Improvement of electrical synchrony in cardiac resynchronization therapy using dynamic atrioventricular delay programming and multipoint pacing.

BACKGROUND: Optimization of cardiac resynchronization therapy (CRT) is often time-consuming and therefore underused in a clinical setting. Novel device-based algorithms aiming to simplify optimization include a dynamic atrioventricular delay (AVD) algorithm (SyncAV, Abbott) and multipoint pacing (MPP, Abbott). This study examines the acute effect of SyncAV and MPP on electrical synchrony in patients with newly and chronically implanted CRT devices. METHODS: Patients with SyncAV and MPP enabled devices were prospectively enrolled during implant or scheduled follow-up. Blinded 12-lead electrocardiographic acute measurements of QRS duration (QRSd) were performed for intrinsic QRSd (Intrinsic), bi-ventricular pacing (BiV), MPP, BiV with SyncAV at default offset 50 ms (BiVSyncAVdef ), BiV with SyncAV at patient-specific optimised offset (BiVSyncAVopt ), MPP with SyncAV at default offset 50 ms (MPPSyncAVdef ), and MPP with SyncAV at patient-specific optimised offset (MPPSyncAVopt ). RESULTS: Thirty-three patients were enrolled. QRSd for Intrinsic, BiV, MPP, BiVSyncAVdef , BiVSyncAVopt , MPPSyncAVdef , MPPSyncAVopt were 160.4 ± 20.6 ms, 141.0 ± 20.5 ms, 130.2 ± 17.2 ms, 121.7 ± 20.9 ms, 117.0 ± 19.0 ms, 121.2 ± 17.1 ms, 108.7 ± 16.5 ms respectively. MPPSyncAVopt led to greatest reduction of QRSd relative to Intrinsic (-31.6 ± 11.1%; p < .001), showed significantly shorter QRSd compared to all other pacing configurations (p < .001) and shortest QRSd in every patient. Shortening of QRSd was not significantly different between newly and chronically implanted devices (-51.6 ± 14.7 ms vs. -52.7 ± 21.9 ms; p = .99). CONCLUSION: SyncAV and MPP improved acute electrical synchrony in CRT. Combining both technologies with patient-specific optimization resulted in greatest improvement, regardless of time since implantation. Whats new Novel device-based algorithms like a dynamic AVD algorithm (SyncAV, Abbott) and multipoint pacing (MPP, Abbott) aim to simplify CRT optimization. Our data show that a combination of patient tailored SyncAV optimization and MPP results in greatest improvement of electrical synchrony in CRT measured by QRS duration, regardless if programmed in newly or chronically implanted devices. This is the first study to our knowledge to examine a combination of these device-based algorithms. The results help understanding the ideal ventricular excitation in heart failure.

[Perioprocedural mortality after ICD implantation]. / Peripoperative Mortalität nach ICD-Implantation.

BACKGROUND: Implantable cardioverter defibrillators (ICD) represent an established treatment in preventing sudden cardiac death in patients with indications for primary or secondary prophylaxis. As for all complex surgical procedures there remains a risk for the occurrence of complications including death also for ICD implantation. The aim of the present study was to analyze the procedure-related mortality in patients after ICD implantation using the data from the obligatory quality assurance program in North-Rhine/Westphalia. METHODS: Data of all 18,625 patients from the quality assurance datasets who underwent ICD implantation in the years 2010-2012 were analyzed. RESULTS: During the in-hospital stay 118 patients (0.6%) died after ICD implantation. Patients > 80 years old had a higher mortality (1.9% vs. 0.5% in patients < 80 years old, p < 0.001) as well as women (0.95% vs. 0.54% in men, p = 0.004) and patients with higher New York Heart Association (NYHA) class (0.3% for NYHA II, 0.7% for NYHA III, 3.4% for NYHA IV, p < 0.001 for all comparisons). The presence of diabetes mellitus (23% of the collective) did not influence the perioperative mortality, whereas renal failure requiring dialysis showed a significantly increased mortality (p < 0.001 compared to patients with creatinine ≤ 1.5 mg/dl and p = 0.002 for patients with creatinine > 1.5 mg/dl not requiring dialysis). Patients with indications for ICD secondary prophylaxis had a significantly higher mortality (1.2% vs. 0.4%, p < 0.001), which increased from 0.6% to 3.7% (p < 0.001) with the occurrence of complications. CONCLUSION: The procedure-related mortality after ICD implantation is increased in patients over 80 years of age, higher NYHA class, patients requiring dialysis, in secondary prevention indications and after the occurrence of perioperative complications.

Applicability of a Novel Formula (Bogossian formula) for Evaluation of the QT-Interval in Heart Failure and Left Bundle Branch Block Due to Right Ventricular Pacing.

BACKGROUND: The presence of left bundle branch block (LBBB) due to right ventricular pacing represents a particular challenge in properly measuring the QTc interval. In 2014, a new formula for the evaluation of QT interval in patients with LBBB was reported. METHODS: 145 patients with implantable cardioverter defibrillator were included in this prospective multicenter observational study. Inclusion criteria were: no permanent right ventricular stimulation, an intrinsic QRS interval of <120 ms, and reduced left ventricular function. 12-lead electrocardiogram recordings during intrinsic rhythm and during right ventricular threshold testing were performed. After LBBB correction using the reported Bogossian formula, the QTc interval was evaluated with Bazett's formula. The corrected QTc interval was compared in each patient with the QTc interval during intrinsic rhythm. All measurements were performed by an experienced electrophysiologist and a trainee who worked independently and in a blinded manner. RESULTS: 74 patients (65 ± 13 years; male n = 42) with apical and 71 patients (68 ± 11 years; male n = 42) with nonapical right ventricular pacing were included in this study. The mean left ventricular ejection fraction was 40 ± 13%. The QTc interval was determined to be 461 ± 34 ms (modified by Bogossian's formula) in paced and 436 ± 34 ms in intrinsic rhythm. The QTc interval was overestimated by ΔQTc of 25 ± 21 ms (mean deviation 5.7%) when using the Bogossian formula. CONCLUSION: The novel Bogossian formula seems to be a reliable tool for QTc interval evaluation in patients with heart failure and right ventricular pacing. However, a slight overestimation of the QT-interval must be respected.

A new experimentally validated formula to calculate the QT interval in the presence of left bundle branch block holds true in the clinical setting.

BACKGROUND: The evaluation of the QT interval in the presence of left bundle branch block (LBBB) is associated with the challenge to discriminate native QT interval from the prolongation due to the increase in QRS duration. The newest formula to evaluate QT interval in the presence of LBBB suggests: modified QT during LBBB = measured QT interval minus 50% of LBBB duration. The purpose of this study is therefore to validate the abovementioned formula in the clinical setting. METHODS: Validation in two separate groups of patients: Patients who alternated between narrow QRS and intermittent LBBB and patients with narrow QRS who developed LBBB after transcatheter aortic valve implantation (TAVI). RESULTS: The acquired mean native QTc intervals and those calculated by the presented formula displayed no significant differences (p > .99 and p > .75). CONCLUSIONS: In this study we proved for the first time the validity and applicability of the experimentally acquired formula for the evaluation of the QT interval in the presence of LBBB in a clinical setting.

Q Wave in the Inferior Leads: There Is More Than Scar.

Q waves can regularly be observed in the 12-lead electrocardiogram either due to heart axis underlying pathology such as subacute myocardial infarction, myocardial scar, or accessory pathways. Rarely, other entities such as circumscribed hypertrophy can induce significant Q wave and represent an important differential diagnosis especially in younger patients. In the setting of atypical chest pain determination of the correct diagnosis can be challenging. Therefore, circumscribed hypertrophy should be taken into account to avoid unnecessary invasive procedures.

U wave during supraventricular tachycardia: simulation of a long RP tachycardia and hiding the common type AVNRT.

The main tool for the differentiation of supraventricular tachycardia is the 12-lead electrocardiogram (ECG). Especially differentiating the atrioventricular nodal reentrant tachycardia (AVNRT) from the atrioventricular reentrant tachycardia (AVRT) due to concealed accessory pathway or from an atrial tachycardia (AT) is very important for catheter setting and ablation approach in an electrophysiological study. In our case we saw the occurrence of a U wave during tachycardia-simulating a pseudo P wave. This mimicked a long RP-tachycardia, although it was a common type AVNRT.

Cerebral blood volume estimation by ferumoxytol-enhanced steady-state MRI at 9.4 T reveals microvascular impact of α1 -adrenergic receptor antibodies.

Cerebrovascular abnormality is frequently accompanied by cognitive dysfunctions, such as dementia. Antibodies against the α1 -adrenoceptor (α1 -AR) can be found in patients with Alzheimer's disease with cerebrovascular disease, and have been shown to affect the larger vessels of the brain in rodents. However, the impact of α1 -AR antibodies on the cerebral vasculature remains unclear. In the present study, we established a neuroimaging method to measure the relative cerebral blood volume (rCBV) in small rodents with the ultimate goal to detect changes in blood vessel density and/or vessel size induced by α1 -AR antibodies. For this purpose, mapping of R2 * and R2 was performed using MRI at 9.4 T, before and after the injection of intravascular iron oxide particles (ferumoxytol). The change in the transverse relaxation rates (ΔR2 *, ΔR2 ) showed a significant rCBV decrease in the cerebrum, cortex and hippocampus of rats (except hippocampal ΔR2 ), which was more pronounced for ΔR2 * than for ΔR2 . Immunohistological analyses confirmed that the α1 -AR antibody induced blood vessel deficiencies. Our findings support the hypothesis that α1 -AR antibodies lead to cerebral vessel damage throughout the brain, which can be monitored by MRI-derived rCBV, a non-invasive neuroimaging method. This demonstrates the value of rCBV estimation by ferumoxytol-enhanced MRI at 9.4 T, and further underlines the significance of this antibody in brain diseases involving vasculature impairments, such as dementia.

[History of cardiac pacemaker therapy in Germany]. / Geschichte der Herzschrittmacher-Therapie in Deutschland.

Cardiac pacemaker therapy began with successful stimulation of human hearts already in the first half of the 20th century. Complete implantation of a pacemaker by the cardiac surgeon Åke Senning on October 8, 1958 at the Karolinska Hospital in Stockholm is considered the actual birth of today's pacemaker therapy. The first pacemaker implantation in Germany was performed by Hans-Joachim Sykosch on October 6, 1961 at the Surgical Clinic of the University of Düsseldorf. Two years later, the first implantation in East Germany (GDR) was carried out by Friedrich Flemming on September 2, 1963 at the Charité in East Berlin. The first pacemaker manufactured in West Germany arrived on the market 1963; East Germany started device production in 1978. In 1974, pacemaker therapy in West Germany showed a 50% survival rate after 6.3 years compared to < 1 year with drug therapy. After initially using bare metal wires, pacemaker leads have significantly improved in both quality and reliability. Development culminated in the leadless pacemaker. Battery development led to a variety of inventions: rechargeable pacemakers, biogalvanic cells, bioenergy sources, nuclear generators and lithium batteries, the latter ultimately prevailed. In the beginning, only fixed-rate ventricular pacemakers were available. Subsequently, systems adapted to physiological requirements were developed: on-demand pacemakers, atrial-based pacing and rate-adaptive systems. However, it was not until the return to direct stimulation of the conduction system that truly physiological stimulation of the heart became possible.

Cephalic Vein Cutdown Is Superior to Subclavian Puncture as Venous Access for Patients with Cardiac Implantable Devices after Long-Term Follow-Up.

BACKGROUND: Cephalic vein cutdown (CVC) and subclavian vein puncture (SVP) are the most commonly used access sites for transvenous lead placement of cardiac implantable electronic devices (CIEDs). Limited knowledge exists about the long-term patency of the vascular lumen housing the leads. METHODS: Among the 2703 patients who underwent CIED procedures between 2005 and 2013, we evaluated the phlebographies of 162 patients scheduled for an elective CIED replacement (median of 6.4 years after the first operation). The phlebographies were divided into four stenosis types: Type I = 0%, Type II = 1-69%, Type III = 70-99%, and Type IV = occlusion. Due to the fact that no standardized stenosis categorization exists, experienced physicians in consensus with the involved team made the applied distribution. The primary endpoint was the occurrence of stenosis Type III or IV in the CVC group and in the SVP group. RESULTS: In total, 162 patients with venography were enrolled in this study. The prevalence of high-degree stenosis was significantly lower in the CVC group (7/89, 7.8%) than in the SVP group (15/73, 20.5%, p = 0.023). In the CVC group, venographies showed a lower median stenosis (33%) than in the SVP group (median 42%). CONCLUSIONS: The present study showed that the long-term patency of the subclavian vein is higher after CVC than after SVP for venous access in patients with CIED.

[Asymptomatic bradycardia and pacemaker : To implant, or not to implant?] / Asymptomatische Bradykardien : Wann ist die Implantation eines Herzschrittmachers sinnvoll?

The cardiac implantable electronic device (CIED) is the therapy of choice for management of symptomatic bradyarrhythmias. However, the indication for CIED implantation in the cases of asymptomatic bradycardias should be carefully individualized. Incidental electrocardiographic findings in asymptomatic patients (e.g., low baseline heart rates, higher than first-degree atrioventricular block or longer pauses) may complicate the physician's decision regarding the necessity of CIED implantation. The main reason is the inherit risk of short- and long-term complications with every CIED implantation, i.e., peri-operative complications, risk of CIED infection, lead fractures, and the necessity for lead extraction. Therefore, before opting for, or against, CIED implantation, several factors should be considered in the subset of asymptomatic patients.

Perioperative complications after pacemaker implantation: higher complication rates with subclavian vein puncture than with cephalic vein cutdown.

PURPOSE: The cephalic vein cutdown (CVC) and the subclavian puncture (SP) is the most common access for pacemaker implantation. The purpose of this study was to compare the peri-/postoperative complications of these approaches. METHODS: A retrospective analysis of the quality assurance data of the state of North Rhine-Westphalia was performed to evaluate the peri-/postoperative complications of first pacemaker implantation according to the venous access. The primary endpoint was defined as the occurrence of one of the following: asystole, ventricular fibrillation, pneumothorax, hemothorax, pericardial effusion, pocket hematoma, lead dislocation, lead dysfunction, postoperative wound infection or other complication requiring intervention. Descriptive analysis was done via absolute, relative frequencies and Odds Ratio. Fisher's exact test was used for comparison of the both study groups. RESULTS: From 139,176 pacemaker implantations from 2010 to 2014, 15,483 cases were excluded due to other/double access. The median age was 78 years and the access used was CVC for 75,251 cases (60.8%) and SP for 48,442 cases (39.2%). The implanted devices were mainly dual-chamber pacemakers (73.9% in the CVC group and 78.4% in the SP group), followed by single-chamber pacemakers VVI (24.9% and 19.9% in the CVC and SP group respectively). There were significantly fewer peri/postoperative complications in the CVC group compared to the SP group (2.49% vs. 3.64%, p = 0.0001, OR 1.47; 95% CI 1.38-1.57). CONCLUSIONS: CVC as venous access for pacemaker implantation has significantly fewer peri/postoperative complications than SP and appears to be an advantageous technique.

A novel algorithm for individualized cardiac resynchronization therapy: rationale and design of the adaptive cardiac resynchronization therapy trial.

BACKGROUND: The magnitude of benefit of cardiac resynchronization therapy (CRT) varies significantly among its recipients; approximately 30% of CRT patients do not report clinical improvement. Optimization of CRT pacing parameters can further improve cardiac function, both acutely and chronically. Echocardiographic optimization is used in clinical practice, but it is time and resource consuming. In addition, optimal settings at rest may change later with activity or cardiac remodeling. The adaptive CRT (aCRT) algorithm was designed to provide automatic ambulatory adjustment of CRT pacing configuration (left ventricular or biventricular pacing) and device delays based on periodic measurement of electrical conduction intervals. METHODS: The aCRT algorithm is currently undergoing evaluation in a prospective, randomized, double-blinded, worldwide clinical trial. The trial enrolled 522 patients, who satisfied standard clinical indications for a CRT device. Within 2 weeks after the implant, the patients were randomized to aCRT versus echo-optimized biventricular pacing (Echo) settings in 2:1 ratio and followed up at 1-, 3-, 6-, and 12-month postrandomization. The noninferiority primary trial objectives at 6-month postrandomization are to demonstrate that (a) the percentage of aCRT patients who improved in their clinical composite score is at least as high as the percentage of Echo patients; (b) cardiac performance as assessed by echocardiography is similar when using aCRT settings versus echo-optimized settings; and (c) aCRT does not result in inappropriate device settings. First and last patient enrollments occurred in November 2009 and December 2010, respectively. CONCLUSIONS: The safety and efficacy of the aCRT algorithm will be evaluated in this ongoing clinical trial.

Long-term prognosis of successful left ventricular substrate modification of electrical storm.

Introduction: The Electrical storm (ES) subsumes a state of electrical instability of the heart, which manifests itself in repeated and potentially fatal ventricular arrhythmias (VA). We examine the long-term effects of substrate modification with regards to mortality, ventricular tachycardia (VT) recurrences and hospitalization depending on age, gender, heart function, scare location, VT documentation, postprocedural electrical stimulation (PES) and induced VTs. Methods: From 08/2008 and 09/2019 160 consecutive patients admitted for ES ablation via electroanatomical mapping were followed up until 04/2021. Results: 50/160 patients showed VT recurrences after 13.8 ± 21.7 (0.0-80.3) months, with a characteristic steep curve directly after ES and then a rapid decline leading to a plateau (first month 10/50 (20%), first year 35/50 VT recurrences (70%) Mortality rates followed a similar pattern also the initial decline was not as steep. 42 patients died during the observation period (26%) after 16.6 ± 16.1 (0.0-67.9) months after ablation day (first month (n = 7, 16.7%) first year (n = 21, 50%). Gender, age, scare localization, missing VT documentation did not worsen outcome. Induction of >3 VTs and lack of PES due to hemodynamic instability significantly decreased effectiveness. Finding the entry significantly increased long-term effects. Conclusion: Ablation of ES is safe and feasible independent of a variety of factors. Employing more sophisticated tools to understand the reentry mechanism will further improve the long-term outcome.

Primary results from the SmartDelay determined AV optimization: a comparison to other AV delay methods used in cardiac resynchronization therapy (SMART-AV) trial: a randomized trial comparing empirical, echocardiography-guided, and algorithmic atrioventricular delay programming in cardiac resynchronization therapy.

BACKGROUND: one variable that may influence cardiac resynchronization therapy response is the programmed atrioventricular (AV) delay. The SmartDelay determined av optimization: a comparison to other AV delay methods used in cardiac resynchronization therapy (SMART-AV) trial prospectively randomized patients to a fixed empirical AV delay (120 milliseconds), echocardiographically optimized AV delay, or AV delay optimized with SmartDelay, an electrogram-based algorithm. METHODS AND RESULTS: a total of 1014 patients (68% men; mean age, 66 ± 11 years; mean left ventricular ejection fraction, 25 ± 7%) who met enrollment criteria received a cardiac resynchronization therapy defibrillator, and 980 patients were randomized in a 1:1:1 ratio. All patients were programmed (DDD-60 or DDDR-60) and evaluated after implantation and 3 and 6 months later. The primary end point was left ventricular end-systolic volume. Secondary end points included New York Heart Association class, quality-of-life score, 6-minute walk distance, left ventricular end-diastolic volume, and left ventricular ejection fraction. The medians (quartiles 1 and 3) for change in left ventricular end-systolic volume at 6 months for the SmartDelay, echocardiography, and fixed arms were -21 mL (-45 and 6 mL), -19 mL (-45 and 6 mL), and -15 mL (-41 and 6 mL), respectively. No difference in improvement in left ventricular end-systolic volume at 6 months was observed between the SmartDelay and echocardiography arms (P=0.52) or the SmartDelay and fixed arms (P=0.66). Secondary end points, including structural (left ventricular end-diastolic volume and left ventricular ejection fraction) and functional (6-minute walk, quality of life, and New York Heart Association classification) measures, were not significantly different between arms. CONCLUSIONS: neither SmartDelay nor echocardiography was superior to a fixed AV delay of 120 milliseconds. The routine use of AV optimization techniques assessed in this trial is not warranted. However, these data do not exclude possible utility in selected patients who do not respond to cardiac resynchronization therapy.

Transseptal use of high-density grid catheter for VT mapping and retrograde hemodynamic support with Impella pump in presence of Mitraclips.

PURPOSE: We sought to establish the technical feasibility of VT-mapping with high-density catheters in patients with Mitraclips, requiring a hemodynamic support. METHODS: A 73-year-old man with ischemic cardiomyopathy and reduced left ventricular ejection fraction (LVEF ~ 20%) was presented due to syncope and adequate shock of his ICD. Due to severe mitral valve regurgitation (MR), two Mitraclips were implanted earlier. The decision for catheter ablation was made in line with current guidelines. Given the increased PAAINESD score, the use of hemodynamic support was required. To employ an Impella pump via the retrograde transaortic approach, LV-mapping and VT-ablation were necessary to be performed via the transseptal approach, which was challenging due to the presence of Mitraclips. The MV passage with the steerable sheath was guided by a quadripolar catheter and 3D transoesophageal echo (TEE). After the 12F steerable sheath had passed the MV, the quadripolar catheter was exchanged by a high-density (HD) Grid® catheter. Hereafter, the Impella pump was placed retrogradely in the LV, and voltage-mapping of the LV and ablation was performed. RESULTS: At the end of the procedure, the Impella pump could be removed in stable hemodynamic conditions. The follow-up after 3, 6, and 12 months showed no new VT episodes. CONCLUSIONS: This case demonstrates the feasibility of the transseptal approach of VT mapping used HD Grid catheter and retrograde hemodynamic support with Impella Pump for VT treatment in patients after Mitraclips implantation. To avoid a damage of the MV and Mitraclips, 3D-TEE is advisable.

Manual vs. automatic capture management in implantable cardioverter defibrillators and cardiac resynchronization therapy defibrillators.

AIMS: The Secura ICD and Consulta CRT-D are the first defibrillators to have automatic right atrial (RA), right ventricular (RV), and left ventricular (LV) capture management (CM). Complete CM was evaluated in an implantable cardioverter defibrillator (ICD) population. METHODS AND RESULTS: Two prospective clinical studies were conducted in 28 centres in Europe and Israel. Automatic CM data were compared with manual threshold measurements, the CM applicability was determined, and adjustments to pacing outputs were analysed. In total, 160 patients [age 64.6 +/- 10.4 years, 77% male, 80 ICD and 80 cardiac resynchronization therapy defibrillator (CRT-D)] were included. The differences between automatic and manual measurements were 2.5 V) due to raised RA threshold in seven (4.4%), high RV threshold in nine (5.6%), and high LV threshold in three patients (3.8%). All high threshold detections and all automatic modulations of pacing output were adjudicated appropriate. CONCLUSION: Complete CM adjusts pacing output appropriately, permitting a reduction in office visits while it may maximize device longevity. The study was registered at ClinicalTrials.gov identifiers: NCT00526227 and NCT00526162.

SmartDelay determined AV optimization: a comparison of AV delay methods used in cardiac resynchronization therapy (SMART-AV): rationale and design.

BACKGROUND: The clinical benefit of cardiac resynchronization therapy (CRT) for patients with moderate-to-severely symptomatic heart failure, left ventricular systolic dysfunction, and ventricular conduction delay is established. However, some patients do not demonstrate clinical improvement following CRT. It is unclear whether systematic optimization of the programmed atrioventricular (AV) delay improves the rate of clinical response. METHODS: SMART-AV is a randomized, multicenter, double-blinded, three-armed trial that will investigate the effects of optimizing AV delay timing in heart failure patients receiving CRT + defibrillator (CRT-D) therapy. A minimum of 950 patients will be randomized in a 1:1:1 ratio using randomly permuted blocks within each center programmed to either DDD or DDDR with a lower rate of 60. The study will include echocardiographic measurements of volumes and function [e.g., left ventricular end-systolic volume (LVESV)], biochemical measurements of plasma biomarker profiles, and functional measurements (e.g., 6-minute hall walk) in CRT-D patients who are enrolled and randomized to fixed AV delay (i.e., 120 ms), AV delay determined by electrogram-based SmartDelay, or an AV delay determined by echocardiography (i.e., mitral inflow). Patients will be evaluated prior to initiation of CRT, 3 and 6 months post-implant. The primary endpoint is the relative change in LVESV at 6 months between the groups. Patient enrollment commenced in May 2008 and the study is registered at clinicaltrials.gov. CONCLUSION: SMART-AV is a randomized, clinical trial designed to evaluate three different methods of AV delay optimization to determine whether systematic AV optimization is beneficial for patients receiving CRT for 6 months post-implant.

Prevalence, clinical correlates and treatment of permanent atrial fibrillation among the elderly: insights from the first prospective population-based study in rural Greece.

To investigate the prevalence of permanent atrial fibrillation (AF), its clinical associated conditions and treatment status in the elderly population in rural Greece. 720 people (46.1% males) older than 65 years (mean age: 72.5 +/- 5.7 years) living in four villages in rural Greece were screened with an electrocardiogram (response rate: 90.5%) for the presence of permanent AF. They underwent a physical examination, including blood pressure (BP) measurement, and body mass index (BMI) calculation, in addition to an interview about their medical history, physical activity, smoking habits, alcohol consumption and medication use. Subjects with AF for whom anticoagulants were contraindicated were identified and stroke risk stratification was performed using the CHADS2 algorithm. The prevalence of permanent AF was 5% (6.6% among men and 3.6% among women) and it increased with age. In the entire population, ECG evidence of myocardial ischaemia and ventricular premature beats were independently associated with the presence of permanent AF (OR 5.266; 95% CI 2.22-12.49, P = 0.0001 and OR 2.61; 95% CI 1.059-6.432, P = 0.037, respectively), while female sex was independently associated with the absence of the AF (OR 0.327; CI 0.147-0.729, P = 0.006). From those patients who were eligible for anticoagulation, 40.6% were treated with anticoagulants, 34.3% were given antiplatelets therapy and the rest received no antithrombotic treatment. This is the first prospective study demonstrating the prevalence, clinical correlates and treatment status of permanent AF in Greece. These results confirm the high prevalence of permanent AF among the elderly and underscore the issue regarding anticoagulants underutilization.

Non-invasive determination of the optimized atrioventricular delay in patients with implanted biventricular pacing devices.

BACKGROUND: Biventricular (BiV) is extensively used in the treatment of congestive heart failure but so far no recommendations for optimized programming of atrioventricular-delay (AVD) settings have been proposed. Can AVD optimization be performed using a simple formula based on non-invasive doppler-echocardiography? METHODS: 25 patients (ejection fraction 30+/-8%) received BiV ICDs. Doppler-echocardiographic evaluation of diastolic and systolic flow was performed for different AVDs (30ms to 150ms) and different stimulation sites (left ventricular (LV), right ventricular and BiV). The optimal atrioventricular delay was calculated applying a simple formula based on systolic and diastolic mechanical delays determined during doppler-echocardiography. RESULTS: The mean optimal AVD was calculated to be 112+/-29ms (50 to 180ms) for BiV, 95+/-30ms (65 to 150ms) for LV and 75+/-28ms (40 to 125ms) for right ventricular pacing with wide interindividual variations. Compared to suboptimal AVDs diastolic optimization improved preejection and ejection intervals independent to pacing site. Optimization of the AVD significantly increased ejection time during BiV pacing (279ms versus 266ms; p<0.05). Compared to LV or right ventricular pacing BiV pacing produced the shortest mean pre-ejection and longest ejection intervals as parameters of improved systolic ventricular contractile synchrony. Diastolic filling times were longest during BiV pacing compared to LV or RV pacing. CONCLUSIONS: Individual programming of BiV pacing devices increases hemodynamic benefit when implementing the inter-individually widely varying electromechanical delays. Optimization applying a simple formula not only improves diastolic ventricular filling but also increases systolic functional parameters.