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Published on: February 26, 2013
Dobutamine-assisted exclusion of left atrial appendage thrombus in atrial fibrillation patients with sludge
Kentaro Minami1, Tomoko Machino-Ohtsuka1,2, Hiro Yamasaki1
1Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Insights
Dobutamine infusion during transoesophageal echocardiography effectively reduced left atrial appendage (LAA) sludge in patients with atrial fibrillation (AF). This intervention improved visualization, aiding in the differentiation of sludge from thrombi.
Area of Science:
- Cardiology
- Medical Imaging
Background:
- Dense spontaneous echo contrast (SEC) and sludge in the left atrial appendage (LAA) pose challenges in differentiating sludge from thrombi during transoesophageal echocardiography (TOE).
- Atrial fibrillation (AF) is associated with increased risk of LAA thrombus formation.
Purpose of the Study:
- To evaluate the feasibility, safety, and efficacy of dobutamine infusion to reduce LAA sludge.
- To improve thrombus detection in patients with AF undergoing TOE.
Main Methods:
- An open-label, single-arm study involving 20 patients with LAA sludge on TOE.
- Intravenous dobutamine infusion was administered, starting at 5 μg/kg/min and increasing to 10 and 20 μg/kg/min until sludge resolution.
- SEC grade and thrombus presence were reassessed at maximum dobutamine dose.
Main Results:
- LAA sludge improved in all patients, with complete resolution in 20% and significant reduction in SEC grade in 80%.
- Dobutamine significantly increased LAA emptying velocity and fraction, LAA wall velocities, and left ventricular (LV) ejection fraction.
- No severe adverse events or hemodynamic instability were observed, with transient, recoverable blood pressure changes.
Conclusions:
- Dobutamine infusion during TOE is a feasible and safe method to reduce LAA sludge.
- Enhanced LAA and LV function with dobutamine facilitates LAA thrombus exclusion in patients with AF.
Background:
Dense spontaneous echo contrast (SEC) and sludge in the left atrial appendage (LAA) complicate differentiation between sludge and thrombi during transoesophageal echocardiography (TOE). We prospectively evaluated the feasibility, safety, and efficacy of dobutamine to reduce sludge and improve thrombus detection in patients with atrial fibrillation (AF).
Methods And Results:
This was an open-label, single-arm, single-center clinical study. A total of 20 patients with LAA sludge on TOE received intravenous dobutamine infusion, starting at 5 μg/kg/min and increasing to 10 and 20 μg/kg/min at 3-min intervals until sludge resolution. SEC grade and thrombus presence were reassessed at the maximum dose. All patients had LAA sludge at baseline, which improved to SEC grade 2 in 5% of patients, grade 1 in 75%, and completely resolved in 20%. Peak dobutamine doses were 5 μg/kg/min in one patient, 10 μg/kg/min in six patients, and 20 μg/kg/min in 13 patients. Dobutamine significantly increased LAA emptying velocity (median: 13.8 to 18.7 cm/s, P < 0.001), emptying fraction (12.8% to 28.9%, P < 0.001), medial and lateral LAA wall velocities (6.6 to 8.4 cm/s, P = 0.012; 5.8 to 7.3 cm/s, P = 0.007, respectively), and left ventricular (LV) ejection fraction (51.8% to 60.0%, P < 0.001). Median heart rate increased from 78 to 89 bpm, while median systolic blood pressure briefly dropped from 116 to 105 mmHg before recovering to 123 mmHg three minutes post-infusion. No severe adverse events or hemodynamic instability occurred.
Conclusion:
By enhancing LAA and LV function, dobutamine infusion during TOE reduces sludge and facilitates LAA thrombus exclusion in patients with AF.
