Heart Disease- Easy to understand

CONGENITAL HEART DISEASE

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Congenital heart disease refers to a structural or functional anomaly of the heart. Congenital heart disease is categorized into cyanotic and noncyanotic disease. Depending on the type of anomaly, patients with congenital heart disease may present at birth with frank cyanosis, heart failure, or extremis; however, many asymptomatic defects are found incidentally. Congenital heart disease occurs most commonly as an isolated defect, but it can also be a part of genetic syndromes such as Down, Turner, or Noonan. The red arrow highlights a congenital heart disease atrial septal defect (between the right and left atrium), seen on contrast-enhanced CT of the heart.

An infant is brought by his mother to the pediatric cardiologist's office for workup of transient cyanosis noted during periods of breath holding, crying, or the Valsalva maneuver. The child is otherwise healthy and growing normally. The cardiologist notes his examination to be within normal limits. He orders an echocardiogram (shown; LA, left aorta; RA, right aorta).

What is the most likely diagnosis?
A. Ventricular septal defect
B. Patent foramen ovale
C. Pulmonary hypertension
D. Tricuspid atresia

Answer: B. Patent foramen ovale

The foramen ovale is a normal fetal structure that allows oxygenated blood from the placenta to bypass the lungs by passing from the right to left atrium (arrow) and into the systemic circulation. At birth, the acute drop in pulmonary vascular resistance creates a pressure differential between the right and left sides of the heart. The increased pressure in the left heart should shut the thin remnant of the septum primum and prevent further right-to-left blood flow. Most children with patent foramen ovale are asymptomatic; however, cyanosis can occur with episodes of increased pulmonary resistance when blood is forced across the patent foramen ovale rather than into the lungs, as with breath holding, the Valsalva maneuver, and crying.

Diagnosis of patent foramen ovale is made via echocardiography and sometimes a "bubble study" (shown). A bubble study is performed by injecting an agitated mixture of saline and air into the peripheral circulation. In the presence of patent foramen ovale, bubbles can be seen crossing the septal defect (yellow arrow) entering the left atrium. In most instances, no therapy is required. Patients who have experienced paradoxical emboli (most notably a cerebral emboli) may require anticoagulation or closure of the patent foramen ovale; however, this is widely debated. Patients who participate in deep sea scuba diving should consider closure of an asymptomatic patent foramen ovale because they are at increased risk for decompression illness after dives.

A 20-month-old child presents with blue fingers and toes over the past few weeks. He has always been sickly with difficulty feeding. However, since developing blue extremities, he breathes easier and feeds without difficulty. On exam, no respiratory distress is noted, but cyanosis is evident. A holosystolic murmur is heard at the cardiac apex. Bedside hematocrit shows the child to be polycythemic. Chest radiograph shows right ventricular hypertrophy and a dilated pulmonary artery. A transesophageal echocardiogram is obtained (shown; Asc Ao, ascending aorta; PA, pulmonary artery).
What is the most likely cause of this child's cyanosis?
A. Aortic stenosis
B. Pulmonary atresia
C. Eisenmenger syndrome
D. Transposition of the great arteries

Answer: C. Eisenmenger syndrome
Eisenmenger syndrome is a sequela of a chronic left-to-right shunt, most commonly a ventricular septal defect (VSD, arrow). Pulmonary overcirculation occurs from left-to-right shunting via the more efficient pumping of the left ventricle, manifested in an infant as failure to thrive, difficulty feeding, and tachypnea. Increased blood flow induces smooth muscle proliferation of pulmonary capillaries leading to pulmonary hypertension. This induces pulmonary vascular dilation (see previous slide), increased pulmonary resistance, and eventual reversal of the shunt yielding cyanosis. Treatment is difficult once the right-to-left shunt has developed because the pulmonary changes are usually irreversible. (LV, left ventricle; RV, right ventricle)

A 9-year-old girl reports that she cannot keep up during play and that her feet are "always freezing" compared with her hands. On exam, the physician notes a short stature, wide shoulders, and webbing of the neck. Her cardiac exam is without murmur, but the blood pressure in her right arm is 146/79 mm Hg and in the right thigh is 91/45 mm Hg. By palpation, her femoral pulse is delayed compared with her radial artery pulse. The physician orders numerous diagnostic tests including an aortic angiogram (shown).
What is the most likely diagnosis causing the patient's symptoms?
A. Coarctation of the aorta
B. Hypoplastic left heart syndrome
C. Aortic stenosis
D. Patent ductus arteriosus (PDA)

Answer: A. Coarctation of the aorta
Coarctation of the aorta is a constricted aortic segment (red arrows), often occurring just distal to the branch point of the left subclavian artery. Symptoms depend on the degree of impediment to flow and include left ventricular hypertrophy, upper extremity hypertension, acute congestive heart failure, and shock. In neonates with critical limits to blood flow through the aorta, closure of the ductus arteriosus at birth can cause abrupt onset of heart failure and shock. Because aortic outflow is acutely diminished, left heart pressure rises secondary to the elevated afterload and blood begins to engorge the left atrium. Elevated left heart pressures can cause new left-to-right shunting through the foramen ovale

Children with coarctation are often asymptomatic, and diagnosis is commonly incidental after noting differences in blood pressure or pulse between the upper and lower extremities. Children may present with leg pain or weakness with exertion. Chest radiograph may show "rib notching" (arrows) as engorged intercostal collateral arteries notch out portions of the inferior border of the ribs. Coarctation is a common manifestation in Turner syndrome (XO karyotype in girls) as in the previous case. Treatment is surgical; however, medical stabilization and presurgical optimization with prostaglandin E1 to either prevent closure or reopen the ductus arteriosus to improve postcoarctation blood flow has become the mainstay of treatment. Image courtesy of Radiopaedia.

A 32-week gestation premature infant is examined in the nursery and found to have a persistent "machinelike" holosystolic murmur heard best over the left sternal border. She has persistent tachycardia and is developing signs of heart failure. An aortogram of her heart is obtained (shown) with dye injected into the descending aorta (PA, pulmonary artery; DAo, descending aorta).
What anomaly is highlighted by the white arrow and is most likely the cause of her symptoms?
A. Aortic stenosis
B. Pulmonary atresia
C. Coarctation of the aorta
D. PDA

Answer: D. PDA
PDA is a persistent fetal connection between the pulmonary artery and the descending aorta. In fetal life, blood is diverted from the pulmonary (high-resistance) to the systemic (low-resistance) system via the ductus. With expansion of the lungs at birth, resistance in the pulmonic system falls below the systemic system and flow passively increases to the lungs. Risk factors for pathologic PDA include prematurity, maternal rubella infection, or exposure to prostaglandins. Symptoms of PDA are based on the degree of blood flow, most commonly a machinelike murmur, but also heart failure due to volume overload. Once recognized, treatment is surgical with ligation of the PDA. Image courtesy of Wikimedia Commons.

Hypoplastic left heart syndrome is a rare congenital defect caused when the left side of the heart underdevelops, resulting in thickened and fibrous left ventricular walls and a slitlike ventricle (star). The mitral and aortic valves may be completely atretic. In fetal life, a PDA allows retrograde filling of the ascending aorta, the brachiocephalic vessels, and coronary vessels, whereas anterograde flow fills and supplies the descending aorta because left ventricular outflow is not adequate. At birth, children can be at risk for coronary or cerebral ischemia if retrograde flow through the PDA is not sufficient to properly perfuse the myocardium and cerebral tissue.

A 26-month-old child is brought to the pediatrician by his mother, who states that he has episodes after crying or eating when his fingertips, toes, and lips become blue (shown). He has passed out after crying spells, and she notes that he is constantly squatting. When he was in the nursery after birth, the mother was told that the baby had a "heart problem with a murmur" but she never followed up. The child has delayed growth and a systolic murmur.
What is the most likely diagnosis?
A. Coarctation of the aorta
B. Tetralogy of Fallot
C. Congenital mitral valve stenosis
D. Hypoplastic left heart

Answer: B. Tetralogy of Fallot
Tetralogy of Fallot consists of 4 anatomic anomalies: (1) right ventricular outflow tract obstruction, (2) right ventricular hypertrophy (demarcated in yellow), (3) a VSD (red arrow), and (4) an anterior shifted aorta "overriding" the VSD (blue arrow). The right ventricular outflow obstruction can vary from mild stenosis of the pulmonary outflow tract to complete pulmonary atresia. All forms of right ventricular outflow obstruction decrease blood flow to the pulmonary system; increase resistance in the right heart during systole, yielding right ventricular hypertrophy; and increase passage of deoxygenated blood across the VSD to the left heart, aorta, and systemic circulation.

Tetralogy often presents with cyanosis in the neonatal period as the PDA closes. However, some children with either less severe right heart outflow obstruction or sufficient aortopulmonary collaterals tolerate tetralogy for the first few years of life. As these children outgrow the collateral blood supply, they are susceptible to cyanotic episodes. They present with "tet spells" or periods of cyanosis (fingertips, toes, and lips) associated with periods of agitation, as described in the previous case. Children may squat to increase peripheral vascular resistance (afterload), which will reduce the amount of blood freely moving through the VSD and force more blood into the pulmonary vasculature.

A 1-month-old infant presents to the emergency department with peripheral cyanosis, diaphoresis, and tachypnea. On exam, the respiratory rate is 56 breaths per minute and rales are heard throughout the lung fields. High-flow oxygen provides some improvement. ECG shows left atrial and ventricular enlargement, and the chest radiograph shows cardiomegaly; increased pulmonary vascular markings; and a large, right-sided aortic arch. The child is stabilized and admitted where a cardiac MR image is obtained (shown; A, ascending aorta; P, pulmonary trunk).
What is the lesion causing this child's symptoms?
A. Aortic stenosis
B. Hypoplastic right heart
C. Truncus arteriosus
D. Patent foramen ovale

Answer: C. Truncus arteriosus
Truncus arteriosus is a rare congenital heart disease occurring in 5-10 of 100,000 births in the United States. A single great artery (TA, truncus arteriosus) leaves the base of the heart giving rise to the ascending aorta, pulmonary trunk, and coronary arteries. Because of mixing of the outflows of the right (venous) and left heart (oxygenated) blood within the truncus, systemic hypoxia and cyanosis paired with pulmonary vasculature overload and congestive heart failure develop. Early operative repair is the mainstay of treatment. Prenatal diagnosis by ultrasound has allowed for better perinatal surgical planning and increased infant survival (A, aorta; PA, pulmonary artery).

An infant born 10 hours ago suddenly develops profound cyanosis. The prenatal course was significant only for maternal diabetes. The physician suspects a cardiac anomaly, but the cardiac echocadiographic lab is down and instead orders a STAT angiogram (shown). The contrast is injected directly into the right ventricle and the outflow tract is highlighted as above.
What is the most likely cardiac anomaly?
A. Hypoplastic left heart
B. Transposition of the great arteries, with the aorta arising from the right heart and the pulmonary trunk from the left heart
C. Atrial septal defect
D. Coarctation of the aorta

Answer: B. Transposition of the great arteries, with the aorta arising from the right heart and the pulmonary trunk from the left heart
Oxygenated blood enters the left heart and is pumped to the lungs via the abnormal pulmonary trunk, whereas venous blood entering the right heart is pumped back into the systemic circulation via the aberrant aorta, bypassing the lungs. This pattern of flow is incompatible with life and requires immediate surgical repair at birth. In the angiogram shown, contrast injected into the RV travels directly to the ascending aorta (AAo) and then to the subclavian (Sc) and carotid (Car) arteries. Note the paucity of contrast in the pulmonary circulation, as there is no mixing of oxygenated and deoxygenated blood.

The anomaly pictured (large white arrow) is a congenital heart disease almost always accompanied by an atrial septal defect (ASD) (usually a patent foramen ovale), ventricular septal defect, hypertrophied right atrium (RA), and a hypoplastic right ventricle (RV). The left ventricle (LV) is responsible for pumping blood through the pulmonary system (made capable by VSD) and systemic circulation (through the normal aorta). However, blood is chronically desaturated secondary to mixing of venous and oxygenated blood.
What is the most likely defect?
A. Transposition of the great arteries
B. Pulmonary atresia
C. Mitral valve atresia
D. Tricuspid atresia

Answer: D. Tricuspid atresia
The term tricuspid atresia describes several anomalies of the tricuspid valve, including the muscular or fibrous form of valve or the fused leaflet form of valve. Blood returning to the right atrium cannot flow to the right ventricle, and all blood must pass through an ASD (white dotted arrow above) to the left atrium, where it flows through the normal mitral valve and into the left ventricle. In order to reach the lungs, blood must be pumped through a PDA or from the left ventricle across a VSD (pictured) into the right ventricle outflow tract and through the pulmonary valve into the pulmonary circulation. Image courtesy of Wikimedia Commons.

The altered circulation in patients with tricuspid atresia not only creates a mixing of deoxygenated and oxygenated blood within the left heart, but precipitates right atrial hypertrophy in order to pump blood across the ASD (red arrow) into the left heart circulation with resulting right ventricular hypoplasticity (black arrow). Clinical findings include cyanosis, heart failure, and a murmur associated with ASD and VSD (holosystolic crescendo/decrescendo murmur). ECG will show signs of right atrial enlargement (tall P waves) and left-axis deviation secondary to the hypoplasticity of the right ventricle. Treatment is surgical, with a common approach connecting the right atrium to the pulmonary trunk to circulate deoxygenated blood directly to the lungs.

An 8-year-old boy is brought to the emergency department by emergency medical services (EMS) after experiencing syncope during gym class at school. He was found unresponsive and asystolic by EMS. Despite the best resuscitative efforts of the emergency department staff, they were not able to regain a spontaneous pulse. Upon autopsy, the valvular defect pictured above is discovered.
What was the most likely cause of this child's death?
A. Aortic valve stenosis
B. Mitral valve prolapse
C. Pulmonary atresia
D. Tricuspid insufficiency

Answer: A. Aortic valve stenosis
Pediatric aortic stenosis causes varying degrees of obstruction of left ventricular outflow. Most commonly, the normal tricuspid aortic valve arises as a bicuspid valve with a fused junction between leaflets and a displaced/stenotic opening (outlined in yellow). Left ventricular hypertrophy develops, placing children at risk for cardiac ischemia because increases in myocardial oxygen demand during growth spurts or exercise cannot be met by the hypertrophied left heart. Failure to meet oxygen needs results in symptoms of easy fatigability, anginal chest pain, and syncope during exercise. Children are at risk for sudden cardiac death. On exam, a systolic ejection murmur and palpable thrill at the suprasternal notch are common.

Two other related congenital defects are subaortic and supra-aortic valvular stenosis. Subaortic stenosis results from an anatomic obstruction to the left ventricular outflow tract causing turbulence to flow. Repeated trauma against the valve damages leaflets and causes regurgitation. Left ventricular hypertrophy develops to overcome turbulence and the resulting aortic insufficiency. Supravalvular aortic stenosis (red arrows) is a narrowing of the ascending aorta distal to the valve. Stenosis results in increased pressures and dilation within the coronary system, increasing the risk for atherosclerotic disease. Also common is elevated blood pressure in the right upper extremity due to preferential direction of the blood flow through the stenotic portion of aorta into the brachiocephalic artery.

Heart Disease by the Numbers: Facts, Statistics, and You

The average person’s heart will beat about 2 billion times in their lifetime. Yet heart disease and heart attack threaten to cut that number short. Learn statistics to find out if you’re at risk and what you can do to protect your ticker and live a longer, healthier life.

- See more at: http://www.healthline.com/health/heart-disease-infographic#sthash.GEMU1tJm.dpuf

    Healthline recently put together an infograph showcasing heart disease statistics and facts to help someone understand their risk for a heart attack or other heart-related issues. You can see the infograhic here: 
http://www.healthline.com/health/heart-disease-infographic

Heart Disease by the Numbers: Facts, Statistics, and You

The average person’s heart will beat about 2 billion times in their lifetime. Yet heart disease and heart attack threaten to cut that number short. Learn statistics to find out if you’re at risk and what you can do to protect your ticker and live a longer, healthier life.

- See more at: http://www.healthline.com/health/heart-disease-infographic#sthash.GEMU1tJm.dpuf