scholarly journals Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study

2016 ◽  
Vol 310 (3) ◽  
pp. H444-H451 ◽  
Author(s):  
Kasper Kyhl ◽  
Ivan Drvis ◽  
Otto Barak ◽  
Tanja Mijacika ◽  
Thomas Engstrøm ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Stroke Volume ◽  
Liver Perfusion ◽  
Liver Volume ◽  
Left Ventricular ◽  
Breath Hold ◽  
Organ Perfusion ◽  
Resonance Imaging ◽  
Pulmonary Hyperinflation

Pulmonary hyperinflation is used by competitive breath-hold divers and is accomplished by glossopharyngeal insufflation (GPI), which is known to compress the heart and pulmonary vessels, increasing sympathetic activity and lowering cardiac output (CO) without known consequence for organ perfusion. Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed from gradient echo sequences, and organ perfusion was evaluated from first-pass images after gadolinium injection. During GPI, lung volume increased by 5.2 ± 1.5 liters (mean ± SD; P < 0.001), while spleen and liver volume decreased by 46 ± 39 and 210 ± 160 ml, respectively ( P < 0.05), and inferior caval vein diameter by 4 ± 3 mm ( P < 0.05). Heart rate tended to increase (67 ± 10 to 86 ± 20 beats/min; P = 0.052) as right and left ventricular volumes were reduced ( P < 0.05). Stroke volume (107 ± 21 to 53 ± 15 ml) and CO (7.2 ± 1.6 to 4.2 ± 0.8 l/min) decreased as assessed after 1 min of GPI ( P < 0.01). Left ventricular myocardial perfusion maximum upslope and its perfusion index decreased by 1.52 ± 0.15 s−1 ( P < 0.001) and 0.02 ± 0.01 s−1 ( P < 0.05), respectively, without transmural differences. Pulmonary tissue, spleen, kidney, and pectoral-muscle perfusion also decreased ( P < 0.05), and yet liver perfusion was maintained. Thus, during pulmonary hyperinflation by GPI, CO and organ perfusion, including the myocardium, as well as perfusion of skeletal muscles, are reduced, and yet perfusion of the liver is maintained. Liver perfusion seems to be prioritized when CO decreases during GPI.

P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Ulbrich ◽  
R S Schoenbauer ◽  
B Kirstein ◽  
J Tomala ◽  
Y Huo ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Atrial Fibrillation ◽  
Magnetic Resonance ◽  
Stroke Volume ◽  
Left Atrial ◽  
Low Voltage ◽  
Left Ventricular ◽  
Left Ventricular Stroke Volume ◽  
Resonance Imaging ◽  
Ventricular Filling

Abstract Background The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known. Objective To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation. Methods From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated. Results Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients. LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03). The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively). The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage. Conclusion The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

scholarly journals Analyses of displacement of the heart and its substructures caused by cardiac movement and identification of compensatory margins based on breath-hold electrocardiograph-gated 4-dimensional magnetic resonance imaging for oesophageal radiotherapy

2020 ◽  
Author(s):  
Guanghui Yang ◽  
Chengrui Fu ◽  
Guanzhong Gong ◽  
Jing Zhang ◽  
Qian Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Papillary Muscle ◽  
Cardiac Cycle ◽  
Left Ventricular ◽  
Breath Hold ◽  
Resonance Imaging ◽  
4D Mri ◽  
Planning Ct ◽  
Anterior Posterior

Abstract Background: Cardiac movement can affect the accuracy of the evaluation of the location of heart and its substructures by planning computed tomography (CT). We aimed to measure the margin displacement and calculate compensatory margins through breath-hold electrocardiograph (ECG)-gated 4-dimensional magnetic resonance imaging (4D-MRI) for oesophageal radiotherapy.Methods: The study enrolled 10 patients with oesophageal radiotherapy plans and pretreatment 4D-MRI data. The displacement of the heart and its substructures was measured between the end of the systolic and diastolic phases in one cardiac cycle. The compensatory margins were calculated by extending the planning CT to cover the internal target volume (ITV) of all structures. Differences between groups were tested with the Kruskal-Wallis H test.Results: The extent of movement of the heart and its substructures during one cardiac cycle were approximately 4.0-26.1 mm in the anterior-posterior (AP),left-right (LR), and cranial-caudal (CC) axes, and the compensatory margins should be applied to the planning CT by extending the margins by 1.7, 3.6, 1.8, 3.0, 2.1, and 2.9 mm for the pericardium, 1.2, 2.5, 1.0, 2.8, 1.8, and 3.3 mm for the heart, 3.8, 3.4, 3.1, 2.8, 0.9, and 2.0 mm for the interatrial septum, 3.3, 4.9, 2.0, 4.1, 1.1, and 2.9 mm for the interventricular septum, 2.2, 3.0, 1.1, 5.3, 1.8, and 2.4 mm for the left ventricular muscle (LVM), 5.9, 3.4, 2.1, 6.1, 5.4, and 3.6 mm for the antero-lateral papillary muscle (ALPM), and 6.6, 2.9, 2.6, 6.6, 3.9, and 4.8 mm for the postero-medial papillary muscle (PMPM) in the anterior, posterior, left, right, cranial, and caudal directions.Conclusions: The locations of the heart and its substructures determined by planning CT were not able to represent the true positions due to cardiac movement, and compensatory margins can be applied to decrease the influence of movement.

scholarly journals Exercise cardiac magnetic resonance imaging: a feasibility study and meta-analysis

2018 ◽  
Vol 315 (4) ◽  
pp. R638-R645 ◽  
Author(s):  
Rhys I. Beaudry ◽  
T. Jake Samuel ◽  
Jing Wang ◽  
Wesley J. Tucker ◽  
Mark J. Haykowsky ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Ejection Fraction ◽  
Stroke Volume ◽  
Cardiac Mri ◽  
Meta Analysis ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
Cardiac Stress ◽  
Response To Exercise

Cardiac stress testing improves detection and risk assessment of heart disease. Magnetic resonance imaging (MRI) is the clinical gold-standard for assessing cardiac morphology and function at rest; however, exercise MRI has not been widely adapted for cardiac assessment because of imaging and device limitations. Commercially available magnetic resonance ergometers, together with improved imaging sequences, have overcome many previous limitations, making cardiac stress MRI more feasible. Here, we aimed to demonstrate clinical feasibility and establish the normative, healthy response to supine exercise MRI. Eight young, healthy subjects underwent rest and exercise cinematic imaging to measure left ventricular volumes and ejection fraction. To establish the normative, healthy response to exercise MRI we performed a comprehensive literature review and meta-analysis of existing exercise cardiac MRI studies. Results were pooled using a random effects model to define the left ventricular ejection fraction, end-diastolic, end-systolic, and stroke volume responses. Our proof-of-concept data showed a marked increase in cardiac index with exercise, secondary to an increase in both heart rate and stroke volume. The change in stroke volume was driven by a reduction in end-systolic volume, with no change in end-diastolic volume. These findings were entirely consistent with 17 previous exercise MRI studies (226 individual records), despite differences in imaging approach, ergometer, or exercise type. Taken together, the data herein demonstrate that exercise cardiac MRI is clinically feasible, using commercially available exercise equipment and vendor-provided product sequences and establish the normative, healthy response to exercise MRI.

scholarly journals Regional contributions to left ventricular stroke volume determined by cardiac magnetic resonance imaging in cardiac resynchronization therapy

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Björn Östenson ◽  
Ellen Ostenfeld ◽  
Anna Werther-Evaldsson ◽  
Anders Roijer ◽  
Zoltan Bakos ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Stroke Volume ◽  
Cardiac Resynchronization Therapy ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Reverse Remodeling ◽  
Resonance Imaging ◽  
Resynchronization Therapy

Abstract Background Cardiac resynchronization therapy (CRT) restores ventricular synchrony and induces left ventricular (LV) reverse remodeling in patients with heart failure (HF) and dyssynchrony. However, 30% of treated patients are non-responders despite all efforts. Cardiac magnetic resonance imaging (CMR) can be used to quantify regional contributions to stroke volume (SV) as potential CRT predictors. The aim of this study was to determine if LV longitudinal (SVlong%), lateral (SVlat%), and septal (SVsept%) contributions to SV differ from healthy controls and investigate if these parameters can predict CRT response. Methods Sixty-five patients (19 women, 67 ± 9 years) with symptomatic HF (LVEF ≤ 35%) and broadened QRS (≥ 120 ms) underwent CMR. SVlong% was calculated as the volume encompassed by the atrioventricular plane displacement (AVPD) from end diastole (ED) to end systole (ES) divided by total SV. SVlat%, and SVsept% were calculated as the volume encompassed by radial contraction from ED to ES. Twenty age- and sex-matched healthy volunteers were used as controls. The regional measures were compared to outcome response defined as ≥ 15% decrease in echocardiographic LV end-systolic volume (LVESV) from pre- to 6-months post CRT (delta, Δ). Results AVPD and SVlong% were lower in patients compared to controls (8.3 ± 3.2 mm vs 15.3 ± 1.6 mm, P < 0.001; and 53 ± 18% vs 64 ± 8%, P < 0.01). SVsept% was lower (0 ± 15% vs 10 ± 4%, P < 0.01) with a higher SVlat% in the patient group (42 ± 16% vs 29 ± 7%, P < 0.01). There were no differences between responders and non-responders in neither SVlong% (P = 0.87), SVlat% (P = 0.09), nor SVsept% (P = 0.65). In patients with septal net motion towards the right ventricle (n = 28) ΔLVESV was − 18 ± 22% and with septal net motion towards the LV (n = 37) ΔLVESV was − 19 ± 23% (P = 0.96). Conclusions Longitudinal function, expressed as AVPD and longitudinal contribution to SV, is decreased in patients with HF scheduled for CRT. A larger lateral contribution to SV compensates for the abnormal septal systolic net movement. However, LV reverse remodeling could not be predicted by these regional contributors to SV.

Estimation of ejection fraction and stroke volume using single- and biplane magnetic resonance imaging of the left cardiac ventricle

2008 ◽  
Vol 49 (9) ◽  
pp. 1016-1023 ◽  
Author(s):  
P. Thunberg ◽  
K. Emilsson ◽  
P. Rask ◽  
A. Kähäri
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Stroke Volume ◽  
Reference Values ◽  
Plane Motion ◽  
Left Ventricular ◽  
Mean Difference ◽  
Resonance Imaging ◽  
Single Plane ◽  
Cardiac Ventricle

Background: In cardiac magnetic resonance imaging (MRI), left ventricular stroke volume (SV) and ejection fractions (EF) are occasionally calculated using single-plane and biplane ellipsoid models. In previous studies, the calculated SV and EF using single- and biplane ellipsoid models have been compared to reference values calculated from short-axis (SA) images. In these studies, however, it has been emphasized that through-plane motion of the basal SA images represents an important source of error, which may result in incorrect reference values. Purpose: To compare the calculated SV and EF using single-plane and biplane ellipsoid models with SV and EF calculated from SA images in which compensation was made for through-plane motion. Material and Methods: A group of 20 patients who underwent MRI examination were included in the study. SV and EF were calculated using the stack of SA images (which had been compensated for through-plane motion) and compared to the SV and EF calculated according to the single- and biplane ellipsoid models. Results: The mean difference between the single-plane model and the reference was -0.3±6.5 for EF and 7.2±17.1 ml for SV. Corresponding comparison between the biplane method and the reference resulted in a mean difference of 0.3±6.1 for EF and 11.8±14.9 ml for SV. Conclusion: The results from this study show that left ventricular EF can be adequately estimated using the single- and biplane ellipsoid models, while SV tends to be overestimated using both geometrical models.

scholarly journals Follow-up magnetic resonance imaging of Löffler endocarditis: a case report

2020 ◽  
Author(s):  
Shinya Ito ◽  
Akihiro Isotani ◽  
Kyohei Yamaji ◽  
Kenji Ando
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Corticosteroid Therapy ◽  
Cardiac Mri ◽  
High Intensity ◽  
Left Ventricular ◽  
Eosinophil Infiltration ◽  
Resonance Imaging ◽  
T2 Weighted Images

Abstract Background  Löffler endocarditis is a condition characterized by cardiac infiltration of eosinophils. Cardiac magnetic resonance imaging (MRI) is a modality for the diagnosis of myocardial damage. Case summary  This is the case of a 77-year-old man with acute decompensated heart failure who was admitted. Transthoracic echocardiography showed preserved left ventricular (LV) systolic function along with LV thrombi attached to the septo-apical wall and the posterior wall, consistent with Löffler endocarditis. Cardiac MRI revealed obliteration of the LV apex and partial filling of the LV cavity, as well as near circumferential subendocardial late gadolinium enhancement (LGE) in the mid- and apical segments. T2-weighted images showed a near circumferential high-intensity area of the LV subendocardial muscle in the mid- and apical segments. High-dose corticosteroids and intravenous heparin were initiated, followed by maintenance warfarin therapy. At 18 months, follow-up cardiac MRI revealed the disappearance of the LV thrombi, and a reduction of LGE, as well as high-intensity areas in the T2-weighted images. Discussion  The high-intensity area of T2-weighted images indicate the presence of subendocardial oedema. Eosinophil-mediated heart damage evolves through three stages: (i) acute necrotic, (ii) thrombotic, and (iii) fibrotic stages. Since the deposition of toxic eosinophil granule proteins and eosinophil infiltration injured the endocardium, the first-line treatment for Löffler endocarditis is corticosteroid therapy. In this case, LGE in the subendocardium and the high-intensity area in the T2-weighted images were reduced at 18 months. High-intensity areas of T2-weighted images in the acute phase might indicate the possibility of therapeutic response to corticosteroid therapy.

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