Pediatric pacemaker infections: Twenty years of experience

AbstractObjective: We sought to evaluate possible predictors of early and late pacemaker infections in children. Methods: A review was performed of all pacemakers implanted in children at The Children's Hospital of Philadelphia between 1982 and 2001. Infections were classified as superficial cellulitus, deep pacemaker pocket infection necessitating removal, or positive blood culture without an identifiable source. Results: A total of 385 pacemakers (224 epicardial and 161 endocardial) were implanted in 267 patients at 8.4 ± 6.2 years. All 2141 outpatient visits were reviewed (median follow-up, 29.4 months; range, 2-232 months). There were 30 (7.8%) pacemaker infections: 19 (4.9%) superficial infections; 9 (2.3%) pocket infections; and 2 (0.5%) isolated positive blood cultures. All superficial infections resolved with intravenous antibiotics. The median time from implantation to infection was 16 days (range, 2 days-5 years). Only 1 deep infection occurred after primary pacemaker implantation. Six patients with deep infections were pacemaker dependent and were successfully managed with intravenous antibiotics, followed by lead-generator removal and implantation of a new pacemaker in a remote location. In univariate analyses trisomy 21 (relative risk, 3.9; P <.01), pacemaker revisions (relative risk, 2.5; P <.01), and single-chamber devices (relative risk, 2.4; P <.05) were identified as predictors of infection. However, in multivariate analyses only trisomy 21 and pacemaker revisions were predictors. Conclusions: The incidences of superficial and deep pacemaker infections were 4.9% and 2.3%, respectively. Trisomy 21 and pacemaker revisions were significant risk factors in the development of infection after pacemaker implantation. For primary pacemaker implantation, the risk of infection requiring system removal is low (0.3%).J Thorac Cardiovasc Surg 2002;124:821-

Long-term outcome of infants with single ventricle and total anomalous pulmonary venous connection

AbstractBackground and methods: Between January 1, 1984, and December 1, 1997, 73 infants with functional single ventricle and total anomalous pulmonary venous connection were admitted to our institution. A retrospective review was undertaken to determine factors influencing survival. Results: Heterotaxy syndrome was present in 52 patients and hypoplastic left heart syndrome in 14. Obstructed total anomalous pulmonary venous connection was present in 21 patients. The pulmonary venous connection was supracardiac in 32 patients, cardiac in 21 patients, infracardiac in 13, and mixed in 7. Twelve patients died before the operation. The remaining 61 patients underwent surgery at a median age of 5 days (range 1 day–2.5 years). Overall survival was 45% at 6 months of age, 37% at 1 year, and 19% at 5 years. Survival for patients undergoing surgery was 54% at 6 months of age, 44% at 1 year, and 23% at 5 years. By univariate analysis with the Cox proportional hazards model, younger age at the time of the initial operation and repair of total anomalous pulmonary venous connection were predictors of mortality. Lung tissue from 14 patients was available for histologic examination. The pulmonary veins were dilated and wall thickness was increased. Increased muscularization of the arteries was seen in 11 patients. Conclusions: The long-term prognosis for children undergoing staged reconstructive operations for single ventricle and total anomalous pulmonary venous connection is poor. Early mortality is high and late death is a continuing risk. Development of the pulmonary vasculature, especially the pulmonary veins, is abnormal, even in children without clinical evidence of pulmonary venous obstruction. (J Thorac Cardiovasc Surg 1999;117:506-14

Modified ultrafiltration improves cerebral metabolic recovery after circulatory arrest

AbstractModified ultrafiltration uses hemofiltration of the patient and bypass circuit after separation from cardiopulmonary bypass to reverse hemodilution and edema. This study investigated the effect of modified ultrafiltration on cerebral metabolic recovery after deep hypothermic circulatory arrest. Twenty-six 1-week-old piglets (2 to 3 kg) were supported by cardiopulmonary bypass (37° C) at 100 ml · kg-1 · min-1 and cooled to 18° C. Animals underwent 90 minutes of circulatory arrest followed by rewarming to 37° C. After being weaned from cardiopulmonary bypass, animals were divided into three groups: controls ( n = 10); modified ultrafiltration for 20 minutes ( n = 9); transfusion of hemoconcentrated blood for 20 minutes ( n = 7). Global cerebral blood flow was measured by xenon 133 clearance methods: stage I--before cardiopulmonary bypass; stage II—5 minutes after cardiopulmonary bypass; and stage III—25 minutes after cardiopulmonary bypass. Cerebral metabolic rate of oxygen consumption, cerebral oxygen delivery, and hematocrit value were calculated for each time point. At point III, the hematocrit value (percent) was elevated above baseline in the ultrafiltration and transfusion groups (44 ± 1.8, 42 ± 1.8 versus 28 ± 1.7, 30 ± 0.7, respectively, p < 0.05). Cerebral oxygen delivery (ml · 100 gm-1 · min-1 ) increased significantly above baseline at point III after ultrafiltration (4.98 ± 0.32 versus 3.85 ± 0.16, p < 0.05) or transfusion (4.59 ± 0.17 versus 3.89 ± 0.06, p < 0.05) and decreased below baseline in the control group (2.77 ± 0.19 versus 3.81 ± 0.16, p < 0.05). Ninety minutes of deep hypothermic circulatory arrest resulted in impaired cerebral metabolic oxygen consumption (ml · 100 gm-1 · min-1 ) at point III in the control group (1.95 ± 0.15 versus 2.47 ± 0.07, p < 0.05) and transfusion group (1.72 ± 0.10 versus 2.39 ± 0.15, p < 0.05). After modified ultrafiltration, however, cerebral metabolic oxygen consumption at point III had increased significantly from baseline (3.12 ± 0.24 versus 2.48 ± 0.13, p < 0.05), indicating that the decrease in cerebral metabolism immediately after deep hypothermic circulatory arrest is reversible and may not represent permanent cerebral injury. Use of modified ultrafiltration after cardiopulmonary bypass may reduce brain injury associated with deep hypothermic circulatory arrest. (J THORAC CARDIOVASC SURG 1995;109:744-52

Modified Ultrafiltration Improves Left Ventricular Systolic Function In Infants After Cardiopulmonary Bypass

AbstractObjective: Our objective was to test the hypothesis that use of modified ultrafiltration after cardiopulmonary bypass improves intrinsic left ventricular systolic function in children.Methods: Twenty-one infants undergoing cardiopulmonary bypass were instrumented with ultrasonic dimension transducers, to measure the anteroposterior minor axis diameter, and a left ventricular micromanometer. Patients were randomized to modified ultrafiltration (n = 11, age 226 ± 355 days, weight 6.7 ± 3.1 kg) or control (n = 10, age 300 ± 240 days, weight 7.0 ± 2.5 kg) (all differences p > 0.05 between groups). Left ventricular systolic function was assessed by means of the slope of the preload-recruitable stroke work index. Myocardial cross-sectional area was measured by echocardiography. Data were acquired immediately after separation from bypass, at steady state, and during transient vena caval occlusion. Data acquisition was repeated after 13 ± 5 minutes of modified ultrafiltration or after 12 ± 5 minutes without modified ultrafiltration in the control group. Inotropic drug support was the same at both study points.Results: In the modified ultrafiltration group, the filtrate volume was 363 ± 262 ml. The hematocrit value increased from 26.0% ± 2.7% to 36.7% ± 9.5% (p = 0.018), myocardial cross-sectional area decreased from 3.72 ± 0.35 cm2 to 3.63 ± 0.36 cm2 (p = 0.04), end-diastolic length increased from 25.6 ± 9.0 mm to 28.8 ± 9.9 mm (p = 0.01), and end-diastolic pressure fell from 5.6 ± 0.8 mm Hg to 4.2  ± 0.8 mm Hg (p = 0.005), suggesting an improved diastolic compliance. In the control group, the hematocrit value, myocardial cross-sectional area, end-diastolic length, and pressure did not change (all p > 0.05). Mean ejection pressure increased in the ultrafiltration group (p = 0.001) but did not change in the control group (p = 0.22). The slope of the preload-recruitable stroke work index increased after ultrafiltration from 52.3 ± 52.0 to 74.2 ± 66.0 (103 erg/cm3) (p = 0.02) but did not change in the control group (p = 0.07). One patient from each group died in the postoperative period. Patients in the ultrafiltration group received less inotropic drug support in the first 24 hours after the operation (156.62 ± 92.31 μg/kg in 24 hours) than patients in the control group (865.33 ± 1772.26 μg/kg in 24 hours, p = 0.03).Conclusions: Use of modified ultrafiltration after cardiopulmonary bypass improves intrinsic left ventricular systolic function, improves diastolic compliance, increases blood pressure, and decreases inotropic drug use in the early postoperative period. (J Thorac Cardiovasc Surg 1998;115:361-70

Congenital heart surgery nomenclature and database project: update and proposed data harvest

The floristic study of trees was carriedout in the Protected Natural Area (PNA)Tenancingo-Malinalco-Zumpahuacan. Theidentified specimens comprise 304 species,165 genera and 72 families. The most representative families are Leguminosae with58 species (Fabaceae 15, Mimosaceae 35and Caesalpiniaceae 8), Fagaceae with 23,Burseraceae with 19 and Moraceae with 14;of wich 242 are native, 20 non native and42 endemic. We identified six distinct typesof vegetation: tropical deciduous forest,tropical subdeciduous forest, montane mesophytic forest, oak forest, pine-oak forest andgallery forest. In addition, we detailed 73new species reports for the State of Mexico.The most species richness occurred in thetropical deciduous forest (170) and galleryforest (104).En el estudio florístico de árboles realizadoen el área natural protegida (ANP) Tenancingo-Malinalco-Zumpahuacán, se registróla presencia de 72 familias, 165 géneros y304 especies, de las cuales 10 son coníferas,293 dicotiledóneas y una monocotiledónea.Las familias con mayor número de especies son Leguminosae (58) (Mimosaceae35, Caesalpiniaceae 8 y Fabaceae 15),Fagaceae (23), Burseraceae (19) y Moraceae (14). De las cuales 242 especies sonnativas, 20 no nativas y 42 endémicas aMéxico. Se reportan 73 nuevos registrosde especies para el Estado de México y sedescriben seis tipos de vegetación: bosquetropical caducifolio, tropical subcaducifolio, de encino, de pino-encino, mesófilode montaña y de galería, de los cuales lamayor riqueza de especies se presentó enel bosque tropical caducifolio (170) y en elbosque de galería (104)