Martin Schwarz

Comparison of transesophageal and transthoracic contrast echocardiography for detection of a patent foramen ovale

Abstract Presence of a patent foramen ovale may indicate paradoxic embolism in patients with otherwise unexplained embolie disease.1–3 Transthoracic contrast echocardiography has been used as a simple technique for detecting patent foramen ovale.4–6 However, particularly in patients with poor transthoracic image quality, presence of a patent foramen ovale might be missed. Transesophageal contrast echocardiography provides superior visualization of the atrial septum and therefore is believed to improve diagnostic accuracy. The present study investigates the influence of image quality on the detection of a patent foramen ovale by both transthoracic and transesophageal contrast echocardiography.

Significance of left-sided heart disease for the detection of patent foramen ovale by transesophageal contrast echocardiography

Detection of patent foramen ovale by contrast echocardiography is based on transient inversion (right atrial pressure higher than left atrial pressure) of the interatrial pressure gradient. Therefore, the presence of left-sided heart disease with potential elevation of left atrial pressure might obscure the diagnosis of patent foramen ovale. Accordingly, 150 patients (88 men, 62 women; mean age 51.7 +/- 15.2 years) were evaluated for a patent foramen ovale by transesophageal contrast echocardiography. Additionally, atrial septal motion during normal respiration and during the Valsalva maneuver was analyzed. Patency of the foramen ovale was observed in 20 (27%) of 74 patients without left-sided heart disease and with previous arterial embolism, in none (0%) of 25 patients with left-sided heart disease and embolism, in 7 (39%) of 18 patients without left-sided heart disease and without embolism and in 3 (9%) of 33 patients with left-sided heart disease and without embolism. The detection rate of patent foramen ovale was lower in patients with than without left-sided heart disease (5% vs. 29%, p = 0.0007) but was similar in patients with and without embolism (20% vs. 19.5%, p = NS). Abnormal atrial septal motion was more frequently observed in patients with left-sided heart disease (p = 0.0003) and was inversely correlated to detection of patent foramen ovale (p = 0.0003). Multivariate analysis revealed an independent association between the absence of left-sided heart disease and the detection of patent foramen ovale (p = 0.0003). These data suggest that in patients with left-sided heart disease, patency of the foramen ovale may be missed even by transesophageal contrast echocardiography.

Noninvasive estimation of coronary flow reserve by transesophageal Doppler measurement of coronary sinus flow

Abstract Currently available methods for the measurement of coronary flow reserve (CFR) are invasive and time-consuming, and need adequate laboratory equipment and staff. 1–4 Furthermore, most of these methods are limited by various methodologic problems. 5,6 Transesophageal echocardiography enables visualization of the distal coronary sinus in most patients. Accordingly, we investigated the ability of transesophageal echocardiography to calculate CFR by Doppler measurement of coronary sinus flow (CSF) at rest and after dipyridamole administration.