Prolongation of conduction time during premature stimulation in the human afrium is primarily caused by local stimulus response latency

BACKGROUNDS: Conventional clinical electrophysiological techniques cannotaccurately differentiate between local stimulus response latencyand propagation time of the atrial response. The purpose ofthis study was to identify and distinguish local stimulus responselatency from impulse propagation time in the human right atriumduring programmed electrical stimulation. METHODS: Pacing was performed from two atrial sites (high and low rightatrium) in 19 patients, using monophasic action potential recording/pacingcombination catheters (interelectrode distance <2 mm). Localstimulus response latency (interval between stimulus art factand upstroke of the local monophasic action potential), andpropagation time (interval between local and remote monophasicaction potential upstroke) were evaluated at a basic cycle length(Sl–SI) of 600 ms and as a function of the extrastimulusproximity (interval between extrastimulus and effective refractoryperiod). Data are presented as means ± SEM. RESULTS: During basic stimulation, local latency was very small (3·8± 1·7 ms). During premature extrastimulation (proximity<70 ms), local latency increased progressively with decreasingcoupling intervals. Prolongation of local latency was most pronouncedduring stimulation close to the effective refractory periodwith local stimulus response latency increasing to 18·3± 1·4 ms (380 ± 7·9%) at 10 ms proximity(P<0·002) and to 27·9 ± 3·7 ms(630 ± 13·2%) at 5 ms proximity, respectively(P<0·0001). The impulse propagation time between thestimulation site and the remote recording site was on average54·5 ± 14·3 ms during basic stimulation,and increased up to 62·1 ± 13·5 ms (14·0± 8·4%), which was not significant. CONCLUSIONS: The intra-atrial impulse propagation remained essentially unchangedduring the entire range of premature stimulation. Local stimulusresponse latency was negligible and constant during late couplingintervals but increased dramatically when extrastimulation approachedthe preceding repolarization phase. This has the following clinicalimpact: first, local stimulus response latency during prematureextrastimulation curbs the targeted a trial response interval;second, local stimulus response latency, not propagation time,seems responsible for the greater functional than effectiverefractory period during electrical stimulation; third, localstimulation; response latency should be considered in pace mappingfor accurate comparison of conduction time before pacing withthat during pacing.     

Key challenges facing American nurse leaders

What are the key challenges facing nurse leaders in the United States? To find out, I asked 20 prominent nurse leaders to respond to that question and tell me their top three issues. Their voices tell a compelling story on challenges faced by the nurse leaders in American healthcare. The focus is no longer just on the process of how care is delivered, but on the outcomes of that care. More attention is being given to documenting that the care is provided according to specific standards associated with better outcomes. Many of the standards are directly related to the care given by nurses, including some indicators that are specifically sensitive to nurse intervention. There is also a new focus on federal reporting of patient satisfaction with the services provide. Producing quality outcomes, high patient satisfaction and effective measurements of both are now a central theme for the entire hospital administrative team. For the nurse leader, however, it represents explicit accountability for managing and leading the staff responsible for providing the patient care. Safety and quality issues are directly linked to financial pressure. Reimbursement for hospital is being whittled away as financial accountability for services receives greater scrutiny from the federal government and private insurers. Close on the heels of the financial challenge is the ever present workforce shortage. The most troublesome challenge identified by these nurse leaders is the absence of an adequate pipeline for nursing leaders. It is an exciting time for nursing in the United States. Challenges to be sure, but these nurse leaders have identified the priorities that will create a successful future.     

Purchasing services to promote the sexual health of young people - contraceptive care for teenagers: A review of the published literature to inform a Regional Health Gain Investment Programme

Sexually active teenagers need a choice of accessible and acceptableservices to provide contraceptive care and advice. This paperpresents examples of good practice in providing care for youngpeople in community settings in the UK but the same models ofcare could be adopted by other European countries. The publishedliterature suggests that informal and drop-in services are needed,with the guarantee of confidentiality to the young person. Afull range of contraceptive care and sexual health promotionshould be available and staff should have expertise in dealingwith young people. All local agencies should work together toincrease knowledge and uptake of such services. Purchasers andproviders of health care should agree a model of care whichis related to local health needs.     

Sudden Cerebral Vasoconstriction During Induced Polymorphic Ventricular Tachycardia and Fibrillation: Further Observations of a Paradoxic Response

To determine the effect of induced polymorphic VT/VF on the cerebral circulation, transcranial Doppler (TCD) ultrasonography was used to prospectively assess changes in cerebral blood flow velocity during ICD implantation. Fourteen patients (13 men, 1 woman, mean age 58 ± 20 years, range 34-74 years) who were survivors of an out of hospital cardiac arrest, were evaluated during routine ICD implantation. TCD ultrasonography was used to assess middle cerebral artery systolic velocity (V_s), diastolic velocity (Vd), pulsatility index (PI = V_s– V_d/V_mean) and resistance index (RI = V_s-V_alV_s) before, during, and after DFT testing with alternating current induction of polymorphic VT/VF. In each of the 14 patients studied, concomitant with the abrupt onset of hypotension, TCD sonography demonstrated a 33%± 28% decrease in diastolic velocity, a 42%± 28% increase in systolic velocity, a 190%± 141% increase in FI, and a 44%± 19% increase in RI. These findings reflect an increase in cerebrovascular resistance secondary to arteriolar vasoconstriction distal to the point of insonation of the middle cerebral artery. This response is paradoxic, as the expected response of the cerebral circulation to hypotension is vasodilation, but it is consistent with observations made in other acute hypotensive settings, such as tilt induced neurocardiogenic syncope.     

Factors influencing intentions to stay and retention of nurse managers: a systematic review

Aims This systematic review aimed to explore factors known to influence intentions to stay and retention of nurse managers in their current position. Background Retaining staff nurses and recruiting nurses to management positions are well documented; however, there is sparse research examining factors that influence retention of nurse managers. Evaluations Thirteen studies were identified through a systematic search of the literature. Eligibility criteria included both qualitative and quantitative studies that examined factors related to nurse manager intentions to stay and retention. Quality assessments, data extraction and analysis were completed on all studies included. Twenty-one factors were categorized into three major categories: organizational, role and personal. Key issues Job satisfaction, organizational commitment, organizational culture and values, feelings of being valued and lack of time to complete tasks leading to work/life imbalance, were prominent across all categories. Conclusion These findings suggest that intentions to stay and retention of nurse managers are multifactoral. However, lack of robust literature highlights the need for further research to develop strategies to retain nurse managers. Implications for nurse management Health-care organizations and senior decision-makers should feel a responsibility to support front-line managers in relation to workload and span of control, and in understanding work/life balance issues faced by managers.