Reappraisal of the Traditional Wenckebach Phenomenon with a Modified Ladder Diagram

Understanding of the traditional Wenckebach phenomenon is enhanced by using a modified ladder diagram where AV conduction in any cycle is represented by a slanted line in the AV bar together with similar AV conduction lines of all the preceding cycles. The diagram facilitates calculation of the duration of RR intervals (equal to the basic PP or sinus interval minus the PR or AV increment applied to this particular cycle) and the duration of the pause (equal to 2 × PP or sinus interval minus the sum of all the increments applied to the AV delay). The modified Wenckebach diagram should help students understand the mysterious clustering of QRS complexes or “paradoxical” increase of the ventricular rate that occurs during a Wenckebach sequence. Ann Noninvasive Electrocardiol 2012;17(1):3–7     

A mixed method evaluation of a group‐based educational programme for CPAP use in patients with obstructive sleep apnea

Rationale, aims and objectives Continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) has a low long‐term adherence. Educational interventions are few and sparsely described regarding content, pedagogical approach and participants' perceptions. The aim was to describe adherence to CPAP treatment, knowledge about OSA/CPAP, as well as OSA patients' perceptions of participating in a group‐based programme using problem‐based learning (PBL) for CPAP initiation. Educational programme The PBL programme incorporated elements from theories and models concerning motivation and habits. Tutorial groups consisting of four to eight patients met at six sessions during 6 months. Methods A sequential explanatory mixed method design was used on 25 strategically selected patients. Quantitative data regarding, clinical variables, OSA severity, CPAP use, and knowledge were collected at baseline, after 2 weeks and 6 months. Qualitative data regarding patients' perceptions of participation were collected after 6 months by semi‐structured interviews using a phenomenographic approach. Results 72% of the patients were adherent to CPAP treatment after 2 weeks and 6 months. All patients improved their baseline knowledge about OSA and CPAP after 2 weeks and sustained it after 6 months. Anxiety and fear, as well as difficulties and needs were motivational factors for participation. Patients described the difficulties of behavioural change, an awareness that improvements do not occur immediately, a realization of the importance of both technical and emotional support and the need for a healthier lifestyle. Conclusion and practice implications A group‐based programme using PBL seems to facilitate adaptive and developmental learning and result in acceptable CPAP adherence levels.     

Addressing the psychosocial needs of cancer patients: a retrospective analysis of a distress screening and management protocol in clinical care

Background: A growing recognition of the impact of distress on the quality of life and adherence to treatment of cancer patients has been documented. As a result, national guidelines and standards of care mandate providers to implement distress screening protocols to connect patients with psychosocial services. However, limited literature has examined whether distressed patients are referred to care and their needs addressed. This article assessed differences in rates of referral and psychosocial services by demographic factors, clinical characteristics, and distress severity. Potential predictors of these two outcomes were investigated.

Methods: A retrospective analysis of patient data abstracted from electronic medical records of a NCI-designated Academic Comprehensive Cancer Center was conducted. Of the 399 cases meeting the inclusion criteria, 302 (75.7%) were screened for distress with the Distress Thermometer. Differences were examined with chi-square, t-tests, and ANOVAs. Predictors were identified with multivariate logistic regressions.

Results: Overall, patients who were identified as distressed were referred to a psychosocial provider (71.4%) and psychosocial services were delivered in approximately 64% of the cases. Referrals and service delivery rates varied by age group, clinic, health insurance coverage, distress severity, and presence of psychosocial issues. Only the distress score predicted the likelihood of being referred, and of a provider intervention to occur.

Conclusions and implications for psychosocial providers: Although the protocol appeared to facilitate referral and service delivery to patients scoring above the cutoff for distress, our results suggest that patients were more likely to not have their distress and psychosocial needs addressed if they were older, without insurance coverage, and were seen in clinics where a social worker was not consistently available. Future studies able to monitor patient outcomes in terms of quality of life, satisfaction with care, and service utilization are recommended.     

Qualität und Wirtschaftlichkeit

Ohne Zusammenfassung     

Long-term outcome in relation to renal sympathetic activity in patients with chronic heart failure.

AIMS: Although cardiac sympathetic activation is associated with adverse outcome in patients with chronic heart failure (CHF), the influence of renal sympathetic activity on outcome is unknown. We assessed the hypothesis that renal noradrenaline (NA) spillover is a predictor of the combined endpoint of all-cause mortality and heart transplantation in CHF. METHODS AND RESULTS: Sixty-one patients with CHF, New York Heart Association (NYHA) I-IV (66% NYHA III-IV), and left ventricular ejection fraction (LVEF) 26+/-9% (mean+/-SD) were studied with cardiac and renal catheterizations at baseline and followed for 5.5+/-3.7 years (median 5.5 years, range 12 days to 11.6 years). Nineteen deaths and 13 cases of heart transplantation were registered. Only renal NA spillover above median, 1.19 (interquartile range 0.77-1.43) nmol/min, was independently associated with an increased relative risk (RR) of the combined endpoint (RR 3.1, 95% CI 1.2-7.6, P=0.01) in a model also including total body NA spillover, LVEF, glomerular filtration rate (GFR), renal blood flow, cardiac index, aetiology, and age. CONCLUSION: Renal noradrenergic activation has a strong negative predictive value on outcome independent of overall sympathetic activity, GFR, and LVEF. These findings suggest that treatment regimens that further reduce renal noradrenergic stimulation could be advantageous by improving survival in patients with CHF.     

Transendothelial transport: the vesicle controversy

The relative contribution of transcytosis vs. large pore transport to the passage of macromolecules across microvascular endothelia has been a controversial issue for nearly half a century. To separate transcytosis from 'porous' transport, the transcytosis inhibitors N-ethylmaleimide (NEM) and filipin have been tested in in situ or ex vivo perfused organs with highly conflicting results. In continually weighed isolated perfused organs, where measurements of pre- and post-capillary resistances, capillary pressure and capillary filtration coefficients can be repeatedly performed, high doses of NEM and filipin increased the bulk transport of macromolecules from blood to tissue, despite producing vasoconstriction. By contrast, in in situ perfused organs, marked reductions in the tissue uptake of albumin tracer have been observed after NEM and filipin. When tissue cooling has been employed as a means of inhibiting (active) transcytosis, results have invariably shown a low cooling sensitivity of albumin transport, compatible with passive transendothelial passage of albumin. This observation is further strengthened by the commonly observed dependence of albumin transport upon the capillary pressure and the rate of transcapillary convection. For low-density lipoprotein (LDL), a cooling-sensitive, non-selective transport component has been discovered, which may be represented by filtration through paracellular gaps, lateral diffusion through transendothelial channels formed by fused vesicles, or by transcytosis. From a physiological standpoint there is little evidence supporting active transendothelial transport of most plasma macromolecules. This seems to be supported by studies on caveolin-1-deficient mice lacking plasmalemmal vesicles (caveolae), in which there are no obvious abnormalities in the transendothelial transport of albumin, immunoglobulins or lipoproteins. Nevertheless, specific transport in peripheral capillaries of several hormones and other specific substances, similar to that existing across the blood-brain barrier, still remains as a possibility.