Characteristics of Bifocal Pacing:

Bifocal RIGHT ventricular stimulation (BRIGHT) is an ongoing, randomized, single-blind, crossover study of atrial synchronized bi-right ventricular (RV) pacing in patients in New York Heart Association heart failure functional class III, a left ventricular ejection fraction <35%, left bundle branch block and QRS complexes ≥120 ms. This analysis compared the electrical and handling characteristics, and the complications of pacing at the RV apex (Ap) with passive, versus RV outflow tract (OT) with active fixation leads. A mean of 1.6 ± 0.9 and 2.2 ± 2.0 attempts were needed to position the Ap and OT leads, respectively (ns). R-wave amplitudes at Ap versus OT were 23 ± 13 mV versus 14 ± 8 mV (n = 36, P < 0.001). R-wave amplitudes at the Ap remained stable between implant and M7. R-wave amplitudes at the OT could not be measured after implantation. In two patients, atrioventricular block occurred during active fixation at the OT. Conduction recovered spontaneously within 4 months. Ventricular fibrillation was induced in one patient during manipulation of an Ap lead in the RV. Marked differences were found between leads positioned in the OT versus Ap, partly related to the difference in lead design. Mean R-wave amplitude was higher at the Ap that at the OT. Ease and success rate of lead implant was similar in both positions.     

RHEUMATOID ARTHRITIS PATIENTS COPING WITHOUT DRUG THERAPY

In view of the variable and unpredictable efficacy and toxicityof non-steroidal anti-inflammatory and disease-modifying anti-rheumaticdrugs, it is not surprising that some patients with rheumatoidarthritis elect to cope without recourse to these medications.We describe four of these patients, consider the lessons tobe learnt, and identify further research that needs to be doneon this aspect of illness behaviour. KEY WORDS: Rheumatoid arthritis, Drug regimens, Illness behaviour, Coping strategies     

Evidence for a light chain restriction of glycoprotein Ib/IX and Ilb/IIIa reactive antibodies in chronic idiopathic thrombocytopenic purpura (ITP)

To address the assumption of clonally restricted antibodies in immune thrombocytopenias we studied sera from 19 patients with chronic ITP known to possess antibodies reactive with glycoprotein (GP) Ib/IX and/or GPIIb/IIIa. These sera were re-analysed using the standard monoclonal antibody immobilization of platelet antigens (MAIPA) assay and 16 patients exhibited IgG antibodies reactive with GPIIb/IIIa; seven patients showed also a reactivity with GPIb/IX. Employing a light-chain-specific MAIPA assay, 75% (12/16) of these sera displayed GPHb/ Ilia-specific antibodies that were light chain restricted; only 13% (2/16) of the GPIIb/IHa reactive sera showed a mixed kappa and lambda phenotype. A light-chain-restricted phenotype was also seen for the GPIb/IX reactive antibodies. To further substantiate these findings, the MAIPA assay was modified in order to avoid interference from human anti-mouse antibodies. A high frequency of light-chain restricted platelet antibodies was also found using the modified MAIPA technique. These results support the hypothesis of a clonal B-cell expansion in immune thrombocytopenias, producing antibodies with a restricted idiotype repertoire and reacting with a limited number of epitopes.     

COSTS OF PROVIDING A RHEUMATOLOGICAL SERVICE

As a result of a management budgeting exercise, the costs ofrheumatology services in two hospitals in the Northern Regionhave been calculated. These comprehensive and itemized chargeswere derived by an external group of accountants. The data fora 1-year period from April 1985 are presented. Differences inboth mean out-patient-visit and in-patient bed-day charges betweenhospitals were found. Factors contributing to these differencesare discussed. The major costs, particularly of in-patient care,are not directly controllable by the clinician. Mean costs perout-patient visit were £26.00 and £36.90 at thetwo hospitals. Costs for in-patient care per bed-day were £49.00and £70.71, respectively. The calculated total cost ofthe rheumatology service in Newcastle was approximately £1.00per capita catchment population per annum. KEY WORDS: Management budgeting, Out-patient costs, In-patient costs, Intra- and inter-hospital differences     

Effects of Stimulation Site on Diastolic Function in Cardiac Resynchronization Therapy

Background : Cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function and clinical status, and prolongs survival of patients suffering from heart failure. An optimal LV site selection is key with respect to improvements in systolic function, though whether a site-specific effect on diastolic function exists is unclear. This study compared the effects of CRT on changes in systolic and diastolic function from 2 LV stimulation sites.
Methods : We studied 21 patients in New York Heart Association functional classes ≥III, and a LV ejection fraction <0.30 and QRS duration > 130 ms. CRT leads were placed in the right ventricle, right atrium, and coronary sinus tributaries. LV stimulation was applied from the postero-lateral and antero-lateral wall. A LV conductance catheter was used to measure LV systolic and diastolic function. Systolic responders had >10% changes in dP/dt_max, and diastolic responders <10% changes in τ during CRT versus baseline. Response was highly dependent on LV lead position for both diastolic and systolic function. Diastolic responders decreased from 29% to 10% of patients, and systolic responders from 76% to 48%, in the best versus the worst lead position, respectively. Improvements in diastolic function were less pronounced than in systolic function (relative change −14% vs +28%, P < 0.05). Overall, 45% were both systolic and diastolic responders, 17% were both systolic and diastolic nonresponders, and 38% had opposite responses .
Conclusions : Changes in systolic and diastolic function were both highly dependent on the LV stimulation site. Diastolic function was less influenced by CRT and a high proportion of patients had discordant results.