Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation.
OBJECTIVE
Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning.


RESULTS
We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228+/-93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64+/-13 vs. 63+/-13 years, respectively), AF duration (20+/-18 vs. 20+/-19 weeks), underlying disease, LA diameter (46+/-7 vs. 47+/-9 mm), left ventricular dimensions, and ejection fraction (47.7+/-11.6 vs. 49.7+/-14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9+/-49% from 28+/-9 cm/s before cardioversion to 25+/-13 cm/s immediately afterwards) than in the control group (reduction of 48+/-20% from 34+/-15 cm/s before cardioversion to 16+/-6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P = 0.046).


CONCLUSIONS
Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion.
Dagres
Nikolaos
N
First Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece. nikolaosdagres@yahoo.de
Karatasakis
George
G
Panou
Fotios
F
Athanassopoulos
Georgios
G
Maounis
Themistoclis
T
Tsougos
Elias
E
Kourea
Kallirrhoe
K
Malakos
Ioannis
I
Kremastinos
Dimitrios Th
DT
Cokkinos
Dennis V
DV
D000328:Adult; D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D016279:Atrial Function, Left / Q000502:physiology; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D016022:Case-Control Studies; D004452:Echocardiography; D004554:Electric Countershock; D005260:Female; D006801:Humans; D000077405:Irbesartan; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013777:Tetrazoles / Q000627:therapeutic use*
D047228:Angiotensin II Type 1 Receptor Blockers; D001713:Biphenyl Compounds; D013777:Tetrazoles; D000077405:Irbesartan