Ragnar Danielsen

Ragnar Danielsen
National University Hospital of Iceland | LSH · Department of Cardiology

Doctor of Medicine, Clinical Professor.

About

128
Publications
6,396
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1,252
Citations
Introduction
Ragnar Danielsen currently works at the Department of Cardiology, National University Hospital of Iceland. Ragnar does research in Cardiology and Internal Medicine (General Medicine). Their current projects are 'Heart failure' , dilated cardiomyopathy and endocarditis.
Additional affiliations
September 1990 - present
National University Hospital of Iceland
Position
  • Managing Director

Publications

Publications (128)
Article
Background: Cancer screening is performed worldwide for several malignancies. Monoclonal gammopathy of undetermined significance (MGUS) precedes multiple myeloma (MM) and related lymphoproliferative disorders (LP). However, less than 5% of all MM patients are diagnosed during their precursor state and individuals who develop MM while being monitore...
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Objective Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinical...
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Monoclonal gammopathy of undetermined significance (MGUS) precedes multiple myeloma (MM). Population-based screening for MGUS could identify candidates for early treatment in MM. Here we describe the Iceland Screens, Treats, or Prevents Multiple Myeloma study (iStopMM), the first population-based screening study for MGUS including a randomized tria...
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Aims: To explore whether variability in dietary cholesterol and phytosterol absorption impacts the risk of coronary artery disease (CAD) using as instruments sequence variants in the ABCG5/8 genes, key regulators of intestinal absorption of dietary sterols. Methods and results: We examined the effects of ABCG5/8 variants on non-high-density lipo...
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Objective The myosin-binding protein C ( MYBPC3 ) c.927-2A>G founder mutation accounts for >90% of sarcomeric hypertrophic cardiomyopathy (HCM) in Iceland. This cross-sectional observational study explored the penetrance and phenotypic burden among carriers of this single, prevalent founder mutation. Methods We studied 60 probands with HCM caused...
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Background: Lipoprotein(a) [Lp(a)] is a causal risk factor for cardiovascular diseases that has no established therapy. The attribute of Lp(a) that affects cardiovascular risk is not established. Low levels of Lp(a) have been associated with type 2 diabetes (T2D). Objectives: This study investigated whether cardiovascular risk is conferred by Lp...
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Features of the QRS complex of the electrocardiogram, reflecting ventricular depolarisation, associate with various physiologic functions and several pathologic conditions. We test 32.5 million variants for association with ten measures of the QRS complex in 12 leads, using 405,732 electrocardiograms from 81,192 Icelanders. We identify 190 associat...
Article
Aims: Non-ischaemic cardiomyopathies (NICM) can cause heart failure and death. Cardiac magnetic resonance (CMR) detects myocardial scar/fibrosis associated with myocardial infarction (MI) and NICM with late gadolinium enhancement (LGE). The aim of this study was to determine the prevalence and prognosis of ischaemic and non-ischaemic myocardial fi...
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Background: Dilated cardiomyopathy (DCM) is an important cause of heart failure. Variants in >50 genes have been reported to cause DCM, but causative variants have been found in less than half of familial cases. Variants causing DCM in Iceland have not been reported before. Methods: We performed a genome-wide association study on DCM based on wh...
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Aims: Coarctation of the aorta (CoA) accounts for 4-8% of congenital heart defects (CHDs) and confers substantial morbidity despite treatment. It is increasingly recognized as a highly heritable condition. The aim of the study was to search for sequence variants that affect the risk of CoA. Methods and results: We performed a genome-wide associa...
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Aortic valve stenosis (AS) is the most common valvular heart disease, and valve replacement is the only definitive treatment. Here we report a large genome-wide association (GWA) study of 2,457 Icelandic AS cases and 349,342 controls with a follow-up in up to 4,850 cases and 451,731 controls of European ancestry. We identify two new AS loci, on chr...
Preprint
Aortic valve stenosis (AS) is the most common valvular heart disease, characterized by a thickened and calcified valve causing left ventricular outflow obstruction. Severe AS is a significant cause of morbidity and mortality, affecting approximately 5% of those over 70 years of age 1,2,3 . Little is known about the genetics of AS, although recently...
Preprint
Coarctation of the aorta (CoA) accounts for 4-8% of congenital heart defects (CHDs) and carries substantial morbidity despite treatment ¹ . We performed a genome-wide association study (GWAS) of CoA among 120 Icelandic cases and 355,166 controls and found association with a rare (frequency = 0.34%) missense mutation p.Arg721Trp in MYH6 (odds ratio...
Article
Background: The screening of Icelandic patients clinically diagnosed with hypertrophic cardiomyopathy resulted in identification of 8 individuals from 2 families with X-linked Fabry disease (FD) caused by GLA(α-galactosidase A gene) mutations encoding p.D322E (family A) or p.I232T (family B). Methods and results: Familial screening of at-risk re...
Article
Objectives: To assess the prevalence of heart failure (HF) in a randomly selected study population of elderly individuals representing the general population of Iceland. Furthermore, to project the number of individuals likely to have HF in the future. Design: Baseline characteristics and clinical data from 5706 individuals who participated in t...
Article
This article is the second of two review articles on coronary artery disease. The focus is on treatment with coverage of medical treatment, intravascular interventions and surgical therapy. The review is aimed at a wide readership of physicians and other health care providers but also at students of various health sciences. Current literature is re...
Article
Coronary artery disease affects thousands of Icelanders and is the most common cause of death in Iceland. In recent years great strides have been taken towards deeper understanding and improved treatment of this common disease, resulting in markedly improved outcomes. This evidence based review article is the first of two on coronary artery disease...
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Objectives: To review, for the first time, the outcome of mitral valve repair operations in Iceland. Material and methods: A retrospective study of all mitral valve repair patients (average age 64 yrs, 74% males) operated in Iceland 2001-2012. All 125 patients had mitral regurgitation; either due to degenerative disease (56%) or functional regur...
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Aims: To evaluate the prevalence of significant aortic valve stenosis (AS) in a randomly selected study population of elderly individuals representing the general population of Iceland. Furthermore, to predict the number of individuals likely to have severe AS in the future. Methods and results: Echocardiography and computed tomography (CT) data...
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Background: The geographic isolation and homogeneous population of Iceland are ideally suited to ascertain clinical and genetic characteristics of hypertrophic cardiomyopathy (HCM) at the population level. Methods and results: Medical records and cardiac imaging studies obtained between 1997 and 2010 were reviewed to identify Icelandic patients...
Article
Introduction: Pulmonary embolism is a serious disease and common among hospitalized patients. The incidence of pulmonary embolism in Iceland is largely unknown. The purpose of this study was to evaluate the incidence, clinical presentation, risk factors and outcome among patients diagnosed with pulmonary embolism at Landspítali, The National Unive...
Article
Mitral valve replacement (MVR) is the second most common valvular replacement procedure after aortic valve replacement (AVR). Studies on the outcome of MVR in Iceland have been missing. We therefore studied short and long-term results following MVR in Iceland, A retrospective nationwide study on 64 patients (mean age 59 years, 63% males) that under...
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To investigate long-term complications and survival following aortic valve replacement (AVR) in patients with aortic stenosis (AS) in Iceland. Included were 156 patients (average age 71.7 yrs, 64.7% males) that underwent AVR for AS at Landspitali between 2002 and 2006. A mechanical prosthesis was used in 29 patients (18.6%) and a bioprosthesis in 1...
Article
Information on surgical outcome of aortic valve replacement (AVR) has not been available in Iceland. We therefore studied the indications, short-term complications and operative mortality in Icelandic patients that underwent AVR with aortic stenosis. This was a retrospective study including all patients that underwent AVR for aortic stenosis at Lan...
Article
Sigurjonsson H, Andersen K, Gardarsdottir M, Petursdottir V, Klemenzson G, Gunnarsson G, Danielsen R, Gudbjartsson T. Cardiac myxoma in Iceland: a case series with an estimation of population incidence, APMIS 2011. Cardiac myxoma (CM) is the most common primary benign tumor of the heart, but the true age-standardized incidence rate (ASR) has remain...
Article
Constricitve pericarditis is an uncommon condition, often of unknown etiology but can be caused by infections, such as tuberculosis, inflammation of the pericardium, radiation therapy or asbestos exposure. Constrictive pericarditis is characterized by fibrosis and often severe calcifications of the pericardial sac which eventually restricts normal...
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To access publisher full text version of this article. Please click on the hyperlink in Additional Links field Constricitve pericarditis is an uncommon condition, often of unknown etiology but can be caused by infections, such as tuberculosis, inflammation of the pericardium, radiation therapy or asbestos exposure. Constrictive pericarditis is char...
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Apical ballooning syndrome is a cardiac syndrome typically characterized by transient focal dyskinesia or akinesia of the mid and apical regions of the left ventricle and hyperkinesia of the basal region. The symptoms and signs of the patient mimic myocardial infarction, with chest pain, electrocardiographic changes and elevation of cardiac enzymes...
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Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/Open AIM OF STUDY: To compare the utility and reliability of coronary angiography with multislice computed tomography (MSCT) and by cardiac catheterisation in assessing atherosclerotic lesions and stenosis. MATERIAL AND METHODS: Data were assessed from 44 su...
Article
To compare the utility and reliability of coronary angiography with multislice computed tomography (MSCT) and by cardiac catheterisation in assessing atherosclerotic lesions and stenosis. Data were assessed from 44 subjects (25 men, 19 women) (mean age 63 years; range 34-80 years) referred to MSCT who also had undergone invasive coronary angiograph...
Article
To investigate the diagnostic approach in Nordic hospitals receiving patients suspected of acute myocardial infarction (MI), especially focusing on implementation of the recently proposed criteria by the European Society of Cardiology (ESC) and the American College of Cardiology (ACC) for the definition of MI. A survey with questionnaires of the di...
Article
Introduction: Several studies suggest that the primary success of percutaneous coronary intervention (PCI) is less in diabetic patients than others and that complications and restenosis are more frequent. This was therefore assessed in icelandic diabetic patients. Methods: From 1987 to 2002 a total of 4435 PCI s were performed and of these 377 (...
Article
Introduction: The literature gives contradictory findings as to whether percutaneous coronary intervention (PCI) is equally successful in women and men. The objectives of this study were to compare between the sexes success and complications after PCI in Iceland. Methods: During the years 1987 to 2000 a total of 3355 PCI s were performed, 798 (2...
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A 30-y-old man with Crohn's disease developed fungemia with Candida albicans. Subsequently, during therapy with fluconazole, Candida glabrata was repeatedly isolated from his blood. Myocardial abscesses were detected in the papillary muscles and interventricular septum. The infection was cured with amphotericin B lipid complex and 5-flucytosine, fo...
Article
Purpose: To evaluate potential changes in clinical indications and the composition of the patient population undergoing percutaneous coronary intervention (PCI) in Iceland from 1987 to 1998. Furthermore, to assess changes in success rate and major complications for the procedure during the study interval in a small nation with one PCI centre. Mat...
Article
Purpose: The objective of the present study is to evaluate how gravity of diabetes influences parasympathetic control of heart rate variability and to compare different methods and conditions of evaluation. Methods: Subjects were 50 males, 20-50 years of age, where 38 had IDDM and 12 were without diabetes. Gravity of diabetes was based on it's dura...
Article
Purpose: There has been considerable interest in the possible role of iron metabolism in coronary artery disease but results published sofar have been inconclusive. Methods: To assess further the role of iron metabolism we studied 387 consecutive patients (294 men, age 58 ±9 (mean ±îSD) years, 93 women, age 62 ±7 years) undergoing diagnostic corona...
Article
Purpose: To evaluate potential changes in indications and the composition of the patient population undergoing percutaneous transluminal coronary angioplasty (PTCA) in Iceland from 1987 to 1998. Furthermore, to assess changes in the success rate and the frequency of major complications and mortality for the procedure in a small nation with one PTCA...
Article
Fibrinogen (FBG) and total coagulation factor VII (FVIIc) concentrations are higher in those patients with coronary artery disease who are at increased future risk of acute ischemic events. The relationship between activated factor VII (FVIIa) and cardiovascular events, however, has not been intensively studied. Data were collected from 401 consecu...
Article
Unlabelled: The aim of the study was to evaluate and compare the hemodynamic and electrocardiographic effects following injection of the non-ionic, low-osmolar contrast medium iopentol (Imagopaque 350, Nycomed Imaging AS, Oslo, Norway) and the ionic, hyper-osmolar contrast medium metrizoate meglumine-Na-Ca (Isopaque Coronar 370, Nycomed Imaging AS...
Article
Purpose: To find risk factors for the appearance of right bundle branch block (RBBB) and to assess the prognosis of people with it. Methods: Subjects were participants in the Reykjavik Study who had acquired RBBB following an examination in a previous stage in this prospective population study, carried out in five stages in 1967-1991. Cases with...
Article
Marfan's syndrome is a heritable collagen disorder manifested by defects in the ocular, skeletal and cardiovascular systems. It is inherited as an autosomal dominant trait. The objectives of this study were to study the prevalence and clinical presentation of Marfan's syndrome in Iceland. We assessed the records of patients diagnosed with Marfan's...
Article
A prospective study was conducted to evaluate how many patients maintain normal sinus rhythm after direct current (DC) cardioversion of atrial arrhythmias and to assess factors predictive of long-term success. The study group consisted of 61 patients (45 men) aged 18-88 years (mean age 66 +/- 11 years) who underwent cardioversion at our department...
Article
Since 1967 the Reykjavík study has monitored coronary artery disease and its risk factors in randomly selected cohorts. From 1979 to 1984, 3246 men and 3545 women aged 45-74 years were studied. Routine biplane chest X rays were assessed by a radiologist who noted the presence or absence of aortic calcification (AC), but had no detailed knowledge of...
Article
To examine left ventricular (LV) myocardial perfusion and function, in systemic sclerosis. Myocardial perfusion was assessed at rest, during cold exposure, and at peak exercise in 10 patients with systemic sclerosis. Seven of the 10 patients were examined with Doppler echocardiography; before and after long-term diltiazem treatment. Compared with a...
Article
The development of autonomic nervous dysfunction (AND) in subjects with diabetes influences life expectancy and may cause sudden death. The present study evaluates disturbances of AND in 41 men with type 1 diabetes mellitus, but without heart symptoms, and the relationship with other long term diabetic complications and blood sugar control. Their a...
Article
A prospective study was conducted to evaluate how many patients maintain sinus rhythm after DC cardioversion of atrial arrhythmias and to assess factors predictive of long-term success. The study group consisted of 61 patients (45 men, 16 women) aged 18-88 years (mean age 66 +/- 11 years) who undervent cardioversion, at the Department of Cardiology...