What is the clinical evidence from this study?

Study design: Cross-Sectional. Population: Healthy volunteers (n=24). Intervention: 4D flow MRI vs. Age and gender groups. Primary outcome: Number of diastolic vortices in the left atrium (p=0.01).

September 21, 2012Open Access

Age, gender, blood pressure, and ventricular geometry influence normal 3D blood flow characteristics in the left heart

Key Result

4D flow MRI demonstrated that left heart flow patterns differ by age and gender, with young individuals having more LA diastolic vortices than older individuals (1.6 vs. 0.7, P=0.01).

Study Design

Type

Cross-Sectional (n=24)

Structured PICO

Do age, gender, blood pressure, and ventricular geometry influence normal 3D blood flow characteristics in the left heart measured by 4D flow MRI in healthy volunteers?

Population

24 healthy volunteers divided into two age groups: <30 years (n=12, 6 women) and >50 years (n=12, 6 women).

Intervention

4D flow magnetic resonance imaging (MRI)

Comparator

Comparison between age groups (<30 years vs >50 years) and gender (men vs women)

Outcome

Systolic and early to mid-diastolic vortex flow characteristics (number of vortices, duration, area, peak velocity inside the vortex) in the left atrium (LA) and left ventricle (LV)surrogate

Normal 3D blood flow patterns in the left heart assessed by 4D flow MRI demonstrate significant differences related to age, gender, blood pressure, and ventricular geometry.

Main Result

Absolute Event Rate: 1.6% vs 0.7%

p-value: p=0.01

Abstract

AIMS: The aim of this study was to assess the effect of age, gender, physiological, and global cardiac function parameters on differences in normal 3D blood flow in the left ventricle (LV) and atrium (LA) using 4D flow magnetic resonance imaging (MRI). METHODS AND RESULTS: Four-dimensional flow MRI was acquired in healthy volunteers of two age and gender groups: 50 years (6 women, n = 12). Systolic and early to mid-diastolic vortex flow (number of vortices, duration, area, peak velocity inside the vortex) in the LA and LV was assessed using intra-cardiac flow visualization based on 3D particle traces and velocity vector fields. A larger number of vortices in the LA were found in young compared with older individuals (number of diastolic vortices: 1.6 ± 0.8 vs. 0.7 ± 0.7, P = 0.01) with higher velocities (54 ± 12 cm/s vs. 41 ± 11 cm/s in systole, 47 ± 13 vs. 31 ± 8 cm/s in diastole, P < 0.05). Vortices in the LV base were smaller in women compared with men (369 ± 133 vs. 543 ± 176 mm(2), P = 0.009), while vortex size was increased in mid-ventricular locations (maximum area: 546 ± 321 vs. 293 ± 174 mm(2), P < 0.05). Correlation analysis revealed significant relationships (P = 0.005-0.048, correlation coefficients = 0.44-0.84) between LA and LV vortex characteristics (number, size, vortex velocities) and blood pressure as well as end-diastolic volume, LV length, and ejection fraction. CONCLUSIONS: Flow patterns in the left heart demonstrated differences related to age, gender, blood pressure, and ventricular geometry. The findings constitute a prerequisite for the understanding of the impact of cardiac disease on intra-cardiac haemodynamics.