Safe Release of Impacted Pacemaker Electrodes

If the original electrode is damaged during pacemaker replacement for battery depletion, the operation becomes substantially more involved and hazardous. By drilling a hole in the back of the electrode connector housing and inserting an Allen wrench into the drill hole, an impacted electrode hub can be pushed free without placing stress on the electrode components. This technique is recommended whenever an electrode hub cannot be easily removed from a pacemaker during a replacement operation, as traction on the electrode not infrequently results in gross or occult damage to the Silastic sheath or conductive elements.     

Improved silastic sleeve temporary cardiac pacing electrodes

New atrial clip-on and ventricular suture-on temporary pacemaker electrode systems were evaluated in dogs. The ability of these electrodes to sense cardiac electrical activity was evaluated during a 14-day period. At no time did the P-wave potential fall below 3.3 mV and the R-wave potential fall below 6.0 mV. The acute pacing thresholds never exceeded 1.025 V and 1.95 mA. All values are well within acceptable standards for temporary pacing. The lead wires were easily, quickly, and painlessly removed without injury to the myocardium, yet the electrical contact remained tight between the lead wire and electrode preventing premature displacement.     

Cardiac arrhythmias and conduction disturbances in the sleep apnea syndrome: Prevalence and significance

The results of 24-hour continuous electrocardiographic monitoring of 23 patients with documented sleep apnea syndrome were reviewed to evaluate the prevalence of cardiac arrhythmias and conduction disturbances in this disorder. During sleep, marked sinus arrhythmia (more than 30 beats/min variation) was found in 18 patients. Extreme sinus bradycardia (heart rate less than 30 beats/min) and sinus pauses (more than 1.8 sec) were found in only two patients. First-degree and type I second-degree atrioventricular block were found in another patient. There was a decrease in grade of ventricular ectopy from wakefulness to sleep. These data suggest that the prevalence of serious arrhythmias and conduction disturbances during sleep in patients with the sleep apnea syndrome is much lower than previously reported.     

Pulmonary function abnormalities after infusion of antihemophilic factor (AHF) concentrates.

Antihemophilic factor (AHF) concentrates contain debris which passes freely through the 170 μ filter routinely used for patient infusion. We have previously shown that this material is composed in part of IgG, fibrinoprotein and cold-insoluble globulin and that it is retained by a screen filter of 40 μ pore size. The purpose of this study was to investigate pulmonary effects of this particulate material in hemophiliac patients receiving frequent AHF infusions.Pulmonary function studies were performed before and after the infusion of a standard dose of AHF concentrate calculated to raise the in vivo factor VIII level to 50 per cent of normal. Using a standard 170 μ filter, five of six patients showed a significant decrease (p < 0.01) in the single breath carbon monoxide diffusing capacity (D_LCO_SB) 30 minutes and 6 hours after the infusion, with values returning to preinfusion levels by 48 hours. Slow vital capacity, forced vital capacity, maximum voluntary ventilation and a helium dilution residual lung volume remained normal in all patients. Two patients who were restudied using a 40 μ filter showed no significant change in the D_LCO_SB after the infusion.We conclude that lodging of particulate material in the pulmonary capillary bed was most likely responsible for the reduced D_lCO_sb. Since the defect was prevented by microfiltration, the use of a finer mesh filter than is currently recommended may be desirable for hemophiliac patients receiving large amounts of AHF concentrate at frequent intervals.     

Herpes zoster and occult malignancy

Herpes zoster and malignancy have both been associated with conditions of immune suppression. It has been well documented that herpes zoster occurs more frequently in patients with a previously diagnosed malignancy, especially lymphoma. To determine whether there is an increased frequency of malignancy subsequent to the diagnosis of herpes zoster, we studied fifty outpatients with herpes zoster and compared them with fifty control patients with psoriasis. In a follow-up period ranging from 24 to 68 months, one individual in the herpes zoster group developed a subsequent malignancy, in comparison to none in the control population and to 1.5 cancer cases expected in the general population. These results support the view that herpes zoster is not a marker for an occult malignancy.     

Perioperative thrombotic complications associated with pediatric liver transplantation: a UNOS database evaluation

Background

This retrospective UNOS database evaluation analyzes the prevalence of preoperative portal vein thromboses (PVT), and postoperative thromboses leading to graft failure in pediatric patients undergoing liver transplantation (LT).