Functional chiral asymmetry in descending thoracic aorta

Area of Science:

• Cardiovascular Physiology
• Medical Imaging
• Fluid Dynamics

Background:

• The human aorta's blood flow is traditionally viewed as pulsatile and axial.
• Understanding the complex flow dynamics within the aorta is crucial for assessing cardiovascular health and organ perfusion.

Purpose of the Study:

• To investigate the presence and characteristics of rotational blood flow and chiral asymmetry in the human descending thoracic aorta.
• To establish the capability of color Doppler ultrasound in detecting rotational flow patterns.

Main Methods:

• Developed a tornado tube model to validate color Doppler ultrasound's ability to detect vortex flow.
• Utilized a pulse duplicator model of the human aortic arch to observe initial rotational flow development.
• Prospectively examined 53 patients using color Doppler esophageal echocardiography to assess descending thoracic aorta flow patterns.

Main Results:

• Rotational flow was detected in the aortic arch and progressed to the descending thoracic aorta.
• In patients, rotational flow was observed at various positions, with a predominant clockwise direction during systole and counterclockwise during diastole in the retro-left ventricular position.
• Prevalence of rotational flow increased with proximity to the retro-left ventricular position, observed in up to 89% of patients.

Conclusions:

• Aortic blood flow possesses a significant rotational component, challenging the purely axial model.
• Chiral asymmetry in descending thoracic aorta flow, with distinct systolic and diastolic rotational directions, was demonstrated.
• The identified aortic rotational flow may have important physiological implications for systemic organ perfusion.