Left Ventricular Diastolic Dysfunction Assessment with Dual-Source CT

<div><p>Purpose</p><p>To assess the impact of left ventricular (LV) diastolic dysfunction on left atrial (LA) phasic volume and function using dual-source CT (DSCT) and to find a viable alternative prognostic parameter of CT for LV diastolic dysfunction through quantitative evaluation of LA phasic volume and function in patients with LV diastolic dysfunction.</p><p>Materials and Methods</p><p>Seventy-seven patients were examined using DSCT and Doppler echocardiography on the same day. Reservoir, conduit, and contractile function of LA were evaluated by measuring LA volume (LAV) during different cardiac phases and all parameters were normalized to body surface area (BSA). Patients were divided into four groups (normal, impaired relaxation, pseudonormal, and restrictive LV diastolic filling) according to echocardiographic findings. The LA phasic volume and function in different stages of LV diastolic function was compared using one-way ANOVA analysis. The correlations between indexed volume of LA (LAVi) and diastolic function in different stages of LV were evaluated using Spearman correlation analysis.</p><p>Results</p><p>LA ejection fraction (LAEF), LA contraction, reservoir, and conduit function in patients in impaired relaxation group were not different from those in the normal group, but they were lower in patients in the pseudonormal and restrictive LV diastolic dysfunction groups (<i>P</i> < 0.05). For LA conduit function, there were no significant differences between the patients in the pseudonormal group and restrictive filling group (<i>P</i> = 0.195). There was a strong correlation between the indexed maximal left atrial volume (LAVmax, r = 0.85, <i>P</i> < 0.001), minimal left atrial volume (LAVmin, r = 0.91, <i>P</i> < 0.001), left atrial volume at the onset of P wave (LAVp, r = 0.84, <i>P</i> < 0.001), and different stages of LV diastolic function. The LAVi increased as the severity of LV diastolic dysfunction increased.</p><p>Conclusions</p><p>LA remodeling takes place in patients with LV diastolic dysfunction. At the same time, LA phasic volume and function parameters evaluated by DSCT indicated the severity of the LV diastolic dysfunction. Quantitative analysis of LA phasic volume and function parameters using DSCT could be a viable alternative prognostic parameter of LV diastolic function.</p></div

Correlation between the indexed LAVmax and different grades of left ventricular diastolic dysfunction.

<p>The indexed LAVmax increased significantly as LV diastolic dysfunction decreased (<i>P</i> < 0.001).</p

Correlation between the indexed LAVp and different grades of left ventricular diastolic dysfunction.

<p>The indexed LAVp increased significantly as LV diastolic dysfunction decreased (<i>P</i> < 0.001).</p

Comparison of the LA volume and function among the 4 study groups.

<p>*<i>P</i> < 0.05, Relative to the other 3 groups</p><p>^§<i>P</i> < 0.05, relative to the normal group,</p><p>^&<i>P</i> < 0.05, relative to the impaired relaxation group,</p><p>Comparison of the LA volume and function among the 4 study groups.</p

2D and 3D fusion image of LA.

<p>The fusion image providing true 3D rendering of LA without taking any geometrical assumptions.</p

Clinical characteristics and echocardiographic variables of the normal group and LV diastolic dysfunction groups.

<p>MI: myocardial infarction; CAD: coronary artery disease; DM: diabetes mellitus; HP: systematic hypertension</p><p>*<i>P</i> < 0.05, relative to the other 3 groups,</p><p>^§<i>P</i> < 0.05, relative to the normal group</p><p>Clinical characteristics and echocardiographic variables of the normal group and LV diastolic dysfunction groups.</p

Correlation between the indexed LAVmin and different grades of left ventricular diastolic dysfunction.

<p>The indexed LAVmin increased significantly as LV diastolic dysfunction decreased (<i>P</i> < 0.001).</p

Where is the left ventricle during cardiopulmonary resuscitation based on chest computed tomography in the expiration with arms down position?

<div><p>Objective</p><p>Patients usually receive cardiopulmonary resuscitation during ventilatory expiration and with their arms down, which does not reflect the normal imaging position. This study used scout images from low-dose chest computed tomography to compare the locations of the left ventricle (LV) in the expiration with arms down position (EAD) and in the full inspirational with arms raised position (IAR).</p><p>Methods</p><p>This cross-sectional study used a convenience sample and evaluated scout images that were obtained during screening with the participants in the EAD and IAR positions. The effective compression point was defined as being on the sternum above the longest anteroposterior diameter (APD) of the LV (using axial computed tomography images). The sternum was divided into three parts and the heart’s position was evaluated on the EAD and the IAR images, and the distance from the xiphoid process to the LV’s sternum landmark (XLVD) was measured. We also examined the compressible organs during CPR based on the EAD and IAR images.</p><p>Results</p><p>We enrolled 127 participants. The LVs were located in the middle of the sternum at EAD for 117 participants (92%) and in the lower half of the sternum at IAR for 107 participants (84%). The mean XLVD was significantly different between the EAD and IAR positions (mean: 85 ± 21 mm vs. 33 ± 17 mm, respectively). The liver’s left lobe was located in the lower half of the sternum at EAD for 118 participants (93%).</p><p>Conclusions</p><p>These findings indicate that the location of the LV during cardiopulmonary resuscitation might be in the middle of the sternum if the patient is treated in the EAD position.</p></div

Comparing distances from the xiphoid process to the sternum landmark according to respiratory phase and arm position.

<p>Comparing distances from the xiphoid process to the sternum landmark according to respiratory phase and arm position.</p

Determining maximal anteroposterior diameter (APD) of the left ventricle (LV) using axial and scout images.

<p>The skin above the maximal APD was searched to identify the sternum landmark representing the LV. </p><p></p><p></p><p>The maximal APD of the LV was measured and aligned in the axial images from the full inspiration with the arms raised position. The centre of the line was defined as the location of the LV (a).</p><p></p><p></p><p>The location of the LV was marked at the skin and a perpendicular line was drawn to the sternum for the sternum landmark of the LV.</p><p></p><p></p><p>A perpendicular line was drawn at the margin of the right atrial contour, and the intersection between the perpendicular line and the right atrial contour was marked.</p><p></p><p></p><p>A straight line was drawn from the heart’s apex to the intersection point at the right atrial contour.</p><p></p><p></p><p>Another perpendicular line was drawn from the radio-opaque marker at the lowest palpable xiphoid process to the line that connected the apex and intersection point. This intersection was defined as the LV sternum landmark for the expiration with the arms down position, and the distance from the sternum landmark to the xiphoid process marker was defined as the XLVD. This method was also applied to the expiration with the arms down position scout images.</p><p></p><p></p><p></p> <p>The maximal APD of the LV was measured and aligned in the axial images from the full inspiration with the arms raised position. The centre of the line was defined as the location of the LV (a).</p> <p>The location of the LV was marked at the skin and a perpendicular line was drawn to the sternum for the sternum landmark of the LV.</p> <p>A perpendicular line was drawn at the margin of the right atrial contour, and the intersection between the perpendicular line and the right atrial contour was marked.</p> <p>A straight line was drawn from the heart’s apex to the intersection point at the right atrial contour.</p> <p>Another perpendicular line was drawn from the radio-opaque marker at the lowest palpable xiphoid process to the line that connected the apex and intersection point. This intersection was defined as the LV sternum landmark for the expiration with the arms down position, and the distance from the sternum landmark to the xiphoid process marker was defined as the XLVD. This method was also applied to the expiration with the arms down position scout images.</p