Aims: Persistent foramen ovale (PFO) is found in 9.2--32% of echocardiographic examinations. The gold standard for the detection of a PFO is transoesophageal echocardiography (TEE) and the mostly used provocation test is the Valsalva manoeuvre. The aim of our study was to evaluate the effectiveness of the Valsalva manoeuvre compared to other provocation tests by simultaneous haemodynamic measurements of the right and left atrial pressure.
Methods: Fifty patients underwent Swan-Ganz catheterization. Right atrial pressure and pulmonary capillary wedge pressure, which corresponds to the left atrial pressure, were measured simultaneously. The following manoeuvres were compared: the Valsalva manoeuvre, coughing, deep inspiration and expiration pressures of 20 mmHg, 40 mmHg and 60 mmHg. The main objective of our study was to compare the occurrence of pressure gradients (right atrial pressure> left atrial pressure). For further quantification mean gradients, time duration of pressure overlap, as well as products of mean gradients and overlap time were analysed.
Results: During the Valsalva manoeuvre a significant pressure gradient could be observed in 84% of the patients, followed by an expiration pressure of 60 mmHg (82%), inspiration (78%), expiration pressure of 40 mmHg (76%), coughing (75%) and an expiration pressure of 20 mmHg (62%). Comparing the mean gradients and the products of mean gradients and overlap time duration during the different manoeuvres, we could detect the significantly best results with the Valsalva manoeuvre.
Conclusions: The Valsalva manoeuvre might be the most effective test to provoke a right-to-left atrial shunt for the detection of a PFO during echocardiographic examinations.