Efficient Spin-to-Charge Conversion via Altermagnetic Spin Splitting Effect in Antiferromagnet RuO_{2}.

The relativistic spin Hall effect and inverse spin Hall effect enable the efficient generation and detection of spin current. Recently, a nonrelativistic altermagnetic spin splitting effect (ASSE) has been theoretically and experimentally reported to generate time-reversal-odd spin current with controllable spin polarization in antiferromagnet RuO_{2}. The inverse effect, electrical detection of spin current via ASSE, still remains elusive. Here we show the spin-to-charge conversion stemming from ASSE in RuO_{2} by the spin Seebeck effect measurements. Unconventionally, the spin Seebeck voltage can be detected even when the injected spin current is polarized along the directions of either the voltage channel or the thermal gradient, indicating the successful conversion of x- and z-spin polarizations into the charge current. The crystal axes-dependent conversion efficiency further demonstrates that the nontrivial spin-to-charge conversion in RuO_{2} is ascribed to ASSE, which is distinct from the magnetic or antiferromagnetic inverse spin Hall effects. Our finding not only advances the emerging research landscape of altermagnetism, but also provides a promising pathway for the spin detection.

[Risk factors for complications of endoscopic full-thickness resection of upper gastrointestinal submucosal tumors].

Objective: To analyze the risk factors for complications of endoscopic full-thickness resection (EFTR) of upper gastrointestinal submucosal tumors (SMTs). Methods: This was a retrospective observational study. The indications for EFTR included: (1) SMTs originating from the muscularis propria layer and growing out of the cavity or infiltrating the deep part of the muscularis propria layer; (2) SMTs diameter <5 cm; and (3) tumor identified as closely adherent to the serous layer during endoscopic submucosal dissection or endoscopic mucosal resection. This study included patients with SMTs originating from the muscularis propria layer in upper digestive tract, diagnosed preoperatively by endoscopic ultrasonography or computed tomography, who were successfully treated with EFTR. Those with incomplete clinical data were excluded. The clinical data of 154 patients with upper gastrointestinal SMTs who underwent EFTR at the Department of Gastroenterology, First Affiliated Hospital of Soochow University from January 2016 to January 2022 were retrospectively analyzed. Post-EFTR complications (such as delayed perforation, delayed bleeding, and postoperative infection, including electrocoagulation syndrome) were monitored and the risk factors for them were analyzed. Results: Among the 154 study patients, 33 (21.4%) developed complications, including delayed bleeding in three (1.9%), delayed perforation in two (1.3%), and postoperative infection in 28 (18.2%). One patient with bleeding was classified as having a major complication (hospitalized for more than 10 days because of complication). According to univariate analysis, complication was associated with tumor diameter >15 mm, operation time >90 minutes, defect closure method(purse string suture), and diameter of resected specimen ≥20 mm (all P<0.05). Multivariate logistic regression analysis showed that operation time >90 minutes (OR=6.252, 95%CI: 2.530-15.446, P<0.001) and tumor diameter >15 mm (OR=4.843, 95%CI: 1.985-11.817, P=0.001) were independent risk factors for complications after EFTR in patients with upper gastrointestinal SMTs. The independent risk factors for postoperative infection in these patients were operation time>90 minutes (OR=4.993, 95%CI:1.964-12.694, P=0.001) and purse string suture (OR=7.142, 95%CI: 1.953-26.123, P=0.003). Conclusion: Patients with upper gastrointestinal SMTs undergoing EFTR with tumor diameter >15 mm or operation time >90 minutes have a significantly increased risk of postoperative complications. Postoperative monitoring is important for these patients with SMTs.

Observation of Spin Splitting Torque in a Collinear Antiferromagnet RuO_{2}.

Current-induced spin torques provide efficient data writing approaches for magnetic memories. Recently, the spin splitting torque (SST) was theoretically predicted, which combines advantages of conventional spin transfer torque (STT) and spin-orbit torque (SOT) as well as enables controllable spin polarization. Here we provide the experimental evidence of SST in collinear antiferromagnet RuO_{2} films. The spin current direction is found to be correlated to the crystal orientation of RuO_{2} and the spin polarization direction is dependent on (parallel to) the Néel vector. These features are quite characteristic for the predicted SST. Our finding not only presents a new member for the spin torques besides traditional STT and SOT, but also proposes a promising spin source RuO_{2} for spintronics.

Hyper-IgE syndrome caused by DOCK8 mutation with a tumour-like lesion of the lip: a case report.

Autosomal recessive hyper-IgE syndrome caused by DOCK8 gene mutation is an immunodeficiency. However, the presentation of a tumour-like lesion of the lip in autosomal recessive hyper-IgE syndrome has not yet been reported. This article reports the case of a 20-year-old man with autosomal recessive hyper-IgE syndrome who presented with a tumour-like lesion of the lip, and hyperplasia and erosion of the gingiva. The clinical manifestations included coarse face and neck skin, a diffuse tumour-like lesion on the upper lip showing a reddish erosive nodular surface with yellowish-white exudation, erosive buccal mucosa, and severe periodontitis. The swollen gingival and palatal mucosa indicated nodular hyperplasia and redness with pseudomembrane. The patient had a significantly increased peripheral blood eosinophil count and serum IgE level and an abnormal T lymphocyte count. His oral lesions improved markedly after prednisolone acetate use and local symptomatic treatment for 2 years. However, the patient unfortunately died of a cerebral infection 6 months after the oral lesions had resolved. The novel features of the labial tumour-like lesion described here extend our understanding of the manifestations of autosomal recessive hyper-IgE syndrome.

[Studies on newly recognized chronic sialadenitis].

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by 131I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

Differential diagnosis of immunoglobulin G4-related sialadenitis and Kimura's disease of the salivary gland: a comparative case series.

The aim of this study was to investigate key points for the differential diagnosis of immunoglobulin G4-related sialadenitis (IgG4-RS) and Kimura's disease (KD) involving the salivary glands. The clinical, serological, radiological, histological, and immunohistochemical features of 85 IgG4-RS cases and 52 KD cases were evaluated comparatively. Seventy-two IgG4-RS cases had enlargement of multiple salivary and/or lacrimal glands; 67 patients had bilateral submandibular gland (SMG) involvement. Unilateral parotid gland involvement (59.6%) and comorbid skin lesions (61.5%) were common in KD. Serum IgG4 was elevated in 94.1% of IgG4-RS cases versus 19.0% of KD cases (cut-off value=266.5mg/dl). KD was more commonly associated with elevated eosinophil counts (86% vs 23.1%) and elevated IgE concentrations (95.5% vs 76.6%). Storiform fibrosis, irregular lymphoid follicles, and increased IgG4-positive cells (112.9±37.6/high-power field (HPF)) were common in IgG4-RS. Acellular fibrosis, regular lymphoid follicles, IgE-positive reticular networks, increased IgE-positive cells (43.4±26.7/HPF), and tryptase-positive mast cells (29.7±13.3/HPF) were usually detected in KD. Computed tomography showed that 85.7% of KD cases involved subcutaneous fat tissue. A superficial hypoechoic and reticular pattern with multiple hypoechoic foci were the sonographic features of the SMG in IgG4-RS. Despite numerous overlapping manifestations, histopathological examination showed meaningful differences in the types of fibrosis, eosinophils, and IgG4-positive cell counts. Comprehensive evaluation of clinical, serological, radiological, and histopathological features are crucial for the differential diagnosis.

[Clinicopathological characteristics and diagnosis of IgG4related sialadenitis].

Immunoglobulin G4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated disease and one of immunoglobulin G4-related diseases (IgG4-RD). Our multidisciplinary research group investigated the clinicopathological characteristics and diagnosis of IgG4-RS during the past 10 years. Clinically, it showed multiple bilateral enlargement of major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands. The comorbid diseases of head and neck region including rhinosinusitis, allergic rhinitis, and lymphadenopathy were commonly seen, which could occur more early than enlargement of major salivary glands. Internal organ involvements, such as autoimmune pancreatitis, sclerosing cholangitis, and interstitial pneumonia could also be seen. Thirty-five (38.5%) patients had the symptom of xerostomia. Saliva flow at rest was lower than normal. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in almost all the cases and the majority of the patients had increased IgE levels. CT, ultrasonography, and sialography showed their imaging characteristics. Histologically it showed marked lymphoplasmacytic inflammation, large irregular lymphoid follicles with expanded germinal centers, prominent cellular interlobular fibrosis, eosinophil infiltration, and obliterative phlebitis. Their immunohistological examination showed marked IgG-positive and IgG4-positive plasma cell infiltration and high IgG4/IgG ratio. The disease could be divided into three stages according to severity of glandular fibrosis. The serum IgG4 level was higher and the saliva secretion lower as glandular fibrosis increased. IgG4-RS should be differentiated from other diseases with enlargement of major salivary gland and lacrimal gland, such as primary Sjögren syndrome, chronic obstructive submandibular sialadenitis, and eosinophilic hyperplastic lymphogranuloma.

Effectiveness of olfactory ensheathing cell transplantation for treatment of spinal cord injury.

The aim of this study was to determine the effectiveness and safety of transplantation of olfactory ensheathing cells for functional repair of the spinal cord. An olfactory bulb was obtained from a 4- to 5-month-old aborted fetus, and it was digested into single olfactory ensheathing cells and then cultured and purified for 1 to 2 weeks. Under general anesthesia, these single-cell suspensions of olfactory ensheathing cells were injected into the corresponding spinal injury site with 0.45-mm-diameter injections. The American Spinal Injury Association (ASIA) Impairment Scale was used to evaluate spinal function. A total of 15 patients (12 men, 3 women; age range, 18-56 years; mean age, 40) were admitted for obsolete spinal injuries. Spinal functions of the 15 patients were observed and followed postoperatively for a period ranging from 2 weeks to 1 month. All the 15 patients exhibited improvements in spinal function, and the improvement tendencies continued. Twelve patients had obvious spinal function improvement, and three had slight improvement according to the ASIA scale, with an obvious difference between preoperation and postoperation measures (P < 0.05). No fevers, infections, functional deteriorations, or deaths were seen. Thus, transplantation of olfactory ensheathing cells promoted spinal and neurofunctional recovery in patients with malignant spinal injuries, and this therapeutic method was safe.

Hierarchical Bayesian scaling of soil properties across urban, agricultural, and desert ecosystems.

Ecologists increasingly use plot-scale data to inform research and policy related to regional and global environmental change. For soil chemistry research, scaling from the plot to the region is especially difficult due to high spatial variability at all scales. We used a hierarchical Bayesian model of plot-scale soil nutrient pools to predict storage of soil organic carbon (oC), inorganic carbon (iC), total nitrogen (N), and available phosphorus (avP) in a 7962-km2 area including the Phoenix, Arizona, USA, metropolitan area and its desert and agricultural surroundings. The Bayesian approach was compared to a traditional approach that multiplied mean values for urban mesic residential, urban xeric residential, nonresidential urban, agricultural, and desert areas by the aerial coverage of each land-use type. Both approaches suggest that oC, N, and avP are correlated with each other and are higher (in g/m2) in mesic residential and agricultural areas than in deserts or xeric residential areas. In addition to traditional biophysical variables, cultural variables related to impervious surface cover, tree cover, and turfgrass cover were significant in regression models predicting the regional distribution of soil properties. We estimate that 1140 Gg of oC have accumulated in human-dominated soils of this region, but a significant portion of this new C has a very short mean residence time in mesic yards and agricultural soils. For N, we estimate that 130 Gg have accumulated in soils, which explains a significant portion of "missing N" observed in the regional N budget. Predictions for iC differed between the approaches because the Bayesian approach predicted iC as a function of elevation while the traditional approach employed only land use. We suggest that Bayesian scaling enables models that are flexible enough to accommodate the diverse factors controlling soil chemistry in desert, urban, and agricultural ecosystems and, thus, may represent an important tool for ecological scaling that spans land-use types. Urban planners and city managers attempting to reduce C emissions and N pollution should consider ways that landscape choices and impervious surface cover affect city-wide soil C, N, and P storage.

Impact of volume loading and load reduction on ventricular refractoriness and conduction properties in canine congestive heart failure.

OBJECTIVES: This investigations was undertaken to examine the alteration of electrophysiologic properties, including refractoriness, strength-interval relations and conduction, with the development of heart failure and to characterize the impact of volume loading on these indexes in the cardiomyopathic setting. METHODS: Electrophysiologic properties in eight dogs with pacing-induced dilated cardiomyopathy were compared with those in six control dogs before and after rapid infusion of 800 ml of intravenous saline. RESULTS: The right ventricular (RV) and left ventricular (LV) effective refractory period (ERP) and absolute refractory period (ARP) were significantly longer in dogs with pacing-induced cardiomyopathy than in control dogs: RV ERP 181 +/- 11 ms versus 138 +/- 7 ms (mean +/- SD) (p < 0.0001) and anterior LV ERP 177 +/- 13 ms versus 128 +/- 11 ms (p < 0.0001), respectively; ARP 159 +/- 14 ms versus 114 +/- 7 ms (p < 0.0001) at the RV site and 153 +/- 12 versus 117 +/- 5 ms (p < 0.0001) at the anterior LV site. After volume loading in cardiomyopathic animals, posterior and anterior LV ERPs became prolonged to 178 +/- 5 ms (p = 0.004) and 189 +/- 14 ms (p = 0.065), respectively, shifting the strength-interval relation in the direction of longer S1S2 coupling intervals. Anterior LV monophasic action potential durations at 90% repolarization also became prolonged from 192 +/- 10 ms to 222 +/- 23 ms (p < 0.012) with volume loading. These findings were not altered by subsequent sodium nitroprusside. Local conduction times parallel and perpendicular to fiber orientation were not altered by development of cardiomyopathy or volume alterations. CONCLUSIONS: The development of dilated cardiomyopathy results in significant prolongation of refractoriness and repolarization that is increased further by volume augmentation but is not reversed by pharmacologic load reduction. Although these abnormalities may contribute to the environment needed for a non-reentrant, triggered or stretch-mediated arrhythmogenic process in cardiomyopathic states, additional studies will be required to demonstrate such a focal mechanism conclusively.

Health in China. Traditional Chinese medicine: one country, two systems.

China is the only country in the world where Western medicine and traditional medicine are practised alongside each other at every level of the healthcare system. Traditional Chinese medicine has a unique theoretical and practical approach to the treatment of disease, which has developed over thousands of years. Traditional treatments include herbal remedies, acupuncture, acupressure and massage, and moxibustion. They account for around 40% of all health care delivered in China. The current government policy of expansion of traditional facilities and manpower is being questioned because many hospitals using traditional Chinese medicine are already underutilized and depend on government subsidies for survival. Research priorities include randomised controlled trials of common treatments and analysis of the active agents in herbal remedies. As more studies show the clinical effectiveness of traditional Chinese medicine, an integrated approach to disease using a combination of Western medicine and traditional approaches becomes a possibility for the future.

The one child family policy: the good, the bad, and the ugly.

Rapid population growth in China during the 1950s and '60s led to the "late, long, few" policy of the 1970s and a dramatic reduction in the total fertility rate. However, population growth remained too high for the economic targets of Deng Xiao Ping's reforms, so the one child family policy was introduced in 1979 and has remained in force ever since. The strategy is different in urban and rural areas, and implementation varies from place to place depending on local conditions. The policy has been beneficial in terms of curbing population growth, aiding economic growth, and improving the health and welfare of women and children. On the negative side there are concerns about demographic and sex imbalance and the psychological effects for a generation of only children in the cities. The atrocities often associated with the policy, such as female infanticide, occur rarely now. China may relax the policy in the near future, probably allowing two children for everyone.

Maternal and child health in China.

China has made great progress in improving the health of women and children over the past two generations. The success has been attributed to improved living standards, public health measures, and good access to health services. Although overall infant and maternal mortality rates are relatively low there are large differences in patterns of mortality between urban and rural areas. The Chinese have developed a hierarchical network of maternal and child health services, with each level taking a supervisory and teaching role for the level below it. Maternal and child health in China came to international attention in 1995 with the promulgation of the maternal and child health law. In China this was seen as a means of prioritising resources and improving the quality of services, but in the West it was widely described as a law on eugenics.

PIP: Improved living standards, public health measures, and good access to health services have allowed China to make great strides in improving the health of women and children over the past two generations. Overall infant and maternal mortality rates are relatively low, but there are large differences in patterns of mortality between urban and rural areas. A law on maternal and child health was passed in 1995 which is comprised of 38 articles on premarital, antenatal, and perinatal health, and guidelines on technical implementation, management, and legal liability. Local governments are obliged to prioritize resources for antenatal and neonatal care, ensure that all health workers are appropriately qualified, and give special emphasis to improving affordable services in poverty stricken areas. Most articles are of the law are positive, although two contain overtly eugenic elements. China has a hierarchical network of maternal and child health services in which each level takes a supervisory and teaching role for the level below it.

Health in China. The healthcare market.

It is now about 15 years since the introduction of the market into health care in China. This produced fundamental changes in the way that health care is financed and resulted in the disappearance of universal free basic health care. Responsibility for provision of health services has been devolved to the provincial and county governments, and healthcare providers have been given considerable financial independence. A fee for service system has been introduced, and several different payment mechanisms are now in operation. The new financing and pricing structures are responsible for greater inequity of access to services and more inefficient use of resources. These problems are widely acknowledged, and a range of solutions is being developed and tested. Since the introduction of the reforms the measurable health status of the population has not declined, probably as a result of overall improved socioeconomic conditions and a continued emphasis on prevention.

Whole saliva and the diagnosis of Sjögren's syndrome: an evaluation of patients who complain of dry mouth and dry eyes. Part 1: Screening tests.

UNLABELLED: Sjögren's syndrome (SS) is a common autoimmune disorder characterised by generalised desiccation, exocrine hypofunction and serologic abnormalities, More than 90% of the patients are women. OBJECTIVE: To determine if whole saliva could be used to diagnose this disease. SETTING: The study was conducted at the School of Dental Medicine, SUNY, at Stony Brook. PATIENTS: There were 49 subjects (48 F; 1 M), the mean age was 54 +/- 13 years. In order to be admitted into the study, they had to complain of dry mouth and dry eyes. TESTS: Whole saliva was collected by the spitting method. "Screening Tests" were employed to measure the salivary flow rate, pH, buffer capacity; lactobacillus and yeast concentrations. Chemical tests were performed to determine protein, albumin, sodium and amylase activity. Lacrimal dryness was assessed by the Schirmer and Rose-Bengal methods. RESULTS: Based on the sialometric findings, the patients were divided into 3 groups: Group 1: those with abnormally low resting (RFR) and stimulated (SFR) flow rates; Group 2: those with a low RFR but normal SFR; and Group 3: those with normal salivary flow rates. The group 1 patients were unique: their saliva demonstrated a low pH and buffer capacity, high lactobacillus and yeast concentrations, decreased protein output and amylase activity, and elevated albumin and sodium. Moreover, virtually all of them had abnormally low lacrimal flow rates. CONCLUSIONS: The findings suggested that whole saliva could be used to provisionally diagnose SS. Critical to this diagnosis was an abnormally low stimulated whole saliva flow rate. Other requisites included a low resting flow rate, the presence of dry mouth and dry eyes and evidence of lacrimal hypofunction. All of these attributes can easily be obtained by dentists in their clinics.

Whole saliva and the diagnosis of Sjögren's syndrome: an evaluation of patients who complain of dry mouth and dry eyes. Part 2: Immunologic findings.

UNLABELLED: Sjögren's syndrome (SS) is a multisystem, autoimmune disease characterised by generalised desiccation, exocrine hypofunction and serologic abnormalities. Last year we showed that the antibodies which are quasi-specific for diagnosis of SS, anti SS-A/Ro and anti SS-B/La, were present in the saliva of patients with this disease. OBJECTIVE: To determine their presence in patients who complain of dry mouth and dry eyes. SETTING: The study was conducted at the School of Dental Medicine, SUNY at Stony Brook. PATIENTS: There were 49 patients (Mean Age = 54 +/- 13 years). TESTS: Serum was analysed for the SS and other antibodies with "Western Blot Autoantibody Strips". RESULTS: The findings showed that there was a strong correlation between the presence of the SS antibodies in the serum and the saliva. The SS antibodies were primarily found in the saliva of the patients whose resting and stimulated, whole saliva, flow rates were abnormally low. Antibodies to other autoimmune disease (lupus, scleroderma and mixed connective tissue disease) were also found in whole saliva. CONCLUSIONS: The findings in Part 1 of this study, of patients who had complained of dry mouth and dry eyes, suggest that those patients, who demonstrated low resting and stimulated flow rates and had lacrimal hypofunction, suffered from SS. The observation in this paper, that the whole saliva of these patients contains the SS antibodies, confirms this diagnosis. The data suggest that whole saliva can be used to establish the diagnosis of SS and other autoimmune diseases.

The use of whole saliva in the differential diagnosis of Sjögren's syndrome.

Sjögren's Syndrome (SS) is a chronic, multisystem, autoimmune disorder. It is characterized by (1) generalized exocrine gland dysfunction, (2) serologic abnormalities, and (3) organ-system changes. Oral changes are a prominent feature of this disease. Among these are xerostomia and hypofunction of the salivary glands. Given the intimate relationship between SS and the salivary glands, it is reasonable to postulate that whole saliva (WS) contains the stigmata associated with the presence of this disease. But few studies have been conducted on this secretion. Indeed, WS has largely been neglected and ignored by physicians, dentists, and scientists. Objections to its use have included the fact that it is "impure", that it does not adequately represent what is present in the salivary glands, that no standards have been established for its rate of flow, and that findings based on it lack specificity. Yet, it is this secretion which coats and protects the hard and soft oral tissues, enables us to prepare our food for digestion, and assists our speech. This review will demonstrate that there is a uniqueness and constancy to whole saliva and that it may be used to diagnose the presence of SS. "Screening tests", which include several simple-to-perform sialometric, chemical, and microbiologic procedures, may be conducted in doctors' offices to establish the "profile" of an SS patient. Electrophoretic studies may be used to study the nature of the salivary proteins, and an immunologic test, which is performed on WS and utilizes Western Blot Autoantibody Strips (ImmunoVision, Springdale, AR), may be used to establish the definitive diagnosis of SS.

Long-term follow-up of heart transplant recipients requiring permanent pacemakers.

BACKGROUND: Permanent pacemaker implantation after heart transplantation is contentious. Indications for these devices in this population are uncertain. The goals of this project were to (1) analyze the time course of donor sinus node dysfunction and atrioventricular block after heart transplantation; (2) evaluate which selected parameters (donor age, ischemic time, heart rate before pacer insertion, and number of rejection episodes) might relate to persistent permanent pacing need, and (3) assess pacemaker complications during follow-up. METHODS: A retrospective analysis of pacemaker implantations (22 cases) was performed in 286 consecutive heart transplantations performed between February 1984 and April 1994 at The Methodist Hospital and Baylor College of Medicine, Houston, Texas. RESULTS: Permanent pacemakers were inserted early after transplantation in 19 patients (mean 24 days); 14 pacemakers were for sinus node dysfunction (bradycardia in five, sinus arrest with junctional escape in eight, and optimization of hemodynamics in one). Symptomatic complete heart block prompted insertion late in two patients (3 and 47 months), and symptomatic sinus pause was the indication for late insertion in one. Recipient mean age was 52.4 years, with mean donor age 29.7 years in patients with pacemakers. By 3 months, 13 of 19 patients receiving pacemakers early (mean preinsertion heart rate 58.3 beats/min) became pacer independent with subsequent mean intrinsic heart rate of 97 beats/min. Recipient or donor age, ischemic time, and rejection episodes did not appear related to long-term pacing need early or late after transplantation. CONCLUSIONS: Inferences from these observations include the fact that many patients with early sinus node dysfunction and bradycardia are not pacer dependent at 3 months. However, those with atrioventricular block early appear to require long-term pacing support. However, the possibility that more aggressive and long-term oral chronotropic medication use after transplantation would obviate early permanent pacemaker need is not addressed. Finally, prospective clinical trials are necessary to precisely characterize benefit of permanent pacemakers and define optimal pacing modes after heart transplantation.