Abstract
OBJECTIVES—(1) To investigate the electrophysiological effects of flecainide and propafenone during atrial fibrillation, and their relation to arrhythmia termination; (2) to investigate the effects of isoprenaline on atrial fibrillation in basal conditions and during treatment with class 1C drugs to evaluate the role of adrenergic stimulation on proarrhythmic events occurring during this treatment. DESIGN—Prospective, single centre study. SETTING—University hospital. METHODS—10 patients with lone paroxysmal atrial fibrillation underwent an electrophysiological study. The dynamic behaviour of MFF (the mean of 100 consecutive atrial fibrillation intervals) was evaluated at two atrial sites after induction of atrial fibrillation either at baseline or after class 1C drug administration (flecainide or propafenone 2 mg/kg). The effects of isoprenaline on MFF and RR interval were also investigated both under basal conditions and during class 1C drug treatment. RESULTS—After induction of atrial fibrillation, mean (SD) MFF shortened with time, and was further shortened by isoprenaline infusion (177 (22) v 162 (16) v 144 (11) ms, p < 0.05). The administration of class 1C drugs reversed this trend and significantly increased the MFF to an average of 295 (49) ms, leading to conversion to sinus rhythm within 10 minutes in all patients. Atrial fibrillation was then reinduced on class 1C drugs: isoprenaline shortened the MFF and RR interval with a trend to AV synchronisation (223 (43) v 269 (49) ms for the MFF, 347 (55) v 509 (92) ms for the RR, p < 0.05); 1:1 sustained AV conduction occurred in two patients, at 187 and 222 beats/min respectively. One of these patients underwent electrical cardioversion because of haemodynamic collapse. CONCLUSIONS—Class 1C drugs are effective at restoring sinus rhythm by increasing the MFF to a much greater extent than observed in self terminating atrial fibrillation episodes, and reversing the spontaneous atrial fibrillation behaviour (progressive shortening of MFF and self perpetuation of atrial fibrillation). MFF prolongation with 1:1 conduction at fast ventricular rates may lead to synchronisation during adrenergic stimulation, with a very short ventricular cycle; hence it is advisable to keep the patients at rest after acute class 1C drug loading or to consider pharmacological modulation of AV conduction for patients who are prone to a fast ventricular response. Keywords: atrial fibrillation; electrophysiology; flecainide; propafenone; isoprenaline
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- Allessie M., Kirchhof C., Scheffer G. J., Chorro F., Brugada J. Regional control of atrial fibrillation by rapid pacing in conscious dogs. Circulation. 1991 Oct;84(4):1689–1697. doi: 10.1161/01.cir.84.4.1689. [DOI] [PubMed] [Google Scholar]
- Boriani G., Biffi M., Capucci A., Botto G. L., Broffoni T., Rubino I., Della Casa S., Sanguinetti M., Magnani B. Oral propafenone to convert recent-onset atrial fibrillation in patients with and without underlying heart disease. A randomized, controlled trial. Ann Intern Med. 1997 Apr 15;126(8):621–625. doi: 10.7326/0003-4819-126-8-199704150-00006. [DOI] [PubMed] [Google Scholar]
- Boriani G., Capucci A., Lenzi T., Sanguinetti M., Magnani B. Propafenone for conversion of recent-onset atrial fibrillation. A controlled comparison between oral loading dose and intravenous administration. Chest. 1995 Aug;108(2):355–358. doi: 10.1378/chest.108.2.355. [DOI] [PubMed] [Google Scholar]
- Botto G. L., Bonini W., Broffoni T., Cappelletti G., Falcone C., Lombardi R., Paulesu A., Pedraglio E., Ferrari G. Regular ventricular rhythms before conversion of recent onset atrial fibrillation to sinus rhythm. Pacing Clin Electrophysiol. 1994 Nov;17(11 Pt 2):2114–2117. doi: 10.1111/j.1540-8159.1994.tb03810.x. [DOI] [PubMed] [Google Scholar]
- Capucci A., Biffi M., Boriani G., Ravelli F., Nollo G., Sabbatani P., Orsi C., Magnani B. Dynamic electrophysiological behavior of human atria during paroxysmal atrial fibrillation. Circulation. 1995 Sep 1;92(5):1193–1202. doi: 10.1161/01.cir.92.5.1193. [DOI] [PubMed] [Google Scholar]
- Capucci A., Boriani G., Botto G. L., Lenzi T., Rubino I., Falcone C., Trisolino G., Della Casa S., Binetti N., Cavazza M. Conversion of recent-onset atrial fibrillation by a single oral loading dose of propafenone or flecainide. Am J Cardiol. 1994 Sep 1;74(5):503–505. doi: 10.1016/0002-9149(94)90915-6. [DOI] [PubMed] [Google Scholar]
- Capucci A., Boriani G., Rubino I., Della Casa S., Sanguinetti M., Magnani B. A controlled study on oral propafenone versus digoxin plus quinidine in converting recent onset atrial fibrillation to sinus rhythm. Int J Cardiol. 1994 Mar 1;43(3):305–313. doi: 10.1016/0167-5273(94)90211-9. [DOI] [PubMed] [Google Scholar]
- Capucci A., Lenzi T., Boriani G., Trisolino G., Binetti N., Cavazza M., Fontana G., Magnani B. Effectiveness of loading oral flecainide for converting recent-onset atrial fibrillation to sinus rhythm in patients without organic heart disease or with only systemic hypertension. Am J Cardiol. 1992 Jul 1;70(1):69–72. doi: 10.1016/0002-9149(92)91392-h. [DOI] [PubMed] [Google Scholar]
- Donovan K. D., Power B. M., Hockings B. E., Dobb G. J., Lee K. Y. Intravenous flecainide versus amiodarone for recent-onset atrial fibrillation. Am J Cardiol. 1995 Apr 1;75(10):693–697. doi: 10.1016/s0002-9149(99)80655-9. [DOI] [PubMed] [Google Scholar]
- Feld G. K., Chen P. S., Nicod P., Fleck R. P., Meyer D. Possible atrial proarrhythmic effects of class 1C antiarrhythmic drugs. Am J Cardiol. 1990 Aug 1;66(3):378–383. doi: 10.1016/0002-9149(90)90856-v. [DOI] [PubMed] [Google Scholar]
- Kirchhof C., Chorro F., Scheffer G. J., Brugada J., Konings K., Zetelaki Z., Allessie M. Regional entrainment of atrial fibrillation studied by high-resolution mapping in open-chest dogs. Circulation. 1993 Aug;88(2):736–749. doi: 10.1161/01.cir.88.2.736. [DOI] [PubMed] [Google Scholar]
- Marcus F. I. The hazards of using type 1C antiarrhythmic drugs for the treatment of paroxysmal atrial fibrillation. Am J Cardiol. 1990 Aug 1;66(3):366–367. doi: 10.1016/0002-9149(90)90851-q. [DOI] [PubMed] [Google Scholar]
- Murdock C. J., Kyles A. E., Yeung-Lai-Wah J. A., Qi A., Vorderbrugge S., Kerr C. R. Atrial flutter in patients treated for atrial fibrillation with propafenone. Am J Cardiol. 1990 Sep 15;66(7):755–757. doi: 10.1016/0002-9149(90)91144-u. [DOI] [PubMed] [Google Scholar]
- Ravelli F., Disertori M., Cozzi F., Antolini R., Allessie M. A. Ventricular beats induce variations in cycle length of rapid (type II) atrial flutter in humans. Evidence of leading circle reentry. Circulation. 1994 May;89(5):2107–2116. doi: 10.1161/01.cir.89.5.2107. [DOI] [PubMed] [Google Scholar]
- Rensma P. L., Allessie M. A., Lammers W. J., Bonke F. I., Schalij M. J. Length of excitation wave and susceptibility to reentrant atrial arrhythmias in normal conscious dogs. Circ Res. 1988 Feb;62(2):395–410. doi: 10.1161/01.res.62.2.395. [DOI] [PubMed] [Google Scholar]
- Stambler B. S., Wood M. A., Ellenbogen K. A. Antiarrhythmic actions of intravenous ibutilide compared with procainamide during human atrial flutter and fibrillation: electrophysiological determinants of enhanced conversion efficacy. Circulation. 1997 Dec 16;96(12):4298–4306. doi: 10.1161/01.cir.96.12.4298. [DOI] [PubMed] [Google Scholar]
- Suttorp M. J., Kingma J. H., Jessurun E. R., Lie-A-Huen L., van Hemel N. M., Lie K. I. The value of class IC antiarrhythmic drugs for acute conversion of paroxysmal atrial fibrillation or flutter to sinus rhythm. J Am Coll Cardiol. 1990 Dec;16(7):1722–1727. doi: 10.1016/0735-1097(90)90326-k. [DOI] [PubMed] [Google Scholar]
- Wang J., Bourne G. W., Wang Z., Villemaire C., Talajic M., Nattel S. Comparative mechanisms of antiarrhythmic drug action in experimental atrial fibrillation. Importance of use-dependent effects on refractoriness. Circulation. 1993 Sep;88(3):1030–1044. doi: 10.1161/01.cir.88.3.1030. [DOI] [PubMed] [Google Scholar]
- Wang Z. G., Pelletier L. C., Talajic M., Nattel S. Effects of flecainide and quinidine on human atrial action potentials. Role of rate-dependence and comparison with guinea pig, rabbit, and dog tissues. Circulation. 1990 Jul;82(1):274–283. doi: 10.1161/01.cir.82.1.274. [DOI] [PubMed] [Google Scholar]
- Wells J. L., Jr, Karp R. B., Kouchoukos N. T., MacLean W. A., James T. N., Waldo A. L. Characterization of atrial fibrillation in man: studies following open heart surgery. Pacing Clin Electrophysiol. 1978 Oct;1(4):426–438. doi: 10.1111/j.1540-8159.1978.tb03504.x. [DOI] [PubMed] [Google Scholar]
- Wijffels M. C., Kirchhof C. J., Dorland R., Allessie M. A. Atrial fibrillation begets atrial fibrillation. A study in awake chronically instrumented goats. Circulation. 1995 Oct 1;92(7):1954–1968. doi: 10.1161/01.cir.92.7.1954. [DOI] [PubMed] [Google Scholar]