Electrocardiographic findings in naturally acquired chagasic heart disease in nonhuman primates

The significance of electrocardiographic (ECG) changes described in animals with Chagas' disease is questionable in view that other non-invasive comparisons have been lacking. 12-lead ECG and two-dimensional echocardiography (echo) was performed in 17 seropositive and 13 seronegative baboons. Similar to humans, a wide variety of ECG outcomes were observed in the infected animals. Standard ECG measurements were not different between groups. Five seropositive (29%) and 3 seronegative (23%) animals had low voltage; 4 seropositives (24%) and 2 (15%) seronegatives had tall P-waves. Precordial Q waves were seen in 10 seropositives (59%) and in 7 (54%) seronegatives without septal abnormalities on two-dimensional echo. One seropositive animal had a 2(nd) degree (Wenckebach) AV block and left anterior fascicular block. Most animals in both groups had diffuse T-wave abnormalities. Echo evidence of systolic dysfunction was found in 4 seropositives and in none of the controls; thus, chagasic heart disease was present in 24% of naturally infected baboons. Since most non-human primates, irrespective of their serology, have diffuse, nonspecific ECG changes not necessarily diagnostic of myocardial disease, two-dimensional echo should be added to their non-invasive assessment.     

Megaesophagus and seroreactivity to Trypanosoma cruzi in a rural community in northeast Brazil

The relationship of symptoms and radiographic abnormalities suggestive of esophageal motility disorders with electrocardiographic (ECG) alterations and seroreactivity to Trypanosoma cruzi was studied in a defined population in a rural area endemic for Chagas' disease in Bahia, Brazil. Between January and June 1981, 680 individuals 5 years of age or older were examined with serologic tests, ECGs and questionnaires for esophageal motility disorder. Of these, 39.9% were seropositive for Chagas' disease. Symptoms of dysphagia occurred 2.5 times more frequently among seropositive individuals than among seronegative individuals. Radiographic esophageal abnormalities were 3.6 times more frequent among seropositive individuals than among seronegative individuals in the symptomatic group. Symptoms and radiographic abnormalities were more common in men than in women although this was not statistically significant. Among seropositive individuals the percentage with symptoms of dysphagia increased with age, with a peak prevalence rate of 23.9% in the 45- to 64-year-old age group. Also, in the seropositive group, 41.7% with X-ray abnormalities of the esophagus and 26.3% with symptoms of dysphagia presented an abnormal ECG.     

Relationship of electrocardiographic abnormalities and seropositivity to Trypanosoma cruzi within a rural community in northeast Brazil

The relationship of infection with Trypanosoma cruzi to ECG abnormalities was studied in a defined population in rural Bahia, Brazil. Of 644 individuals 10 years of age or older who had complement fixation tests for antibodies to T. cruzi and ECGs, 53.7% were seropositive. ECG abnormalities were more common in seropositive individuals than in seronegative individuals, and more common in men than in women. The peak prevalence rate of abnormal ECGs occurred among seropositive individuals between 25 and 44 years of age; in this age group ECG abnormalities occurred 9.6 times more frequently among seropositive individuals than among seronegative individuals. The most common abnormalities were ventricular conduction defects, and right bundle branch block with or without fascicular block occurred in 10.7% of the infected population. PR intervals were longer in seropositive individuals than in seronegative individuals. Ventricular extrasystoles were slightly more common in seropositive individuals. A declining prevalence rate of abnormal ECGs among older seropositive individuals suggested selective mortality due to Chagas' heart disease.     

A nine year prospective study of Chagas' disease in a defined rural population in northeast Brazil

The association between infection with Trypanosoma cruzi and the development of electrocardiographic alterations and mortality was studied longitudinally for 9 years in a population residing in an endemic area in Castro Alves, Bahia, Brazil. Annual censuses were begun in 1973. At 3 year intervals from 1974 to 1983, the population was examined serologically and subjected to electrocardiography using standardized techniques. Of 1,751 individuals registered during the 10 censuses, 1,541 (88%) were examined serologically at least once. Of 747 individuals in constant residence and originally seronegative, 24 were seropositive upon subsequent evaluation, giving a seroconversion rate of 4.92/1,000 person-years (PY). The overall rate of development of an abnormal ECG was 25.7/1,000 PY for seropositive individuals and 12.5/1,000 PY for seronegative individuals, a relative risk of 2. The 10-14-year-old seropositive group had the highest risk of developing ECG abnormalities (24.1/1,000 PY, relative risk = 3.5). The age-adjusted mortality rate of seropositive individuals was slightly higher than for seronegative individuals (8.9 vs. 7.8/1,000 PY). In sero-positive individuals, mortality was strongly associated with the presence of ventricular conduction defects and arrhythmias. Ventricular conduction defects appeared most frequently in younger individuals. Older individuals presented the highest risk of development of frequent and multifocal extrasystoles.     

Chronic Chagas' heart disease in the elderly: a clinicopathologic study

A retrospective study of the medical records of our hospital from 1965 to 1985 was carried out to characterize for the first time chronic Chagas' heart disease in the elderly (more than 70 years old). A total of 25 patients (mean age = 76) were suitable for the study. Congestive heart failure, sudden cardiac death, thromboembolism and atypical chest pain were found in 68, 16, 8 and 8% of cases, respectively. Ventricular premature contractions (60%), right bundle branch block (32%), left anterior hemiblock (28%), atrial fibrillation (28%) and right bundle branch block associated with left anterior hemiblock (20%) were the ECG changes most frequently found. A morphological study was performed on 8 (32%) patients. All of them showed cardiac abnormalities, with apical aneurism being detected in 100% of cases. At autopsy, pulmonary embolism was observed in 3(37%) of these patients who presented with congestive heart failure, ventricular premature contractions and/or intraventricular conduction defect and/or atrial fibrillation. Thus, the characteristics of chronic Chagas' heart disease in the elderly are similar to those found in middle-aged patients. We suggest that these patients are important for the study of the pathogenesis of chronic Chagas' heart disease because they may have less aggressive pathophysiologic mechanisms than middle-aged patients.     

Chagas' disease in northern California. No longer an endemic diagnosis

Chagas' disease has long been considered a diagnosis endemic to South and Central America, with over 10 million seropositive cases in Brazil alone, and over 25 percent of infants in rural Brazil with demonstrable parasitemia. In northern California, progressive biventricular heart failure developed in a 75-year-old woman with a history of right bundle branch block, sinus bradycardia, and ventricular dysrhythmias. Echocardiography showed a characteristic pattern of inferoposterior hypokinesis with relatively intact septal motion. Complement fixation titers for Trypanosoma cruzi were diagnostic. The chronic forms of Chagas' disease may not be manifest until 30 years after the insect bite. It is this factor of prolonged latency, in relation to modern migration and relocations, that makes Chagas' disease no longer an endemic diagnosis.     

Electrocardiographic characteristics in a population with high rates of seropositivity for Trypanosoma cruzi infection

This study was conducted in Posse, a rural community in Goiàs, Brazil. Persons were recruited into the study through house-to-house sampling of all houses in the sampled area. Blood samples were collected for seropositivity assessments for Trypanosoma cruzi and an electrocardiogram was assessed using a portable system. The results demonstrate significant differences between seropositive and seronegative persons for electrocardiographic (ECG)-derived traits. Seropositive persons had substantially longer QRS and QT intervals than seronegative persons. The PR interval was significantly different between seropositive and seronegative persons. Conduction abnormalities were observed more frequently in seropositive than seronegative persons. Right bundle branch block, an ECG abnormality typical of Chagas disease, was observed in 15% of seropositive persons compared with less than 1% of seronegative persons. Results indicate that T. cruzi infection and subsequent Chagas disease will continue to be major health problems for the foreseeable future in this typical rural area of Brazil.     

冠脉造影正常心电图提示缺血改变患者的临床病因分析

目的 探讨心电图有缺血性改变(ST-T异常或有病理性Q波)的冠状动脉造影正常患者可能存在的病因及其发病机理.方法选择曾在我院住院,心电图有缺血性改变(ST-T异常或有病理性Q波),伴或不伴胸闷、胸痛临床症状而冠状动脉造影正常的患者608例(其中心电图ST-T异常526例,异常Q 波52例,同时有ST-T异常和异常Q 波30例,心电图异常伴胸闷、胸痛的446例).冠脉造影显示病变狭窄≥50%诊断为冠心病,＜50%定义为冠脉造影正常.结果 608例冠脉造影正常患者中,高血压365例、心血管神经症84例、X综合征41例、心瓣膜病26例,这些疾病为患者主要病因,患者心电图异常或出现胸闷、胸痛症状可能与上述疾病有关.结论高血压、心血管神经症、X综合征、心瓣膜病为心电图有缺血性改变,伴或不伴胸闷、胸痛临床症状而冠脉造影正常患者的主要病因,患者心电图异常或出现胸闷、胸痛症状可能与这些疾病有关.     

Circadian profiles of heart rate and its instantaneous variability in patients with chronic Chagas' disease

INTRODUCTION AND OBJECTIVES: Impairment of the autonomous nervous system in early stages of Chagas' disease is still a matter of debate, although multiple approaches (including heart rate response to orthostatism and the Valsalva maneuver, and spontaneous variability) have been used to ascertain its occurrence. The circadian profile of heart rate and its variability have not been investigated in patients with Chagas' disease. PATIENTS AND METHOD: We analyzed the 24-hour heart rate by Holter recordings in 63 patients with and without ECG alterations, who had positive serological findings for Chagas' disease. These results were compared with those in 22 healthy subjects matched for sex and age. Mean 24-hour heart rate and its circadian amplitude were analyzed with Cusum analysis and nocturnal dip. In a subgroup of 45 subjects (30 with Chagas' disease and 15 healthy controls), heart rate instantaneous variability (24-hour pNN50 and r-MSSD) and circadian amplitude were also calculated by Cusum analysis. RESULTS: 24-hour and diurnal heart rates were lower in patients with Chagas' disease than in healthy subjects (P<.05). Circadian amplitude and dip were lower in patients, but these differences did not reach statistical significance. In the subgroup of 45 subjects, the reductions in instantaneous heart rate variability (pNN50 and r-MSSD) in Chagasic patients were small, and circadian amplitudes were preserved, when compared with healthy subjects. CONCLUSIONS: The lower heart rate in patients with Chagas' disease occurred only during diurnal activity, and instantaneous heart rate variability was preserved. These findings suggest an alteration in the sympathetic branch of the autonomous nervous system. The circadian heart rate profile, which has not been studied previously in patients with Chagas' disease, does not seem appreciably blunted in this stage of the disease.     

Thyroid autoantibodies: a good marker for the study of symptomless autoimmune thyroiditis

In 3737 subjects without clinically thyroid disorders we evaluated the incidence of thyroid microsomal and thyroglobulin antibodies. These autoantibodies were found in 7% of a normal population, in 9% of patients with various non-autoimmune diseases, and in 11-16% of groups who either had or were at risk for autoimmune diseases: patients with IDDM, vitiligo, alopecia areata, idiopathic hypoparathyroidism, Addison's disease, and first-degree relatives of IDDM patients. Functional thyroid evaluation with TRH test was performed in 197 seropositive subjects and 144 seronegative controls. One-quarter (26%) of the subjects with thyroid autoantibodies showed functional abnormalities on TRH testing, whereas only 2.8% of the 144 seronegative controls showed subclinical hypothyroidism. After an observation period of 12-44 months, 102 persistently seropositive subjects were reassessed and 31% of them showed an impairment in TRH test response.     

Morphologic and functional characterization of Chagasic heart disease in non-human primates

Chagasic heart disease has been documented in non-human primates, but noninvasive characterization of systolic and diastolic function has not been previously reported. Seventeen seropositive (12 females; mean age, 20) and 13 age- and gender-matched seronegative baboons underwent Doppler echocardiography. Systolic function indices included left ventricular (LV) fractional shortening (FS %), velocity of circumferential fiber shortening (VCF, circ/sec), LV mass index, and left and right ventricular ejection fractions (RVEF %). Diastolic function indices included transmitral E-wave, A-wave, E/A ratio, E-deceleration time, and isovolumic relaxation time. Twelve-lead electrocardiographic (ECG) recordings were obtained. There were no significant differences between groups for body size or blood pressure. Seropositive and seronegative groups revealed diffuse non-specific T wave changes precluding differentiation; however, tall "P" waves were seen in four seropositive and two seronegative baboons. Four of the 17 (24%) seropositive baboons had decreased FS (25 +/- 8% versus 40 +/- 5%, P < 0.005) and VCF (1.05 +/- 0.36 circ/sec versus 1.84 +/- 0.23 circ/sec, P < 0.0001), prolonged isovolumic relaxation time (71 +/- 16 msec versus 55 +/- 9 msec, P < 0.02), and reduced RVEF (44 +/- 9% versus 54 +/- 4%, P < 0.05), as compared with the other seropositive baboons. We conclude that chagasic heart disease is present in 24% of the naturally infected baboons in this study. ECG evidence of right atrial enlargement was more common in the seropositive animals. There were systolic and diastolic abnormalities of both ventricles. The LV systolic dysfunction may be segmental or diffuse.     

Neurologic Manifestations<br />of HIV Infection Without AIDS:Follow-UP of a Cohort<br />of Homosexual and Bisexual Men

To identify neurological abnormalities in HIV infection, 159 HIV-seropositive men without AIDS and 76 seronegative controls underwent standardized general and neurological examinations, lumbar puncture (LP), neuropsychological (NP) assessment, and brain magnetic resonance (MR) imaging. History, physical, and laboratory evaluations were repeated every six months. NP tests (all subjects) and MR imaging (seropositives only) was repeated every 6-12 months; LP (seropositives only) was repeated yearly. Mean follow-up was 24.6 months. Neurological abnormalities, most related to hearing, were seen in 60 (38.2%) of 157 seropositives and 23 (30.3%) of 76 controls at baseline (p = NS). During follow-up, 43 (31.6%) of 136 seropositives had persistent hearing abnormalities compared to 9 (14.1%) of 64 seronegatives (p = 0.008). Seven HIV-seropositives developed peripheral neuropathy; this was more common among those with hearing abnormalities (p = 0.03). HIV-seropositives performed less well on NP tests than controls, but overall performance did not decline. Worsening brain atrophy by MR imaging or cerebrospinal fluid abnormalities are more common in HIV-seropositives than seronegatives and may share a common mechanism with peripheral neuropathy. Further study is needed to determine whether these abnormalities portend more serious neurological disease.     

山东省克山病病区与非病区1～15岁人群的心电图比较

为观察克山病发病区无自觉症状人群与非病区无自觉症状人群的心电图改变，以推断克山病发病区无自觉症状人群的整体心脏健康状况，随机检查了山东省克山病发病区2049人和非病区1595名无自觉症状1－15岁人群的心电图异常情况，结果表明两组人群的异常心电图改变项目不尽相同，但总的异常心电图检出率无明显差异，说明山东省克山病发病区人群与非病区人群的心脏健康状况基本接的。     

Destructive arthritis, rheumatoid factor, and HLA-DR4. Susceptibility versus severity, a case-control study

In response to the continuing debate as to whether seronegative rheumatoid arthritis (RA) and seropositive RA are part of the same disease spectrum or are distinct disorders, we evaluated 720 patients with definite and classic RA, of whom 53 subjects had definite persistently seronegative destructive disease. For all but 1 seronegative RA patient, a seropositive RA case control was identified and matched for age, disease duration, degree of destruction on hand radiographs, and disease-modifying drug therapy. DR typing was undertaken on these 105 patients, together with scoring of hand radiographs. The frequency of DR4 was 69% in seropositive RA patients and 60% in seronegative RA patients (P = 0.22), versus 36% in 318 healthy controls (P = 0.008 and P = 0.007 versus seropositive and seronegative RA, respectively). Patients were matched and rematched with different controls in a series of subanalyses in order to make comparisons of hand radiograph scores. We found that HLA-DR4 was associated with destructive RA in both seropositive and seronegative RA patients. In general, DR4+ patients had more severe disease by radiologic criteria than did DR4- patients. Thus, HLA-DR4 may be an additive factor to the serologic status and may be more closely related to disease severity than to disease susceptibility.     

THERAPEUTIC INTERVENTION IN RHEUMATOID ARTHRITIS: A CASE-CONTROLLED COMPARISON OF SERONEGATIVE AND SEROPOSITIVE DISEASE

The records of 684 patients with rheumatoid arthritis (RA) attendinga referral centre were evaluated. All available patients (62cases) with definite seronegative disease were matched, wherepossible, for sex, age and year of onset with seropositive controls(54 cases). Seronegative females were just as likely as thosewho were seropositive to require treatment with disease-modifyingantirheumatic drugs, whereas seronegative males were significantlyless likely to do so than seropositive controls. There wereno major differences in outcome or drug toxicity. Orthopaedicsurgery was equally common in the two groups, with a similarspectrum of procedures, but there was a trend towards more frequentupper limb large joint arthroplasty in the seronegative group,and this was particularly evident when elbow prostheses wereconsidered. Seronegative rheumatoid disease (at least in females)may be as severe as seropositive disease in a referral-centrepopulation and should be treated with similar vigour. KEY WORDS: Rheumatoid factor, Rheumatism, Arthritis, Rheumatoid.     

Cardiac Arrhythmias in Chagas'Heart Disease

Chagas’ Heart Disease. Chagas’ disease is a chronic parasitosis affecting most LatinAmerican countries, Its most important clinical manifestation is a late developing chronicmyocarditis and, much less frequently, an early acute myocarditis, Chagasic myocardial damage is microfocal and disseminated throughout the heart, In most cases, the coexistence ofareas of myocytic degeneration, inflammatory infiltration, and fibrosis suggests a permanentevolving process. Commonly, chronic chagasic myocarditis resemhies a dilated cardiomyopa–thy, with characteristic ECG abnormalities (atrial and ventricular extrasystoles, intraventricular and/or AV conduction disturbances, and primary ST-T wave changes), Since myocardialdamage is scattered throughout the heart, the ECG abnormalities (arrhythmias, conductiondisturbances, and repolarization changes) are also representative of the widespread cardiacinvolvement. Thus, sick sinus syndrome, atrial extrasystoles, intraatrial conduction disturbances, and atrial fibrillation or flutter are common findings in different stages of the disease, At the ventricular level, both conduction disturbances and arrhythmias are conspicuousexpressions of the myocardial damage. Right bundle branch block alone or in combinationwith left anterior hemiblock are the most common conduction defects, Further compromise ofthe conduction system can lead to different degrees of AV block, Chagas’ disease is the maincause of bundle branch block and AV block in endemic areas, In advanced cases of Chagas'heart disease, ventricular premature contractions are extremely frequent, multiforM. andrepetitive (couplets and runs of ventricular tachycardia), and show R on T phenomenon, Thesearrhythmias are usually aggravated by increased sympathetic tone, implying an enbanced riskof cardiac sudden death among chagasic patients, which is sometimes the first manifestation ofthe illness, Chronic chagasic myocarditis is the leading cause of cardiovascular death, mostly asa consequence of heart failure and sudden death, in areas where the disease is endemic.     

Increased risk of bacterial pneumonia in HIV-infected intravenous drug users without AIDS

Although patients with AIDS have been noted to be at risk for bacterial pneumonia as well as opportunistic infections, little is known about the risk of bacterial pneumonia in HIV-infected populations without AIDS. To determine the incidence of bacterial pneumonia in a well defined population of intravenous drug users (IVDUs), and to examine any association with HIV infection, we prospectively studied 433 IVDUs without AIDS, enrolled in a longitudinal study of HIV infection in an out-patient methadone maintenance program. At enrollment, 144 (33.3%) subjects were HIV-seropositive, 289 (66.7%) were seronegative. Over a 12-month period, 14 out of 144 (9.7%) seropositive subjects were hospitalized for community-acquired bacterial pneumonia, compared with six out of 289 (2.1%) seronegative subjects. The cumulative yearly incidence of bacterial pneumonia was 97 out of 1000 for seropositives and 21 out of 1000 for seronegatives (risk ratio = 4.7, P less than 0.001). Eleven out of 14 (78.6%) cases among the seropositive patients were due to either Streptococcus pneumoniae [5] or Hemophilus influenzae [6]. Two out of 14 (14.3%) cases among the seropositives were fatal. Stratifying by level of intravenous drug use indicated that even among subjects not reporting active intravenous drug use at study entry, eight out of 82 (9.8%) seropositives compared with three out of 211 (1.4%) seronegatives were hospitalized for bacterial pneumonia over the study period (risk ratio = 6.9, P less than 0.01). This study shows a markedly increased incidence of bacterial pneumonia associated with HIV infection in IVDUs without AIDS.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac involvement in African and American trypanosomiasis

American trypanosomiasis (Chagas disease) and human African trypanosomiasis (HAT; sleeping sickness) are both caused by single-celled flagellates that are transmitted by arthropods. Cardiac problems are the main cause of morbidity in chronic Chagas disease, but neurological problems dominate in HAT. Physicians need to be aware of Chagas disease and HAT in patients living in or returning from endemic regions, even if they left those regions long ago. Chagas heart disease has to be taken into account in the differential diagnosis of cardiomyopathy, primarily in patients with pathological electrocardiographic (ECG) findings, such as right bundle branch block or left anterior hemiblock, with segmental wall motion abnormalities or aneurysms on echocardiography, and in young patients with stroke in the absence of arterial hypertension. In HAT patients, cardiac involvement as seen by ECG alterations, such as repolarisation changes and low voltage, is frequent. HAT cardiopathy in general is benign and does not cause relevant congestive heart failure and subsides with treatment. We review the differences between the American and African trypanosomiasis with the main focus on the heart.     

American trypanosomiasis and electrocardiographic alterations among industrial workers in São Paulo, Brazil

In this article, we evaluate electrocardiographic (ECG) alterations among urban workers from a mechanical-metallurgical industry in Sao Paulo, Brazil. In a cross-sectional survey carried out in 1980, we found 2.2% positive serological testing for Trypanosoma cruzi infection among 27,081 workers. A comparison between seropositive workers and a random sample of seronegative workers frequency-matched by age and occupation revealed that seropositive workers had a much lower educational level, and that a higher proportion of seropositive workers had ECG abnormalities (42.7%) when compared to those negative for T. cruzi infection (19.8%). The high frequency of ECG abnormalities suggests the need to provide medical assistance to these workers, without any kind of discrimination and to bring in a form of management that would decrease this dangerous risk to the workers and people around them.     

An outbreak of Chagas' disease in southwestern Bahia, Brazil

An outbreak of 20 cases of acute Chagas' disease followed the movement of Triatoma infestans into the county of Riacho de Santana, Bahia, Brazil. The outbreak was unusual in that the majority of cases occurred in adults. Vector control measures were implemented. Three years after the outbreak, a rural community was examined to determine the extent of human infection and disease due to Trypanosoma cruzi. Ninety of 440 residents (20.5%) had serologic evidence of infection, but rates of electrocardiographic (EKG) abnormalities were low. Comparison of age-specific rates of seropositivity and EKG abnormalities with rates from areas with endemic Chagas' disease supported the hypothesis of a recent epidemic. Control measures appear to have interrupted transmission in the region.