Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation.
ABSTRACT The conventional treatment strategy for patients with atrial fibrillation who are to undergo electrical cardioversion is to prescribe warfarin for anticoagulation for three weeks before cardioversion. It has been proposed that if transesophageal echocardiography reveals no atrial thrombus, cardioversion may be performed safely after only a short period of anticoagulant therapy.
In a multicenter, randomized, prospective clinical trial, we enrolled 1222 patients with atrial fibrillation of more than two days' duration and assigned them to either treatment guided by the findings on transesophageal echocardiography or conventional treatment. The composite primary end point was cerebrovascular accident, transient ischemic attack, and peripheral embolism within eight weeks. Secondary end points were functional status, successful restoration and maintenance of sinus rhythm, hemorrhage, and death.
There was no significant difference between the two treatment groups in the rate of embolic events (five embolic events among 619 patients in the transesophageal-echocardiography group [0.8 percent]) vs. three among 603 patients in the conventional-treatment group [0.5 percent], P=0.50). However, the rate of hemorrhagic events was significantly lower in the transesophageal-echocardiography group (18 events [2.9 percent] vs. 33 events [5.5 percent], P=0.03). Patients in the transesophageal-echocardiography group also had a shorter time to cardioversion (mean [+/-SD], 3.0+/-5.6 vs. 30.6+/-10.6 days, P<0.001) and a greater rate of successful restoration of sinus rhythm (440 patients [71.1 percent] vs. 393 patients [65.2 percent], P=0.03). At eight weeks, there were no significant differences between the two groups in the rates of death or maintenance of sinus rhythm or in functional status.
The use of transesophageal echocardiography to guide the management of atrial fibrillation may be considered a clinically effective alternative strategy to conventional therapy for patients in whom elective cardioversion is planned.
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ABSTRACT: Atrial fibrillation (AF) unfavorably affects cardiac output and may cause acute incapacitation in flight due to loss of the atrial systole, which mainly contributes to the diastolic filling of the ventricles. Although it is the most common type of arrhythmia, it is rare in pilots and not compatible with aviation. We present two AF cases incidentally detected in two jet pilots. The first case was a 39-yr-old male jet pilot with a lone AF. Since there was no structural abnormality or thrombus in the left atrial appendage on transesophageal echocardiography (TEE), the patient was converted to sinus rhythm via direct current cardioversion (DCC). The pilot returned to flying duties after a follow-up period without any recurrent arrhythmia. The second case was a 23-yr-old male jet pilot who had suffered six attacks of paroxysmal AF. Conversion to sinus rhythm was provided by DCC at once and the second via pharmacological cardioversion. Also, spontaneous conversion to sinus was observed during two attacks of AF during the follow-up period. There were no abnormalities on physical examination, echocardiography, and laboratory tests. Although the cardiac ablation procedure was applied, the patient couldn't be treated successfully. Thereafter the pilot was treated with sotalol and warfarin and was permanently disqualified from flying duties. Arrhythmia is among the frequent causes for aviators to be disqualified from flying duties. AF particularly should not be overlooked due to its potential for sudden incapacitation during flight via acute hypotension or thromboembolic events.Aviation Space and Environmental Medicine 07/2012; 83(7):706-10. · 0.88 Impact Factor
Article: External validation of a novel transthoracic echocardiographic tool in predicting left atrial appendage thrombus formation in patients with nonvalvular atrial fibrillation.[show abstract] [hide abstract]
ABSTRACT: BACKGROUND: A recent study demonstrated that in patients with nonvalvular atrial fibrillation (AF), a ratio of left ventricular ejection fraction (LVEF) to the left atrial volume index (LAVI) of <1.5 has 100% sensitivity for detecting left atrial appendage (LAA) thrombus. We sought to validate this prediction tool in an external cohort. METHODS: We conducted a cohort study of consecutive AF patients who underwent transoesophageal echocardiogram (TEE) to 'rule-out' LAA thrombus and had a prior transthoracic echocardiogram (TTE). The LAVI and LVEF were measured to calculate LVEF/LAVI ratio. The sensitivity and specificity of LVEF/LAVI <1.5 were calculated. RESULTS: Among 215 subjects, 19 (8.8%) had LAA thrombus and also had a higher mean CHADS(2) score (2.5 vs. 1.9, P = 0.04), lower mean LVEF (24 vs. 44%, P < 0.001), higher mean LAVI (44 mL/m(2) vs. 30 mL/m(2), P < 0.001), and higher prevalence of cardiac failure (79 vs. 52%, P = 0.02). The LVEF and LAVI were found to be independent predictors of LAA thrombus (P < 0.05). The LVEF/LAVI ratio diagnosed LAA thrombus with an area under the curve = 0.83 by the receiver operator characteristics curve analysis (P < 0.001). All 19 (100%) subjects with LAA thrombus had LVEF/LAVI <1.5 vs. 87 (44%) among those without LAA thrombus (P < 0.001). The sensitivity and specificity of LVEF/LAVI <1.5 were 100 and 55.6%, respectively. CONCLUSION: This investigation validates a simple TTE prediction rule to exclude the diagnosis of LAA thrombus, which may obviate the need for pre-cardioversion TEE in selected patients with nonvalvular AF.European Heart Journal – Cardiovascular Imaging 01/2013; · 2.32 Impact Factor
Article: Contrast enhanced transesophageal echocardiography in patients with atrial fibrillation referred to electrical cardioversion improves atrial thrombus detection and may reduce associated thrombembolic events.[show abstract] [hide abstract]
ABSTRACT: AIMS: Transesophageal echocardiography (TEE) is the gold standard for the detection of thrombi in patients with atrial fibrillation (AF) before undergoing early electrical cardioversion (CV). However, TEE generates inconclusive results in a considerable number of patients. This study investigated the influence of contrast enhancement on interpretability of TEE for the detection of left atrial (LA) thrombi compared to conventional TEE and assessed, whether there are differences in the rate of thromboembolic events after electrical cardioversion. METHODS: Of 180 patients with AF (51 females, 65.2+/-13years) who were referred to CV, 90 were examined with native imaging and contrast enhancement within the same examination (group 1), and 90 were examined with native TEE alone and served as control (group 2). Cineloops of the multiplane examination of the LA and LA appendage (LAA) were stored digitally before and, in group 1, after intravenous bolus application of a transpulmonary contrast agent. Images of group 1 were assessed offline and the diagnosis of LA thrombi was made semi-quantitatively: 1= thrombus present; 2=inconclusive result; 3=no thrombus. The presence of spontaneous echocontrast (SEC) was registered and flow velocity in the LA appendage (LAA-flow) was measured. All patients in whom CV was performed were followed up for 1 year or until relapse of AF. CV related adverse events were defined as any thrombembolic event within 1 week after CV. RESULTS: No serious adverse events occurred during TEE and contrast enhanced imaging. In group 1 atrial thrombi were diagnosed in 14 (15.6%) during native and in 10 (11.1%) patients during contrast enhanced imaging (p<0.001). Of the 10 patients with thrombi in the contrast TEE group, 7 revealed a decreased LAA-flow (<=0,3m/s) and 8 showed moderate or marked SEC. Uncertain results were significantly more common during native imaging than with contrast enhanced TEE (16 vs. 5 patients, p<0.01). Thrombi could definitely be excluded in 60 (66.7%) during conventional and in 75 patients (83.3%) during contrast enhanced TEE (p<0.01). CV was performed subsequently after exclusion of thrombi and at the discretion of the investigator. In group 1, 74 patients (82.2%) were cardioverted and no patient suffered a CV related complication (p=0.084). In group 2, 76 patients (84.4%) underwent CV, of whom 3 suffered a thrombembolic complication after CV (2 strokes, 1 peripheral embolism). CONCLUSION: In patients with AF planned for CV contrast enhancement renders TEE images more interpretable, facilitates the exclusion of atrial thrombi and may reduce the rate of embolic adverse events.Cardiovascular Ultrasound 01/2013; 11(1):1. · 1.26 Impact Factor