June 1, 2005
View Full PaperComparison of transthoracic echocardiography using second harmonic imaging, transcranial Doppler and transesophageal echocardiography for the detection of patent foramen ovale in stroke patients
Key Result
Transcranial Doppler correctly identified all 44 patent foramen ovales detected by TTE and TEE, and matched negative results in 59 of 63 patients, showing excellent negative predictive value.
Study Design
Type
Observational (n=107)
Blinding
Blinded reader
Structured PICO
Do transthoracic echocardiography with second harmonic imaging and transcranial Doppler accurately detect patent foramen ovale compared to transesophageal echocardiography in stroke patients?
P
Population
107 patients hospitalized for stroke
I
Intervention
Transthoracic echocardiography (TTE) using second harmonic imaging and transcranial Doppler (TCD)
C
Comparator
Transesophageal echocardiography (TEE)
O
Outcome
Detection of right-to-left shunt (patent foramen ovale)surrogate
Transcranial Doppler has an excellent negative predictive value for excluding patent foramen ovale in stroke patients, highlighting limitations of relying solely on transesophageal echocardiography.
Limitations
- Unable to determine a cause for the four positive TCD tests among patients with negative TEE and TTE results.
Abstract
AIMS: The comparison of three imaging methods to determine which is the most accurate and reliable for the detection of right-to-left shunt. METHODS AND RESULTS: One hundred and seven patients who were hospitalized for stroke underwent: a transthoracic echocardiography (TTE) using second harmonic, a transcranial Doppler (TCD) and a transesophageal echocardiography (TEE) from August 2003 to April 2004. All studies were recorded on a videotape and were studied by a physician blinded to the study. With TTE and TEE, we found 44 (41%) patent foramen ovales. All contrast tests were positive with TCD for these 44 patients. For two patients, the contrast test was positive only with TTE and TCD. We found four false negative contrast tests with TTE. Among the 63 patients who had a negative contrast test with TEE and TTE, the results were the same with TCD for 59 of them; we were not able to determine a cause for the four positive tests. CONCLUSION: This study confirms that transesophageal echocardiography has limitations in the diagnosis of patent foramen ovale. In this study, the negative predictive value of transcranial Doppler was excellent. Therefore, this examination is able to exclude a patent foramen ovale with a high level of confidence.