Relationship between left ventricular vortex and preejectional flow velocity during isovolumic contraction studied by...

Area of Science:

• Cardiovascular Physiology
• Echocardiography
• Hemodynamics

Background:

• The intraventricular vortex (IVC) plays a role in left ventricular (LV) function.
• Understanding the relationship between IVC vortex dynamics and LV outflow tract (LVOT) velocity is crucial for assessing cardiac performance.

Purpose of the Study:

• To investigate the relationship between the left ventricular (LV) isovolumic contraction (IVC) vortex and preejectional flow velocity in the LV outflow tract (V_LVOT).

Main Methods:

• Color Doppler vector flow mapping was used to acquire apical long-axis view loops.
• Data were collected from 76 patients with dilated cardiomyopathy, 61 with coronary artery disease, and 36 healthy controls.

Main Results:

• In healthy individuals, the IVC vortex reached the LV base, and transmitral A velocity was the sole independent predictor of V_LVOT.
• In patients, V_LVOT correlated with IVC vortex characteristics (range, area, flux), LV size, LVEF, mitral annular velocities, and E/e' ratio.
• IVC vortex range and corrected area flux, LV end-systolic diameter, and IVC time were independent predictors of V_LVOT in patients.

Conclusions:

• Transmitral A velocity efficiently transfers momentum in healthy individuals via a normal IVC vortex.
• In patients with LV dysfunction, momentum transfer depends on LV dimensions, function, and IVC vortex characteristics.