Bioavailability of Hydrocortisone Retention Enemas in Normal Subjects

The bioavailability of two commercial formulations of hydrocortisone rectal enemas, Rectoid® and Cortenema,® was determined in 12 normal volunteers. Relative to an intravenous dose, 50–90% of a dose given rectally was available to the systemic circulation in most subjects provided the retention time exceeded eight hours. The bioavailability and retention times of both enemas were similar. The results suggest that the likelihood for adrenal suppression from hydrocortisone rectal enemas is similar to that resulting from equal doses of oral hydrocortisone.     

Fasciola hepatica: comparison of immature and mature immunoreactive glycoproteins

A comparison of the 35S-methionine metabolically labelled immunoreactive glycoproteins of immature and mature F. hepatica was carried out by one-and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sera of rabbits infected for 3 weeks reacted much more strongly with glycoproteins of immature flukes than with glycoproteins of mature flukes as compared to sera of rabbits infected for 9 weeks. Several of the immunoreactive glycoproteins were also released by immature F. hepatica into the culture medium. At least one was a component of the T1 type granules. Analysis of the in vitro translation products of mature F. hepatica indicated that the initial humoral immune response of rabbit hosts may be directed against carbohydrate moieties.     

Safety and Effectiveness of Transvenous Lead Extraction in Octogenarians

Transvenous Lead Extraction . Introduction: As the population ages, the number of elderly patients with implantable cardiac devices referred for transvenous lead extraction will dramatically increase in Western countries. The safety and effectiveness of lead extraction in elderly patients has not been well evaluated. We report the safety and effectiveness of transvenous lead extraction in octogenarians. Methods and Results: From January 2005 to January 2011, we reviewed data from consecutive patients ≥ 80 years referred to our institutions for transvenous lead extraction because of cardiac device infection or lead malfunction. Clinical characteristics, procedural features, and periprocedural major and minor complications were compared between octogenarians and younger patients. Out of 849 patients undergoing lead extraction in the participating institutions during the study period, 150 (18%) patients were octogenarians (mean age 84 years; range 80–96; 64% males). A significantly higher percentage of octogenarians presented with chronic renal failure (55% vs 26%; P < 0.001), history of malignancy (22% vs 6%; P < 0.001), and chronic obstructive pulmonary disease (46% vs 19%; P < 0.001). Complete lead extraction rates were similar in the 2 age groups (97% in octogenarians vs 96% in patients <80 years; P = 0.39). Periprocedural death occurred in 2 (1.3%) patients ≥80 years and in 5 (0.72%) patients <80 years (P = 0.45 for comparison). No differences in terms of other periprocedural major and minor complications were found between the 2 age groups. Conclusion: Despite presenting with a significantly higher rate of comorbidities, transvenous lead extraction can be performed safely and successfully in octogenarians. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1103‐1108, October 2012)     

Treatment of Patients with Prior Exit Block Using a Novel Steroid-Eluting Active Fixation Lead

An increased interest has developed in active fixation leads for several reasons. Exit block is an uncommon complication that is seen with both active and passive fixation leads. Exit block has not been a significant problem with passive fixation steroid-eluting leads and has been treated with these leads. A new steroid-eluting active fixation lead was examined for its performance in patients in whom exit block had previously occurred. The lead function was evaluated prospectively in 24 patients with a history of exit block (15 ventricular and 9 atrial). The results in patients with atrial exit block are encouraging with an average chronic stimulation threshold of 0.19 msecs at 2.5 volts. Results in the ventricle are less encouraging with 3 occurrences of recurrent exit block in 15 patients; however, the remaining patients had a good mean threshold of 0.21 ±0.11 msecs at 2.5 volts. There were a remarkable number of non–lead related complications suggesting that this is a substantially different group than routine implantations.     

Rectus Abdominis as a Source of Myopotentials Inhibiting Demand Pacemakers

We examined four patients with a demand pacemaker who exhibited transient symptoms of vertigo while trying to rise from the supine position. In two of these there was an epicardial pacing system with the pacemaker in the abdominal wall superficial to the rectus abdominis muscle; in the other two cases the pacing system was transvenous with the pacemaker superficial to the right pectoralis major muscle. It was found that the "pseudovertigo" was due to pacemaker inhibition caused by rectus abdominis myopotentials in all four patients. Changing the pacing mode from demand to fixed-rate resulted in the disappearance of all symptoms at rest and during exercise.     

A Permanently Implanted Endocardial Electrode Complicating Ventricular Tachycardia with A Second VT

A VVI pacemalter was permanently implanted for the purpose of suppressing recurrent ventricular tachycardia (VT). Not only did the device fail to suppress the VT, but also the permanent endocardial electrode caused a second VT which was more rapid and clinically more severe. When a new VT occurs in the presence of a permanently implanted ventricular pacing system, the implanted electrode should he considered as one of the possible etiologic causes for the VT.     

Recipient to Donor Conduction of Atrial Tachycardia Following Orthotopic Heart Transplantation

We report a case of atrial tachycardia in a 60-year-old male 8 years postorthotopic heart transplantation. At electrophysiology study, the clinical rhythm was found to arise from the remnant of the recipient atrium and was successfully terminated by delivery of radiofrequencv energy. Surgical scars formed at the anastomosis of the recipient and donor atrium during the time of orthotopic heart transplantation are thought to electrically isolate the two areas. Although rarely recognized, dysrhythmias originating from the recipient atrial remnant may occur more often than previously thought.     

Intravascular Extraction of Chronic Pacemaker Leads: Efficacy and Follow-Up

Extraction of chronic pacemaker leads has been recommended for infections, prevention of venous thrombosis, migration, and possible perforation. Success with constant traction techniques has been variable, and the cost and morbidity of open chest surgical procedures are prohibitive. Efficacy of a new system for lead extraction using intravascular techniques was analyzed. The system (Cook Pacemaker) uses a locking stylet, which is secured at the distal electrode by counterclockwise rotation to reinforce the lead and facilitate traction, and dilator sheaths that are used to free the lead from adhesions in the venous system. In a series of 56 patients (ages 19–88)who presented for lead extraction because of erosion (5), infection (14), lead replacement (35), or other (2), 86 leads were extracted. Thirty-two were atrial leads and 54 ventricular; 23 had active fixation and 63 passive. Average duration of implant was 58 ±42 months (range 1–264). Eighty-four leads were totally removed and two partially removed. For these two leads, the distal tip was not removed; in both cases the locking stylet was not secured at the distal electrode due to obstruction within the lead. Two patients developed arm edema following the procedure, which resolved with elevation. One patient developed a subclavian thrombosis, which resolved with warfarin anticoagulation. Four patients have expired due to unrelated causes. In conclusion, this intravascular approach for extraction of chronic leads is effective, and the procedure is safe when performed by experienced personnel.