Outline Overview of the boot-shaped heart sign Tetralogy of Fallot Overview Radiology Prognosis and Treatment Haider , Ehsan A. "The Boot-shaped Heart Sign." Radiology.rsna.org. RSNA, 1 Jan. 2008. Web. 23 July 2012. <http://radiology.rsna.org/content/246/1/328.full>.
The Boot-shaped Heart Sign Frontal chest radiograph T he shape of a wooden boot Tetralogy of Fallot Haider , Ehsan A. "The Boot-shaped Heart Sign." Radiology.rsna.org. RSNA, 1 Jan. 2008. Web. 23 July 2012. <http://radiology.rsna.org/content/246/1/328.full>.
Haider , Ehsan A. "The Boot-shaped Heart Sign." Radiology.rsna.org. RSNA, 1 Jan. 2008. Web. 23 July 2012. <http://radiology.rsna.org/content/246/1/328.full>. Haider, Ehsan A. "The Boot-shaped Heart Sign." Radiology.rsna.org. RSNA, 1 Jan. 2008. Web. 23 July 2012. <http://radiology.rsna.org/content/246/1/328.full>.
Tetralogy of Fallot One of the most common cyanotic congenital heart conditions (75%) Accounts for 10% of all congenital heart diseases Has estimated prevalence of 1 in 2,000 birth
Congenital Heart Diseases
Congenital Heart Diseases Acyanotic Simple and single lesion Mechanism Left-to-right shunt Obstructive lesion Cyanotic Multiple and probable complex lesions Capillary reduced hemoglobin > 5 gm% (Oxygen saturation < 85%) Mechanism Right-to-left shunt Common mixing Parallel circulations
Tetralogy of Fallot Eccentric septation of the truncus arteriosus Conotruncal septum is displaced anteriorly The infundibular septum fails to fuse with the top of the interventricular septum high VSD The anterior part of aortic valve (superior border of the VSD) overrides the ventricular septum overiding aorta The right ventricular outflow tract obstruction or Pulmonary stenosis Right ventricular hypertrophy —right ventricle at systemic pressure—later in life
Embryogenesis of the heart Witmer , Lawrence M. "Developmental Anatomy of the Heart and the Embryological Basis for Cardiac Defects." Ohio University, Athens. 23 July 2012. Lecture .
Tetralogy of Fallot Obstruction of the right ventricular outflow tract High VSD Overriding aorta Right ventricle hypertrophy + Atrial septal defect Pentalogy of Fallot Cukukoglu , Sardar M. "Cyanotic Diseases." Escardio.org. N.p ., 2010. Web. 23 July 2012. <http://www.escardio.org/congresses/euroecho2010/Documents/teaching-course-slides/euroecho2010-cyaotic-disease-Kucukoglu-591.pdf>.
Tetralogy of Fallot Cyanosis Severe cases ↔ at birth ↔ severe PS Mild cases ↔ much later ↔ mild PS Squatting Dyspnea Failure to thrive
Tetralogy of Fallot Degree of pulmonary stenosis determines the clinical picture If mild, the clinical picture of VSD is shown instead However the muscular element of pulmonary stenosis is nearly always progressive Eventually reversing the left to right shunt to be permanently right to left before the first birthday
Radiology in Tetralogy of Fallot The Boot-shaped Heart sign “ coeur en sabot” The UPPER part of the Boot: flat / concave pulmonary trunk The TOE--upward pointing cardiac apex: concentric right ventricular hypertrophy Accentuated by large lung volume, small thymus, and lordotic projection
Radiology in Tetralogy of Fallot Heart size The heart is usually not enlarged at birth Unless there is a large left-to-right shunt Could be enlarged in later life from biventricular hypoxic failure Pulmonary vasculature—decreased Aortic arch Always enlarged 25% has right-sided aortic arch might be associated with absent left pulmonary artery resulting in less pulmonary vasculature in the left lung
Upturned cardiac apex sign Concentric right ventricular hypertrophy However not seen in severe pulmonic stenosis with intact interventricular septum (RV systolic pressure >>> systemic systolic pressure) Maybe related to right ventricular hypertrophy with altered development of the left ventricle and abnormal horizontal ventricular septum O nly encountered in congenital heart lesions and not in acquired right ventricular hypertrophy
Gallard , Frank. " Tetralogy of Fallot ." Radiopaedia.org. N.p ., 5 Jan. 2010. Web. 23 July 2012. <http://radiopaedia.org/images/156636>.
MRI E xquisite anatomical and functional information Detailed assessment of the pulmonary artery is particularly important R epair of the cardiac defects without addressing pulmonary artery hypoplasia / stenosis has a poor outcome The main pulmonary artery or right pulmonary artery/ascending aorta < 0.3 Primary repair would be unsuccessful Bridging shunt operation may be of benefit Assessment of coronary artery origin essential to surgical planning
Prognosis Depends on timing Best outcome seen in patients repaired before the age of 5 90% of untreated tetralogy patients succumb by the age of 10 years Residual right ventricular dysfunction is common Up to 10% of patients require re-operation within 20 years
Treatment Primary repair Preferred usually performed at the time of diagnosis Palliative shunt typically in pulmonary arterial hypoplasia Post-surgical complications conduction dysfunction valvular dysfunction
Reference Haider , Ehsan A. "The Boot-shaped Heart Sign." Radiology.rsna.org . RSNA, 1 Jan. 2008. Web. 23 July 2012. <http://radiology.rsna.org/content/246/1/328.full >. Grainger, Ronald G. Grainger & Alison's Diagnostic Radiology . 4th ed. Vol. 1. N.p .: Churchill Livingstone, 2003. Print . Cukukoglu , Sardar M. "Cyanotic Diseases." Escardio.org. N.p ., 2010. Web. 23 July 2012. <http://www.escardio.org/congresses/euroecho2010/Documents/teaching-course-slides/euroecho2010-cyaotic-disease-Kucukoglu-591.pdf>. Gallard , Frank. " Tetralogy of Fallot ." Radiopaedia.org. N.p ., 5 Jan. 2010. Web. 23 July 2012. <http://radiopaedia.org/images/156636>. " Cyanotic Heart Diseases." Learningradiology.com. N.p ., n.d . Web. 23 July 2012. <www.learningradiology.com/.../cyanoticheartdz.pdf>. Witmer , Lawrence M. "Developmental Anatomy of the Heart and the Embryological Basis for Cardiac Defects." Ohio University, Athens. 23 July 2012. Lecture.