Chiari's network: normal anatomic variant or risk factor for arterial embolic events?

Area of Science:

• Cardiology
• Echocardiography
• Congenital Heart Anomalies

Background:

• Chiari's network is a congenital remnant of the right valve of the sinus venosus.
• Previously, it was considered to have little clinical significance, with autopsy prevalence ranging from 1.3% to 4%.

Purpose of the Study:

• To determine the prevalence of Chiari's network in patients undergoing transesophageal echocardiography (TEE).
• To investigate associations between Chiari's network and other cardiac lesions.
• To identify typical clinical findings related to this anomaly.

Main Methods:

• Review of video recordings from 1,436 adult patients who underwent TEE over 30 months.
• Comparison of echocardiographic contrast studies in patients with Chiari's network versus a control group of 160 patients without the network.

Main Results:

• Chiari's network was identified in 2% of patients (29/1,436).
• Significant associations included patent foramen ovale (83%), intense right-to-left shunting (55%), and atrial septal aneurysm (24%).
• The network was more common in patients with unexplained arterial embolism (4.6% vs. 0.5%), with patent foramen ovale being the sole identified cause in 62% of these cases.

Conclusions:

• The prevalence of Chiari's network is 2% in patients undergoing TEE, aligning with autopsy findings.
• Chiari's network may promote the persistence of a patent foramen ovale and atrial septal aneurysm.
• The anomaly may facilitate paradoxical embolism by altering embryonic right atrial flow patterns.