ACYANOTIC CONGENITAL HEART

DISEASEDR.BINDU GOPINATH

ACYANOTIC CONGENITAL HEART DISEASE

The condition of acyanotic heart defect occurs when shunting (flowing) of blood occurs from the left side of the heart to the right side of the heart due to a structural defect . Patients retain normal levels of oxyhemoglobin saturation in systemic circulation.

CLASSIFICATION

•Common shunt lesions• Ventricular septal defect(VSD)• Atrial septal defect(ASD)• Patent ductus arteriosus(PDA)

•Common stenotic lesions• Coarctation of aorta.

SIGNS AND SYMPTOMS

• Shortness of breath • Congested cough• Diaphoresis• Fatigue• Frequent respiratory infections• Tachycardia• Tachypnoea• Respiratory distress• Mild cyanosis (in right sided heart failure)• Poor growth and development (from increased energy spent on

breathing)

VSD

• VSD is a defect in the ventricular septum , the wall dividing the left and right ventricles of the heart .• The ventricular septum consists of an inferior muscular

and superior membranous portion and is extensively innervated with conducting cardiomyocytes• Membranous ventricular septal defects are more

common than muscular ventricular septal defects, and are the most common congenital cardiac anomaly

PATHOPHYSIOLOGY• During ventricular contraction, or systole, some of the blood

from the left ventricle leaks into the right ventricle, passes through the lungs and re enters the left ventricle via the pulmonary veins and left atrium.• This has two net effects. First, the circuitous refluxing of blood

causes volume overload on the left ventricle. Second, because the left ventricle normally has a much higher systolic pressure (~120 mmHg) than the right ventricle (~20 mmHg), the leakage of blood into the right ventricle therefore elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms.• In serious cases, the pulmonary arterial pressure can reach

levels that equal the systemic pressure. This reverses the left to right shunt, so that blood then flows from the right ventricle into the left ventricle, resulting in cyanosis, as blood is by-passing the lungs for oxygenation.

VSD

CLASSIFICATION• The classification is based on the location of the VSD on the right ventricular surface

of the inter ventricular septum and is as follows

• Type 1 (Subarterial) (Supracristal) (Conal septal defect) (Infundibular)

Found in 5-7% of patients, more in Asians related to the pulmonary valve

• Type 2 (Perimembranous) (Paramembranous) (Conoventricular)

Most common variety found in 70%

• Type 3 (Inlet) (AV canal type)

Commonly associated with atrioventricular septal defect, found in about 5%

• Type 4 (Muscular)

Located in the muscular septum, found in 20%. Can be sub classified again based on the location into anterior, apical, posterior and mid

• Type 5: Gerbode (Left ventricular to right atrial communication)

Due to absence of Atrioventricular septum.

SYMPTOMS AND SIGNS• No signs of cyanosis in the early stage.

• however uncorrected VSD can increase pulmonary resistance leading to the reversal of the shunt and corresponding cyanosis.

• Signs

• Pansystolic murmur along lower left sternal border.

• Palpable thrill( palpable turbulence of blood flow)

• Larger VSDs may cause a parasternal heave

• Displaced apex beat (the palpable heartbeat moves laterally over time, as the heart enlarges.

• Fail to thrive

• Tachypnoea

DIAGNOSIS

1 Auscultation – Pansystolic murmur2 ECHO3 x-ray chest

TREATMENT• Smaller congenital VSDs often close on their own, as the heart grows, and in such cases may be treated conservatively.• Ventricular septum defect in infants is initially treated medically with cardiac glycosides (e.g., digoxin10-20 µg/kg per day), loop diuretics (e.g., furosemide 1–3 mg/kg per day) and ACE inhibitors (e.g., captopril 0.5–2 mg/kg per day• VSD Device closure

• VSD closure• Indications1. Failure of congestive cardiac failure to

respond to medications2. VSD with pulmonic stenosis3. Large VSD with pulmonary hypertension4. VSD with aortic regurgitation

Surgical treatment

ASDAtrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Normally, the atria are separated by a dividing wall, the interatrial septum. If this septum is defective or absent, then oxygen-rich blood can flow directly from the left side of the heart to mix with the oxygen-poor blood in the right side of the heart, or vice versa. This can lead to lower-than-normal oxygen levels in the arterial blood that supplies the brain, organs, and tissues.

PATHOPHYSIOLOGY

In case of a large ASD , which may result in a clinically remarkable left-to-right shunt, blood will shunt from the left atrium to the right atrium. This extra blood from the left atrium may cause a volume overload of both the right atrium and the right ventricle. If untreated, this condition can result in enlargement of the right side of the heart and ultimately heart failure.

PATHOPHYSIOLOGY

If the ASD is left uncorrected, the pulmonary hypertension progresses and the pressure in the right side of the heart will become greater than the left side of the heart. This reversal of the pressure gradient across the ASD causes the shunt to reverse; a right-to-left shunt will exist. This phenomenon is known as Eisenmenger's syndrome. Once right-to-left shunting occurs, a portion of the oxygen-poor blood will get shunted to the left side of the heart and ejected to the peripheral vascular system. This will cause signs of cyanosis

TYPES OF ASD1. Ostium secondum – most common type comprises 6–10% of all

congenital heart diseases1. The secundum atrial septal defect usually arises from an

enlarged foramen ovale, inadequate growth of the septum secundum, or excessive absorption of the septum primum. Ten to twenty percent of individuals with ostium secundum ASDs also have mitral valve prolapse

2. If the ostium secundum ASD is accompanied by an acquired mitral valve stenosis, that is called Lutembacher's syndrome.

2. Patent foramen ovale – it is a remnant of the fetal foramen ovale3. Ostium primum – commonly classified as an atrioventricular septal defect4. Sinus venosus ASD - the defect in the septum involves the venous inflow of either the superior vena cava or the inferior vena cava

SYMPTOMS AND SIGNS

•Dyspnoea on exertion• Fatigue• Swelling of feet• Frequent lung infections• palpitation• Auscultation – systolic ejection murmur• Fixed splitting of S2

DIAGNOSISDiagnosis in children•Most individuals with a significant ASD are diagnosed in utero or in early childhood with the use of ultrasonography or auscultation of the heart sounds during physical examination.• X-ray chest• Echo• ECG – incomplete right bundle branch block

TREATMENT

• Percutaneous device closure• surgical closure

PDA

•Patent ductus arteriosus (PDA) is a congenital disorder in the heart wherein a neonate's ductus arteriosus fails to close after birth.• The ductus arteriosus is a normal fetal blood vessel that closes soon after birth. In a PDA, the vessel does not close and remains "patent" (open) resulting in irregular transmission of blood between two of the most important arteries close to the heart, the aorta and the pulmonary artery.

PDA

PDA is common in neonates with persistent respiratory problems such as hypoxia, and has a high occurrence in premature children. In hypoxic newborns, too little oxygen reaches the lungs to produce sufficient levels of bradykinin and subsequent closing of the DA. Premature children are more likely to be hypoxic and thus have PDA because of their underdeveloped heart and lungs.

SYMPTOMS AND SIGNS•Dyspnoea•Tachycardia•Poor growth•Respiratory problems•Continuous machine like murmur on auscultation•Left subclavicular thrill•Bounding pulse•Widened pulse pressure

DIAGNOSIS

• Auscultation- continuous machine like murmur• X-ray chest – cardiomegaly• Echo

TREATMENT

• Medical management

• NSAID(inhibitors of PG synthesis) such as indomethacin have been used to close PDA , because PGE1 is responsible for the ductus to keep patent.

• PDA device closure

• Surgical closure

COARCTATION OF AORTA•Coarctation of aorta, or aortic narrowing is a congenital condition whereby the aorta narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts. Aortic coarctation is considered when a section of the aorta is narrowed to an abnormal width.

• The word “coarctation” means narrowing. Coarctations are most common where the aorta—the major artery leading away from the heart—arches toward the abdomen and legs.

COARCTATION OF AORTA•The aortic arch may be small in babies with coarctation. When a patient has a coarctation, the left ventricle has to work harder. Since the aorta is narrowed, the left ventricle must generate a much higher pressure than normal in order to force enough blood through the aorta to deliver blood to the lower part of the body. If the narrowing is severe enough, the left ventricle may not be strong enough to push blood through the coarctation, thus resulting in lack of blood to the lower half of the body.

CLASSIFICATION

•Preductal - The narrowing is proximal to the ductus arteriosus •Ductal Coarctation: The narrowing occurs at the insertion of the ductus arteriosus.•Postductal coarctation: The narrowing is distal to the insertion of the ductus arteriosus

SYMPTOMS AND SIGNS• Symptoms may be absent with mild coarctation.

• Difficulty breathing

• Poor apetite or trouble feeding

• Failure to thrive

• Dizziness or shortness of breath

• Fainting or near fainting episodes

• Chest pain

• Fatigue

• Leg pain with exercise

• Arterial hypertension in the arms with low blood pressure in the lower extremities

• Weak pulses in the femoral arteries

DIAGNOSIS

1.X-ray –post stenotic dilation of the aorta results in figure 3 sign

2.MR or CT angiography3.Cardiac catheterization

TREATMENT• Conservative if asymptomatic• Surgical resection of the narrow segment if there is arterial hypertension.• 1. Aortic resection with end to end anastomosis• 2. Patch aortoplasty• 3. L subclavian flap angioplasty• 4 . Bypass graft repair• 5. Balloon angioplasty