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- Sun, Y, et al.
(författare)
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Estimation of volume flow rate by surface integration of velocity vectors from color Doppler images.
- 1995
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Ingår i: Journal of the American Society of Echocardiography. - 0894-7317 .- 1097-6795 .- 0735-1097 .- 1558-3597. ; 8:6, s. 904-914
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Tidskriftsartikel (refereegranskat)abstract
- A new Doppler echocardiographically based method has been developed to quantify volume flow rate by surface integration of velocity vectors (SIVV). Electrocardiographic-gated color Doppler images acquired in two orthogonal planes were used to estimate volume flow rate through a bowl-shaped surface at a given time and distance from the probe. To provide in vitro validation, the method was tested in a hydraulic model representing a pulsatile flow system with a restrictive orifice. Accurate estimates of stroke volume (+/- 10%) were obtained in a window between 1.2 and 1.6 cm proximal to the orifice, just before the region of prestenotic acceleration. By use of the Bernoulli's equation, the estimated flows were used to generate pressure gradient waveforms across the orifice, which agreed well with the measured flows. To demonstrate in vivo applicability, the SIVV method was applied retrospectively to the determination of stroke volume and subaortic flow from the apical three-chamber and five-chamber views in two patients. Stroke volume estimates along the left ventricular outflow tract showed a characteristic similar to that in the in vitro study and agreed well with those obtained by the Fick oxygen method. The region where accurate measurements can be obtained is affected by instrumental factors including Nyquist velocity limit, wall motion filter cutoff, and color flow sector angle. The SIVV principle should be useful for quantitative assessment of the severity of valvular abnormalities and noninvasive measurement of pulsatile volume flows in general.
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- Hedén, Bo, et al.
(författare)
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Agreement between artificial neural networks and experienced electrocardiographer on electrocardiographic diagnosis of healed myocardial infarction
- 1996
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Ingår i: Journal of the American College of Cardiology. - 0735-1097. ; 28:4, s. 1012-1016
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. The purpose of this study was to compare the diagnoses of healed myocardial infarction made from the 12-lead electrocardiogram (ECG) by artificial neural networks and an experienced electrocardiographer. Background. Artificial neural networks have proved of value in pattern recognition tasks. Studies of their utility in ECG interpretation have shown performance exceeding that of conventional ECG interpretation programs. The latter present verbal statements, often with an indication of the likelihood for a certain diagnosis, such as 'possible left ventricular hypertrophy'. A neural network presents its output as a numeric value between 0 and 1; however, these values can be interpreted as Bayesian probabilities. Methods. The study was based on 351 healthy volunteers and 1,313 patients with a history of chest pain who had undergone diagnostic cardiac catheterization. A 12-lead ECG was recorded in each subject. An expert electrocardiographer classified the ECGs in five different groups by estimating the probability of anterior myocardial infarction. Artificial neural networks were trained and tested to diagnose anterior myocardial infarction. The network outputs were divided into five groups by using the output values and four thresholds between 0 and 1. Results. The neural networks diagnosed healed anterior myocardial infarctions at high levels of sensitivity and specificity. The network outputs were transformed to verbal statements, and the agreement between these probability estimates and those of an expert electrocardiographer was high. Conclusions. Artificial neural networks can be of value in automated interpretation of ECGs in the near future.
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- Liuba, Petru, et al.
(författare)
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Predictors of early postoperative complications after arterial switch operation of newborns with transposition of the great arteries
- 2014
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Ingår i: Journal of the American College of Cardiology. - 0735-1097. ; 63:12, Suppl 1, s. 584-584
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Konferensbidrag (refereegranskat)abstract
- Background: Lund is one of the two tertiary referral centers for pediatric cardiac surgery in Sweden, with nearly 350 surgical procedures every year. We performed a retrospective analysis of newborns and infants with transposition of the great arteries (TGA) operated with arterial switch (ASO) during the past 10 years. Methods: a single-institution retrospective analysis of nearly 100 newborns and infants with transposition of the great arteries (TGA) operated with arterial switch during the past 10 years. Postoperative morbidity and mortality during the the first month was recorded.Patients with TGA/double outlet right ventricle were excluded from the analysis. Results: 103 patients with TGA (median for birth weight, gestational week, and age at surgery: 3.5 kg, 39 weeks, and 4 days) were included. There was only 1 death. Surgery beyond 5 days of age (n=46) was associated with prolonged mechanical ventilation (p
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- Pettersson, Jonas, et al.
(författare)
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Changes in high-frequency QRS components are more sensitive than ST segment deviation for detecting acute coronary artery occlusion
- 2000
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Ingår i: Journal of the American College of Cardiology. - 0735-1097. ; 36:6, s. 1827-1834
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES This study describes changes in high-frequency QRS components (HF-QRS) during percutaneous transluminal coronary angioplasty (PTCA) and compares the ability of these changes in HF-QRS and ST-segment deviation in the standard 12-lead electrocardiogram (ECG) to detect acute coronary artery occlusion. BACKGROUND Previous studies have shown decreased HF-QRS in the frequency range of 150–250 Hz during acute myocardial ischemia. It would be important to know whether the high-frequency analysis could add information to that available from the ST segments in the standard ECG. METHODS The study population consisted of 52 patients undergoing prolonged balloon occlusion during PTCA. Signal-averaged electrocardiograms (SAECG) were recorded prior to and during the balloon inflation. The HF-QRS were determined within a bandwidth of 150–250 Hz in the preinflation and inflation SAECGs. The ST-segment deviation during inflation was determined in the standard frequency range. RESULTS The sensitivity for detecting acute coronary artery occlusion was 88% using the high-frequency method. In 71% of the patients there was ST elevation during inflation. If both ST elevation and depression were considered, the sensitivity was 79%. The sensitivity was significantly higher using the high-frequency method, p < 0.002, compared with the assessment of ST elevation. CONCLUSIONS Acute coronary artery occlusion is detected with higher sensitivity using high-frequency QRS analysis compared with conventional assessment of ST segments. This result suggests that analysis of HF-QRS could provide an adjunctive tool with high sensitivity for detecting acute myocardial ischemia.
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- Andersson, Bert, 1952, et al.
(författare)
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The DD genotype of the angiotensin-converting enzyme gene is associated with increased mortality in idiopathic heart failure.
- 1996
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097. ; 28:1, s. 162-7
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate the association between the homozygous DD (deletion) genotype of the angiotensin-converting enzyme gene and survival and cardiac function in patients with idiopathic congestive heart failure.The DD genotype gene is a linkage marker for an etiologic mutation at or near the angiotensin-converting enzyme gene and has been associated with increased risk for the development of coronary artery disease, left ventricular hypertrophy and left ventricular dilation after myocardial infarction. We investigated the association between this angiotensin-converting enzyme genotype and mortality in a population-based cohort of patients with idiopathic congestive heart failure.The genotype was determined in 193 patients recruited from a large unselected population of patients with congestive heart failure (n = 2,711). The patients were studied with echocardiography, and survival data were obtained after 5 years of follow-up. A control group from the general population (n = 77) was studied by a similar procedure.The frequency of the D allele was not significantly different in the study and control groups (0.57 vs 0.56, p = NS). Long-term survival was significantly worse in the patients with the DD genotype than in the remaining patients (5-year survival rate 49% vs. 72%, p = 0.0011 as assessed by log rank test). The independent importance of the DD genotype for prognosis was verified by a multivariate Cox proportional hazards analysis, by which the odds ratio for mortality and the DD genotype was 1.69 (95% confidence interval 1.01 to 2.82). The only significant difference in cardiac function data between the two groups was an increase in left ventricular mass index in the DD group (153 +/- 57 vs 134 +/- 44 g/m2, p = 0.019).Angiotensin-converting enzyme gene DD polymorphism was associated with poorer survival and an increase in left ventricular mass in patients with idiopathic heart failure. The results suggest a possible pathophysiologic pathway between angiotensin-converting enzyme gene polymorphism, angiotensin-converting enzyme activity, myocardial hypertrophy and survival. Therefore, the DD genotype may be a marker of poor prognosis in patients with congestive heart failure.
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- Chiale, P A, et al.
(författare)
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High prevalence of antibodies against beta 1- and beta 2-adrenoceptors in patients with primary electrical cardiac abnormalities.
- 1995
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097. ; 26:4, s. 864-9
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This study sought to determine the prevalence of autoantibodies directed against the beta-adrenoceptors in patients with primary electrical cardiac abnormalities, including atrial arrhythmias, ventricular arrhythmias and conduction disturbances, in the absence of any other cardiac abnormality. BACKGROUND: Using synthetic peptides corresponding to the predicted sequences for the second extracellular loop of the human beta 1- and beta 2-adrenoceptors as antigenic targets, autoantibodies directed against the beta-adrenoceptors were recently shown to occur in patients with idiopathic dilated cardiomyopathy and Chagas' heart disease. METHODS: Eighty-six patients (57 with primary electrical abnormalities, 29 with idiopathic dilated cardiomyopathy) and 101 healthy and cardiopathic control subjects were studied. Antibodies against the beta 1- and beta 2-peptides were detected with an enzyme immunoassay performed in blinded manner. In nine selected (seropositive) cases, the immunoglobulin G (IgG) fraction was tested for functional effects on the rate of beating of cultured neonatal rat cardiomyocytes. RESULTS: Antibodies recognizing the beta 1- and beta 2-peptides were found in 11 (52.3%) of 21 patients with ventricular arrhythmias (p < 0.01), 5 (35.7%) of 14 patients with conduction disturbances (p < 0.05), 3 (13.6%) of 22 patients with atrial arrhythmias (p > 0.05) and 11 (37.9%) of 29 patients with dilated cardiomyopathy (p < 0.05) compared with 15 (14.8%) of 101 control subjects. A rapid increase in the rate of beating of the cultured cardiomyocytes was induced by IgG from a selected group of patients, suggesting an agonist-like interaction with a functional epitope. This response was mediated by stimulation of both the beta 1- and beta 2-adrenoceptors in the patients with primary ventricular arrhythmias but only the beta 1-adrenoceptors in the patients with idiopathic dilated cardiomyopathy. CONCLUSIONS: Primary ventricular arrhythmias and conduction disturbances, like idiopathic cardiomyopathy, show a high prevalence of antibodies interacting with functional epitopes of the beta-adrenoceptors, suggesting a common or similar abnormal immunoregulatory process.
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- Frostfeldt, Gunnar, et al.
(författare)
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Low molecular weight heparin (Dalteparin) as adjuvant treatment to thrombolysis in acute myocardial infarction-a pilot study : BIOchemical markers in acute coronary syndromes (BIOMACS II)
- 1999
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Ingår i: Journal of the American College of Cardiology. - 0735-1097 .- 1558-3597. ; 33:3, s. 627-633
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This randomized, double blind, placebo-controlled pilot trial evaluated the effect of dalteparin as an adjuvant to thrombolysis in patients with acute myocardial infarction regarding early reperfusion, recurrent ischemia and patency at 24 h. BACKGROUND: Low-molecular-weight heparin, given subcutaneously twice daily without monitoring, might be an attractive alternative to conventional intravenous heparin in the treatment of acute myocardial infarction. METHODS: In 101 patients dalteparin/placebo 100 IU/kg was given just before streptokinase and a second injection 120 IU/kg after 12 h. Monitoring with continuous vector-ECG was done to obtain signs of early reperfusion and later ischemic episodes. Blood samples for myoglobin were obtained at start and after 90 min to evaluate signs of reperfusion. Coronary angiography was performed after 20-28 h to evaluate TIMI-flow in the infarct-related artery. RESULTS: Dalteparin added to streptokinase tended to provide a higher rate of TIMI grade 3 flow in infarct-related artery compared to placebo, 68% versus 51% (p = 0.10). Dalteparin had no effects on noninvasive signs of early reperfusion. In patients with signs of early reperfusion, there seemed to be a higher rate of TIMI grade 3 flow, 74% versus 46% (myoglobin) (p = 0.04) and 73% versus 52% (vector-ECG) (p = 0.11). Ischemic episodes 6-24 h. after start of treatment were fewer in the dalteparin group, 16% versus 38% (p = 0.04). CONCLUSIONS: When dalteparin was added as an adjuvant to streptokinase and aspirin, there were tendencies for less ECG monitoring evidence of recurrent ischemia and better patency at 24 h, warranting further study.
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- Goel, Kashish, et al.
(författare)
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Novel Cyp2C19 Genetic Variants associated with Stent Thrombosis : a Next Generation Sequencing Study
- 2018
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 71:11, s. 1205-1205
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundCommonly tested Loss-of-function (LOF) alleles in CYP2C19 are present in 30-40% of patients who experience stent thrombosis. The objective of this study was to identify novel genetic variants in CYP2C19 gene associated with stent thrombosis.MethodsWe included 70 patients with definite stent thrombosis while on clopidogrel who had stored DNA samples in our institutional (n=12) or PLATO trial (n=70) biorepository. Cases were matched 1:1 with controls for age, race, sex, diabetes, type of stent, and presentation. All controls were on clopidogrel and free of recurrent events. Clinical Pharmacogenetics (PGx) Implementation Consortium (CPIC) guidelines were used to determine the list of known PGx variants and dbSNP version 142 was used to assess novel variants. Whole exome sequencing was performed using the protocol for Agilent's SureSelect Human All Exon v5 + UTRs 75 MB kit and additional custom primers were designed to cover the entire CYP2C19 gene.ResultsMean age was 63 ± 12 years, and 71% were male. We identified a total of 456 single nucleotide variants (SNV) in the CYP2C19 gene (cases: 376; controls: 288), of which 5 were synonymous, 6 non-synonymous, 46 indels and 449 intronic SNVs. There were 168 vs. 80 novel CYP2C19 variants and 10 vs. 5 indels in cases vs. controls, respectively. Four SNVs (3 missense and 1 synonymous) were present only in cases, whereas 3 SNVs (1 misssense, 1 synonymous and 1 intron) were unique to controls. There were no detectable differences in the frequency of LOF CYP2C19*2 allele (cases 34% vs. controls 31%) or other CPIC annotated PGx variants in cases and controls. After excluding the known PGx variants, there were 10 indels (all intronic) out of which 7 were novel in cases and were not present in controls.ConclusionWe describe several novel genetic variants in the CYP2C19 gene in patients treated with clopidogrel after coronary stenting. We identified 168 novel SNVs and 10 novel indels in the CYP2C19 gene of patients with stent thrombosis. Four SNVs and 9 indels were unique to cases. Functional validation of these CYP2C19 genetic variants may provide important insights of CYP2C19 and the pathophysiology of stent thrombosis in clopidogrel treated patients.
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- Hagstrom, Emil, et al.
(författare)
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IMPACT OF BODY WEIGHT AT AGE 20 AND WEIGHT GAIN DURING ADULTHOOD ON MIDLIFE CORONARY ARTERY CALCIUM IN 15,000 MEN AND WOMEN : AN INTERIM ANALYSIS OF THE SWEDISH CARDIOPULMONARY BIOIMAGE STUDY
- 2019
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 1692-1692
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundElevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS), we investigated the association between weight at age 20, weight gain to midlife and coronary artery calcium score (CACS) at midlife.MethodsIn the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on CACS at midlife, self-reported body weight at age 20 and weight at examination in SCAPIS were recorded.ResultsCACS in midlife was significantly higher with increasing weight at age 20 (p<0.001 for both sexes), and then increased with weight gain until midlife at all levels of body weight at age 20 after adjusting for age, height, smoking, alcohol intake, education level, exercise levels and LDL cholesterol. However, the association with weight gain was only significant in men (p = 0.047), not in women (p=0.474). No significant interaction was seen between weight at age 20 and midlife weight with CACS. The effect of weight at age 20 on CACS was significantly more marked in men than in women, as was the effect of weight gain (p<0.001 for both interactions).ConclusionWeight at age 20 and weight gain to midlife were both related to CACS, but much more markedly so in men than in women, indicating a generally larger effect of both early adult weight and further weight gain until midlife on CACS in men, compared to women.
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- Holm, M, et al.
(författare)
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TICAGRELOR PHARMACOKINETICS IN NSTEMI
- 2016
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Ingår i: JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY. - 0735-1097. ; 67:13, s. 543-543
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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- Jernberg, Tomas, et al.
(författare)
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N-terminal pro brain natriuretic peptide on admission for early risk stratification of patients with chest pain and no ST-segment elevation
- 2002
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Ingår i: Journal of the American College of Cardiology. - 0735-1097 .- 1558-3597. ; 40:3, s. 437-445
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- OBJECTIVES: The study evaluated the prognostic value of single measurement of N-terminal pro brain natriuretic peptide (NT-proBNP) obtained on admission in patients with symptoms suggestive of an acute coronary syndrome and no ST-segment elevation. BACKGROUND: Patients with symptoms suggestive of an acute coronary syndrome and no ST-segment elevation constitute a large and heterogeneous population. Early risk stratification has been based on clinical background factors, electrocardiography (ECG) and biochemical markers of myocardial damage. The neurohormonal activation has, so far, received less attention. METHODS: The NT-proBNP was analyzed on admission in 755 patients admitted because of chest pain and no ST-segment elevation. Patients were followed concerning death for 40 months (median). RESULTS: The median NT-proBNP level was 400 (111 to 1646) ng/l. Compared to the lowest quartile, patients in the second, third and fourth quartiles had a relative risk of subsequent death of 4.2 (1.6 to 11.1), 10.7 (4.2 to 26.8) and 26.6 (10.8 to 65.5), respectively. When NT-proBNP was added to a Cox regression model including clinical background factors, ECG and troponin T, the NT-proBNP levels were independently associated with prognosis. CONCLUSIONS: A single measurement of NT-proBNP on admission will substantially improve the early risk stratification of patients with symptoms suggestive of an acute coronary syndrome and no ST-segment elevation. A combination of clinical background factors, ECG, troponin T and NT-proBNP obtained on admission will provide a highly discerning tool for risk stratification and further clinical decisions.
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