Differences in left ventricular and left atrial function assessed during breath-holding and breathing

Area of Science:

• Cardiology
• Medical Imaging
• Physiology

Background:

• Cardiac magnetic resonance (MR) imaging is crucial for assessing cardiac function.
• Standardized imaging protocols are essential for reliable and reproducible results.
• Patient respiratory state (breath-holding vs. free-breathing) can potentially influence cardiac function measurements.

Purpose of the Study:

• To quantify differences in systolic and diastolic left ventricular (LV) and left atrial (LA) function parameters obtained using identical cardiac MR techniques.
• To compare parameters acquired during inspiratory breath-holding versus free-breathing (breath-hold to breathing differences).

Main Methods:

• 56 subjects without heart failure underwent 3T MR cine and phase contrast imaging during inspiratory breath-holding and free breathing.
• LV and LA volumetric function parameters were derived from cine segmentation.
• Transmitral and myocardial velocities were measured using phase contrast imaging.
• Bland-Altman analysis compared breath-hold and breathing parameters; variance component analysis assessed repeatability.

Main Results:

• Significant differences were observed in LV volumetric function (e.g., end-diastolic volume, ejection fraction) between breath-holding and breathing.
• LA volumetric function parameters (e.g., maximum volume, ejection fractions) also showed significant variations.
• Early-diastolic velocities (transmitral and tissue) differed significantly between the two respiratory states.
• The variability between breath-hold and breathing measurements exceeded the repeatability of measurements within each state.

Conclusions:

• Systolic and diastolic LV and LA function parameters acquired during inspiratory breath-holding and free-breathing differ significantly.
• Large inter-individual variations in breath-hold-to-breathing differences are possible.
• The patient's respiratory state must be considered for accurate interpretation and comparison of cardiac MR imaging results, especially during follow-up assessments.