Sequence variants with large effects on cardiac electrophysiology and disease.

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.

Coding variants in and increase risk of atrial fibrillation.

Most sequence variants identified hitherto in genome-wide association studies (GWAS) of atrial fibrillation are common, non-coding variants associated with risk through unknown mechanisms. We performed a meta-analysis of GWAS of atrial fibrillation among 29,502 cases and 767,760 controls from Iceland and the UK Biobank with follow-up in samples from Norway and the US, focusing on low-frequency coding and splice variants aiming to identify causal genes. We observe associations with one missense (OR = 1.

A frameshift deletion in the sarcomere gene MYL4 causes early-onset familial atrial fibrillation.

Aims: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in man, causing substantial morbidity and mortality with a major worldwide public health impact. It is increasingly recognized as a highly heritable condition. This study aimed to determine genetic risk factors for early-onset AF.

Large-scale whole-genome sequencing of the Icelandic population.

Here we describe the insights gained from sequencing the whole genomes of 2,636 Icelanders to a median depth of 20×. We found 20 million SNPs and 1.5 million insertions-deletions (indels).

[Cardiac perforation following pacemaker implantation - a case series from Iceland].

Introduction: Perforation of the heart is a serious complication following pacemaker implantation that can cause life threatening bleeding and cardiac tamponade. Here we describe five cases that were diagnosed in Iceland during a four year period.

Materials And Methods: This population-based case series includes five patients diagnosed with cardiac perforation following pacemaker insertion at Landspítali and Akureyri Hospital from January 1, 2007 to December 31, 2010.

[Endocarditis in Iceland 2000-2009, a national survey incidence, microbiology and prognosis].

Introduction: The objective of this study was to analyze the incidence, clinical features, microbiology and prognosis of patients with infective endocarditis (IE) in Iceland, and to compare the results with a previous study made in Iceland 1976-85.

Material And Methods: A retrospective study including all patients diagnosed with IE in Iceland 2000-2009. Information was obtained from medical records.

A giant unruptured aneurysm of the sinus of Valsalva together with ectasia of the left coronary artery.

A sinus of Valsalva aneurysm is defined as a dilatation of the aortic sinuses, between the aortic valve annulus and the sinotubular junction. They are rare and most frequently involve the right coronary sinus. We report a case of an unruptured giant sinus of Valsalva aneurysm in a patient associated with ectasia of the left main stem and left anterior descending coronary artery.

Variants conferring risk of atrial fibrillation on chromosome 4q25.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans and is characterized by chaotic electrical activity of the atria. It affects one in ten individuals over the age of 80 years, causes significant morbidity and is an independent predictor of mortality. Recent studies have provided evidence of a genetic contribution to AF.

[Congenital heart defects in Iceland 1990-1999.].

Objective: About 1% of live born children have congenital heart defects (CHD). Knowledge of the true incidence of CHD is important because of the risk of bacterial endocarditis in patients with heart defects. This knowledge could also serve as a basis for research on the etiology of CHD.

Congenital cardiac malformations in Iceland from 1990 through 1999.

Introduction And Background: About 1% of live-born children have congenital malformations of the heart. The aim of our study was to investigate the incidence of such defects in children born in Iceland during a period of 10 years, extending from 1990 through 1999.

Materials And Methods: Information about the patients was obtained from medical records from two hospitals that cover the whole country, a private clinic of pediatric cardiologists, an echocardiography database, autopsy reports, and death certificates.