Nadolol decreases the incidence and severity of ventricular arrhythmias during exercise stress testing compared with β1-selective β-blockers in patients with catecholaminergic polymorphic ventricular tachycardia

BackgroundCatecholaminergic polymorphic ventricular tachycardia (CPVT) is an inheritable cardiac disease predisposing to malignant ventricular arrhythmias.ObjectiveWe aimed to explore the incidence and severity of ventricular arrhythmias in patients with CPVT before the initiation of β-blocker treatment, when treated with β1-selective β-blockers, and when treated with nadolol.MethodsIn this study, 34 patients with CPVT were included (mean age 34 ± 19 years; 15 (44%) women; 30 (88%) ryanodine receptor 2 variant positive). We performed 3 bicycle exercise stress tests in each patient: (1) before the initiation of β-blocker treatment, (2) after >6 weeks of treatment with β1-selective β-blockers and (3) after >6 weeks of treatment with nadolol. We recorded resting and maximum heart rates and the most severe ventricular arrhythmia occurring. Severity of arrhythmias was scored as 1 point for no arrhythmias or only single ventricular extrasystoles, 2 points for >10 ventricular extrasystoles per minute or bigeminy, 3 points for couplets, and 4 points for nonsustained ventricular tachycardia or sustained ventricular tachycardia.ResultsResting heart rate was similar during treatment with nadolol and β1-selective β-blockers (54 ± 10 beats/min vs 56 ± 14 beats/min; P = .50), while maximum heart rate was lower during treatment with nadolol compared with β1-selective β-blockers (122 ± 21 beats/min vs 139 ± 24 beats/min; P = .001). Arrhythmias during exercise stress testing were less severe during treatment with nadolol compared with during treatment with β1-selective β-blockers (arrhythmic score 1.6 ± 0.9 vs 2.5 ± 0.8; P < .001) and before the initiation of β-blocker treatment (arrhythmic score 1.6 ± 0.9 vs 2.7 ± 0.9; P = .001); however, no differences were observed during treatment with β1-selective β-blockers compared with before the initiation of β-blocker treatment (arrhythmic score 2.5 ± 0.8 vs 2.7 ± 0.9; P = .46).ConclusionThe incidence and severity of ventricular arrhythmias decreased during treatment with nadolol compared with during treatment with β1-selective β-blockers. β1-Selective β-blockers did not change the occurrence or severity of arrhythmias compared with no medication

Cardiac Mechanical Alterations and Genotype Specific Differences in Subjects With Long QT Syndrome

AbstractObjectivesThis study aimed to explore systolic and diastolic function and to investigate genotype-specific differences in subjects with long QT syndrome (LQTS).BackgroundLQTS is an arrhythmogenic cardiac ion channelopathy that traditionally has been considered a purely electrical disease. The most commonly affected ion channels are the slow potassium channel, IKs (KCNQ1 gene/LQT1), and the rapid potassium channel, IKr (KCNH2 gene/LQT2). Recent reports have indicated mechanical abnormalities in patients with LQTS.MethodsWe included 192 subjects with genotyped LQTS (139 LQT1, 53 LQT2). Healthy persons of similar age and sex as patients served as controls (n = 60). Using echocardiography, we assessed systolic function by left ventricular (LV) ejection fraction (EF), global longitudinal strain (GLS), and contraction duration (16 LV segments). Mechanical dispersion was calculated as standard deviation of contraction duration. Time difference between contraction duration and QT interval from electrocardiography (ECG) was defined as electromechanical time difference. We assessed diastolic function by transmitral filling velocities, early diastolic myocardial velocity (e′), and left atrial volume index (LAVI). Heart rate corrected QT interval (QTc) was assessed from 12-lead ECG.ResultsSystolic function by GLS was reduced in subjects with LQTS compared with healthy controls (−22.1 ± 2.1% vs. −23.0 ± 2.0%, p = 0.01), and GLS was worse in subjects with LQT2 compared with subjects with LQT1 (p = 0.01). Subjects with LQTS had longer contraction duration (426 ± 41 ms vs. 391 ± 36 ms, p < 0.001) and more dispersed contractions (33 ± 14 ms vs. 21 ± 7 ms, p < 0.001) compared with healthy controls. Diastolic function was also reduced in subjects with LQTS compared with healthy controls; e′ was lower (10.7 ± 2.7 cm/s vs. 12.5 ± 2.0 cm/s, p < 0.001), and LAVI was increased (30 ± 8 ml/m2 vs. 26 ± 5 ml/m2, p = 0.01), also when adjusted for age and other possible confounders.ConclusionsSubjects with LQTS had a consistent reduction in both systolic and diastolic function compared with healthy controls. Differences in myocardial function between subjects with LQT1 and subjects with LQT2 may indicate that mechanical alterations in LQTS are genotype specific

The Female Athlete's Heart: Facts and Fallacies.

Purpose of the review For many years, competitive sport has been dominated by men. Recent times have witnessed a significant increase in women participating in elite sports. As most studies investigated male athletes, with few reports on female counterparts, it is crucial to have a better understanding on physiological cardiac adaptation to exercise in female athletes, to distinguish normal phenotypes from potentially fatal cardiac diseases. This review reports on cardiac adaptation to exercise in females. Recent findings Recent studies show that electrical, structural, and functional cardiac changes due to physiological adaptation to exercise differ in male and female athletes. Women tend to exhibit eccentric hypertrophy, and while concentric hypertrophy or concentric remodeling may be a normal finding in male athletes, it should be evaluated carefully in female athletes as it may be a sign of pathology. Although few studies on veteran female athletes are available, women seem to be affected by atrial fibrillation, coronary atherosclerosis, and myocardial fibrosis less than male counterparts. Summary Males and females exhibit many biological, anatomical, and hormonal differences, and cardiac adaptation to exercise is no exception. The increasing participation of women in sports should stimulate the scientific community to develop large, longitudinal studies aimed at a better understanding of cardiac adaptation to exercise in female athletes

Speckle Tracking Echocardiography for the Assessment of the Athlete's Heart: Is It Ready for Daily Practice?

PURPOSE OF REVIEW: To describe the use of speckle tracking echocardiography (STE) in the biventricular assessment of athletes' heart (AH). Can STE aid differential diagnosis during pre-participation cardiac screening (PCS) of athletes? RECENT FINDINGS: Data from recent patient, population and athlete studies suggest potential discriminatory value of STE, alongside standard echocardiographic measurements, in the early detection of clinically relevant systolic dysfunction. STE can also contribute to subsequent prognosis and risk stratification. Despite some heterogeneity in STE data in athletes, left ventricular global longitudinal strain (GLS) and right ventricular longitudinal strain (RV ɛ) indices can add to differential diagnostic protocols in PCS. STE should be used in addition to standard echocardiographic tools and be conducted by an experienced operator with significant knowledge of the AH. Other indices, including left ventricular circumferential strain and twist, may provide insight, but further research in clinical and athletic populations is warranted. This review also raises the potential role for STE measures performed during exercise as well as in serial follow-up as a method to improve diagnostic yield

Digitalisering i Husbanken - En kvalitativ studie av brukerforståelser og brukererfaringer

Modernisering av offentlig sektor har vist seg å være en nødvendighet for å opprettholde den velferdsstaten vi har i dag. Nåværende regjering har derfor en ambisjon om «fornying, forenkling og forbedring» av statlige etater og dette innebærer blant annet digitalisering av tjenester. I denne oppgaven undersøker jeg digitaliseringsprosesser i en offentlig etat: Husbanken. Jeg har spesielt fokusert på digitalisering av bostøttetjenesten. Oppgavens problemstilling er: Hvordan defineres og karakteriseres brukeren i offentlig sektors digitaliseringsarbeid, og hva er brukernes erfaringer med digitaliserte tjenester i Husbanken, med spesielt fokus på bostøtte? For å besvare denne problemstillingen har jeg analysert noen relevante dokumenter, og gjennomført dybdeintervju av et utvalg ansatte i Husbanken. Disse ble foretatt under en hospiteringsperiode i Husbanken Midt-Norge høsten 2017. Dokumentanalysen viste at brukeren ble omtalt som «vanskeligstilt på boligmarkedet». Disse har jeg kalt sluttbrukere. Brukerbegrepet favnet derimot bredere i Digitaliseringsrundskrivet hvor det er snakk om digitalisering i offentlig sektor. Derfor har jeg lagd to brukerkonstruksjoner: Husbankens ansatte som interne brukere, og kommuner og sluttbrukere som eksterne brukere. De offentlige dokumentene er opptatt av å plassere brukeren i sentrum, og understreker viktigheten av at det lages gode, enkle verktøy for dem. Hva dette innebærer, er lite konkretisert. I intervjuene kom det frem at selv om digitalisering av bostøtte fungerer for noen sluttbrukere, byr det også på en rekke utfordringer, spesielt i overgangsfasen mellom papirbaserte og digitale løsninger. På landsbasis har mindre enn halvparten av sluttbrukerne tatt i bruk de digitale søknadsskjemaene, noe som også indikerer utfordringer med innføringen av denne tjenesten. Informantene forteller om merarbeid for seg selv og kommunene og frustrerte sluttbrukere som har vanskeligheter for å tilpasse seg på grunn av manglende ressurser og kompetanse. Likevel finnes det blant de interne brukerne, optimisme om at ambisjonene bak digitalisering av tjenester vil realiseres med tiden. Mine funn tyder imidlertid på at det å trekke de interne brukerne med i utviklingen av de digitaliserte tjenestene, god og omfattende opplæring av sluttbrukerne og mulighetene til å bruke flere teknologiske plattformer for å bruke av tjenestene, er nødvendige tiltak for at digitaliseringsprosessene skal lykkes

Offshore Wind Turbine Modelling State of the Art and future development

Denne masteroppgaven presenterer state of the art teknologier og utviklingstrender for vindturbiner. Offshore vind blir sett på som en lovende del av energisektoren i målet mot et bytte til fornybare energikilder. DNV sin prognose for 2050 viser at offshore vind vil stå for 33 prosent av den globale energiproduksjonen hvor flytende vind utgjøre totalt 4 prosent av global energiproduksjon. For å senke kostnaden av energi fra offshore vind er det viktig å skalere opp turbin-størrelsen. Per i dag er de operasjonelle kostnadene for flytende vindparker 5 ganger større enn for parker med bunnfaste vind-turbiner. Kravene for den flytende strukturen gjør ofte at mengden stål er dobbelt så stor sammenliknet med bunnfaste turbiner. For å øke størrelsen på vindturbinene og undersøke nye designkonsepter kreves det kompliserte digitale verktøy for modellering og simulering for analyse av de ulike kreftene på turbinens komponenter. En tilnærming kalt multi-body-simulering blir undersøkt. Tilnærmingen inkluderer både vind og bølgekrefter. Ulik programvare for simulering og modellering tilgjengelig diskuteres. Standarder gjeldende slik som IEC 61400 serien og et utvalg DNV-standarder blir undersøkt for å se om det er gap mellom regler og standarder tilgjengelig og utviklingen innen sektoren. Det er flere hull siden flere standarder kun gjaldt mindre turbiner. Det utvikles og arbeids hele tiden med standardene og reglene, så flere nye versjoner er utgitt som gjelder større vindturbiner. Det er likevel flere designkonsepter som ikke er dekket av standardene slik som delt forankring og delt flytende struktur. Med større turbiner blir rotorfarten lavere. Dette gjør direct-drive generatorer en interessant løsning istedenfor å bruke girbokser. Girboksen er i dag den komponenten som har størst skader og fører til mest nedetid. Ved å bytte ut girboksene, kan altså de operasjonelle kostnadene senkes og føre til at flytende offshore vind kan være bedre rustet for fremtiden

Arrhythmogenic right ventricular cardiomyopathy (ARVC)- Impact of exercise on cardiac outcome, differential diagnoses and risk stratification of arrhythmic events

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiac disease with risk of ventricular arrhythmia, heart failure and sudden cardiac death. We investigated 110 mutation-positive ARVC subjects (37 athletes). Athletic activity was associated with impaired myocardial function and increased frequency of ventricular arrhythmia in individuals with ARVC. Athletic activity may aggravate and accelerate cardiac disease in ARVC. Right ventricular outflow tract ventricular tachycardia (RVOT-VT) is supposed to be a benign disease, while ARVC is a far from a benign disease. Discrimination between early phase ARVC and RVOT-VT can be challenging. In totally 165 patients, we showed that individuals with early phase ARVC had worse impact on the RV and lower amount of premature ventricular beats compared to RVOT-VT patients. These new parameters may help correct diagnosis in patients with unclear phenotypes. Prediction of arrhythmic events in early phase ARVC is challenging. We investigated early risk markers to improve risk stratification in 162 ARVC subjects. In early ARVC, signal averaged ECG and RV parameters were early risk markers. A combination of new echocardiographic and electrical parameters improved risk stratification in early ARVC