| 1. |
- Diamant, Ulla-Britt, et al.
(författare)
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Two automatic QT algorithms compared with manual measurement in identification of long QT syndrome
- 2010
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 43:1, s. 25-30
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Long QT syndrome (LQTS) is an inherited disorder that increases the risk of syncope and malignant ventricular arrhythmias, which may result in sudden death.METHODS: We compared manual measurement by 4 observers (QT(manual)) and 3 computerized measurements for QT interval accuracy in the diagnosis of LQTS: 1. QT measured from the vector magnitude calculated from the 3 averaged orthogonal leads X, Y, and Z (QTVCG) and classified using the same predefined QTc cut-points for classification of QT prolongation as in manual measurements; 2. QT measured by a 12-lead electrocardiogram (ECG) program (QTECG) and subsequently classified using the same cut-points as in (1) above; 3. The same QT value as in (2) above, automatically classified by a 12-lead ECG program with thresholds for QT prolongation adjusted for age and sex (QTinterpret). The population consisted of 94 genetically confirmed carriers of KCNQ1 (LQT1) and KCNH2 (LQT2) mutations and a combined control group of 28 genetically confirmed noncarriers and 66 unrelated healthy volunteers.RESULTS: QT(VCG) provided the best combination of sensitivity (89%) and specificity (90%) in diagnosing LQTS, with 0.948 as the area under the receiver operating characteristic curve. The evaluation of QT measurement by the 4 observers revealed a high interreader variability, and only 1 of 4 observers showed acceptable level of agreement in LQTS mutation carrier identification (kappa coefficient >0.75).CONCLUSION: Automatic QT measurement by the Mida1000/CoroNet system (Ortivus AB, Danderyd, Sweden) is an accurate, efficient, and easily applied method for initial screening for LQTS.
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| 2. |
- Holmqvist, Fredrik, et al.
(författare)
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A decade of catheter ablation of cardiac arrhythmias in Sweden : ablation practices and outcomes
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:10, s. 820-830
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Catheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing 'real-world' data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported.Methods and Results: Consecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff-Parkinson-White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7-7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%).Conclusion: Catheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.
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| 3. |
- Holmqvist, Fredrik, et al.
(författare)
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Increasing Ablation Volumes And A Shift Towards More Complex Arrhythmias : Data From The Swedish National Catheter Ablation Registry
- 2018
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Konferensbidrag (refereegranskat)abstract
- Background: Catheter ablation has become the treatment of choice for many tachyarrhythmias. The ablation techniques are continuously refined and the indications expanded, enabling treatment of more complex substrates. Hence, the spectrum of treated arrhythmias is likely to have changed over time, but compelling data on this are lacking.Objective: The present study set out to explore the changing pattern of ablations performed in the setting of a universal, single-payer healthcare system, using data from the Swedish national catheter ablation registry.Methods: The Swedish National Catheter Ablation Registry covers virtually all (>97%) catheter ablations performed in Sweden since 2005 and comprises 42,192 ablations on 32,237 individual patients. In the present analysis, all ablations performed between 2005 and 2016 were included.Results: In 2005, there were 7 ablation centers in Sweden performing a total of 1,584 ablations (226/center; 175/million). In 2016, 11 ablation centers performed 5,022 ablations (457/center; 502/million). Ablation of atrial fibrillation increased from 326 ablations (21% of all) in 2005 to 2,063 (41%) in 2016. Although, the number of ablation procedures for ventricular tachycardia and premature ventricular contractions is increasing, it is still on a relatively modest level (Figure). In contrast to other reports, there is no apparent decline in the number of accessory pathway ablations.Conclusion: In the setting of a universal, single-payer healthcare system, the number of ablations more than tripled over a 10-year period. Ablation of atrial fibrillation is the main driver behind this increase and accounted for 41% of all ablations in Sweden in 2016.
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| 4. |
- Höglund, Niklas, 1968-
(författare)
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Atrial fibrillation : treatment, associated conditions and quantification of symptoms
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia. There is a need for new pharmacological treatment strategies since the current antiarrhythmic drugs have a modest efficacy and may have severe side effects. Cardioversion (CV) of AF offers an opportunity to study related conditions in sinus rhythm (SR) and during AF. Since catheter ablation of AF is a symptomatic treatment, it is important to have tools for measurement of arrhythmia-related symptoms. Aims: To evaluate the effect of atorvastatin on maintaining SR after CV of persistent AF. To assess if highsensitivity C-reactive protein (hsCRP) predicts the recurrence of AF after CV in a population randomized to treatment with either atorvastatin or placebo. To quantify the symptomatic effect of left atrial catheter ablation of AF. To assess if the restoration of SR by CV, in a population with persistent AF, affects sleep apnea. Methods: Paper I: A total of 234 patients were randomized to treatment with either high dose atorvastatin or placebo prior to CV. Paper II: In a pre-specified substudy which included 128 of the patients in study I, hsCRP was analyzed before and after CV. Paper III: Umea 22 Arrhythmia Questions (U22) is a questionnaire that quantifies paroxysmal tachycardia symptoms. A total of 105 patients underwent first-time pulmonary vein isolation and answered U22 forms at baseline and follow-up 304 (SD 121) days after ablation. Paper IV: Polysomnography was performed before and after CV in 23 patients with persistent AF scheduled for elective CV. Results: Paper I: An intention-to-treat analysis with the available data, by randomization group, showed that 57 (51%) in the atorvastatin group and 47 (42%) in the placebo group were in SR 30 days after CV (OR 1.44, 95%CI 0.85–2.44, P=0.18). Paper II: HsCRP did not significantly predict recurrence of AF at 30 days. However, after adjusting for treatment with atorvastatin, hsCRP predicted the recurrence of AF (OR 1.14, 95% CI 1.01–1.27). Six months after CV, hsCRP at randomization predicted recurrence of AF in both univariate analysis (OR 1.30, 95% CI 1.06–1.60) and in multivariate logistic regression analysis (OR 1.33, 95% CI 1.06– 1.67). Paper III: The U22 scores for well-being, arrhythmia as cause for impaired well-being, derived timeaspect score for arrhythmia, and discomfort during attack detected relevant improvements of symptoms after the ablation. U22 showed larger improvement in patients undergoing only one procedure than in patients who later underwent repeated interventions. Paper IV: Obstructive sleep apnea occurred in 17/23 patients (74%), and central sleep apnea in 6/23 patients (26%). Five patients had both obstructive and central sleep apnea. SR at follow-up was achieved in 16 patients. The obstructive apnea-hypopnea index, central apneahypopnea index, and the number of patients with obstructive or central sleep apnea did not differ before and after restoration of SR. Conclusions: Atorvastatin is not a treatment option with regards to maintaining SR after CV in patients with persistent AF. HsCRP was associated with AF recurrence 1 and 6 months after successful CV of persistent AF. U22 quantifies the symptomatic improvement after AF ablation with adequate internal consistency and construct validity. Both obstructive and central sleep apneas are highly prevalent in patients with persistent AF. Obstructive sleep apneas are unaffected by the CV of AF to SR.
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| 5. |
- Höglund, Niklas, et al.
(författare)
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Cardioversion of atrial fibrillation does not affect obstructive sleep apnea
- 2017
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis. - 0300-9734 .- 2000-1967. ; 122:2, s. 114-118
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sleep apnea is common in patients with atrial fibrillation, but the effect of the cardioversion of atrial fibrillation to sinus rhythm on central and obstructive apneas is mainly unknown. The primary aim of the study was to analyze the association between cardioversion of atrial fibrillation and sleep apneas, to investigate whether obstructive or central sleep apneas are reduced following cardioversion. A secondary objective was to study the effect on sleep quality. Methods: Twenty-three patients with atrial fibrillation were investigated using overnight polysomnography, including esophagus pressure monitoring and ECG, before and after the cardioversion of persistent atrial fibrillation. Results: Obstructive sleep apnea occurred in 17/23 patients (74%), and central sleep apnea in 6/23 patients (26%). Five patients had both obstructive and central sleep apnea. Sinus rhythm at follow-up was achieved in 16 patients. The obstructive apnea-hypopnea index, central apnea-hypopnea index, and the number of patients with obstructive or central sleep apnea did not differ before and after restoration of sinus rhythm. Sleep time, sleep efficiency, time in different sleep stages, and subjective daytime sleepiness were normal and unaffected by cardioversion. Conclusions: Both obstructive and central sleep apneas are highly prevalent in patients with persistent atrial fibrillation. Obstructive sleep apneas are unaffected by the cardioversion of atrial fibrillation to sinus rhythm. The sleep pattern is normal and unaffected by cardioversion in patients with atrial fibrillation. Clinical Trial Registration: Trial number NCT00429884.
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| 6. |
- Höglund, Niklas, et al.
(författare)
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U22 protocol as measure of symptomatic improvement after catheter ablation of atrial fibrillation
- 2013
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Ingår i: Upsala Journal of Medical Sciences. - : Informa Healthcare. - 0300-9734 .- 2000-1967. ; 118:4, s. 240-246
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. Left atrial catheter ablation is useful as symptomatic treatment in selected patients with atrial fibrillation (AF). Evaluation requires measurement of arrhythmia-related symptoms. Many of the published protocols have drawbacks and have been used in AF only, with no possible comparison to other ablations that compete for the same resources. U22 is a published protocol that quantifies paroxysmal tachycardia symptoms through scales with 11 answer alternatives, translated into discrete numerical scales 0-10. It has been shown to reflect the clinical improvement after ablation of supraventricular tachycardia. Here we report the use of U22 in measuring improvement after catheter ablation for AF. Material and methods. A total of 105 patients underwent first-time ablation for AF and answered U22 and SF-36 forms at baseline and follow-up 304 (SD 121) days after ablation. Independently, the patients underwent a clinical follow-up. All decisions regarding medication and reablation were taken without knowledge of the symptom scores. Results. The U22 scores for well-being, arrhythmia as cause for impaired well-being, derived time-aspect score for arrhythmia, and discomfort during attack detected relevant improvements of symptoms after the ablation. U22 showed larger improvement in patients undergoing only one procedure than in patients who later underwent repeated interventions, thus reflecting the independent clinical decision for reablation. Conclusion. U22 quantifies the symptomatic improvement after AF ablation with adequate internal consistency and construct validity. U22 mirrors aspects of the arrhythmia symptomatology other than SF-36.
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| 11. |
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| 14. |
- Kesek, Milos, et al.
(författare)
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Entrapment of circular mapping catheter in the mitral valve
- 2007
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Ingår i: Heart rhythm : the official journal of the Heart Rhythm Society. - New York, NY : Elsevier. - 1547-5271. ; 4:1, s. 17-19
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Ablation procedures in the left atrium for treatment of atrial fibrillation are becoming increasingly common. The procedure often involves placing one or two circular mapping catheters in the left atrium. Entrapment of an ablation catheter in the mitral valve during ablations of left-sided accessory pathways by the retrograde approach has been described in two earlier published reports. More recently, several reports describe similar entrapment of a mapping catheter. In a recently published review, however, only one case of unspecified valve damage was registered among 8745 atrial fibrillation procedures. OBJECTIVE: The purpose of this study was to evaluate patients with entrapment. METHODS: Retrospective analysis of electrophysiological results. RESULTS: We describe three patients with entrapment during ablations for atrial fibrillation. The entrapments occurred with three different operators at three different electrophysiological laboratories within 2 years. The complication described here may be more common than is widely appreciated. CONCLUSIONS: From our figures, we estimate the incidence of the complication to 0.9% (95% confidence interval, 0.2-2.5%).
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| 15. |
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| 16. |
- Kesek, Milos, et al.
(författare)
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Heart rate variability during sleep and sleep apnoea in a population based study of 387 women
- 2009
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 29:4, s. 309-315
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Tidskriftsartikel (refereegranskat)abstract
- Increased sympathetic activity during sleep has been suggested as a link between obstructive sleep apnoea syndrome and cardiovascular disease. Heart rate variability (HRV) is a measure of autonomic effect on the heart. Different parameters have been associated with sympathetic and parasympathetic activity. We have studied HRV in different sleep stages and related the HRV-pattern to sleep apnoea in a population-based sample of 387 women. We investigated the HRV-parameters standard deviation of all R-R intervals (SDNN), root of the averaged square of successive differences (RMSSD), low frequency component (LF), high frequency component (HF), ratio of low frequency component to high frequency component LF/HF and VSAI [variation in sympathetic activity between rapid eye movement (REM) and slow wave sleep, defined as LF(REM)-LF(SWS)]. The HRV-parameters were compared with the results of a full-night polysomnography. Hourly incidence of obstructive episodes was used for classifying the subjects into four apnoea-hypopnoea index (AHI)-groups (<5, > or =5 and <15, 15-30 and >30 events). Individual sleep stages were analysed by pooling all recordings. Women with high AHI had higher heart rate and LF/HF ratio. In subjects with AHI >30, LF/HF ratio however dropped to same level as with AHI <5. Subjects with high AHI had low VSAI. Levels of SDNN, LF and LF/HF ratio during REM and light sleep were similar to wakefulness. In slow wave sleep the parameters decreased. In conclusion, moderately increased prevalence of obstructive apnoeas was associated with signs of higher sympathetic activity. High AHI was however associated with a HRV-pattern suggestive of depressed sympathetic drive and lowered ability to increase it during REM.
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| 17. |
- Kesek, Milos, et al.
(författare)
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Increased risk of late pacemaker implantation after ablation for atrioventricular nodal reentry tachycardia : A 10-year follow-up of a nationwide cohort
- 2019
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Ingår i: Heart Rhythm. - : Elsevier. - 1547-5271 .- 1556-3871. ; 16:8, s. 1182-1188
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Tidskriftsartikel (refereegranskat)abstract
- Background: Catheter ablation of the slow pathway is the standard treatment of atrioventricular nodal reentry tachycardia (AVNRT) with a well described low risk of periprocedural atrioventricular block. Less is known about the risk of pacemaker implantation late after ablation.Objective: We aimed to quantify the risk of late pacemaker implantation in a countrywide cohort undergoing first-time ablation for AVNRT.Methods: All patients undergoing first-time ablation for AVNRT in Sweden from 2004 to 2014 were identified from the Swedish catheter ablation registry and matched against the Swedish Pacemaker and ICD registry. The cohort was compared to patients ablated for an accessory pathway (AP) and to matched controls.Results: During follow-up of 2039 days, pacemaker was implanted later than 30 days after ablation in 96 of 6842 patients with AVNRT (1.4%), 29 of 4065 patients with AP (0.7%) (P = .001), and 124 of 33,270 controls (0.4%) (P < .00001). A periprocedural pacemaker (≤30 days postablation) was implanted in 32 of 6877 patients with AVNRT (0.5%) and 9 of 4079 patients with AP (0.2%) (P = .05). With cryoablation, 5 patients needed periprocedural pacemaker implantation. Pacemakers were implanted before ablation in 88 of 6977 patients with AVNRT (1.3%) and 11 of 4100 patients with AP (0.3%); the prevalence of pacemaker implants in controls was 124 of 33,270 (0.4%) (P < .00001 for both comparisons).Conclusion: The risk of late pacemaker implantation after AVNRT ablation was low but 3 times higher than that in the control population and 3 times higher than the risk of periprocedural pacemaker implantation. Similar results were observed with cryoablation and radiofrequency ablation. Ablation may not be the cause of increased late pacemaker implantation risk.
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| 18. |
- Kesek, Milos
(författare)
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Kammararytmier och AV-block
- 2010. - 4:e
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Ingår i: Akut kranskärlssjukdom. - : Liber. - 9789147093885 ; , s. 198-207
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 19. |
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| 20. |
- Kesek, Milos, et al.
(författare)
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Nondipolar content of T wave derived from a myocardial source simulation with increased repolarization inhomogeneity.
- 2009
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Ingår i: Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc. - 1542-474X. ; 14:2, s. 185-192
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Several conditions with repolarization disturbances are associated with increased level of nondipolar components of the T wave. The nondipolar content has been proposed as a measure of repolarization inhomogeneity. This computer simulation study examines the link between increased nondipolar components and increased repolarization inhomogeneity in an established model. METHODS: The simulation was performed with Ecgsim software that uses the equivalent double-layer source model. In the model, the shape of transmembrane potential is derived from biological recordings. Increased repolarization inhomogeneity was simulated globally by increasing the variance in action potential duration and locally by introducing changes mimicking acute myocardial infarction. We synthesized surface ECG recordings with 12, 18, and 300 leads. The T-wave residue was calculated by singular value decomposition. The study examined the effects of the number of ECG leads, changes in definition of end of T wave and random noise added to the signal. RESULTS: Normal myocardial source gave a low level of nondipolar content. Increased nondipolar content was observed in the two types of increased repolarization inhomogeneity. Noise gave a large increase in the nondipolar content. The sensitivity of the result to noise increased when a higher number of principal components were used in the computation. CONCLUSIONS: The nondipolar content of the T wave was associated with repolarization inhomogeneity in the computer model. The measure was very sensitive to noise, especially when principal components of high order were included in the computations. Increased number of ECG leads resulted in an increased signal-to-noise ratio.
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| 24. |
- Kesek, Milos, et al.
(författare)
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Reduction of fluoroscopy duration in radiofrequency ablation obtained by the use of a non-fluoroscopic catheter navigation system.
- 2006
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Ingår i: Europace. - : Oxford University Press (OUP). ; 8:12, s. 1027-30
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Radiofrequency (RF) ablation requires placement of several catheters at critical positions. The catheters are positioned with fluoroscopy, resulting in a significant radiation exposure. We have investigated to what degree an intracardiac navigation system reduces the fluoroscopy duration in different groups of routine RF ablations. METHODS AND RESULTS: The fluoroscopy time was evaluated in 365 consecutive routine RF ablations, performed between 2002 and 2005. An intracardiac navigation system (LocaLisa, Medtronic) was used from 2003. The data were prospectively entered into a database and subsequently retrieved, and the procedures classified as being performed with fluoroscopy only or with the aid of the LocaLisa system. After introduction of the LocaLisa system, the median fluoroscopy time decreased from 24 to 10 min in the 141 atrioventricular nodal re-entry tachycardia (AVNRT) ablations and from 43 to 28 min in the 71 atrial flutter (AFl) ablations (P<0.005 for both). In the 145 Wolff-Parkinson-White (WPW) ablations, a decrease from 27 to 23 min was observed (P=0.03). The decrease in AVNRT and AFl, but not in WPW was associated with the introduction of the LocaLisa system. CONCLUSION: The use of the LocaLisa system during RF ablations significantly reduced the fluoroscopy time in AVNRT and AFl ablations, by a median of 58% and 46%, respectively.
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