The effects of wall stretch on ventricular conduction and refractoriness in the whole heart

2011 ◽  
pp. 180-186 ◽  
Author(s):  
Robert W. Mills ◽  
Adam T. Wright ◽  
Sanjiv M. Narayan ◽  
Andrew D. McCulloch
Keyword(s):  
Whole Heart ◽  
Ventricular Conduction

Ventricular conduction stability test: a method to identify and quantify changes in whole heart activation patterns during physiological stress

EP Europace ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 1422-1431
Author(s):  
Matthew J Shun-Shin ◽  
Kevin M W Leong ◽  
Fu Siong Ng ◽  
Nicholas W F Linton ◽  
Zachary I Whinnett ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Cardiac Death ◽  
Physiological Stress ◽  
Exercise Treadmill ◽  
Abnormal Rate ◽  
Length Changes ◽  
Mapping Techniques ◽  
Whole Heart ◽  
Activation Times ◽  
Ventricular Conduction

Abstract Aims Abnormal rate adaptation of the action potential is proarrhythmic but is difficult to measure with current electro-anatomical mapping techniques. We developed a method to rapidly quantify spatial discordance in whole heart activation in response to rate cycle length changes. We test the hypothesis that patients with underlying channelopathies or history of aborted sudden cardiac death (SCD) have a reduced capacity to maintain uniform activation following exercise. Methods and results Electrocardiographical imaging (ECGI) reconstructs >1200 electrograms (EGMs) over the ventricles from a single beat, providing epicardial whole heart activation maps. Thirty-one individuals [11 SCD survivors; 10 Brugada syndrome (BrS) without SCD; and 10 controls] with structurally normal hearts underwent ECGI vest recordings following exercise treadmill. For each patient, we calculated the relative change in EGM local activation times (LATs) between a baseline and post-exertion phase using custom written software. A ventricular conduction stability (V-CoS) score calculated to indicate the percentage of ventricle that showed no significant change in relative LAT (<10 ms). A lower score reflected greater conduction heterogeneity. Mean variability (standard deviation) of V-CoS score over 10 consecutive beats was small (0.9 ± 0.5%), with good inter-operator reproducibility of V-CoS scores. Sudden cardiac death survivors, compared to BrS and controls, had the lowest V-CoS scores post-exertion (P = 0.011) but were no different at baseline (P = 0.50). Conclusion We present a method to rapidly quantify changes in global activation which provides a measure of conduction heterogeneity and proof of concept by demonstrating SCD survivors have a reduced capacity to maintain uniform activation following exercise.

scholarly journals Free‐running 3D whole heart myocardial T 1 mapping with isotropic spatial resolution

2019 ◽  
Vol 82 (4) ◽  
pp. 1331-1342 ◽  
Author(s):  
Haikun Qi ◽  
Olivier Jaubert ◽  
Aurelien Bustin ◽  
Gastao Cruz ◽  
Huijun Chen ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Isotropic Spatial Resolution ◽  
Free Running ◽  
Whole Heart

scholarly journals Auto Whole Heart Segmentation from CT images Using an Improved Unet-GAN

2021 ◽  
Vol 1769 (1) ◽  
pp. 012016
Author(s):  
Kening Le ◽  
Zeyu Lou ◽  
Weiliang Huo ◽  
Xiaolin Tian
Keyword(s):  
Ct Images ◽  
Whole Heart

scholarly journals Self-navigated 3D whole-heart MRA for non-enhanced surveillance of thoracic aortic dilation: a comparison to CTA

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
P Poskaite ◽  
M Pamminger ◽  
C Kranewitter ◽  
C Kremser ◽  
M Reindl ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Aortic Aneurysm ◽  
Thoracic Aortic Aneurysm ◽  
Aortic Dilation ◽  
Subjective Image Quality ◽  
Contrast Enhanced ◽  
Whole Heart ◽  
Enhanced Computed Tomography ◽  
Contrast Enhanced Computed Tomography

Abstract Funding Acknowledgements Type of funding sources: None. Background The natural history of thoracic aortic aneurysm (TAA) is one of progressive expansion. Asymptomatic patients who do not meet criteria for repair require conservative management including ongoing aneurysm surveillance, mostly carried out by contrast-enhanced computed tomography angiography (CTA). Purpose To prospectively compare image quality and reliability of a prototype non-contrast, self-navigated 3D whole-heart magnetic resonance angiography (MRA) with contrast-enhanced computed tomography angiography (CTA) for sizing of thoracic aortic aneurysm (TAA). Methods Self-navigated 3D whole-heart 1.5 T MRA was performed in 20 patients (aged 67 ± 8.6 years, 75% male) for sizing of TAA; a subgroup of 18 (90%) patients underwent additional contrast-enhanced CTA on the same day. Subjective image quality was scored according to a 4-point Likert scale and ratings between observers were compared by Cohen’s Kappa statistics. Continuous MRA and CTA measurements were analyzed with regression and Bland-Altman analysis. Results Overall subjective image quality as rated by two observers was 1 [interquartile range (IQR) 1-2] for self-navigated MRA and 1.5 [IQR 1-2] for CTA (p = 0.717). For MRA a perfect inter-observer agreement was found for presence of artefacts and subjective image sharpness (κ=1). Subjective signal inhomogeneity correlated highly with objectively quantified inhomogeneity of the blood pool signal (r = 0.78-0.824, all p &lt;0.0001). Maximum diameters of TAA as measured by self-navigated MRA and CTA showed excellent correlation (r = 0.997, p &lt; 0.0001) without significant inter-method bias (bias -0.0278, lower and upper limit of agreement -0.74 and 0.68, p = 0.749). Inter- and intraobserver correlation of aortic aneurysm as measured by MRA was excellent (r = 0.963 and 0.967, respectively) without significant bias (all p ≤ 0.05). Conclusion Self-navigated 3D whole-heart MRA enables reliable contrast- and radiation free aortic dilation surveillance without significant difference to standardized CTA while providing predictable acquisition time and by offering excellent image quality. Abstract Figure.

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