Catecholamine Levels and Pacing Behavior of QT-Driven Pacemakers During Exercise

It is thought that increasing catecholamine levels in the heart are partly responsible for shortening of the repolarization time and so indirectly for the pacing behavior of the QT driven pacemaker. Adrenaline and noradrenaline (NA) plasma levels were determined at rest, during symptom-limited exercise, and during recovery more than 1 month after the implantation of a 919 or a Rhythmyx pacemaker (Vitatron, The Netherlands) in eight patients (age 54-85 yrs). Significant increases were detected in NA level (from 0.57 +/- 0.23 ng/mL to 2.15 +/- 0.76 ng/mL), but not in the circulating adrenaline level. The correlation coefficient of the mean pacing rate and the mean NA level during exercise and recovery was 0.963 (P less than 0.0001), the correlation coefficient with the mean oxygen consumption was 0.888 (P less than 0.01). No correlation with the adrenaline level was observed. The correlation coefficient of the changes of pacing rate and the changes of NA level during exercise and recovery was 0.882 (P less than 0.005). The pacing rate of the new generation of QT driven pacemakers is closely correlated with the noradrenaline spillover in the plasma, not with the adrenaline level. A short delay (less than 1 minute) is observed in the adaptation.     

Primary Sepsis Presenting as Fulminant Hepatic Failure

Four patients who were referred to the Liver Failure Unit withan initial diagnosis of fulminant hepatic failure were foundto have severe bacterial infeclion from a primary septic focusas the cause of their illness. Clinical and biochemical characteristicswere not helpful in differentiating these patients from thosewith hepatic failure from other causes, and only a high degreeof suspicion will prevent delay in the diagnosis of underlyingsepsis and initiation of appropriate treatment. The possiblemechanisms respomible for this uncommon association are discussed.     

Uptake in breast cancer screening: A sociogeographical analysis

During the period 1992 to 1994, the female population aged 40to 69 years old and living in Gent, Belgium, was invited througha personal letter to participate in a breast cancer screeningprogramme. The women were asked to consult a physician beforereferral to a local radiologist. After six months, a reminderletter was sent. The eligible population amounted to 40,713women. Of these, 22.5% were recorded to have attended for ascreening mammography. The uptake levels were analysed per statisticalsector, which is a more or less homogeneous quarter in socialrespect. The age-standardized participation ranged from 6 to42% among the 150 sectors taken into account. The participationwas definitely highest in well-to-do neighbourhoods and lowestin the poorer inner-city quarters. In a multivariate analysis,social exclusion indicators such as percentage of persons onwelfare and percentage of unoccupied dwellings ranked first.On condition that this social gradient is confirmed on an individualbasis, sociogeographical analysis may well be a powerful toolin area-based health promotion campaigns.     

Combination of Flecainide and Mexiletine for the Treatment of Ventricular Tachyarrhythmias

A combination of oral flecainide and mexiletine was given to 11 patients in whom monotherapy with one of these drugs was ineffective for the suppression of inducible ventricular tachycardia or fibrillation. In eight of 11 studies, combination therapy prevented inducibility of a sustained ventricular tachycardia or resulted in induction of only nonsustained tachycardia (P = 0.0003, when compared to monotherapy). In one patient, a slow ventricular tachycardia was induced. During exercise testing ventricular tachycardia occurred in two of these nine patients, and ventricular fibrillation in another patient. Seven patients received combination on the long term, for a mean of 18 months. One patient had recurrences of ventricular tachycardia which was well tolerated. Another patient had a recurrent episode of ventricular fibrillation, but was successfully resuscitated. Severe congestive heart failure occurred in two patients. ACE inhibitors were given to them and to another four patients. No other important unwanted effects occurred. The combination of mexiletine and flecainide is very effective in suppressing inducible sustained ventricular tachycardia. The efficacy of this combination to prevent recurrences of ventricular tachyarrhythmias is acceptable. Exercise testing is of importance to unmask proarrhythmic effects before discharge from hospital.     

Scabies with Clinical Features and Positive Darier Sign Mimicking Mastocytosis

Abstract:  Scabies is a common human parasitic infection in infants and children. But diagnosis pitfalls are frequent in infants, in whom the clinical presentation is usually atypical and different from adults. We report a misleading case of a 5-month-old child, who presented with pruritic brown–red macules of the trunk showing a positive Darier's sign, suggestive of an urticaria pigmentosa.     

Remote Monitoring of Implantable Cardioverter Defibrillators:

A prospective study evaluating the functionality and ease of use of the Medtronic CareLink^® Network, "CareLink," was conducted at ten investigational sites. This internet-based remote monitoring service allows clinicians to remotely manage their patients' implantable cardioverter defibrillators (ICDs) and chronic diseases. The network is comprised of a patient monitor, a secure server, and clinician and patient websites. Under clinician direction, patients interrogated their ICDs at home, and transmitted data to secure servers via a standard telephone line. Comprehensive device data and a 10-second presenting rhythm electrogram were captured by the monitor and available for access and review on the clinician website. The information could also be printed using a standard desktop computer with internet access. During this study, patients were asked to transmit device data twice, at least 7 days apart, as scheduled by the clinic. Monitor functionality was assessed, and ease of using the system components was evaluated via questionnaires completed by patients and clinicians following each data transmission and review. Fifty-nine patients (64 ± 14 years, range 22-85 years) completed 119 transmissions with only 14 calls to the study support center. Clinician review of data transmissions revealed several clinically significant findings, including silent AF discovery, assessment of antiarrhythmic drug efficacy in a previously diagnosed AF patient, previously unobserved atrial undersensing, and ventricular tachycardia. ICD patients found the monitor easy to use. Clinicians were pleased with the performance of the network and the quality of the web-accessed data, and found it comparable to an in-office device interrogation. CareLink is a practical tool for routine device management and may allow timely identification of clinically important issues. (PACE 2004; 27[Pt. I]:757–763)