Mechano-energetics of the asynchronous and resynchronized heart

Abnormal electrical activation of the ventricles creates major abnormalities in cardiac mechanics. Local contraction patterns, as reflected by measurements of local strain, are not only out of phase, but often also show opposing length changes in early and late activated regions. As a consequence, the efficiency of cardiac pump function (the amount of stroke work generated by a unit of oxygen consumed) is approximately 30% lower in asynchronous than in synchronous hearts. Moreover, the amount of work performed in myocardial segments becomes considerably larger in late than in early activated regions. Cardiac Resynchronization Therapy (CRT) improves mechano-energetics of the previously asynchronous heart in various ways: it alleviates impediment of the abnormal contraction on blood flow, it increases myocardial efficiency, it recruits contraction in the previously early activated septum and it creates a more uniform distribution of myocardial blood flow. These factors act together to increase the range of cardiac work that can be delivered by the patients’ heart, an effect that can explain the increased exercise tolerance and quality of life reported in several CRT trials

Identity Disturbances and Self-other Differentiation in Schizophrenics, Borderlines, and Normal Controls

The present study investigates identity disorders in schizophrenics and borderlines. Nineteen schizophrenics and 17 borderlines were compared with 18 normal controls. The technique used was an adapted version of the repertory grid test to describe the self and nine significant others (i.e., family members). Three indices were derived from the 10 person x 20 self-generated-attribute matrix to measure the extent to which self was differentiated from others: (1) overlap of salient attributes, (2) overlap of opposite attributes, and (3) degree of differentiation among others. Results showed that both schizophrenics and borderlines describe themselves more in terms of opposites than in terms of salient attributes. Differentiation among significant others was severely impaired in schizophrenics and preserved in borderlines. These findings were interpreted as a failure of the individuation process in schizophrenics and as an incomplete construal of self-identity in borderlines. (C) 1995 by W.B. Saunders Compan

Validation of non invasive pressure/flow relationship in pulmonary hypertension. echocardiography vs catheterisation

info:eu-repo/semantics/nonPublishe