| 1. |
- Aagaard, Philip, et al.
(författare)
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Early Repolarization in Middle-Age Runners-Cardiovascular Characteristics.
- 2014
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Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 46:7, s. 1285-1292
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aimed to assess the prevalence and patterns of early repolarization (ER) in middle-age long-distance runners, its relation to cardiac structure and function, and its response to strenuous physical activity. Methods: Male first-time cross-country race participants >45 yr were assessed pre-and postrace by medical history and physical examination, 12-lead ECG, vectorcardiography, blood tests, and echocardiography. ER was defined either as ST elevation or J wave and categorized according to localization and morphology. Results: One hundred and fifty-one subjects (50 +/- 5 yr) were evaluated before the race, and 47 subjects were evaluated after the race. Altogether, 67 subjects (44%) had ER. Subjects with versus without ER had a lower resting HR (56 +/- 8 vs 69 +/- 9 bpm, P = 0.02), lower body mass index (24 +/- 2 vs 25 +/- 3 kg.m(-2), P < 0.001), higher training volume (3.0 +/- 2.6 vs 2.1 +/- 2.7 h.wk(-1), P = 0.03), and faster 30-km running times (194 +/- 28 vs 208 +/- 31 min, P = 0.01). Vectorcardiography parameters in subjects with ER showed more repolarization heterogeneity: vector gradient (QRS-T-area) (120 +/- 25 vs 92 +/- 29 mu Vs, P < 0.001), T-area (105 +/- 18 vs 73 +/- 23 mu Vs, P < 0.001), and T-amplitude (0.63 +/- 0.13 vs 0.53 +/- 0.16 mm, P < 0.001); these parameters were inversely related to HR (r = -0.37 to -0.48, P < 0.001). ER disappeared in 15 (75%) of 20 subjects after the race. Conclusions: ER is a common finding in middle-age male runners. This ECG pattern, regardless of morphology and localization, is associated with normal cardiac examinations including noninvasive electrophysiology, features of better physical conditioning, and disappears after strenuous exercise in most cases. These findings support that ER should be regarded as a common and training-related finding also in middle-age physically active men.
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| 2. |
- Aagaard, Philip, et al.
(författare)
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Tidig repolarisation på EKG - Definitioner, prevalens och prognostisk betydelse.
- 2015
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Ingår i: Läkartidningen. - 1652-7518. ; 112
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Tidskriftsartikel (refereegranskat)abstract
- Early repolarization defined as antero-lateral ST-segment elevation exists in 1-2 % of the general population and has been considered a benign ECG finding for decades. However, early repolarization, defined as infero-lateral J-waves, has in recent studies been associated with an increased - albeit low - risk of sudden and cardiovascular death. This ECG pattern is present in 3-13% of the general population. However, exercise training can induce all types of early repolarization, and the prevalence in the athletic population rises to 20-90%. There is large variability between sports (higher in endurance athletes) and also throughout the season (higher during times of peak fitness). In athletes, early repolarization, regardless of type, is considered benign. In asymptomatic non-athletes, the absolute risk is too low to use this ECG finding in clinical practice. In individuals with J-wave syndrome, on the other hand, ICD implantation should be strongly considered to prevent sudden cardiac death.
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| 3. |
- Akerstrom, Finn, et al.
(författare)
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Association between catheter ablation of atrial fibrillation and mortality or stroke
- 2024
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Ingår i: Heart. - : BMJ PUBLISHING GROUP. - 1355-6037 .- 1468-201X. ; 110, s. 163-169
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Tidskriftsartikel (refereegranskat)abstract
- Objective Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically. Methods We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke. Results Patients who underwent catheter ablation were healthier (mean CHA(2)DS(2)-VASc score 1.4 +/- 1.4 vs 1.6 +/- 1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5 +/- 2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07). Conclusions Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.
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| 4. |
- Andersen, Kasper, 1974-
(författare)
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Physical Activity and Cardiovascular Disease
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim was to investigate associations of fitness and types and levels of physical activity with subsequent risk of cardiovascular disease.Four large-scale longitudinal cohort studies were used. The exposures were different measures related to physical activity and the outcomes were obtained through linkage to the Swedish In-Patient Register. In a cohort of 466 elderly men without pre-existing cardiovascular disease, we found that skeletal muscle morphology was associated with risk of cardiovascular events. A high amount of type I (slow-twitch, oxidative) skeletal muscle fibres was associated with lower risk of cardiovascular events and high amount of type IIx was associated with higher risk of cardiovascular events. This association was only seen among physically active men. Among 39,805 participants in a fundraising event, higher levels of both total and leisure time physical activity were associated with lower risk of heart failure. The associations were strongest for leisure time physical activity. In a cohort of 53,755 participants in the 90 km skiing event Vasaloppet, a higher number of completed races was associated with higher risk of atrial fibrillation and a higher risk of bradyarrhythmias. Further, better relative performance was associated with a higher risk of bradyarrhythmias. Among 1,26 million Swedish 18-year-old men, exercise capacity and muscle strength were independently associated with lower risk of vascular disease. The associations were seen across a range of major vascular disease events (ischemic heart disease, heart failure, stroke and cardiovascular death). Further, high exercise capacity was associated with higher risk of atrial fibrillation and a U-shaped association with bradyarrhythmias was found. Higher muscle strength was associated with lower risk of bradyarrhythmias and lower risk of ventricular arrhythmias.These findings suggest a higher rate of atrial fibrillation with higher levels of physical activity. The higher risk of atrial fibrillation does not appear to lead to a higher risk of stroke. In contrast, we found a strong inverse association of higher exercise capacity and muscle strength with vascular disease. Further, high exercise capacity and muscle strength are related to lower risk of cardiovascular death, including arrhythmia deaths. From a population perspective, the total impact of physical activity on cardiovascular disease is positive.
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| 5. |
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| 6. |
- Braunschweig, Frieder
(författare)
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Implantable devices in heart failure : studies on biventricular pacing and continuous hemodynamic monitoring
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic heart failure is a highly symptomatic syndrome associated with increasing prevalence, frequent hospital admissions and high treatment costs. Despite recent advances in drug therapy, morbidity and mortality are still high. Thus, there is a clear need for additional therapeutic options and better diagnostic tools in order to improve the management of patients with heart failure. This thesis investigated two novel device techniques for the treatment and management of patients with chronic heart failure. Biventricular pacing: Approximately 30% of patients with heart failure have wide QRS complexes on the surface ECG as a sign of disturbed intraventricular conduction. This leads to asynchronous ventricular contraction and relaxation with impaired systolic and diastolic function and increased mitral regurgitation. Biventricular pacing aims to resynchronize the ventricular activation by simultaneous stimulation of the right and left ventricle. Study I evaluated effects of this therapy on functional status and quality of life (QoL) in 16 patients with NYHA III-IV heart failure. After 6 months of biventricular pacing, NYHA-class, the 6-minute walking distance and QoL had improved significantly. This clinical improvement translated into a marked decrease in the need for hospital care the year after pacemaker implantation. Study II, a European multicenter study, confirmed these findings in 75 NYHA III heart failure patients. The clinical benefits of biventricular pacing were sustained over 12 months of treatment both in patients with sinus rhythm and atria] fibrillation. In addition, an improvement in left ventricular ejection fraction and a reduction in mitral regurgitation was observed. Study III investigated the effects of a 2-week treatment cessation of long term biventricular pacing. Myocardial blood flow (MBF) and oxygen consumption (MV02) was assessed by 11-C-acetate positron emission tomography at rest and during low dose dobutamine stress in 6 responders to biventricular pacing. Although MBF was unchanged by biventricular pacing there was significant less increase of MV02 during stress, when the pacemaker had been switched off for 2 weeks. Continuous hemodynamic monitoring: An implantable hemodynamic monitor (IHM) continuously records central hemodynamic information from a pressure lead in the right ventricle. The system is implanted similar to a pacemaker. In study IV, 32 heart failure patients with an IHM were followed during 9 months. Retrospective analysis of hemodynamic trends showed significant (>20%) pressure changes in 9/12 cases of volume overload exacerbation requiring in-hospital treatment. These changes occurred 4±2 days prior to the clinical event. Hospitalizations decreased when the hemodynamic information was used for clinical decision making. Study V evaluated the potential usefulness of the IHM for the optimization of diuretic treatment in 4 patients with stable heart failure. Diuretics were decreased by 50% during the first week, completely withdrawn during the second and reinstituted in the initial dose during the third. In parallel with other clinical measures, the IHM was a sensible tool for detecting changes in volume load and was useful to find the optimal diuretic dose. In study VI an IHM was used to investigate the relationship between N-terminal pro brain natriuretic peptide (NTproBNP) and cardiac filling pressures. NT-proBNP plasma. levels measured on a single occasion varied largely between patients and were only weakly correlated with filling pressures. However, serial measurements of NT-proBNP in the same individual correlated significantly to hemodynamic parameters and reflected individual changes in cardiac filling pressures over time. Conclusions: Biventricular pacing improves symptoms and exercise tolerance in patients with heart failure and intraventricular conduction delay and favorably impacts the need for hospitalizations. Clinical improvement is sustained over 12 months follow-up and may in part depend on changes in myocardial oxygen metabolism. Continuous hemodynamic monitoring is potentially useful to indicate impending volume exacerbations and to tailor diuretic therapy, which may prevent hospitalizations for heart failure. Serial measurements of NT-proBNP are correlated with hemodynamic changes in the individual patient and may be useful to guide outpatient treatment. In the future, a hemodynamic sensor may be incorporated in pacemakers or defibrillators implanted in patients with heart failure, serving as an integrated heart failure management device.
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| 7. |
- Braunschweig, Frieder, et al.
(författare)
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New York Heart Association functional class, QRS duration, and survival in heart failure with reduced ejection fraction : implications for cardiac resychronization therapy.
- 2017
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Ingår i: European Journal of Heart Failure. - : Wiley-Blackwell. - 1388-9842 .- 1879-0844. ; 19:3, s. 366-376
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Symptom severity assessed by NYHA functional class and QRS duration are essential criteria for selection of heart failure (HF) patients for CRT. This study assessed the relationship between NYHA class, QRS duration, and survival in a nationwide HF registry.METHODS AND RESULTS: We studied 13 423 patients with HF in NYHA class II-IV and LVEF <40% in the Swedish Heart Failure Registry. Survival was followed via the Swedish Population Registry. Of 12 534 patients without CRT (age 71 ± 12 years, 29% women), 51% and 49% were in NYHA class II and III-IV, respectively. Patients in NYHA class II compared with class III-IV were younger (69 vs. 73 years), and had a better systolic function (49% vs. 58% with LVEF <30%), P <0.001 for all, and a favourable co-morbidity profile. QRS duration was 116 ± 29 ms in NYHA class II and 119 ± 29 ms in NYHA class III-IV with QRS ≥120 ms found in 37% vs. 44%, and an LBBB in 23% vs. 28% (P < 0.001 for all). Upon multivariable Cox regression adjusting for 40 clinically relevant variables, mortality risk was higher in NYHA class III-IV vs. class II, with a hazard ratio (HR) of 1.31, 95% confidence interval (CI) 1.23-1.40. Mortality was also higher with QRS prolongation ≥120 ms vs. narrow QRS. The HR in NYHA class II patients with non-LBBB was 1.19 (95% CI 1.05 - 1.36) and in those with LBBB it was 1.16 (95% CI 1.03-1.41). The corresponding HRs in NYHA class III-IV were 1.33 (95% CI 1.21-1.47) and 1.12 (95% CI 1.02-1.22). There was no significant interaction between the effects of NYHA class and QRS duration or morphology on mortality. Applying different scenarios to estimate guideline adherence, fewer patients with NYHA class II (range 14.4-42.6%) compared with NYHA class III-IV (18.0-45.4%) had received a CRT device when indicated.CONCLUSIONS: In HF with reduced LVEF, QRS prolongation is common and independently linked to worse survival. The increase in mortality risk associated with QRS prolongation of both LBBB and non-LBBB morphology is similar in NYHA class II and III-IV.
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| 8. |
- Braunschweig, Frieder, et al.
(författare)
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Paroxysmal regular supraventricular tachycardia: the diagnostic accuracy of the transesophageal ventriculo-atrial interval.
- 2011
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Ingår i: Annals of Noninvasive Electrocardiology. - 1542-474X. ; 16:4, s. 327-335
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To establish the diagnostic accuracy of the transesophageal ventriculo-atrial (VA) interval in patients with paroxysmal supraventricular tachycardia (PSVT) and normal baseline electrocardiogram (ECG). Methods: The transesophageal VA interval during tachycardia was recorded in 318 patients (age 45 ± 17 years, 58% female) with PSVT and a normal surface ECG between attacks. Subsequently, all patients underwent an ablation procedure establishing the correct tachycardia diagnosis. Results: AV nodal reentrant tachycardia (AVNRT), AV reentrant tachycardia through a concealed accessory pathway (AVRT), and ectopic atrial tachycardia (EAT) were found in 213, 95, and 10 cases, respectively. Receiver operating characteristic curve analysis identified an optimal cutoff for a binary categorization of AVNRT versus AVRT/EAT at ≤80 ms (area under the curve 0.891). Owing to a biphasic distribution, AVNRT was very likely at VA intervals ≤90 ms with a sensitivity, specificity, and positive predictive value (PPV) of 87%, 91%, and 95%. In the range 91–160 ms the corresponding values for AVRT were 88%, 95%, and 88% (90%, 99%, and 98% in male patients). In the small group with VA intervals >160 ms (n = 29), the diagnosis was less clear (PPV of 67% for AVNRT). Conclusions: In patients with sudden onset regular tachycardia and a normal ECG during sinus rhythm, a transesophageal VA interval of ≤80 ms has the highest diagnostic accuracy to diagnose AVNRT versus AVRT/EAT. Overall, the biphasic distribution of VA intervals suggests considering AVNRT at 90 ms and below and AVRT between 91 and 160 ms (in particular in male patients) while the diagnosis is vague at VA intervals above 160 ms.
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| 9. |
- Braunschweig, Frieder, et al.
(författare)
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Transient repolarization instability following the initiation of cardiac resynchronization therapy.
- 2011
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Ingår i: EP Europace. - : Oxford University Press (OUP). - 1532-2092. ; 13:9, s. 1327-1334
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Tidskriftsartikel (refereegranskat)abstract
- Aims Cardiac resynchronization therapy (CRT) may cause changes in ventricular repolarization (VR), particularly in the initial phase of treatment. This study investigated the effect of CRT cessation and re-initiation on parameters of VR duration and heterogeneity at different paced heart rates. Methods Cardiac resynchronization therapy was inactivated for 2 weeks in 16 treatment responders to CRT. QT and JT intervals were measured on the surface electrocardiogram at 60, 70, and 80 bpm (randomized order) and vectorcardiography (VCG) was performed with CRT ‘on’ (day 0), ‘off’ (day 0, 1, 7, and 14) and after CRT re-initiation (day 14, 15, 16, and 21). On day 0 (‘on’) and 14 (‘off’) echocardiography, the 6 min walking distance and brain natriuretic peptide were assessed. Results The QT interval at baseline (CRT ‘on’), measured at 60, 70, and 80 bpm, was 482 ± 31, 468 ± 37, and 457 ± 39 ms, respectively, and decreased by 5, 5, and 6% during the first week following CRT cessation (all P< 0.05). Immediately after re-initiation on day 14, it increased again by 20 ± 18 (4%; P< 0.05), 34 ± 39 (8%; P< 0.01), and 16 ± 38 ms (4%, ns) followed by a gradual decrease towards previous ‘off’ levels. Similar changes were observed for the JT interval. Ventricular repolarization duration was significantly shortened by increasing the paced heart rate from 60 to 70 and 80 bpm. Vectorcardiography parameters reflecting VR gradients (ST-vector magnitude, Tarea, and Tavplan) increased significantly (by 31, 45, and 71%) after CRT cessation. A similar but non-significant pattern was observed after CRT re-initiation. Conclusion The increase in repolarization duration and gradients observed after CRT initiation suggests a transient state of VR instability that can be attenuated by programming of higher paced heart rates during the initial phase of treatment.
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| 10. |
- Forslund, Tomas, et al.
(författare)
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Improved Stroke Prevention in Atrial Fibrillation After the Introduction of Non-Vitamin K Antagonist Oral Anticoagulants
- 2018
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Ingår i: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 49:9, s. 2122-2128
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: The purpose of this study was to investigate the impact of improved antithrombotic treatment in atrial fibrillation after the introduction of non-vitamin K antagonist oral anticoagulants on the incidence of stroke and bleeding in a real-life total population, including both primary and secondary care.Methods: All resident and alive patients with a recorded diagnosis for atrial fibrillation during the preceding 5 years in the Stockholm County Healthcare database (Vårdanalysdatabasen) were followed for clinical outcomes during 2012 (n=41 008) and 2017 (n=49 510).Results: Pharmacy claims for oral anticoagulants increased from 51.6% to 73.8% (78.7% among those with CHA2DS2-VASc ≥2). Non-vitamin K antagonist oral anticoagulant claims increased from 0.4% to 34.4%. Ischemic stroke incidence rates decreased from 2.01 per 100 person-years in 2012 to 1.17 in 2017 (incidence rate ratio, 0.58; 95% CI, 0.52-0.65). The largest increases in oral anticoagulants use and decreases in ischemic strokes were seen in patients aged ≥80 years who had the highest risk of stroke and bleeding. The incidence rates for major bleeding (2.59) remained unchanged (incidence rate ratio, 1.00; 95% CI, 0.92-1.09) even in those with a high bleeding risk. Poisson regression showed that 10% of the absolute ischemic stroke reduction was associated with increased oral anticoagulants treatment, whereas 27% was related to a generally decreased risk for all stroke.Conclusions: Increased oral anticoagulants use contributed to a marked reduction of ischemic strokes without increasing bleeding rates between 2012 and 2017. The largest stroke reduction was seen in elderly patients with the highest risks for stroke and bleeding. These findings strongly support the adoption of current guideline recommendations for stroke prevention in atrial fibrillation in both primary and secondary care.
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