Propafenone-Induced Torsade de Pointes: Cross-Reactivity with Quinidine

A 77-year-oid/emale with new onset atrial fibrillation occurring in the absence of structural heart disease developed torsade de pointes during therapy with quinidine bisulfate 500 mg orally every 8 hours. Ten days after quinidine therapy had been discontinued she developed torsade de pointes while receiving propafenone 300 mg orally every 8 hours. This case demonstrates that propafenone may be associated with torsade de pointes and suggests a cross-reactivity between this effect and prior occurrence of torsade de pointes on Class IA antiarrhythmic drug therapy.     

Quinidine reduces biliary clearance of digoxin in man

Quinidine is known to reduce the renal clearance of digoxin, but this effect does not completely explain the influence of quinidine on the total clearance of digoxin. We therefore studied the effect of quinidine administration on biliary clearance of digoxin in five patients with atrial fibrillation. Biliary clearance of digoxin under steady state conditions before and during treatment with quinidine was investigated using a duodenal-marker-perfusion technique. Quinidine caused an average 42% (range 21-65%, P less than 0.02) reduction of the measured biliary clearance of digoxin. We conclude that the biliary effect adds to the previously demonstrated inhibitory effect of quinidine on the renal clearance of digoxin and helps to explain the decrease in total clearance of the drug. This is the first demonstration in man of a pharmacokinetic drug interaction at the level of biliary excretion.     

Transient Data Stream Dissociation in Computerized Data Acquisition System Masquerading as a Sensing Abnormality

During testing of a CPI model 1715 ICD, an apparent sensing abnormality was noted following shock delivery for VF. Close inspection of the recording prior to the defib-rillation attempt revealed that the surface leads spontaneously lost 848 ms of data while the event marker was unaffected. Computer simulations revealed that an inadequate buffer size for the ampHfied (surface ECC) data was the likely source of data loss. It is important to recognize tbat a discordance between surface leads and event marker may represent an abnormality in tlie data acquisition system and simulate an ICD or lead malfunction.     

Age‐Specific Differences in Women with Implantable Cardioverter Defibrillators: An International Multi Center Study

Background: Common psychological adjustment difficulties have been identified for groups of implantable cardioverter defibrillator patients, such as those who are young (<50 years old), have been shocked, and are female. Specific aspects and concerns, such as fears of death or shock and body image concerns, that increase the chance of distress, have not been examined in different aged female implantable cardioverter defibrillator (ICD) recipients. The aim of the study was to investigate these areas of adjustment across three age groups of women from multiple centers. Methods: Eighty‐eight female ICD patients were recruited at three medical centers: Shands Hospital at the University of Florida, Brigham and Women's Hospital in Boston, and Royal North Shore Hospital in Sydney, Australia. Women completed individual psychological assessment batteries, measuring the constructs of shock anxiety, death anxiety, and body image concerns. Medical record review was conducted for all patients regarding cardiac illnesses and ICD‐specific data. Results: Multivariate and univariate analyses of variance revealed that younger women reported significantly higher rates of shock and death anxiety (Pillai's F = 3.053, P = 0.018, η²_p= 0.067) and significantly greater body image concerns (Pillai's F = 4.198, P = 0.018, η²_p= 0.090) than middle‐ and older‐aged women. Conclusions: Women under the age of 50 appear to be at greater risk for the development of psychosocial distress associated with shock anxiety, death anxiety, and body image. Clinical‐based strategies and interventions targeting these types of adjustment difficulties in younger women may allow for improved psychosocial and quality of life outcomes.     

Mycobacterial Infections After Renal Transplantation

Mycobacterial infections occurred in 11 of 633 (1.7 per cent)recipients of successful renal transplants. There were no casesof tuberculosis in patients receiving chemoprophylaxis, butamongst those who did not receive prophylaxis disease occurredin six of the 27 (22 per cent) high-risk patients. The majorcause of morbidity during treatment was renal allograft rejection,largely due to reduction in immunosuppressive drug therapy.     

Gender Differences in the Clinical Characteristics and Atrioventricular Nodal Conduction Properties in Patients With Atrioventricular Nodal Reentrant Tachycardia

Gender Differences in Patients With AVNRT. Introduction: The detailed electrophysiological characteristics of the gender differences associated with atrioventricular nodal reentrant tachycardia (AVNRT) have not been clarified. This study investigated the gender‐related electrophysiological differences in a large series of patients undergoing radiofrequency catheter ablation. Methods and Results: A total of 2,088 consecutive AVNRT patients (men/women 869/1,219) who underwent catheter ablation were enrolled in this study. We evaluated the gender differences in their electrophysiological characteristics. Women had a significantly younger age of onset, higher incidence of multiple jumps, shorter AH interval, atrial effective refractory period (ERP), anterograde fast pathway ERP, anterograde slow pathway ERP, and retrograde slow pathway ERP, and longer ventricular ERP than men. The incidence of baseline ventriculoatrial dissociation was lower in women than in men. Women needed less isoproterenol/atropine to induce AVNRT. No gender differences in the radiation exposure time, procedure time, complication rate, acute success rate, or second procedure rate were noted. Both typical and atypical AVNRT were more predominant in women. In the patients with atypical AVNRT, there was no significant gender difference in incidence of baseline ventriculoatrial dissociation; however, the retrograde slow pathway ERP was significantly shorter in women than in men. Women of premenopausal age (≤50 years old) had a significantly higher incidence of anterograde multiple jumps and a retrograde jump phenomenon, and a shorter anterograde slow pathway ERP and retrograde slow pathway ERP than those of women over 50 years old. Conclusion: Gender differences in the anterograde and retrograde AV nodal electrophysiology were noted in the patients with AVNRT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1114‐1119)     

The Novel Electrophysiology of Complex Fractionated Atrial Electrograms: Insight from Noncontact Unipolar Electrograms

Unipolar Characteristics of CFAEs. Background: The noncontact mapping (NCM) system possesses the merit of global endocardial recording for unipolar and activation mapping. Objective: We aimed to evaluate the unipolar electrogram characteristics and activation pattern over the bipolar complex fractionated atrial electrogram (CFAE) sites during atrial fibrillation (AF). Methods: Twenty patients (age 55 ± 11 years old, 15 males) who underwent NCM and ablation of AF (paroxysmal/persistent = 13/7) were included. Both contact bipolar (32–300 Hz) and NCM virtual unipolar electrograms (0.5–300 Hz) were simultaneously recorded along with the activation pattern (total 223 sites, 11 ± 4 sites/patient). A CFAE was defined as a mean bipolar cycle length of ≤ 120 ms with an intervening isoelectric interval of more than 50 ms (Group 1A, n = 63, rapid repetitive CFAEs) or continuous fractionated activity (Group 1B, n = 59, continuous fractionated CFAEs), measured over a 7.2‐second duration. Group 2 consisted of those with a bipolar cycle length of more than 120 ms (n = 101). Results: The Group 1A CFAE sites exhibited a shorter unipolar electrogram cycle length (129 ± 11 vs 164 ± 20 ms, P < 0.001), and higher percentage of an S‐wave predominant pattern (QS or rS wave, 63 ± 13% vs 35 ± 13%, P < 0.001) than the Group 2 non‐CFAE sites. There was a linear correlation between the bipolar and unipolar cycle lengths (P < 0.001, R = 0.87). Most of the Group 1A CFAEs were located over arrhythmogenic pulmonary vein ostia or nonpulmonary vein ectopy with repetitive activations from those ectopies (62%) or the pivot points of the turning wavefronts (21%), whereas the Group 1B CFAEs exhibited a passive activation (44%) or slow conduction (31%). Conclusions: The bipolar repetitive and continuous fractionated CFAEs represented different activation patterns. The former was associated with an S wave predominant unipolar morphology which may represent an important focus for maintaining AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 640‐648, June 2010)     

1992 and the Consumer

This paper summarises the journey so far towards the ‘single market’. Consumers may expect to benefit from increased choice and cheaper prices but the possibility that quality, as judged by % of characterising ingredient, will be lowered, is a cause for concern. The consumer will have to rely increasingly on labels, assuming that the label information is adequate. Quantitative ingredient information is desirable but provides technical difficulties for manufacturers. A voluntary ‘quality mark’ scheme could be a satisfactory replacement for compositional standards but would have to be carefully controlled by independent assessors. The abolition of frontier controls creates a dilemma between the desire to have free trade within the community and the need to give a high priority to public health.