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Conotruncal variations in the normal heart
Asia Pacific
Heart J 1998;7(1)
Royal
Children’s
Hospital
Paediatric
Cardiac
Symposium SUPPLEMENT
the complex group there were 7 deaths (7/36) - 19.4%. This difference was significant (p
Conotruncal
Actuarial survival, after definitive surgery, was 90% at 10 years. Freedom from reoperation, after definitive repair, was 0.7 at 10 years. In the entire cohort, freedom from death or re-operation was 0.6 at 10 years. We concluded that patients with complex forms of double outlet right ventricle, especially those with multiple VSDs, should be considered for Fontan/cavopulmonary shunt surgery, if the anatomy and physiology is “suitable”. Biventricular repair may be an option, for some of these patients, when the complicating anomalies, in the individual case, can be dealt with relatively easily and are not likely to increase the risk of repair.
Variations In The Normal Heart Vijaya M Nay&
Solomon Victor
The Heart Institute, Chennai, India The outflow tracts of both the ventricles were perhaps first illustrated by Leonardo da Vinci. There is a midline bulbus cordis in the heart of snakes with 3 bulbar ridges. The bulbus is lateralised to the right in frogs and has a spiral valve inside. In the turtle and snake the truncus is replaced by 2 aortae and 1 pulmonary artery connected to the right ventricle. The bulbus is incorporated in the ventricle. In the crocodile, the right aorta is connected to the left ventricle. The left aorta and pulmonary artery are connected to the right ventricle. In birds and mammals, the bulbus is absorbed into the outflow of both ventricles. There is muscle between the aortic and mitral valves.
coronary sinuses. It is probable that this musculature is of bulbar origin. In 1 heart we have seen inferior displacement of the right coronary cusp with more extensive muscularisation of the right coronary sinus. We have also seen a patient with degeneration of the aortic valve with caudal intraventricular displacement of right and left coronary sinus and extensive muscularisation of the right and left aortic sinuses. We have seen muscularisation of the right and left coronary cusps of the aortic valve in another patient. It is of interest that the sinuses related to the pulmonary valve are uniformly muscularised because of the presence of bulbar musculature all around. The absence of musculature in the non-coronary and adjacent left coronary sinus is possibly due to absorption of the bulbar musculature. The extent of membranous septum varies in relation to the non-coronary cusp. It may be localised to the region below right coronary cusp, non-coronary cusp commissure or extend up to the aortic leaflet of the mitral valve. This is reflected by the varying size of the membranous septum in relation to the anteroseptal commissure of the tricuspid valve. The location of the coronary orifices in relation to the commissures varies widely.
In humans, the free wall of the outflow tract of the right ventricle is of bulbus origin. The left wall which should have been present between the aortic and mitral valves has disappeared. The bulbar septum descends down to join the trabecular septum. The conus papillary muscle and the trabeculum septomarginalis (TSM) represent the lower limit of the bulbar contribution to the right side of the interventricular septum (IVS) . We have studied 120 normal autopsy hearts. The configuration of the TSM varied from heart to heart as regards its prominence, size, termination, and number, extent and size of the anterior trabeculations. On the left side of the IVS, a left TSM is seen rarely as a prominent band which marks the caudal limit of the bulbar contribution to the septum. However, the configuration of the left side of the IVS also varies with a varying smooth area between the aortic leaflet and the trabeculated portion, possibly reflecting the varying contribution of the bulbus to the septum on the left side. The trabeculated septum may almost reach the aortic valve. We have observed that there is muscularisation of the adjacent halves of the right and left coronary sinuses and no muscle in the non-coronary and adjacent left/right
Thus, in the normal heart, the configuration of the outflow tract of both ventricles varies and is unique to each heart. Clinical abnormalities related to malincorporation of bulbus in the ventricle would result in varying combination of anomalous muscle bundle of the right ventricle (double-chambered right ventricle), subaortic membrane, idiopathic hypertrophic subaortic stenosis, asymmetric septal hypertrophy, septal defect in muscularisation of bulbar septum, aortic sinus/aortic/pulmonary leaflet aneurysm of membranous septum, and aneurysm of sinus of Valsalva.
61
Heart J 1998;7(1)
Royal
Children’s
Hospital
Paediatric
Cardiac
Symposium SUPPLEMENT
the complex group there were 7 deaths (7/36) - 19.4%. This difference was significant (p
Conotruncal
Actuarial survival, after definitive surgery, was 90% at 10 years. Freedom from reoperation, after definitive repair, was 0.7 at 10 years. In the entire cohort, freedom from death or re-operation was 0.6 at 10 years. We concluded that patients with complex forms of double outlet right ventricle, especially those with multiple VSDs, should be considered for Fontan/cavopulmonary shunt surgery, if the anatomy and physiology is “suitable”. Biventricular repair may be an option, for some of these patients, when the complicating anomalies, in the individual case, can be dealt with relatively easily and are not likely to increase the risk of repair.
Variations In The Normal Heart Vijaya M Nay&
Solomon Victor
The Heart Institute, Chennai, India The outflow tracts of both the ventricles were perhaps first illustrated by Leonardo da Vinci. There is a midline bulbus cordis in the heart of snakes with 3 bulbar ridges. The bulbus is lateralised to the right in frogs and has a spiral valve inside. In the turtle and snake the truncus is replaced by 2 aortae and 1 pulmonary artery connected to the right ventricle. The bulbus is incorporated in the ventricle. In the crocodile, the right aorta is connected to the left ventricle. The left aorta and pulmonary artery are connected to the right ventricle. In birds and mammals, the bulbus is absorbed into the outflow of both ventricles. There is muscle between the aortic and mitral valves.
coronary sinuses. It is probable that this musculature is of bulbar origin. In 1 heart we have seen inferior displacement of the right coronary cusp with more extensive muscularisation of the right coronary sinus. We have also seen a patient with degeneration of the aortic valve with caudal intraventricular displacement of right and left coronary sinus and extensive muscularisation of the right and left aortic sinuses. We have seen muscularisation of the right and left coronary cusps of the aortic valve in another patient. It is of interest that the sinuses related to the pulmonary valve are uniformly muscularised because of the presence of bulbar musculature all around. The absence of musculature in the non-coronary and adjacent left coronary sinus is possibly due to absorption of the bulbar musculature. The extent of membranous septum varies in relation to the non-coronary cusp. It may be localised to the region below right coronary cusp, non-coronary cusp commissure or extend up to the aortic leaflet of the mitral valve. This is reflected by the varying size of the membranous septum in relation to the anteroseptal commissure of the tricuspid valve. The location of the coronary orifices in relation to the commissures varies widely.
In humans, the free wall of the outflow tract of the right ventricle is of bulbus origin. The left wall which should have been present between the aortic and mitral valves has disappeared. The bulbar septum descends down to join the trabecular septum. The conus papillary muscle and the trabeculum septomarginalis (TSM) represent the lower limit of the bulbar contribution to the right side of the interventricular septum (IVS) . We have studied 120 normal autopsy hearts. The configuration of the TSM varied from heart to heart as regards its prominence, size, termination, and number, extent and size of the anterior trabeculations. On the left side of the IVS, a left TSM is seen rarely as a prominent band which marks the caudal limit of the bulbar contribution to the septum. However, the configuration of the left side of the IVS also varies with a varying smooth area between the aortic leaflet and the trabeculated portion, possibly reflecting the varying contribution of the bulbus to the septum on the left side. The trabeculated septum may almost reach the aortic valve. We have observed that there is muscularisation of the adjacent halves of the right and left coronary sinuses and no muscle in the non-coronary and adjacent left/right
Thus, in the normal heart, the configuration of the outflow tract of both ventricles varies and is unique to each heart. Clinical abnormalities related to malincorporation of bulbus in the ventricle would result in varying combination of anomalous muscle bundle of the right ventricle (double-chambered right ventricle), subaortic membrane, idiopathic hypertrophic subaortic stenosis, asymmetric septal hypertrophy, septal defect in muscularisation of bulbar septum, aortic sinus/aortic/pulmonary leaflet aneurysm of membranous septum, and aneurysm of sinus of Valsalva.
61