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- Boriani, Giuseppe, et al.
(författare)
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Plateau waveform shape allows a much higher patient shock energy tolerance in AF patients.
- 2007
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Ingår i: Journal of cardiovascular electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 18:7, s. 728-34
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- OBJECTIVES: To evaluate the possible pain reduction of the plateau waveform in atrial fibrillation (AF) patients. BACKGROUND: Previous studies have indicated that reduced amplitude waveforms would be less painful than a conventional (65/65% tilt) biphasic waveform. Computer modeling suggested that a moderately long (10-12 msec) plateau (flat topped) shock waveform would deliver equivalent effectiveness with the lowest possible peak amplitude. METHODS: We enrolled 27 patients at two sites with persistent AF with a total of 220 shocks delivered during internal atrial cardioversion using an interleaved crossover design. Patient response was scored in three ways: (1) a verbally reported discomfort score, (2) visual analog scale (VAS), and (3) a blinded observer reporting a contraction score. RESULTS: All scores were significantly reduced (P < 0.0001) by the plateau waveform with impressive statistics: Verbal discomfort (3.51 +/- 0.13 to 2.89 +/- 0.12), VAS (7.00 +/- 0.56 to 5.91 +/- 0.36), and contraction scores (1.94 +/- 0.12 to 1.62 +/- 0.12). The average pain threshold shift (TS) for the Verbal score was 2.34, while that for the VAS score was 2.30. (This means that the patient typically could tolerate 2.34 times as much energy with the plateau waveform for the same level of verbally reported discomfort.) The contraction TS was less at 1.57. Response scores were also corrected for the shock sequence number to control for the sensitization effect from multiple shocks. This increased the TS for the Verbal score to 3.58, but the shock number was not significant for the VAS. A pulmonary artery electrode return was associated with lower pain compared with a coronary sinus position. CONCLUSION: A plateau shaped biphasic waveform resulted in significantly increased shock energy pain tolerances. Controlling for session sensitization, patients tolerated over three times as much energy for the same verbally reported discomfort score.
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- Husser, Daniela, et al.
(författare)
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Validation and clinical application of time-frequency analysis of atrial fibrillation electrocardiograms
- 2007
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 18:1, s. 41-46
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Fibrillatory rates can reliably be obtained from surface ECGs during atrial fibrillation (AF) and correspond with right atrial (RA) and coronary sinus (CS) rates, while both the relation with pulmonary venous (PV) rates and determinants of fibrillatory waveform are unknown. Class III antiarrhythmic drugs prolong atrial refractoriness and decrease its dispersion, effects that may be reflected in ECG parameters. Consequently, this study sought (1) to investigate the relation between ECG fibrillatory rate and waveform characteristics with intraatrial/PV fibrillatory activity and (2) to noninvasively monitor class III antiarrhythmic drug effects in patients with AF. Methods and Results: Thirty-six patients with drug-refractory AF who underwent catheter-based pulmonary vein isolation and had AF at the beginning of the procedure were studied. A positive correlation between V1 rates obtained by time-frequency analysis and RA (R = 0.97, P < 0.001), CS (R = .71, P < 0.001), and PV rates (R = 0.65, P = 0.001) was found. Exponential decay defined as decay of the curve that connects power maxima of dominant and harmonic frequency components correlated with RA rate dispersion (R = 0.53, P = 0.004). In amiodarone-treated patients (n = 7), V1 rate (286 +/- 64 vs. 371 +/- 40 fpm, P < 0.001) and exponential decay (1.06 +/- 0.29 vs. 1.38 +/- 0.38, P = 0.034) were lower than in patients without amiodarone (n = 29). In 19 additional patients with persistent AF, oral dofetilide treatment decreased mean fibrillatory rate from 377 +/- 57 to 294 +/- 50 fpm (P < 0.001) and exponential decay from 1.24 +/- 0.43 to 0.85 +/- 0.22 (P = 0.002). Conclusions: Fibrillatory waves of surface ECG lead V1 closely reflect right atrial, and, to a lesser degree, left atrial activity. Time-frequency analysis allows noninvasive monitoring of antiarrhythmic drug effects on fibrillatory rate and waveform.
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| 7. |
- Jais, Pierre, et al.
(författare)
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Stepwise catheter ablation of chronic atrial fibrillation : Importance of descrete anatomic sites for termination
- 2006
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 17:Suppl 3, s. 28-36
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic atrial fibrillation (CAF) can be acutely terminated using a combination of approaches targeting thoracic veins, left atrial areas showing rapid/heterogeneous electrical activity, and by linear ablation. This observational study emphasizes the crucial role for conventional endocardial mapping to identify discrete anatomical sites, ablation of which is indispensable for the achievement of atrial fibrillation (AF) termination. Methods: Eighty consecutive patients with CAF underwent catheter ablation using the stepwise approach. Pulmonary vein isolation and roof-line ablation were performed as the initial two steps in all patients. In the presence of locally rapid or heterogeneous activity, ablation was then performed at all sites within the left atrium and coronary sinus (CS) region with the endpoint of local organization or slowing. If AF persisted, the mitral isthmus was targeted. Patients in whom AF terminated during one of these five ablation steps were differentiated from those in whom AF was terminated by radiofrequency ablation at a single discrete anatomic site within 1 minute. Electrograms at discrete anatomic sites of termination were classified according to morphology. Results: Termination of AF was achieved in 69 (86%) patients by ablation alone. In 50 patients (72%), this occurred while following the predetermined ablation schema. In the remaining 19 patients (28%), ablation targeting a discrete site (preferentially located at the CS, the base of left atrial appendage, and the interatrial septum) terminated AF. Such sites were identified by (1) continuous electrical activity and fractionation and (2) bursts of short cycle activity (130–160 msec), centrifugal activation or local activation gradients, indicating sources perpetuating AF. Conclusion: In 28% of patients with termination of CAF, the final successful ablation site is anatomically discrete and displays electrophysiological characteristics that can be effectively identified by point and activation mapping. Failure to identify these sites may significantly reduce the likelihood of termination of CAF by catheter ablation.
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- Platonov, Pyotr, et al.
(författare)
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Left Atrial Posterior Wall Thickness in Patients with and without Atrial Fibrillation: Data from 298 Consecutive Autopsies.
- 2008
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 19:7, s. 689-692
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Radiofrequency ablation of atrial fibrillation (AF) is associated with energy delivery on the posterior left atrial (LA) wall with small but significant risk of life-threatening complications. Anatomy of LA walls has been described, but wall thickness in patients with AF has not been studied systematically. The aim of the present study was to describe LA posterior wall thickness in patients with and without history of AF. Methods and Results: Heart mass and LA wall thickness was measured during 298 consecutive autopsies (142 male, age 61 +/- 17 years). LA posterior wall was measured at three levels: between the superior pulmonary veins (SPV), in the center of the posterior LA wall (CPV), and between the inferior pulmonary veins (IPV). Information about AF history was obtained from medical records. Fifty-nine subjects (20%) had documented AF. They were older than subjects without AF (74 +/- 10 years vs 58 +/- 17 years, P < 0.0001) and had greater heart mass (522 +/- 114 g vs 389 +/- 99 g, P < 0.0001). LA posterior wall thickness increased from the most superior to the most inferior measured level (2.3 +/- 0.9 mm vs 2.5 +/- 1.0 mm vs 2.9 +/- 1.3 mm for SPV, CPV, and IPV, respectively; P < 0.001). Subjects with AF history had thinner LA posterior wall at CPV and IPV compared with those without AF. Conclusions: LA posterior wall thickness is described on a large series of consecutive autopsies. LA posterior wall is found to be generally thinner in patients with history of AF. Study results have clinical implications for understanding complication risk and improvement of safety of AF ablation procedures.
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