Determination of the Optimum Number of Cardiac Cycles to Differentiate Intra‐Pulmonary Shunt and Patent Foramen Ovale by Saline Contrast Two‐ and Three‐Dimensional Echocardiography

Abstract

This study demonstrates for the first time that the 4th cardiac cycle rule differentiates PFO and IPS most optimally by 2D and 3DTTE. 3DTTE appears to have higher sensitivity for diagnosing IPS. These data suggest that 3DTTE is preferable when IPS is to be diagnosed. Both methods are similar for diagnosing PFO.

Intrapulmonary Shunt and SCUBA Diving: Another Risk Factor?

“…It is expected, in the presence of a PFO, that injected bubbles will immediately appear in the left cardiac cavities. However, if this crossover occurs after at least 4 cardiac cycles, the site of arterialization is outside the heart …”

Patent foramen ovale: the current state of play

“…A PFO is confirmed by contrast in the left atrium within three cardiac cycles following opacification of the right atrium (figure 2 ) ; any longer than five cardiac cycles is suggestive of an intrapulmonary shunt 14 15. Shunt size can be quantified based by the number of bubbles seen in a single still frame (small: <10; moderate: 10–20; large: >20 bubbles) at rest and after provocative manoeuvres 16.…”

“…Shunt size can be quantified based by the number of bubbles seen in a single still frame (small: <10; moderate: 10–20; large: >20 bubbles) at rest and after provocative manoeuvres 16. Data is emerging that 3D TTE with contrast may be more effective than 2D, and similar to TOE with contrast at identifying PFO 14 17…”

Démarche diagnostique d’une hypoxémie « nue » de l’adulte

“…Néanmoins, le passage de microbulles ne permet parfois pas de trancher formellement entre un shunt intracardiaque ou un shunt intra-pulmonaire, ce que permet le plus souvent l'échocardiographie. [19].…”

“…Dans les autres cas, l'arrivée des bulles dans les cavités gauches est plus retardée. [19] Le FOP est un tunnel reliant les 2 oreillettes via un système de type valvulaire qui ne peut provoquer un court-circuit que dans le sens droit-gauche. Il est alors responsable d'une hypoxémie par passage de sans veineux systémique désaturé dans la circulation artérielle systémique.…”