Changes in overall ventricular myocardial architecture in the setting of a porcine animal model of right ventricular dilation
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Changes in overall ventricular myocardial architecture in the setting of a porcine animal model of right ventricular dilation. / Agger, Peter; Ilkjær, Christine; Laustsen, Christoffer; Smerup, Morten; Frandsen, Jesper R; Ringgaard, Steffen; Pedersen, Michael; Partridge, John B; Anderson, Robert H; Hjortdal, Vibeke.
In: Journal of Cardiovascular Magnetic Resonance, Vol. 19, 93, 27.11.2017.Research output: Contribution to journal › Journal article › Research › peer-review
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T1 - Changes in overall ventricular myocardial architecture in the setting of a porcine animal model of right ventricular dilation
AU - Agger, Peter
AU - Ilkjær, Christine
AU - Laustsen, Christoffer
AU - Smerup, Morten
AU - Frandsen, Jesper R
AU - Ringgaard, Steffen
AU - Pedersen, Michael
AU - Partridge, John B
AU - Anderson, Robert H
AU - Hjortdal, Vibeke
PY - 2017/11/27
Y1 - 2017/11/27
N2 - BACKGROUND: Chronic pulmonary regurgitation often leads to myocardial dysfunction and heart failure. It is not fully known why secondary hypertrophy cannot fully protect against the increase in wall stress brought about by the increased end-diastolic volume in ventricular dilation. It has been assumed that mural architecture is not deranged in this situation, but we hypothesised that there might be a change in the pattern of orientation of the aggregations of cardiomyocytes, which would contribute to contractile impairment.METHODS: We created pulmonary valvular regurgitation by open chest, surgical suturing of its leaflets in seven piglets, performing sham operations in seven control animals. Using cardiovascular magnetic resonance imaging after 12 weeks of recovery, we demonstrated significantly increased right ventricular volumes in the test group. After sacrifice, diffusion tensor imaging of their hearts permitted measurement of the orientation of the cardiomyocytes.RESULTS: The helical angles in the right ventricle approached a more circumferential orientation in the setting of right ventricular RV dilation (p = 0.007), with an increased proportion of surface-parallel cardiomyocytes. In contrast, this proportion decreased in the left ventricle. Also in the left ventricle a higher proportion of E3 angles with a value around zero was found, and conversely a lower proportion of angles was found with a numerical higher value. In the dilated right ventricle the proportion of E3 angles around -90° is increased, while the proportion around 90° is decreased.CONCLUSION: Contrary to traditional views, there is a change in the orientation of both the left ventricular and right ventricular cardiomyocytes subsequent to right ventricular dilation. This will change their direction of contraction and hinder the achievement of normalisation of cardiomyocytic strain, affecting overall contractility. We suggest that the aetiology of the cardiac failure induced by right vetricular dilation may be partly explained by morphological changes in the myocardium itself.
AB - BACKGROUND: Chronic pulmonary regurgitation often leads to myocardial dysfunction and heart failure. It is not fully known why secondary hypertrophy cannot fully protect against the increase in wall stress brought about by the increased end-diastolic volume in ventricular dilation. It has been assumed that mural architecture is not deranged in this situation, but we hypothesised that there might be a change in the pattern of orientation of the aggregations of cardiomyocytes, which would contribute to contractile impairment.METHODS: We created pulmonary valvular regurgitation by open chest, surgical suturing of its leaflets in seven piglets, performing sham operations in seven control animals. Using cardiovascular magnetic resonance imaging after 12 weeks of recovery, we demonstrated significantly increased right ventricular volumes in the test group. After sacrifice, diffusion tensor imaging of their hearts permitted measurement of the orientation of the cardiomyocytes.RESULTS: The helical angles in the right ventricle approached a more circumferential orientation in the setting of right ventricular RV dilation (p = 0.007), with an increased proportion of surface-parallel cardiomyocytes. In contrast, this proportion decreased in the left ventricle. Also in the left ventricle a higher proportion of E3 angles with a value around zero was found, and conversely a lower proportion of angles was found with a numerical higher value. In the dilated right ventricle the proportion of E3 angles around -90° is increased, while the proportion around 90° is decreased.CONCLUSION: Contrary to traditional views, there is a change in the orientation of both the left ventricular and right ventricular cardiomyocytes subsequent to right ventricular dilation. This will change their direction of contraction and hinder the achievement of normalisation of cardiomyocytic strain, affecting overall contractility. We suggest that the aetiology of the cardiac failure induced by right vetricular dilation may be partly explained by morphological changes in the myocardium itself.
U2 - 10.1186/s12968-017-0404-0
DO - 10.1186/s12968-017-0404-0
M3 - Journal article
C2 - 29178894
VL - 19
JO - Journal of Cardiovascular Magnetic Resonance
JF - Journal of Cardiovascular Magnetic Resonance
SN - 1097-6647
M1 - 93
ER -
ID: 195151781