Internal Cardioversion of Chronic Atrial Fibrillation in Patients

Transvenous internal cardioversion of chronic AF using a right atrium (RA) coronary sinus (CS) vector requires more energy than cardioversion of paroxysmal AF. Chronic AF is not terminated in 25% of patients using biphasic shocks up to 10 J. We therefore evaluated efficacy, safety, and tolerability of internal cardioversion using a "unipolar' configuration (RA to skin patch) and biphasic shocks in patients with long-lasting AF and different heart disease. In each patient, biphasic R have synchronous shocks were delivered between a large defibrillating surface area electrode in the RA and a skin patch in the left prepectoral position. Defibrillation protocol started with a test shock of 0.4 J. Shocks were repeated and increased until termination of AF or a maximum of 34 J. Sedation was used when the patient described the shock as painful. This study included 11 patients with a mean age of 67 ± 8 years (range 56–83). AF duration was ± 1 month in all patients with a mean duration of 11 ± 11 months (range 2–36). Underlying heart disease was present in all patients and the mean left atrial dimension was 43 ± 9 mm (range 26–57). AF was terminated in 10 of 11 patients (91 %) with a mean delivered energy of the successful shocks of 18.7 ± 8.7 J (median energy 16.9 J; range 7.3–32.5) and a mean leading edge voltage of 564 ± 129 V. The mean shock impedance at the defibrillation threshold was 71 ± 13 Ω, (range 59–103). A total of 131 shocks were delivered without any complication and proarrhythmia episodes. We conclude that low energy "unipolar" internal cardioversion is a simple, safe, and effective technique for termination of chronic AF in patients with heart disease. The procedure is often tolerated under light sedation.     

Comparison of Biphasic and Monophasic Pulses: Does the Advantage of Biphasic Shocks Depend on the Waveshape?

With present implantable defibrillators, the ability to vary the defibrillation technique has been shown to increase the number of patients suitable for transvenous system. As newer waveforms become available, the need for a flexible device may change. In addition, although it has been shown that the option of biphasic waveform may increase the defibrillation efficacy, this may depend upon the shape of the biphasic waveform used. Thirty patients undergoing transvenous defibrillator implant were included in the study. In 20 patients (group I), defibrillation efficacy of simultaneous monophasic, sequential monophasic, and biphasic waveform with 50% tilt was determined randomly. Similarly, in ten patients (group II) testing of simultaneous monophasic shocks and biphasic waveforms with 65% and 80% tilt was performed in random order. The electrode system used consisted of two transvenous leads and a subcutaneous patch in all 30 patients. In group I, 50% tilt biphasic waveform consistently provided similar or better defibrillation efficacy compared to monophasic waveforms (biphasic 7.5 ±5.1 joules vs simultaneous 17 ± 7.8 joules, P < 0.01; and vs sequential 17 ± 8.4 joules, P <0.01). In group II, 65% tilt biphasic pulse required less energy for defibrillation as compared with simultaneous monophasic shocks (9.6 ± 4.5 joulesvs 15.6 ± 5.1 joules, P = 0.04). No significant difference was observed in terms of defibrillation threshold between 80% tilt biphasic shocks and simultaneous monophasic pulses (11.8 ± 6 joules vs 15.6 ±5.1 joules, P = NS). Biphasic shocks with smaller tilt delivered using a triple lead system more uniformly improved defibrillation threshold over standard monophasic waveforms.     

Formulation and testing of a nursing assessment form for mental patients as a basis for individualized nursing care

RAYA A., MANTAS J., PRIAMI, M., ANDREA S., BROKALAKI H., KYRITSIH. & ANDROULAKI O. (1995) Journal of Psychiatric and Mental Health Nursing 2 , 23–32: Formulation and testing of a nursing assessment form for mental patients as a basis for individualized nursing care. : The study described here was designed to develop and test a form of nursing assessment of mental patients for use as a basis for individualized holistic nursing care in any setting.
Nursing assessment was made of 581 mental patients receiving care in either mental hospitals, psychiatric departments of general hospitals or in mental health centres. Subjects were observed, interviewed and asked to complete a structured assessment form. Major variables studied were physical nursing problems/needs with nine categories, psychosocial nursing problems/needs with nine categories, sex, age, and physical and psychiatric disorders. Data were analysed with frequency distribution and comparative techniques, correlational procedures, and the multiple linear regression statistical procedure.
The frequency distribution of psychiatric diagnoses showed that schizophrenic disorders were the most frequent in the total sample. However, there were more depressive patients in the general hospital group. Physical nursing problems/needs were significantly related with psychosocial nursing problems/needs, affective-depressive disorders, sex and age as well as negatively related with psychotic and anxiety disorders. Psychosocial nursing problems/needs were significantly related with schizophrenic and psychotic disorders, physical disorders and with the younger age groups.
It was concluded that the psychiatric nursing assessment should encompass the areas of personal characteristics, and physical and psychological problems of the patient, and thus lead to practicing psychiatric nursing, that is, holistic psychosomatic nursing.     

Linear and cyclic synthetic peptides related to the main autophosphorylation site of the Src tyrosine kinases as substrates and inhibitors of Lyn †

Tyrosine protein kinases (TPKs) of the src family contain two major phosphoacceptor sites which are homologous to the Tyr 416 and Tyr 527 of pp60^c-src. The former represents the main autophosphorylation sites of these enzymes, and its phosphorylation correlates with increased kinase activity. It has previously been demonstrated that the Src-like tyrosine kinase expressed by the oncogene lyn displays a high affinity toward the heptapeptide H-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-OH, which reproduces the main autophosphorylation site of the Src family enzymes [Donella-Deana, A., Marin, O., Brunati, A.M. & Pinna, L.A. (1992) Eur. J. Biochem. 204 , 1159–1163]. Our study was addressed to the synthesis of some derivatives of this sequence in order to obtain both peptide substrates suitable for the detection of the Src-like tyrosine kinase activity and active site-directed inhibitors specific for this class of enzymes. For this purpose we synthesized by classical solution methods the heptapeptide and its dimeric form. Moreover, in order to improve the proteolytic resistance of these peptides we also synthesized their cyclic derivatives and their N-terminal acetylated and C-terminal amidated analogs. The correlation between the different structural properties induced by the modifications of the native sequence and the propensity of the peptides to act as Lyn substrates was examined. The kinetic data obtained indicate that the extent of the peptide phosphorylation varies considerably depending on the flexibility and length of the analogs. While the cyclization and the C-terminal amidation of the heptapeptide are detrimental for the Lyn activity, dimeric derivatives display very favourable kinetic constants. In particular the cyclic dimer is an especially suitable substrate for the tyrosine kinase and a powerful inhibitor of both the phosphorylation activity of Lyn and the enzyme autophosphorylation. © Munksgaard 1995.     

Origin of the vertebrate inner ear: evolution and induction of the otic placode

The vertebrate inner ear forms a highly complex sensory structure responsible for the detection of sound and balance. Some new aspects on the evolutionary and developmental origin of the inner ear are summarised here. Recent molecular data have challenged the longstanding view that special sense organs such as the inner ear have evolved with the appearance of vertebrates. In addition, it has remained unclear whether the ear originally arose through a modification of the amphibian mechanosensory lateral line system or whether both evolved independently. A comparison of the developmental mechanisms giving rise to both sensory systems in different species should help to clarify some of these controversies. During embryonic development, the inner ear arises from a simple epithelium adjacent to the hindbrain, the otic placode, that is specified through inductive interactions with surrounding tissues. This review summarises the embryological evidence showing that the induction of the otic placode is a multistep process which requires sequential interaction of different tissues with the future otic ectoderm and the recent progress that has been made to identify some of the molecular players involved. Finally, the hypothesis is discussed that induction of all sensory placodes initially shares a common molecular pathway, which may have been responsible to generate an 'ancestral placode' during evolution.     

Utilization of Defibrillators and Resynchronization Therapy at the Time of Evaluation at a Heart Failure and Cardiac Transplantation Center

Background: Internal cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality, but are underutilized in routine clinical practice. The use of these devices in patients at the time of an initial evaluation at an advanced heart failure and cardiac transplantation center is unknown. Methods: We retrospectively analyzed consecutive patients who were enrolled in a database examining parameters of cardiopulmonary exercise testing in chronic heart failure (CHF) patients at the time of an initial outpatient evaluation at a tertiary care center. Rates of ICD and CRT use in eligible patients were determined. Results: Two hundred two patients had an average age of 54 ± 13 years and an average peak oxygen consumption (pVO₂) of 12.5 ± 4.5 mL/kg/min. Of 97 patients eligible for an ICD only, 57% had an ICD at the time of evaluation. Sixty‐four percent of ICD‐eligible male patients had an ICD compared to 36% of ICD‐eligible female patients (P = 0.015). Of 105 patients meeting criteria for CRT, 54% had a CRT device. There was no difference between CRT use in eligible male and female patients. Conclusions: ICDs and CRT are underutilized in patients with severe CHF at the time of evaluation at a tertiary care center despite young age, objective functional limitation, and active consideration for advanced CHF therapies. Female patients have lower rates of ICD use than male patients. (PACE 2010; 988–993)     

Dissociation between Anterograde and Retrograde Conduction during Transvenous Cryoablation of Parahissian Accessory Pathways

Ablation of parahissian accessory pathways (APs) is a challenging procedure because of the high risk to provoke “iatrogenic” atrioventricular (AV) nodal block. The feasibility and safety of cryoablation (CA) have been already demonstrated both in patients with AV nodal reentry tachycardia and in those with anteroseptal APs. However, dissociation between anterograde and retrograde conduction after CA has not yet been described. We report two cases of CA of parahissian AP associated with transient dissociation between anterograde and retrograde conduction. (PACE 2011; 34:e98–e101)     

FLUMAZENIL IN ALCOHOL WITHDRAWAL: A DOUBLE-BLIND PLACEBO-CONTROLLED STUDY

The purpose of the present study was to study -aminobutyricacid (GABA)-A receptor function in alcohol-dependent subjectsduring withdrawal, using the benzodiazepine antagonist flumazenil.In particular, we wanted to examine the hypotheses that an endogenousinverse agonist ligand at the GABA-A benzodiazepine receptor(GBzR) is active during withdrawal (in which case flumazenilshould be anxiolytic), or whether chronic alcohol intake resultsin a shift in sensitivity of the receptor in the inverse agonistdirection (in which case flumazenil should be anxiogenic). Resultsfrom 15 alcohol-dependent subjects in a double-blind placebo-controlledcross-over study showed that flumazenil was neither anxiolyticnor anxiogenic, although withdrawal scores were reduced duringthe course of the study. The fact that flumazenil was not anxiogenic,as it is in panic disorder, suggests that the GBzR is functioningdifferently in these two clinically similar conditions.