Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead

GRADAUS, R., et al. : Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead. Dual-chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short-term follow-up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (  age 63 ± 8 years  ; LVEF  0.44 ± 0.16  ; New York Heart Association [NYHA]  2.4 ± 0.4  , previous open heart surgery in all patients). The operation time was  79 ± 29  minutes, the fluoroscopy time  4.7 ± 3.1  minutes. No perioperative complications occurred. The intraoperative atrial sensing was  1.7 ± 0.5 mV  , the atrial pacing threshold product was  0.20 ± 0.14 V/ms  (  range 0.03–0.50 V/ms  ). The defibrillation threshold was  8.8 ± 2.7 J  . At prehospital discharge and at 1-month and 3-month follow-up, atrial sensing was  1.9 ± 0.9, 2.1 ± 0.5, and 2.7 ± 0.6 mV  , respectively, (  P = NS, P < 0.05, P < 0.05  to implant, respectively), the mean atrial threshold product  0.79, 1.65, and 1.29 V/ms  , respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.     

Atrial Arrhythmias in Long-QT Syndrome under Daily Life Conditions: A Nested Case Control Study

Background: The long-QT syndromes (LQTS) are inherited electrical cardiomyopathies characterized by prolonged ventricular repolarization and ventricular arrhythmias. Several genetic reports have associated defects in LQTS-causing genes with atrial fibrillation (AF). We therefore studied whether atrial arrhythmias occur in patients with LQTS under daily-life conditions.
Methods: We systematically assessed atrial arrhythmias in LQTS patients and matched controls using implanted defibrillators or pacemakers as monitors of atrial rhythm in a nested case-control study. Twenty-one LQTS patients (3 male; 39 ± 18 years old; 18 on β blocker, ICD therapy duration 6.3 ± 2.7 years; 4 LQT1, 6 LQT2, 2 LQT3) were matched to 21 control subjects (13 male; 50 ± 19 years old; 3 on β blocker; pacemaker therapy duration 8.5 ± 5.5 years; 19 higher-degree AV block, 2 others). LQTS patients were identified by a systematic search of the LQTS patient databases in Münster and Munich.
Results: One-third (7 of 21) of the LQTS patients developed self-terminating atrial arrhythmias (atrial cycle lengths <250 ms). Only one control patient developed a single episode of postoperative AF (P < 0.05 vs LQTS).
Conclusions: LQTS patients at high risk for ventricular arrhythmias may develop short-lasting atrial arrhythmias under daily-life conditions, suggesting that prolonged atrial repolarization may contribute to the initiation of AF.     

European guidelines for the certification of professionals in sleep medicine: report of the task force of the European Sleep Research Society

In recent years, sleep medicine has evolved into a full-grown discipline, featuring a multidisciplinary approach to diagnosis and treatment of patients with sleep disorders. Sleep medicine cuts across the boundaries of different conventional disciplines and is therefore open to medical and non-medical professionals with different specialty backgrounds. The aim of the current paper is to introduce a qualification for those professionals whose main occupation is to practice sleep medicine in the setting of a sleep medicine centre. The drafting of guidelines dealing with requirements for such qualification was entrusted to a task force by the European Sleep Research Society. The guidelines are the result of a progressive consensus procedure in which standards were defined for education, training, and evaluation. The final step along this pathway is a theoretical and practical examination, providing proof of proficiency in the field of sleep medicine. This paper describes the object of specific competences, the scope of sleep medicine, and the qualification procedures that pertain to three professional categories: medical specialists, non-medical professionals with a university master degree (such as psychologists and biologists), and nurses and technologists. Indices of preceding practical experience and theoretical knowledge are presented in Appendices 1 and 2 . These guidelines are a European standard. They may be adapted in the future according to new scientific insights. National certification programs that comply with these guidelines may be subject to homologation by the ESRS.     

Stressful life events and disability in early rheumatoid arthritis

The objective was to investigate the relationship of stressfullife events and disability in early rheumatoid arthritis (RA),taking into account a possible stress-buffering effect of thesocial network. As part of a European study (EURIDISS), 337early RA patients in France and The Netherlands (mean diseaseduration = 2.3 years) were interviewed for life events whichhad occurred in the past year. The social network compositionwas assessed using a standardized interview schedule and describedby network density and proximity characteristics. Disabilitywas assessed with the Health Assessment Questionnaire (HAQ)cross-culturally adapted to the French and Dutch languages.Subjects reported a median of 2 significant life events overthe past year. On average they had 20 persons in their socialnetwork. The disability was significantly higher when the numberof life events experienced was higher (r = 0.11; p<0.05)and when the number of social network members in monthly contactwith the subjects was lower (r = –0.13; p<0.05). Controllingfor country, the HAQ score increased significantly with thedisease duration, disease activity variables, number of lifeevents related to RA or to another health problem and decreasedwith the number of social network members. A significant (numberof health-related life events)x(number of social network members)cross-product term entered the model which fitted the data better(R² =0.51). Factors associated with disability are disease duration,disease activity, number of health-related life events and numberof social network members in monthly contact. The results suggesta stress-buffering effect of the social network in coping withstressful life events in early RA.     

Association between Cardiac Autonomic Function and Coping Style in Healthy Subjects

The link between personality and cardiac function is insufficiently characterized. We postulated that in a healthy population, cardiac autonomic function is linked to coping style. In 276 healthy volunteers, between the ages of 18 and 71, the Utrecht Coping List was used to evaluate different coping strategies. Trait anxiety was scored by the Spielberger State Trait Anxiety Inventory. A 24-hour Holter recording was used to calculate heart rate variability (HRV). For HRV parameters and coping mechanisms this study demonstrated gender-specific differences and correlations with age. In men (n = 141) higher active coping was associated with less global autonomic activity or SDANN (r_s=−0.27, P < 0.001). This relationship was most prevalent in young (18–30 years) men (r_s=−0.45, P < 0.005). Higher expression of negative emotions or anger was related to both higher vagal (r_s= 0.23 for rMSSD, P < 0.01) tone and higher LF power (r_s= 0.23, P < 0.01). In young men expression of negative emotions or anger was associated with LF power (r_s= 0.37, P < 0.01) and in middle-aged (31–50 years) men with vagal tone (r_s= 0.43 for rMSSD, P < 0.005) and heart rate (r_s=−0.41, P < 0.005). Higher comforting ideas was related to higher LF power (r_s= 0.23 for LF power, P < 0.005), and this especially in middle-aged men (r_s= 0.37, P < 0.01). In women (n = 135), no significant correlations between coping style and HRV indices were found. We conclude that in normal individuals, at least in men, our findings suggest a relationship between coping style and cardiac autonomic function.     

Chemical shift differences between free and Fab-bound peptide correlate with a two-stage selection of peptide sequences from a random phage display library to delineate critical and non-critical residues for antibody recognition

Epitope libraries provide a method to identify peptide ligands for antibodies, receptors or other binding proteins. As such, they provide a powerful tool to rapidly identify lead ligands in the drug discovery process. In an attempt to correlate structural information with the results from peptide screening, we have used NMR spectroscopy of peptide/antibody complexes to demonstrate that core residues identified through a two-stage selection process undergo a larger structural change upon binding antibody than do positions in the peptide amenable to a variety of side chains. The model system used was the M2 monoclonal antibody/Flag? octapeptide epitope system. We have analyzed two peptides: Ac-Asp-Tyr-Lys-Leu-Gly-Asp-Asp-Leu-NH₂ (peptide l), which contains several non-core positions randomized, and Ac-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Leu-NH₂ (peptide 2), which closely corresponds to the original Flag? sequence. Enrichment of the peptides with ¹⁵N facilitated the investigation by permitting spectral editing of the peptide resonances in the presence of antibody. For peptide 1 the absolute shifts for the free vs. Fab-bound peptide were found to be largest for the amide groups of Asp-1 and Asp-6, in agreement with classification of these residues as critical by the phage display library selection process. For peptide 2 the largest absolute shifts were observed for Asp-1 and Asp-4, with the other aspartic acid residues also showing significant but smaller changes. © Munksgaard 1995.