{"id":6454,"date":"2026-10-19T09:48:55","date_gmt":"2026-10-19T09:48:55","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-laeknavisindum-hildur-margret-aegisdottir\/"},"modified":"2026-10-19T09:48:55","modified_gmt":"2026-10-19T09:48:55","slug":"doktorsvorn-i-laeknavisindum-hildur-margret-aegisdottir","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-laeknavisindum-hildur-margret-aegisdottir\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00e6knav\u00edsindum – Hildur Margr\u00e9t \u00c6gisd\u00f3ttir"},"content":{"rendered":"
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F\u00f6studaginn 12. desember 2025 ver Hildur Margr\u00e9t \u00c6gisd\u00f3ttir doktorsritger\u00f0 s\u00edna \u00ed l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: Erf\u00f0ir hjartsl\u00e1ttartruflana, rafl\u00edfe\u00f0lisfr\u00e6\u00f0i hjartans og yfirli\u00f0s.\u00a0Genetics of heart rhythm disorders, cardiac electrophysiology and syncope.<\/p>\n

Andm\u00e6lendur eru dr. Arthur AM Wilde, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lasj\u00fakrah\u00fasi\u00f0 \u00ed Amsterdam, og dr. Eir\u00edkur Steingr\u00edmsson, pr\u00f3fessor vi\u00f0 L\u00e6knadeild H\u00cd.<\/p>\n

Umsj\u00f3narkennari var Dav\u00ed\u00f0 O. Arnar, pr\u00f3fessor og lei\u00f0beinandi Hilma H\u00f3lm, s\u00e9rfr\u00e6\u00f0ingur. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefnd Ingibj\u00f6rg J\u00f3na Gu\u00f0mundsd\u00f3ttir, s\u00e9rfr\u00e6\u00f0ingur, R\u00f3sa Bj\u00f6rk \u00de\u00f3r\u00f3lfsd\u00f3ttir, s\u00e9rfr\u00e6\u00f0ingur og Dan\u00edel F. Gu\u00f0bjartsson, yfirma\u00f0ur t\u00f6lfr\u00e6\u00f0ideildar \u00cdE.<\/p>\n

S\u00e6d\u00eds S\u00e6varsd\u00f3ttir, pr\u00f3fessor og deildarforseti L\u00e6knadeildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 9:00.<\/p>\n

\u00c1grip<\/strong><\/p>\n

\u00c1hrif erf\u00f0a \u00e1 ofansleglahra\u00f0takt og lei\u00f0slutruflanir \u00ed hjarta, sem og yfirli\u00f0, hafa veri\u00f0 l\u00edti\u00f0 ranns\u00f6ku\u00f0. Meginmarkmi\u00f0 \u00feessa doktorsverkefnis var a\u00f0 \u00f6\u00f0last inns\u00fdn \u00ed meinger\u00f0 \u00feeirra me\u00f0 notkun v\u00ed\u00f0t\u00e6krar erf\u00f0amengisleitar og vi\u00f0b\u00f3tara\u00f0fer\u00f0a eins og genaskora og Mendelskrar slembir\u00f6\u00f0unar. \u00cd fyrsta hluta verkefnisins fundust tengsl t\u00edu erf\u00f0abreytileika vi\u00f0 ofansleglahra\u00f0takt, sem benda me\u00f0al annars til a\u00f0 virkni natr\u00edumj\u00f3naganga, kal\u00edumj\u00f3naganga og \u00f3sj\u00e1lfr\u00e1\u00f0a taugakerfisins eigi \u00fe\u00e1tt \u00ed h\u00e6ttu \u00e1 ofansleglahra\u00f0takti. \u00cd \u00f6\u00f0rum hluta fundust tengsl 162 erf\u00f0abreytileika vi\u00f0 lei\u00f0slutruflanir \u00ed hjarta og voru margir \u00feeirra einnig me\u00f0 tengsl vi\u00f0 g\u00e1ttatif og hjartav\u00f6\u00f0vakvilla. Mendelsk slembir\u00f6\u00f0un undirstrika\u00f0i orsaka\u00e1hrif af g\u00e1ttatifi \u00e1 sj\u00fakan s\u00ednushn\u00fat en gaf ekki til kynna beint orsakasamband milli hjartav\u00f6\u00f0vakvilla og lei\u00f0slutruflana. Me\u00f0al erf\u00f0abreytileikanna var au\u00f0gun \u00ed bindisetum fyrir GATA-4 og ESRRG, sem eru tj\u00e1ningar\u00fe\u00e6ttir sem eiga hlut \u00ed ofvexti \u00e1 hjartav\u00f6\u00f0va. \u00cd \u00feri\u00f0ja og seinasta hlutanum fundust tengsl 18 erf\u00f0abreytileika vi\u00f0 yfirli\u00f0, en hvorki erf\u00f0abreytileikarnir n\u00e9 genaskor byggt \u00e1 \u00e1hrifum \u00feeirra tengdust \u00f6\u00f0rum sj\u00fakd\u00f3mum. Au\u00f0gun me\u00f0al erf\u00f0abreytileikanna \u00ed stj\u00f3rnsv\u00e6\u00f0um sem eru s\u00e9rt\u00e6k taugavef, og \u00e1hrif \u00feeirra \u00e1 stj\u00f3rnun hjartsl\u00e1ttarhra\u00f0a benda \u00e1 hlutverk \u00farvinnslu \u00f3sj\u00e1lfr\u00e1\u00f0a taugakerfisins \u00ed meinger\u00f0 yfirli\u00f0a. Ofangreindar ranns\u00f3knir veita n\u00fdja inns\u00fdn inn \u00ed erf\u00f0ir sj\u00fakd\u00f3ma \u00ed lei\u00f0slukerfi hjarta og yfirli\u00f0s og tengsl \u00feeirra vi\u00f0 a\u00f0ra hjartasj\u00fakd\u00f3ma og \u00f3sj\u00e1lfr\u00e1\u00f0a taugakerfi\u00f0.<\/p>\n

Abstract<\/strong><\/p>\n

The genetic background of cardiac paroxysmal supraventricular tachycardias (PSVTs), conduction disorders (CDs), and syncope is poorly understood. The aim of this doctoral project was to provide insights into the pathophysiology of PSVTs, CDs and syncope through a genome-wide approach, and through adjunct methods such as genetic scores and Mendelian randomization. In the first part of the project, we identified ten associations with PSVTs which support that activity of sodium ion channels, potassium ion channels and the autonomic nervous system, among others, have a role in the risk of PSVTs. In the second, we found 162 associations with CDs, of which many also associated with atrial fibrillation and cardiomyopathies. Mendelian randomization validated a causal role for atrial fibrillation in sinus node dysfunction risk but did not support a straightforward causal relationship between cardiomyopathies and CDs. Among the CD variants, there was enrichment at binding sites for GATA-4 and ESRRG, both of which are transcription factors involved in myocardial hypertrophy. In the third and final part, we found 18 associations between sequence variants and syncope, but neither the variants nor a genetic score based on their effects associated with other diseases. Enrichment in neural-specific regulatory regions and effects of the variants on heart rate regulation pointing to a role of central processing and the autonomic nervous system in the pathophysiology of syncope. These studies provide novel insights into the genetics of diseases of the cardiac conduction system and syncope, and their relationship with other heart disease and the autonomic nervous system.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Hildur Margr\u00e9t \u00c6gisd\u00f3ttir er f\u00e6dd \u00e1ri\u00f0 1990 \u00ed Reykjav\u00edk. H\u00fan lauk kand\u00eddatspr\u00f3fi \u00ed l\u00e6knisfr\u00e6\u00f0i vi\u00f0 H\u00e1sk\u00f3la \u00cdslands 2015 og starfa\u00f0i \u00e1 kl\u00edn\u00edskum deildum Landsp\u00edtala \u00fear til h\u00fan h\u00f3f st\u00f6rf hj\u00e1 hjarta- og \u00e6\u00f0asj\u00fakd\u00f3masvi\u00f0i \u00cdslenskrar erf\u00f0agreiningar \u00e1ri\u00f0 2018. \u00c1ri\u00f0 2020 h\u00f3f h\u00fan doktorsn\u00e1m \u00ed l\u00e6knav\u00edsindum me\u00f0 \u00e1herslu \u00e1 erf\u00f0ir hjartsl\u00e1ttartruflana og yfirli\u00f0s. Hildur starfar n\u00fa einnig sem l\u00e6knir \u00e1 Heilsug\u00e6slunni \u00ed Hl\u00ed\u00f0um og mun hefja s\u00e9rn\u00e1m \u00ed heimilisl\u00e6kningum \u00ed byrjun \u00e1rs 2026. Foreldrar Hildar eru Sigr\u00ed\u00f0ur Ann\u00fd Gunnlaugsd\u00f3ttir og \u00c6gir Brei\u00f0fj\u00f6r\u00f0 Sigurgeirsson. Samb\u00fdlisma\u00f0ur hennar er \u00d3lafur Freyr Birkisson og saman eiga \u00feau tv\u00e6r d\u00e6tur, \u00fe\u00e6r Sigr\u00ed\u00f0i Krist\u00ednu (7 \u00e1ra) og Berg\u00fe\u00f3ru Margr\u00e9ti (4 \u00e1ra).<\/p>\n<\/div><\/div>","protected":false},"featured_media":5872,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2025-12-12T09:00:00+00:00","_phd_date_end":"2025-12-12T12:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Erf\u00f0ir hjartsl\u00e1ttartruflana, rafl\u00edfe\u00f0lisfr\u00e6\u00f0i hjartans og yfirli\u00f0s. 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