Congenital heart block : a study of diagnostics, pathogenesis, prognosis and treatment

Congenital heart block (CHB) is a rare condition with considerable mortality. In most patients the disease is associated with fetal exposure to maternal SSA-Ro and/or SSB-La autoantibodies (AB) and develops in fetal life. Accuracy in fetal diagnostics is important to distinguish benign from life threatening conditions. Transplacental steroid treatment to improve survival has been tried but the effect is unclear. The majority of exposed children do not develop CHB, but sometimes transitory conduction abnormalities, normalizing at birth, with unknown outcome in childhood. Pacemaker (PM) therapy to CHB patients is lifesaving, but does not always prevent development of heart failure. The aims of this thesis were to study: The differential diagnostics in fetal bradycardia (paper I), the effect of transplacental steroid treatment and risk factors associated with a poor outcome (paper II), the clinical pathogenesis of antibody exposure (paper III) and PM treatment in young patients with complete atrioventricular block (CAVB) (paper IV). In paper I, the diagnostic accuracy with Echo Doppler techniques was studied retrospectively in a regional cohort of 65 patients with fetal bradycardia. We found that the bradyarrhythmic mechanism was identified correctly in all but one patient. Benign blocked atrial bigeminies showed close resemblance to second-degree AVB in a few cases, but could be differentiated with meticulous measurements. In paper II, the effects of exposure to transplacental treatment with fluorinated steroids in fetal second- and third degree AVB were studied retrospectively in a multicenter, multinational setting of 175 patients. Ninety-one percent were alive at birth and survival rate in the neonatal period was 93%, similar in treated and untreated fetuses. Risk factors (RF) associated with a poor outcome were gestational age < 20 weeks, ventricular rate =50, hydrops and impaired left ventricular function (LVF) at diagnosis. The presence of =1 RF was associated with a 10-fold increase in mortality before birth and a 6-fold increase in the neonatal period, independent of treatment. In paper III, the effects of prenatal exposure to maternal autoantibodies on heart function and conduction properties were investigated in a cross-sectional follow-up of pre-school children who did not develop fetal complete heart block. Sixteen patients who developed AV time interval prolongation in utero (group A) were compared with 41 who did not (group B). Ten percent (6/57) exposed to maternal autoantibodies in fetal life had developed first- degree AVB at follow-up, in spite of a normal ECG at birth or at 1 month of age. All 6 had prolonged AV-time intervals in utero. LVF in terms of M-mode, was normal in all patients, but myocardial performance index was slightly higher in group A. In paper IV, the outcome of young patients with CAVB and PM was studied retrospectively in a national cohort of 127 patients. Survival rate after 9 years of PM treatment was 96% and 8% developed LV dysfunction. There was a gender difference in cardiac status prior to PM but not at FU. Exposure to antibodies did not change the outcome significantly, but diagnosis <1 month of age and LV dysfunction before PM were associated with a poor outcome

Comparison of Single-Grip Harvester Productivity in Clear- and Shelterwood Cutting

An increased interest in the use of shelterwood stands to promote regeneration has led to an interest in how singlegrip harvester productivity is affected by shelterwood cutting compared to clearcutting. A comparative time study of a large singlegrip harvester was made in a spruce stand in northern Sweden. Three treatments were used. Shelterwood cutting leaving: 1) a sparse stand, 2) a dense residual stand, and 3) clearcutting. Each treatment was replicated three times. Results show that productivity decreases from 64 m3 per effective hour in clearcutting to 54 and 41 m3 per effective hour when shelterwoods with 259 and 381 stems ha1, respectively, were retained

High levels of tissue plasminogen activator (tPA) antigen precede the development of type 2 diabetes in a longitudinal population study. The Northern Sweden MONICA Study

BACKGROUND: Impaired fibrinolysis is found in impaired glucose tolerance and type 2 diabetes, associated with components of the metabolic syndrome. There are no data concerning fibrinolysis in subjects with normal glucose tolerance that convert to diabetes. METHODS: We studied the activities of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) and the levels of tPA antigen (a marker of endothelial dysfunction) in 551 subjects with normal glucose tolerance in 1990 in relation to incident diabetes during nine years of follow-up. RESULTS: Subjects with diabetes at follow-up (n = 15) had significantly lower baseline tPA activity and higher PAI-1 activity and tPA antigen than non-converters. The risk of diabetes increased linearly across quartiles of PAI-activity (p = 0.007) and tPA antigen (p < 0.001) and decreased across quartiles of tPA activity (p = 0.026). The risk of diabetes with low tPA activity or high PAI-1 activity persisted after adjustment for age and sex but diminished to a non-significant level after further adjustments. The odds ratio of diabetes for high tPA antigen was 10.4 (95% confidence interval 2.7–40) adjusted for age and sex. After further adjustment for diastolic blood pressure, waist circumference, insulin, triglycerides, fasting and post load glucose the odds ratio was 6.5 (1.3–33, p = 0.024). CONCLUSIONS: Impaired fibrinolysis and endothelial dysfunction are evident in subjects with normal glucose tolerance who later develop diabetes. High tPA antigen is predictive of future diabetes independent from the metabolic syndrome

Gender differences in trends of acute myocardial infarction events: The Northern Sweden MONICA study 1985 – 2004

<p>Abstract</p> <p>Background</p> <p>The registration of non-fatal and fatal MI events initiated 1985 in the WHO MONICA project has been ongoing in northern Sweden since the end of the WHO project in 1995. The purpose of the present study was to analyze gender differences in first and recurrent events, case fatality and mortality in myocardial infarction (MI) in Northern Sweden during the 20-year period 1985 – 2004.</p> <p>Methods</p> <p>Diagnosed MI events in subjects aged 25–64 years in the Counties of Norrbotten and Västerbotten were validated according to the MONICA protocol. The total number of events registered up to January 1, 2005 was 11,763: 9,387 in men and 2,376 in women.</p> <p>Results</p> <p>The proportion of male/female events has decreased from 5.5:1 to 3:1. For males the reductions were 30% and 70% for first and recurrent MI, respectively, and for women 0% and 40% in the 55–64 year group. For both sexes a 50% reduction in 28-day case fatality was seen in the 25–64 year-group. Mortality was reduced by 69% and 45% in men and women, respectively.</p> <p>Conclusion</p> <p>First and recurrent events of myocardial infarction was markedly reduced in men over the 20-year observation period, but for women the reduction was seen only for recurrent infarctions. Case fatality, on the other hand, was markedly reduced for both sexes. As a result of the positive effects on incidence and case fatality a substantial reduction was seen in total mortality, most pronounced for men.</p

Better long-term survival in young and middle-aged women than in men after a first myocardial infarction between 1985 and 2006. an analysis of 8630 patients in the Northern Sweden MONICA Study

<p>Abstract</p> <p>Background</p> <p>There is conflicting and only scant evidence on the effect of gender on long-term survival after a myocardial infarction (MI). Our aim was to analyse sex-specific survival of patients for up to 23 years after a first MI in northern Sweden and to describe time trends.</p> <p>Methods</p> <p>The Northern Sweden MONICA Myocardial Infarction Registry was linked to The Swedish National Cause of Death Registry for a total of 8630 patients, 25 to 64 years of age, 6762 men and 1868 women, with a first MI during 1985-2006. Also deaths before admission to hospital were included. Follow-up ended on August 30, 2008.</p> <p>Results</p> <p>Median follow-up was 7.1 years, maximum 23 years and the study included 70 072 patient-years. During the follow-up 45.3% of the men and 43.7% of the women had died. Median survival for men was 187 months (95% confidence interval (CI) 179-194) and for women 200 months (95% CI 186-214). The hazard ratio (HR) for all cause mortality after adjustment for age group was 1.092 (1.010-1.18, <it>P </it>= 0.025) for females compared to males, <it>i.e</it>. 9 percent higher survival in women. After excluding subjects who died before reaching hospital HR declined to 1.017 (95%CI 0.93-1.11, <it>P </it>= 0.7). For any duration of follow-up a higher proportion of women were alive, irrespective of age group. The 5-year survivals were 75.3% and 77.5%, in younger (<57 years) men and women and were 65.5% and 66.3% in older (57-64 years) men and women, respectively. For each of four successive cohorts survival improved. Survival time was longer for women than for men in all age groups.</p> <p>Conclusions</p> <p>Age-adjusted survival was higher among women than men after a first MI and has improved markedly and equally in both men and women over a 23-year period. This difference was due to lower risk for women to die before reaching hospital.</p

Environmentally Reformed Travel Habits During the 2006 Congestion Charge Trial in Stockholm—A Qualitative Study

Policy measures that reduce or replace road traffic can improve environmental conditions in most large cities. In Stockholm a congestion charge was introduced during a test period in 2006. This was a full-scale trial that proved to meet its targets by reducing traffic crossing the inner city segment during rush hours by 20%. Emissions of carbon dioxide and particles were also substantially reduced. This study, based on in-depth interviews with 40 inhabitants, analyses how and why new travel habits emerged. The results show that particular, sometimes unexpected, features of everyday life (habits, resources, opportunities, values, etc.) were crucial for adjustment of travel behaviour in relation to the policy instrument. One example was that those accustomed to mixing different modes of transport on a daily basis more easily adapted their travel in the targeted way. On a more general level, the results revealed that the policy measure could actually tip the scales for the individual towards trying out a new behaviour

Endocardial pacing compared to epicardial left ventricle pacing and right ventricle pacing: A single-center long-term experience in a pediatric population

Background and aims: Pediatric pacing is usually performed as epicardial pacing in small children in need of pacemaker therapy. Epicardial pacing compared with transvenous pacing for pediatric complete atrioventricular block (CAVB) has different strengths and weaknesses. The epicardial left ventricular wall position of the lead has been considered superior, in terms of contraction pattern, compared to a transvenous right ventricular stimulation. We aimed to compare QRS duration and cardiac function before and after the switch from epicardial to transvenous pacing in a pediatric population. Methods: Pediatric patients with congenital or acquired CAVB, who underwent a switch from epicardial-to transvenous pacing at our center from 2005 to 2021, were identified through the national ICD- and Pacemaker Registry. Data regarding clinical status, ECG, and echocardiography before and after the switch and at last follow-up were collected. Results: We included 15 children. The median age at the switch was 6.7 (4.4–11.7) years with a median weight of 21 (15–39) Kg. The median QRS duration with the transvenous systems was 136 (128–152) ms vs. a QRS duration during epicardial stimulation of 150 (144–170) ms with a median difference in QRS duration of 14 (6–20) ms. Children with a post-surgical AV block had a broader QRS duration, both with epicardial and endocardial stimulation. Before the switch, there was one patient with impaired left ventricular function (LVF) but with normal left ventricular end-diastolic diameters. After the switch, one patient developed symptomatic LV dysfunction with the recovery of LVF at the last follow-up after being implanted with a cardiac resynchronization therapy device. Conclusions: Our report of pediatric patients after switching from epicardial to transvenous pacing shows how transvenous pacing is not inferior to epicardial pacing in terms of QRS duration and no significant deterioration of cardiac function was detectable

Evaluation of four qualitative methods for detection of beta-lactamase production in Staphylococcus and Micrococcus species

Four qualitative methods for the detection of beta-lactamase production in Staphylococcus and Micrococcus species were evaluated and compared with a quantitative macroiodometric reference method. The disc diffusion test with penicillin G and the cloverleaf method could not separate beta-lactamase-positive from beta-lactamase-negative strains. Two applications of the chromogenic cephalosporin test, using uninduced strains and strains grown on blood agar plates, gave a large number of false negative and false positive results. False negative reactions were most common among uninduced strains, while the false positive reactions were most often recorded for Staphylococcus saprophyticus. A high degree of efficiency was recorded for the nitrocefin spot test, using induced strains grown on antibiotic susceptibility agar, and for the starch-iodine plate method. The starch-iodine plate with methicillin as inducer gave the most reliable results