| 1. |
- Ingemansson, Max, et al.
(författare)
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Intravenous MgSO4 alone and in combination with glucose, insulin and potassium (GIK) prolong the atrial cycle length in chronic atrial fibrillation
- 2000
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 2:2, s. 106-114
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To investigate the effects of parenteral administration of MgSO4, and glucose, insulin, and potassium (GIK), on the dominant atrial cycle length during chronic atrial fibrillation (CAF). METHODS AND RESULTS: The length of the dominant atrial cycle (DACL) in the power-frequency spectrum of the QRST-suppressed lead V1 ECG was identified before and after intravenous administration of MgSO4 alone and after 5 and 10 h of MgSO4 and GIK infusion, in 13 patients with CAF. The changes in DACL were compared with changes in heart rate (HR), blood pressure and blood parameters. MgSO4 alone increased the DACL from 146(13) (mean(SD)) (control) to 153(14) ms (P < 0.01) and decreased the HR from 102(22) to 95(18) beats x min(-1) (P < 0.05). After 5 h of MgSO4 and GIK infusion the DACL was increased compared with control, from 146(13) to 152(11) ms (P < 0.01), but unchanged compared with that after the bolus infusion of MgSO4. HR was decreased compared with control (102(22)) and the bolus infusion of MgSO4 (95(18)) to 87(15) beats x min(-1) after 5 h of intervention. The DACL was further increased after 10 h of MgSO4 and GIK infusion compared with both control (from 146(13) to 157(11) ms), (P < 0.01) and the 5h infusion (152(11) to 157(11) ms), (P < 0.05). No further changes were seen in HR after 10 h (87(17)) of intervention. There were indications of an inverse relationship between total changes in HR (deltaHR) and DACL (deltaDACL) during the interventions (P < 0.05). CONCLUSION: Bolus infusion of MgSO4 prolongs the DACL and decreases HR in CAF. A further prolongation of DACL was seen after 10 h of MgSO4 and GIK infusion compared with control and with 5 h of intervention. Changes in DACL and HR during the entire intervention period showed an inverse relationship. The antiarrhythmic properties of MgSO4 and the GIK solution in CAF clearly require further attention.
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| 2. |
- Li, Z, et al.
(författare)
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Dispersion of atrial repolarization in patients with paroxysmal atrial fibrillation
- 2001
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 3:4, s. 285-291
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Tidskriftsartikel (refereegranskat)abstract
- To study the role of the dispersion of atrial repolarization (DAR) in the genesis of atrial fibrillation (AF), monophasic action potentials (MAP) were recorded simultaneously from a catheter at the high lateral right atrium (HLRA) and a catheter moving around the high, middle and low lateral right atrium (RA) the high, anterior and posterior septal RA and the RA appendage in 15 patients with paroxysmal AF and 15 patients with atrioventricular nodal re-entry tachycardia (AVNRT) or concealed Wolff-Parkinson-White syndrome (WPW) without history of AF. After recordings during sinus rhythm (SR), MAPs were recorded during programmed stimulation (PS) via the HLRA catheter at a drive cycle length (CL) of 500 ms. Thus, MAPs were recorded simultaneously from 2 sites at a time and sequentially from 4 to 12 sites during SR, drive pacing and PS. Taking the MAP at the HLRA as reference, the dispersion of repolarization time (dispersion of RT) and its two components, the dispersions of activation time (dispersion of AT) and MAP duration (dispersion of MAP duration) among the 4 to 12 sites were calculated and taken as parameters of DAR. RESULTS: During SR and PS, the maximal dispersion of RT was significantly greater in AF than in control patients, 113+/-49 ms vs 50+/-28 ms (P<0.001) and 114+/-56 vs 70+/-43 ms (P<0.05) respectively. The increased dispersion of RT in the AF group was caused by increases in both dispersion of MAP duration and dispersion of AT. CONCLUSION: During SR and PS, DAR increased in patients with paroxysmal AF due to increases in dispersion of MAP duration and dispersion of AT, which suggests the involvement of both repolarization and conduction disturbances in the development of paroxysmal AF.
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| 3. |
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| 4. |
- Platonov, Pyotr, et al.
(författare)
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Detection of inter-atrial conduction defects with unfiltered signal-averaged P-wave ECG in patients with lone atrial fibrillation
- 2000
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092. ; 2:1, s. 32-41
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To demonstrate a possible inter-atrial conduction delay in patients with lone paroxysmal atrial fibrillation (PAF) using 'unfiltered' signal-averaged P-wave ECG (PSAECG) and compare these results with those obtained with conventional filter settings. METHODS AND RESULTS: Twenty one patients with lone PAF and 20 healthy volunteers (control group) were enrolled in the study. An orthogonal lead surface ECG was high-pass filtered at 0.8 Hz, averaged with template matching, and combined into a spatial magnitude ('unfiltered' technique). Results were compared with conventionally filtered (40-300 Hz) PSAECG. The filtered technique revealed no differences in P-wave duration between the two groups (121 +/- 12 vs 128 +/- 15 ms, control and PAF groups respectively, ns). Double-peaked P-wave spatial magnitudes (interpeak distance >30 ms) were revealed in 11 of 21 PAF patients but only in two of 18 controls (P<0.01). The nadir in the spatial magnitude was located significantly later in the PAF group (114 +/- 13 vs 103 +/- 9 ms, P<0.01). CONCLUSION: 'Unfiltered' PSAECG revealed significant differences in orthogonal P-wave morphology in patients with lone PAF, indicating the possibility of an inter-atrial conduction delay, while conventional P-wave duration analysis failed to discriminate between the two groups.
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| 5. |
- Platonov, Pyotr, et al.
(författare)
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Further evidence of localized posterior interatrial conduction delay in lone paroxysmal atrial fibrillation
- 2001
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 3:2, s. 100-107
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Prolongation of interatrial conduction time has been reported in patients with paroxysmal atrial fibrillation (PAF). The study objective was to localize the region of the conduction delay in patients with lone PAF. METHODS AND RESULTS: Twenty-one patients with lone PAF and 23 patients with AV nodal re-entrant tachycardia ablation without history of PAF (control group) were recruited. Endocardial recordings were made during sinus rhythm and programmed atrial stimulation. The authors measured the interatrial conduction time, the 'right-sided' conduction time between the high lateral right atrium and the proximal coronary sinus (RA-CSp), and the 'left-sided' conduction time between the proximal and the distal coronary sinus (CSp-LA). During sinus rhythm, the interatrial conduction time was longer in the PAF group (103 +/- 19 vs 86 +/- 12 ms, P<0.01) due to delay of right-sided conduction (RA-CSp was 74 +/- 20 vs 56 +/- 10 ms, P<0.01). During programmed stimulation at the distal coronary sinus, the maximal RA-CSp time was also longer in the PAF group (110 +/- 47 vs 69 +/- 16 ms, P<0.05). No differences in CSp-LA time were observed. CONCLUSION: This study supports the role of posterior septal right atrial conduction disturbances in the genesis of lone PAF.
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| 6. |
- Platonov, Pyotr, et al.
(författare)
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Morphology of inter-atrial conduction routes in patients with atrial fibrillation.
- 2002
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 4:2, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Inter-atrial conduction disturbance is associated with the presence of atrial fibrillation (AF), although little is known about the anatomy of the inter-atrial connections. METHODS AND RESULTS: Twenty-seven hearts from in-hospital deaths were examined and stratified in two groups with regard to their history of AF. Measurements of atrial weight were performed after excising the atria at the level of the atrioventricular valve plane and separation from the inter-atrial septum (IAS). In addition, in 15 of 27 hearts (seven AF, eight non-AF) the IAS was sliced into 10 microm thick parallel histological sections at intervals of 1 mm starting at the valve plane and ending at the atrial roof. The sections were stained with van Gieson's stain. The variable morphology of the anterior and posterior inter-atrial connective muscle bundles is described. The total number of inter-atrial connections varied from 1 to 5. The anterior route (Bachmann's bundle) was not found in seven of 15 specimens. CONCLUSION: Inter-atrial connections are characterized by substantial variability in morphology and in the distribution of bundles. This may account for part of the variable susceptibility to AF.
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| 7. |
- Priori, Silvia G., et al.
(författare)
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Task Force on Sudden Cardiac Death, European Society of Cardiology
- 2002
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Ingår i: Europace. - : Oxford University Press (OUP). - 1099-5129 .- 1532-2092. ; 4:1, s. 3-18
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Tidskriftsartikel (refereegranskat)abstract
- The European Society of Cardiology has convened a Task Force on Sudden Cardiac Death in order to provide a comprehensive, educational document on this important topic. The main document has been published in the European Heart Journal in August 2001[1]. The Task Force has now summarized the most important clinical issues on sudden cardiac death and provided tables with recommendations for risk stratification and for prophylaxis of sudden cardiac death. The present recommendations are specifically intended to encourage the development and revision of national guidelines on prevention of sudden cardiac death. The common challenge for cardiologists, physicians of other medical specialties and health professionals throughout Europe is to realize the potential for sudden cardiac death prevention and to contribute to public health efforts to reduce its burden.
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| 8. |
- Yuan, Shiwen, et al.
(författare)
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Recording monophasic action potentials using a platinum-electrode ablation catheter
- 2000
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 2:4, s. 312-319
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: The monophasic action potential (MAP) is conventionally recorded using Ag-AgCl electrodes which are not suitable for delivering radiofrequency currents. To be able to use the sharp MAP upstroke for identifying the local activation, as a step towards the development of a MAP-guided catheter ablation technique, the possibility of recording MAP via platinum electrodes of an ordinary ablation catheter was explored. METHODS AND RESULTS: One hundred and forty-two MAP recordings from the endocardium were obtained via an ablation catheter in 40 patients undergoing electrophysiological study/catheter ablation. During sinus rhythm and pacing, 90% of the ventricular and 100% of the atrial MAPs had stable baselines. The amplitudes were 13 +/- 4.2 mV for ventricular and 2.4 +/- 0.8 mV for atrial MAPs. During mapping and ablation, MAPs and uni- and bipolar electrograms were recorded simultaneously using the same tip electrode in eight patients. The MAPs provided more distinct local activation than the electrograms. During 17 MAP recordings, additional MAPs were recorded simultaneously using an Ag-AgCl electrode catheter in the immediate vicinity of the ablation catheter. The MAPs taken with the ablation catheter had characteristics consistent with those taken with the Ag-AgCl catheter. CONCLUSIONS: (1) Platinum electrodes can be used for timely recording of MAPs in patients. (2) It is feasible to record MAPs and deliver radiofrequency currents via the same platinum-tip electrode. These findings suggest that MAP-guided catheter ablation is technically possible.
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