Frequency and Clinical Manifestations of Patients with Primary Immunodeficiency Disorders in Iran: Update from the Iranian Primary Immunodeficiency Registry

Primary immunodeficiency disorders (PID) are a heterogeneous group of diseases, characterized by an increased susceptibility to infections. A total of 930 patients (573 males and 357 females) are registered in Iranian PID Registry (IPIDR) during three decades. Predominantly antibody deficiencies were the most common (38.4%), followed by congenital defects of phagocyte number and/or function (28.3%), other well-defined immunodeficiency syndromes (17.7%), combined T- and B-cell immunodeficiencies (11.0%), complement deficiencies (2.4%), and diseases of immune dysregulation (2.3%). Common variable immunodeficiency was the most frequent disorder (20.8%), followed by chronic granulomatous disease, ataxia-telangiectasia, btk deficiency, selective IgA deficiency, and T-B-severe combined immunodeficiency. The frequency of other PID disorders was less than 50 in number (<5%). There is an increasing trend in recognition of more PID in the recent years. Construction of such registry is not only important for its epidemiological aspect but also for its role in increasing the physician's knowledge about such disorders.     

Optimization of Shocking Lead Configuration for Transvenous Atrial Defibrillation

Optimum Electrodes for Atrial Defibrillation. Introduction : High atrial defibrillation energy requirements (ADER) in patients with chronic atrial fibrillation (AF) may limit the acceptance of transvenous atrial defibrillation. We evaluated an optimized defibrillation electrode configuration that could help to reduce the ADKR in patients with AF.
Methods and Results : We tested ten different configurations in nine dogs with AF (3.33 ± 2.92 days) induced by rapid atrial pacing. The configurations were: right atrial (RA) appendage as anode und coronary sinus (CS) as cathode; RA and innominate vein (I) as anode to CS (cathode); RA-CS (anode) to I (cathode); I-CS (anode) to RA (cathode); RA and left lateral subcutaneous patch (P) as anode to CS (cathode); RA-CS (anode) to P (cathode); P-CS (anode) to RA (cathode); superior vena cava (SVC) and CS (anode) to RA (cathode); RA-CS (anode) to SVC (cathode); and RA-SVC (anode) to CS (cathode). ADER was defined as the voltage needed to defibrillate the atria in 10% to 90% of 20 consecutive shocks. Three lead systems had ADER lower than the RA (anode) to CS (cathode) configuration, which required a mean of 143 ± 58 volts. These three were: RA-SVC (anode) to CS (cathode) 103 ± 29 V; I-CS (anode) to RA (cathode) 129 ± 39 V; and P-CS (anode) to RA (cathode) 130 ± 38 V. The remaining configurations had ADER higher than the RA (anode) to CS (cathode) configuration.
Conclusion : Adding an additional shocking electrode may reduce ADER when compared with the RA (anode) to CS (cathode) configuration. This concept could he incorporated into future implantable atrial defibrillators or used for refractory patients undergoing temporary transvenous cardioversion.     

Nutritional management of pregnancy in patients on home parenteral nutrition

Summary. Three pregnancies are reported in two patients on home parenteral nutrition for intestinal failure. The nutritional regimen, 2300 kcal (9.63 MJ) (18% as lipid emulsion), 14 g amino acid nitrogen and electrolytes supplied daily in a'big bag', was based on the measured resting energy expenditure and urinary nitrogen excretion during the third trimester in a 30-year-old woman on home parenteral nutrition. Commercial preparations of trace elements were added to the infusion as dictated by serum levels. Iron, iodine and fluoride were given orally, and vitamin B₁₂ by monthly intramuscular injection. There were no serious deficiencies in trace elements and maternal weight-gain and fetal growth were satisfactory in all three pregnancies. The two pregnancies in one patient went to term and both infants had birthweights at the 50th centile for gestational age. The second patient who had had two spontaneous abortions went into premature labour at 30 weeks and gave birth to a baby with a minor facial deformity who subsequently developed the idiopathic respiratory distress syndrome. All three placentas were histologically normal. The growth and development of all three babies has been satisfactory. This nutritional regimen should be adequate for most pregnant patients who have attained a normal nutritional status on parenteral nutrition.     

The Effects of Electrode-Tissue Contact on Radiofrequency Lesion Generation

During the generation of radiofrequency (RF) lesions in the ventricular myocardium, the maintenance of adequate electrode-tissue contact is critically important. In this study, lesion dimensions and temperature and impedance changes were evaluated while controlling electrode-tissue contact levels (?5, 0, +1, and +3 mm) and power levels (10, 20, and 30 W). This data was used to assess the ability of impedance and temperature monitoring to provide useful information about the quality of electrode-tissue contact. The results show that as the electrode-tissue contact increases, so does the amount of temperature rise. Witb the electrode floating in blood (-5 contact), the average maximum temperature increase with 20 and 30 W was only 7 ± 1 and 11 ± 2°C, respectively. At 20 and 30 W the temperature plateaued sbortly after the initiation of power application. With good electrode-tissue contact (+1 mm or +3 mm), the temperature increase within the first 10 seconds was significantly greater than the temperature increase from baseline with poor contact (0 mm or ?5 mm) and reached a maximum of 60 ± 1°C after 60 seconds of power application. As the electrode-tissue contact increased, so did the rate and level of impedance decrease. However, the rate of impedance decrease was slower compared to the rate of temperature rise. With the electrode floating in blood, the maximum impedance decreases with 20 and 30 W were 6 ± 6 Ω and 9 ± 5 Ω, respectively. The impedances plateaued after a few seconds of power application. With the electrode in good contact, the maximum impedance decreases with 20 and 30 W were 25 ±2Ω and 20 ± 6 Ω, respectively. In these cases the rate of the impedance decrease plateaued after 40 seconds of power application.The increase in lesion diameter and depth correlate well with decreasing impedance and increasing temperature. However, lesion depth appears to correlate better with impedance than temperature. We conclude that, since the electrode-tissue contact is not known prior to the application of power to the endocardium, in the absence of a temperature control system, the power should initially be set at a low level. The power sbould be increased slowly over 20–30 seconds, and then maintained at its final level for at least 90 seconds to allow for maximal lesion depth maturation. The power level should be lowered if the impedance drop exceeds 15 Ω.