ACUTE CHANGES IN ATRIAL HAEMODYNAMICS AFTER ELECTRICAL AND DRUG CARDIOVERSION IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION.

Introduction: Сardioversion (CV) in patients with persistent atrial fi brillation (AF) and restoration of sinus rhythm (SR) are associated with mechanical dysfunction of the left atrium (LA) and left atrial appendage (LAA), which is named “atrial stunning” (AS). Mechanism of AS is not yet clear. AS further leads to decrease in left atrial appendage average velocity (LAAAV) and to increase in spontaneous echo contrast (SEC) degree and increases in the risk of thromboembolism after successful cardioversion. The duration and the degree of AS seem to depend on the duration of AF. Hypothesis: CV in patients with a persistent AF is associated with a high risk of thromboembolic events, which is associated not only with thrombus formation in conditions of prolonged AF, but also with thrombus formation «de novo» after the restoration of SR. The negative factor of the electrical trauma of the heart is always present in electrical CV (ECV), while it is absent in pharmacological CV (PhCV). So, it is possible to suggest that in cases of PhCV the degree of AS may be less pronounced.
Methods: 40 patients (Pts) with persistent AF were included in the study. Pts were randomly divided to receive either ECV (n=20) or PhCV (n=20). In the ECV group under the general anesthesia Pts were given direct-current synchronized electrical shock (150-170J). In the PhCV group Pts were given an infusion of a new class III drug refralon. All 40 Pts were anticoagulated by enoxaparin. Transesophageal echocardiography was performed in all patients before and one day after recovery of SR. LAAPV, SEC were measured in all cases before and after cardioversion.
Results: Baseline characteristics (male/female, age, duration of AF, left ventricular ejection fraction and left atrial volume, hypertension, diabetes mellitus, CHA2DS2 VASc score) were similar in both groups . The conversion rate was 90% in the PhCV group and 95 % in the ECV group (p<0,54). PhCV group demonstrated the decrease of LAAAV from 42,2±3,4 to 31,0±3,4 cm/s (p=0,02) and LAA EF from 39,8±14,7 to 31,5±15,6%(p=0,02) and the increase of SEC by 50% (p=0,02). ECV group showed the same changes: the decrease of LAAAV from 36,8 ±8,6 to 22,9± 4,8 cm/s (p=0,02) and LAA EF from 45,8±16,2 to 29,4±8,8% (p=0,0035) and the increase of SEC by 100% (p=0,053). Thrombus in LAA was revealed one day after successful CV in one patient from PhCV group.
Conclusions: Development of AS doesn’t depend on the mode of conversion of AF. AS is a function of persistent AF becoming apparent at the restoration of SR. AS is responsible for the postcardioversion thrombus formation in LA/LAA and possible cardioembolism despite the restoration of SR. One case of thrombus detection after PhCV confi rms this statement. The decrease of LA pump function was less pronounced in PhCV group.

1. Голицын С.П., Панченко E.П., Попов С.В. и др. Национальные рекомендации по диагностике и лечению фибрилляции предсердий 2012 г. // Российский кардиологический журнал. 2013. 4 (102). приложение 3.

2. ESC Guidelines for the management of atrial fi brillation developed in collaboration with EACTS. // European Heart Journal. Volume 37. Issue 38. 7 October 2016. Pages 2893-2962.

3. Klein AL, Murray RD, Black IW et al. Integrated backscatter for quantifi cation of left atrial spontaneous echo contrast // JACC. Volume 28. Issue 1. July 1996. Pages 222-231.

4. Weigner MJ, Caulfi eld TA, Danias PG at al. Risk for clinical thromboembolism associated with conversion to sinus rhythm in patients with atrial fi brillation lasting less than 48 hours.// Ann Intern Med. 1997 Apr 15.126(8):615-20.

5. Чучалин А.Г., Яснецова В.В. Федеральное руководство по использованию лекарственных средств (формулярная система). 2016.

6. Юричева Ю. А., Майков Е. Б., Соколов С. Ф и др. Первый опыт клинического применения нового антиаритмического препарата III класса ниферидила у больных с персистирующей формой фибрилляции предсердий. // Кардиология 2011. 1:55-64.

7. Fatkin D, Kelly RP, Feneley MP. Relations between left atrial appendage blood fl ow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. // J Am Coll Cardiol. 1994 Mar 15. 23(4):961-9.

8. Khan IA. Atrial stunning: determinants and cellular mechanisms. // Am Heart J. 2003 May;145(5):787-94.

9. Li-Wei Lo, Shih-Ann Chen. Cardiac remodeling after atrial fi brillation ablation. // J Atr Fibrillation. 2013 Jun-Jul;6(1):877.

10. Jong-Il Choi, Seong Mi Park, Jae Seok Park. Changes in left atrial structure and function after catheter ablation and electrical cardioversion for atrial fi brillation. // Circ J 2008;72:2051-2057.

11. M Takagi, A Doi, N Shirai et al. Acute improvement of atrial mechanical stunning after electrical cardioversion of persistent atrial fi brillation: comparison between biatrial and single atrial pacing. // Heart 2005;91:58-63.

12. Kottkamp H. Fibrotic atrial cardiomyopathy: a specifi c disease/syndrome supplying substrates for atrial fi brillation, atrial tachycardia, sinus node disease, AV node disease, and thromboembolic complications. // J Cardiovasc Electrophysiol 2012;23:797-799.