation, right ventricular systolic function, pulmonary artery pressure, and myocardial mechanical dyssynchrony. The following definitions of a favorable CRT response were used: left ventricular ejection fraction (LVEF) improvement more >5% acutely following CRT, LVEF improvement >20% at 12-month follow-up, and a LV end-systolic volume (LVESV) decrease >15% at 12-month follow-up. Results For the LVEF improvement >5%, the best predictor was isovolumetric relaxation time (IVRT; P=.035). For improvement of LVEF >20%, the best predictors were left ventricular stroke index (LVSI; P=.044) and left ventricular fractional shortening (LVFS; P=.031). For the drop in left ventricular systolic volume (LVESV >15%), the best predictor was septal-to-lateral wall delay (ΔT) (P=.043, RR=1.023, 95% CI for RR=1.001-1.045). Conclusion The definition of a favorable CRT response influenced the optimal predictor variable(s). Standardization of defining a favorable response to CRT is needed to guide clinical decision making processes.

Introduction In this study, we sought to determine whether myocardial contractile reserve (CR) assessed by dobutamine stress echocardiography (DSE) can identify patients who experience nearly complete normalization of left ventricular (LV) function after the implantation of a cardiac resynchronization therapy (CRT) pacemaker. Material and methods The study group consisted of 55 consecutive patients with non-ischemic dilated cardiomyopathy, LV ejection fraction (LVEF) < 35%, and prolonged QRS complex duration, who were scheduled for CRT pacemaker implantation. The DSE (20 µg/kg/min) was performed in all patients. The CR assessment was based on a change in the wall motion score index (ΔWMSI) and ΔLVEF during DSE. Super-response was defined as an increase in LVEF to > 50% and reduction in left ventricular end-systolic dimension to < 40 mm 12 months following the CRT implantation. Results A total of 7 patients (12.7%) were identified as super-responders to CRT. When compared to non-super-responders, these patients had significantly higher values of the dobutamine-induced change in ΔWMSI (1.031 ±0.120 vs. 0.49 ±0.371, p < 0.01), and ΔEF (17.9 ±2.2 vs. 8.8 ±6.2, p < 0.01). Receiver operating characteristic analysis showed that dobutamine-induced changes in ΔWMSI ≥ 0.7 and ≥ 14% for ΔEF are the best discriminators for a super-response. Patients with ΔWMSI ≥ 0.7 and ΔEF ≥ 14% are significantly less often hospitalized (p < 0.01) for worsening of heart failure during 28.5 ±3.0 months of the follow-up. Conclusions Contractile reserve assessed by DSE can identify patients with dilated cardiomyopathy who are likely to experience near normalization of LV function following CRT.

Subcutaneous Defibrillation Introduction A purely subcutaneous implantable cardioverter defibrillator (ICD) requires higher energy but may be an effective alternative to transvenous ICDs to deliver lifesaving therapies. Objective To identify combinations of anteroposterior subcutaneous shock pathways and waveforms with defibrillation efficacy comparable to transvenous ICDs. Methods Defibrillation testing was performed in 141 patients temporarily implanted with an active can emulator and subcutaneous coil electrodes. The patients were subdivided into 5 groups within 2 study phases. In all groups, a posterior electrode was positioned with its tip close to the spine. In the first study phase, 2 different can locations were evaluated: (1) an inframammary pocket (IM-1–750), or (2) a conventional infraclavicular pocket (IC-1–750). In both cases, a 70 J biphasic shock was used (peak voltage 750 V; 270 μF capacitance). In the second phase, configuration IC-1–750 was enhanced by the addition of a second (parasternal) subcutaneous electrode (IC-2–750). Furthermore, the effects of a different 70 J shock waveform (1,000 V, 160 μF) were evaluated for configurations IM-1–750 and IC-2–750 (becoming IM-1–1000 and IC-2–1000). Results The proportion of patients satisfying a defibrillation safety margin test of 2 consecutive successes at ≤50 J was 74%, 11%, and 44%, respectively, for the IM-1–750, IC-1–750, and IC-2–750 configurations, and 93% and 86% for the IM-1–1000 and IC-2–1000 configurations. Conclusions Defibrillation efficacy comparable to that of a transvenous system was achieved with an anteroposterior subcutaneous ICD configuration, with 160 μF capacitance, 1,000 V, and 70 J output. An infraclavicular pocket location becomes feasible if a parasternal subcutaneous coil is added.

Heart failure (HF) is increasing in prevalence and is a major cause of morbidity and mortality despite advances in medical and device therapy. Autonomic imbalance, with excess sympathetic activation and decreased vagal tone, is an integral component of the pathophysiology of HF.The INOVATE-HF (Increase of Vagal Tone in Heart Failure) trial assessed the safety and efficacy of vagal nerve stimulation (VNS) among patients with HF and a reduced ejection fraction.INOVATE-HF was a multinational, randomized trial involving 85 centers including patients with chronic HF, New York Heart Association functional class III symptoms and ejection fraction ≤40%. Patients were assigned to device implantation to provide VNS (active) or continued medical therapy (control) in a 3:2 ratio. The primary efficacy endpoint was composite of death from any cause or first event for worsening HF.Patients (n = 707) were randomized and followed up for a mean of 16 months. The primary efficacy outcome occurred in 132 of 436 patients in the VNS group, compared to 70 of 271 in the control group (30.3% vs. 25.8%; hazard ratio: 1.14; 95% confidence interval: 0.86 to 1.53; p = 0.37). During the trial, the estimated annual mortality rates were 9.3% and 7.1%, respectively (p = 0.19). Quality of life, New York Heart Association functional class, and 6-min walking distance were favorably affected by VNS (p 0.05), but left ventricular end-systolic volume index was not different (p = 0.49).VNS does not reduce the rate of death or HF events in chronic HF patients. (INcrease Of VAgal TonE in CHF [INOVATE-HF]; NCT01303718).

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. Methods. In this observational, cross-sectional, multicenter, international study, 584 patients in 30 centers in Serbia and Slovenia, older than 18 years and with AF or in sinus rhythm with a history of AF, were included. The assessment of the efficacy of treatment of AF was performed by analyzing the frequency of adequate therapeutic effect of medication in rhythm or frequency control in patients with AF. Results. The results confirmed that the highest incidence of AF duration is more than seven days, and is accompanied by symptoms. Inadequate frequency regulation was registered at 8.9% of patients. Hypertension was registered in two-thirds of all patients, while other cardiovascular risk factors were registered in about one-third of patients. An echocardiographic finding in the group of patients with AF confirms generally adequate left ventricular function with a slightly enlarged left atrium (4.6±0.8 cm). Increasing age and time from the first episode of AF decreases the probability of maintaining sinus rhythm, while symptomatic AF had a positive impact on the presence of sinus rhythm. Propafenone, sotalol and amiodarone showed a statistically significant connection with a positive therapeutic response, while β-blockers had a negative impact on the probability of establishing and maintaining sinus rhythm. Conclusion. Characteristics of therapeutic approaches, risks, comorbidity of patient populations in Slovenia and Serbia correspond to the fullest extent with the recommendations for good clinical practice, which further stresses the need for extensive measures in these regions.

Objectives: The aim of this study was to assess the performance of echocardiographic parameters to predict response to cardiac resynchronization therapy (CRT). Background: CRT reduces morbidity and mortality due to the proper selection of candidates for CRT. Methods: The 12-month trial was performed on 70 optimally medicated patients with standard inclusion criteria: NYHA class III or IV heart failure, left ventricular ejection fraction (LVEF) ≤ 35%, and QRS ≥ 120 ms. All parameters were evaluated by conventional and tissue Doppler-based methods. Indicator of positive CRT response was more than 20% in improvement of LVEF. Results: LVEF increased >20% in 42 patients. Out of 43 tested baseline echocardiographic parameters, 12 showed statistical difference between responders and nonresponders. Out of these 12 parameters, six (LVSV, LVSI, LVFS, RVd, VPMR, and PISA) had modest to moderately good ability to predict LVEF response with sensitivity ranging from 62.2% to 82.4%, and specificity ranging from 56.5% to 81.2%. For those parameters, the area under the receiver-operating characteristic curve for positive response to CRT was ≤0.76. Multivariate regression analysis resulted in selection of LVSI and LVFS as possible predictive independent parameters for a good response. The cutoff value for LVSI was 38.7 mL/m2 (P = 0.045) and for LVFS was 13% (P = 0.032). Conclusions: Contribution of LVSI and LVFS is to be confirmed in larger trials. Simplicity of their assessment by conventional echocardiography could be an argument for adding them to the inclusion criteria for CRT in severe heart failure patients. (Echocardiography 2012;29:267-275)

Aims In chronic heart failure (CHF), reduced vagal activity correlates with increased mortality and acute decompensation. Experimentally, chronic vagus nerve stimulation (VNS) improved left ventricular (LV) function and survival; clinically, it is used for the treatment of drug-refractory epilepsy. We assessed safety and tolerability of chronic VNS in symptomatic CHF patients, using a novel implantable nerve stimulation system. The secondary goal was to obtain preliminary data on clinical efficacy. Methods and results This multi-centre, open-label phase II, two-staged study (8-patient feasibility phase plus 24-patient safety and tolerability phase) enrolled 32 New York Heart Association (NYHA) class II-IV patients [age 56 +/- 11 years, LV ejection fraction (LVEF) 23 +/- 8%]. Right cervical VNS with CardioFit (BioControl Medical) implantable system started 2-4 weeks after implant, slowly raising intensity; patients were followed 3 and 6 months thereafter with optional 1-year follow-up. Overall, 26 serious adverse events (SAEs) occurred in 13 of 32 patients (40.6%), including three deaths and two clearly device-related AEs (post-operative pulmonary oedema, need of surgical revision). Expected non-serious device-related AEs (cough, dysphonia, and stimulation-related pain) occurred early but were reduced and disappeared after stimulation intensity adjustment. There were significant improvements (P

Background: Managed Ventricular Pacing (MVP) and Search AV+ (SAV+) are two pacing algorithms designed to reduce ventricular pacing, MVP promotes conduction by operating in AAI/R mode with backup ventricular pacing during atrioventricular block (AVB). SAV+ operates in DDD/R mode with a nominal AV extension of 290 ms during atrial sensing and 320 ms during atrial pacing. The reduction in ventricular pacing was compared with these two algorithms in pacemaker patients. Methods: The EnRhythm and EnPulse clinical studies assessed the Percentage of ventricular pacing (% VP) after 1 month. Each patient's AVB status was assigned using the following hierarchical categories: persistent third-degree AVB (p3AVB), episodic third-degree AVB (e3AVB), second-degree AVB (2AVB), first-degree AVB (1AVB), and no AVB (nAVB). The% VP was tabulated for each AVB status category. Results: Data were available from 322 patients of whom 129 received DDD(R) pacing with the MVP algorithm activated and 193 patients with DDD(R) pacing and the SAV+ function activated, each for a month period. MVP resulted in a significantly lower median % VP than SAV+ in all AVB categories except for p3AVB: nAVB (0.3 vs 2.9, P < 0.0001), 1AVB (0.9% vs 80.6%. P < 0.0001), 2AVB (37.6 vs 99.3. P < 0.002), e3AVB (1.2 vs 42.2, P = 0.02), p3AVB (98.9 vs 100, P = 1.00). Conclusion: MVP resulted in a greater reduction in% VP than SAV+ across all patient groups except persistent third-degree AV block. The greatest reduction in%VP was observed in patients with mildly impaired AV conduction. (Less)

Background: In patients requiring permanent pacing, preservation of intrinsic ventricular activation is preferred whenever possible. The Search AV+ (SAV+) algorithm in Medtronic EnPulse(TM) dual-chamber pacemakers can increase atrioventricular (AV) intervals to 320 ms in patients with intact or intermittent AV conduction. This prospective, multicenter study compared the percentage of ventricular pacing with and without AV interval extension. Methods: Among 197 patients enrolled in the study, the percentage of ventricular-paced beats was evaluated via device diagnostics at the 1-month follow-up. Patient cohorts were defined by clinician assessment of conduction via a 1:1 AV conduction test at the 2-week follow-up. The observed percentage of ventricular pacing with SAV + ON and the predicted percentage of ventricular pacing with SAV + OFF were determined from the SAV + histogram data for the period between the 2-week and 1-month follow-up visits. Results: Of 197 patients, 110 (55.8%) had intact 1:1 AV conduction, of which 109 had 1-month data. SAV + remained ON in 991109 patients; 10 patients had intrinsic A-V conduction intervals beyond SAV + nominal and therefore SAV + disabled. The mean percentage of ventricular pacing in the 109 patients was SAV+ ON = 23.1% (median 3.7%) versus SAV + OFF = 97.2% (median 99.7%). In 87 patients without 1:1 AV conduction, SAV + was programmed OFF in 6, automatically disabled in 52, and remained ON in 29. In 8 of these patients, 80-100% reduction in ventricular pacing was observed with SAV + ON. Conclusion: The Search AV+ algorithm in the EnPulse pacemaker effectively promotes intrinsic ventricular activation and substantially reduces unnecessary ventricular pacing. (Less)

Background The Medtronic EnPulse™ pacemaker incorporates the new atrial capture management (ACM) algorithm to automatically measure atrial capture thresholds and subsequently manage atrial pacing outputs. Objectives The purpose of this study was to evaluate the clinical performance of ACM. Methods Two hundred patients with an indication for a dual-chamber pacemaker underwent implantation. ACM thresholds and manually measured atrial pacing thresholds were assessed at follow-up visits. Clinical equivalence was defined as the ACM-measured threshold being within −0.25 V to +0.5 V of the manually measured threshold. The clinician analyzed all ACM measurements performed in-office for evidence of proarrhythmia. Results All 200 implanted patients had a 1-month visit, and validated manual and in-office ACM threshold data were available for 123 patients. The ACM threshold was 0.595 ± 0.252 V, and the manual threshold was 0.584 ± 0.233 V. The mean difference was 0.010 V with a 95% confidence interval of (−0.001, 0.021). The mean difference over all visits was 0.011 V. For all patients, the individual threshold differences were within the range of clinical equivalence at all visits. No atrial arrhythmias were observed during 892 ACM tests in 193 patients. Conclusion This study demonstrated that the ACM algorithm is safe, accurate, and reliable over time. ACM was demonstrated to be clinically equivalent to the manual atrial threshold test in all patients at 1 month and over the entire follow-up period of up to 6 months. ACM ensures atrial capture, may save time during follow-up, and can be used to manage atrial pacing outputs.

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 centers 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. METHOD. A multi-site, biventricular pacemaker, with a special electrode for left-half heart stimulation was implanted in the coronary sinus of 17 patients who had suffered systolic heart failure (12 male and 5 female, average age 59.9 years). For all of them, the duration of the QRS interval was longer than 120 ms, with left bundle branch morphology, and an ejection fraction below 30%. All the patients were NYHA class II or III. Prior to and after the implantation, a 12-channel ECG and ECHO were carried out, a b-minute hall walk test was performed, additionally, the total walked distance on a flat surface was measured, the general condition of the patient was evaluated, the number of medications being taken was noted, as was the number of days of hospitalization. RESULTS. The average time from diagnosis to implantation was 22 months, and the average post-operative follow-up was 14 months. Two of the patients died 10 and 7 months after the implantation, due to a new myocardial infarction and refractory heart failure. In addition, one patient did not show any improvement after the implantation of the multi-site pacemaker (there were three "non-responder" patients). All the other patients felt much better: decreased NYHA class for I - II class, increased left ventricle ejection fraction, reduced use of diuretics, increased b-minute hall walk distance and general walk distance on a flat surface, and decreased number of days of hospitalization. CONCLUSION. Resynchronisation heart failure therapy in the majority of patients with systolic left ventricular dysfunction and a prolonged QRS interval considerably improves cardiac function, in addition to reducing symptoms and hospital stays.

BackgroundMagnetic resonance imaging (MRI) can be safely performed in patients with magnetic resonance (MR)–conditional pacemaker systems but remains relatively contraindicated with non–MR-conditional pacemaker systems.ObjectiveThe purpose of this study was to evaluate the safety of MRI without positioning restrictions in patients with an MR-conditional pacemaker and currently a non–MR-conditional Medtronic CapSureFix Novus 5076 lead(s).MethodsThe study randomized 266 patients in a 2:1 ratio to the MRI group (177 patients) or to the control group (89 patients). At 9–12 weeks postimplant, the MRI group underwent MRI at 1.5 T. Primary end points were MRI-related complication-free rate and noninferiority of the MRI group compared to the control group with regard to the proportion of patients with an increase of ≤0.5 V in right atrial (RA) and right ventricular (RV) pacing capture thresholds from immediately before MRI to 1-month after MRI.ResultsNo MRI-related complications occurred in 156 MRI-scanned patients who were followed through 1-month post-MRI. Differences in the proportion of patients with ≤0.5 V pacing capture threshold changes from pre-MRI to 1-month post-MRI were minimal between the groups for RA (proportions of 100% in both groups; a P value cannot be calculated) and RV leads (proportions of 99.3% in the MRI group and 100% in the control group; noninferiority test, P < .0001). Proportions of patients with acceptable sensing amplitude changes from pre-MRI to 1-month post-MRI were also similar between the 2 groups for RA and RV leads (noninferiority test, P < .0001 and P = .0004, respectively). No arrhythmias occurred during MRI.ConclusionMRI scans can be performed safely without positioning restrictions in patients with Medtronic CapSureFix Novus 5076 leads connected to an MR-conditional pacemaker.

Aims The aim of the study was to assess the value of coronary flow reserve (CFR) for predicting improvement of left ventricular function after cardiac resynchronization therapy (CRT). Methods and results Study population included 40 patients (mean age 58 ± 9 years) with heart failure (ejection fraction 25, 7 ± 5, 4%) and QRS duration of 158 ± 22 ms, planned for CRT. Before and after CRT implantation, CFR was measured non-invasively during hyperaemia induced with adenosine. Responders were defined by decrease in end-systolic volume ≥15%. Follow-up echocardiography and CFR measurements were obtained after 6 months. At baseline there was no significant difference in left ventricular ejection fraction (LVEF), QRS duration, 6 min walk test distance and coronary flow velocity at rest between responder ( n = 26) vs. non-responder group ( n = 14, P = ns). Before CRT implantation, responders compared with non-responders, showed a greater increase in coronary flow velocity during hyperaemia, and consequently higher CFR: 2.41 ± 0.60 vs. 1.61 ± 0.45 ( P = 0.001). There was significant correlation between CFR before CRT implantation and LVEF after 6 months ( r = 0.545, P = 0.001). End-diastolic, end-systolic left ventricular diameter, and CFR before CRT were predictors of LV functional improvement. By multivariate analysis, only CFR before CRT was independent predictor of left ventricular recovery in the follow-up period ( P = 0.001). Conclusion Our results demonstrate that preserved CFR in patients with dilated cardiomyopathy is predictive of left ventricular improvement after CRT implantation.

Introduction. Persistent left superior vena cava represents a congenital vascular defect of the venous system, which often makes standard 58 cm endocardial lead placement impossible. Case Outline. A right chamber approach by the left cephalic vein was tried. This was impossible because standard endocardial lead (SJM Isoflex S 1646T, bipolar lead, 58 cm in length, body diameter 7 French) was too short for this patient. A unipolar lead for coronary sinus (Medtronic ATTEIN 4193-88), 88 cm in length, body diameter 4 French, was placed in the posterior branch of the coronary sinus. With such positioning of the lead, a VVI pacemaker pacing was enabled. The operation lasted for 48 minutes, and the time of total X-ray exposure was 9.6 minutes. The values that were achieved were: threshold 0.3 V, pulse width 0.37 ms, maximum R 22.55 mV. Ten months after the implantation, the values were: thresh- old 0.3 V, maximum R 28.8 mV. Conclusion. Persistent left superior vena cava in some cases makes standard 58 cm endocardial lead placement impossible due to its joining to the right atrium over the dilated coronary sinus. Coronary sinus lead placement in the posterior or lateral coronary sinus branch represents an acceptable alternative approach for pacemaker lead placement in these patients.

A purely subcutaneous implantable cardioverter defibrillator (ICD) requires higher energy but may be an effective alternative to transvenous ICDs to deliver lifesaving therapies.To identify combinations of anteroposterior subcutaneous shock pathways and waveforms with defibrillation efficacy comparable to transvenous ICDs.Defibrillation testing was performed in 141 patients temporarily implanted with an active can emulator and subcutaneous coil electrodes. The patients were subdivided into 5 groups within 2 study phases. In all groups, a posterior electrode was positioned with its tip close to the spine. In the first study phase, 2 different can locations were evaluated: (1) an inframammary pocket (IM-1-750), or (2) a conventional infraclavicular pocket (IC-1-750). In both cases, a 70 J biphasic shock was used (peak voltage 750 V; 270 μF capacitance). In the second phase, configuration IC-1-750 was enhanced by the addition of a second (parasternal) subcutaneous electrode (IC-2-750). Furthermore, the effects of a different 70 J shock waveform (1,000 V, 160 μF) were evaluated for configurations IM-1-750 and IC-2-750 (becoming IM-1-1000 and IC-2-1000).The proportion of patients satisfying a defibrillation safety margin test of 2 consecutive successes at ≤50 J was 74%, 11%, and 44%, respectively, for the IM-1-750, IC-1-750, and IC-2-750 configurations, and 93% and 86% for the IM-1-1000 and IC-2-1000 configurations.Defibrillation efficacy comparable to that of a transvenous system was achieved with an anteroposterior subcutaneous ICD configuration, with 160 μF capacitance, 1,000 V, and 70 J output. An infraclavicular pocket location becomes feasible if a parasternal subcutaneous coil is added.

Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control).To examine whether synchronized LVP (sLVP) resulted in better clinical outcomes.First, stratification by percent sLVP (%sLVP) and multivariate Cox proportional hazards model was used to assess the relationship between %sLVP and clinical outcomes. Second, outcomes were compared between patients in the aCRT arm (n = 318) and control patients (n = 160) stratified by intrinsic AV interval at randomization.In the aCRT arm, %sLVP ≥50% (n = 142) was independently associated with a decreased risk of death or heart failure hospitalization (hazard ratio 0.49; 95% confidence interval 0.28-0.85; P = .012) compared with %sLVP50% (n = 172). A greater proportion of patients with %sLVP ≥50% improved in Packer's clinical composite score at 6-month (82% vs. 68%; P = .002) and 12-month (80% vs. 62%; P = .0006) follow-ups compared to controls. In the subgroup with normal AV (n = 241), there was a lower risk of death or heart failure hospitalization (hazard ratio 0.52; 95% confidence interval 0.27-0.98; P = .044) with the aCRT algorithm. A greater proportion of patients in the aCRT arm improved in the clinical composite score at 6-month (81% vs. 69%; P = .041) and 12-month (77% vs. 66%; P = .076) follow-ups compared to controls.Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.

Introduction. Brugada syndrome is an arrhythmogenic disease characterized by coved ST segment elevation and J point elevation of at least 2 mm in at least two of the right precordial ECG leads (V1-3) and ventricular arrhythmias, syncope, and sudden death. Risk stratifications of patients with Brugada electrocardiogram are being strongly debated. Case Outline. A 23-year-old man was admitted to the Coronary Care Unit of the Clinical Centre “Bežanijska kosa” due to weakness, fatigue and chest discomfort. The patient suffered from fainting and palpitations. There was a family history of paternal sudden death at 36 years. Electrocardiogram showed a coved ST segment elevation of 4 mm in leads V1 and V2, recognised as spontaneous type 1 Brugada pattern. Laboratory investigations revealed normal serum cardiac troponin T and serum potassium, and absence of inflammation signs. Echocardiographic finding was normal, except for a mild enlargement of the right atrium and ventricle. The diagnosis of Brugada syndrome was made by Brugada-type 1 electrocardiogram and the family history of sudden death

The aim of this study was to assess the performance of echocardiographic parameters to predict response to cardiac resynchronization therapy (CRT).CRT reduces morbidity and mortality due to the proper selection of candidates for CRT.The 12-month trial was performed on 70 optimally medicated patients with standard inclusion criteria: NYHA class III or IV heart failure, left ventricular ejection fraction (LVEF) ≤ 35%, and QRS ≥ 120 ms. All parameters were evaluated by conventional and tissue Doppler-based methods. Indicator of positive CRT response was more than 20% in improvement of LVEF.LVEF increased20% in 42 patients. Out of 43 tested baseline echocardiographic parameters, 12 showed statistical difference between responders and nonresponders. Out of these 12 parameters, six (LVSV, LVSI, LVFS, RVd, VPMR, and PISA) had modest to moderately good ability to predict LVEF response with sensitivity ranging from 62.2% to 82.4%, and specificity ranging from 56.5% to 81.2%. For those parameters, the area under the receiver-operating characteristic curve for positive response to CRT was ≤0.76. Multivariate regression analysis resulted in selection of LVSI and LVFS as possible predictive independent parameters for a good response. The cutoff value for LVSI was 38.7 mL/m(2) (P = 0.045) and for LVFS was 13% (P = 0.032).Contribution of LVSI and LVFS is to be confirmed in larger trials. Simplicity of their assessment by conventional echocardiography could be an argument for adding them to the inclusion criteria for CRT in severe heart failure patients.

This paper was published under the Open Access publication model but it should have been published under the standard publication model. The funding statement should be disregarded and the copyright line should read as follows: Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2011. For permissions please email: moc.puo@snoissimrep.slanruoj. The online version of this paper has been corrected accordingly. The authors apologize for the error.

Cardiac resynchronization therapy (CRT) has important role in the contemporary treatment of heart failure, systolic dysfunction and mechanical disynchrony. Classical indications for CRT are severe heart failure (NYHA class III or IV), a broad QRS (more than 120 ms) and left ejection fraction less than 35% despite optimal medical therapy. Several have studies demonstrated the important role of echocardiography in patient selection for CRT, follow up and estimation of CRT effects, as well as the optimization of biventricular pacemaker. Basically, there are three types of cardiac asynchrony: interventricular asynchrony, between the right and left ventricle, intraventricular asynchrony, between the myocardial segments within the left ventricle and atrioventricular asynchrony, between the atria and ventricles. Although many echocardiographic techniques are used in patient selection for CRT, no ideal approach has yet been found. There are several techniques and parameters used in the assessment of myocardial asynchrony: two dimensional (2D) echocardiography, one dimensional echocardiography (M-mode), Doppler echocardiography, different modalities of tissue Doppler including Colour Coded Tissue Doppler Imaging - TDI, measurements of local tissue deformation indices (strain and strain rate), speckle tracking, 3D echocardiography, semiquantitative assessment of myocardial border, vector velocity imaging. Each of these techniques has advantages and limitations. A special accent in this revue is on the consensus report from the American Society of Echocardiography Dyssynchrony Writing group. According to this consensus report color coded tissue Doppler is the most appropriate technique for myocardial asynchrony estimation and patients selection for CRT. The same group recommended that definitive decision for CFT implantation should not be based only on echocardiographic analysis, but rather on the whole clinical aspect of the patient.

Introduction Enhancement of vagal nerve activity has a strong experimental rationale as a potential therapeutic approach to patients with severe Congestive Heart Failure (CHF). The CardioFit (BioControl Medical, Ltd.) is an implantable system capable of delivering chronic vagus nerve stimulation (CVNS) synchronized with the heart beat via a multipolar stimulation lead. Methods Twenty-nine patients with stable CHF, NYHA class II–IV, LVEF ≤ 35% on optimal medical therapy were enrolled and successfully implanted in a 7-site international 6-month safety and efficacy pilot study. Optimization of CVNS parameters occurred during a four week run-in period, two to four weeks post-implantation. Results Twenty subjects (mean age 57 years, range 30 –75; ischemic etiology in 70%; prior ICD in 50%) completed six-month follow-up; one NYHA class IV subject died due to worsening HF two months after implantation. At 6-months, 14 subjects had improved their NYHA class, and 6 remained stable. A significant improvement (p < 0.05) was found in the subjects’ quality of life (MLwHF® questionnaire); exercise capacity (6-minute walk test; see graph); and blindly evaluated LV ejection fraction (from 24 ± 2% to 29 ± 2%). The most commonly reported transient adverse events were expected side-effects of CVNS such as pain at cuff site (n = 6), cough (n = 7), and voice alteration (n = 5), which were resolved by optimizing stimulation parameters. Conclusions Chronic Vagus Nerve Stimulation in patients with advanced heart failure is feasible and appears to be well tolerated and safe. Initial data suggest a favorable trend of clinical outcomes. At this point a large scale randomized controlled study is warranted.

Aims Unnecessary right ventricular pacing has deleterious effects and becomes more significant when cumulative percent ventricular pacing (Cum%VP) exceeds 40% of time. The Managed Ventricular Pacing (MVP) mode has been shown to significantly reduce the percent ventricular pacing compared to the DDD/R mode. This study assessed the percent of ventricular pacing in a standard pacemaker population programmed to MVP and for which patients it is possible to achieve a Cum%VP

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. There were 42 patients (25 males; 59.5%), without symptoms or signs of coronary disease or heart failure, and with normal echocardiograms. According to BNP levels, the patients were divided into three groups: with BNP levels lower than 80 pg/ml, BNP ranging from 81-150 pg/ml, and BNP levels over 151 pg/ml. Results In the first group (27 patients), BNP levels were significantly higher on VVI compared to DDD mode, both at rest and after exercise (p

Introduction: Cardiac resynchronization therapy (CRT) is relatively new tool in treatment of chronic heart failure (HF), especially in dilated cardiomyopathy (DCM) with the left bundle branch block (LBBB). Objective: The Objective of our study was to assess the success of CRT in treatment of severe HF and the role of echocardiography in the evaluation of Results of such therapy. Method: The group consisted of 19 patients, 13 males and 6 females, mean age 58.0?8.22 years (47-65 years) with CRT applied for DCM, severe HF (NYHA III-IV), LBBB and ejection fraction (EF)

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. (Circ J 2005; 69: 116 -118)