Atrial Septal Defect

ASD: Signs and Symptoms ASD: Signs and Symptoms

• Usually no symptoms in children• If very large can cause fatigue, poor

growth

• In adulthood can lead to pulmonary hypertension, atrial arrhythmias or congestive heart failure

• Usually a split S2 (second heart sound)• Murmur heard as large amount of blood

forced through normal size pulmonary valve

Characteristics: An ASD is classified by its size and size and locationlocation.

• Size

• Most small defects close on their own as the heart grows during childhood.

• They usually allow only a small amount of blood to flow between the atria.

• Moderate to large defects are much less likely to close on their own.

• They allow two or more times the normal amount of blood to flow through the right side of the heart.

Location Three major types of ASD exist

• SecundumSecundum. This defect is in the middle of the septum. It is the most common form of ASD. About 7 out of every 10 babies born with ASD have this type. This type often closes on its own, unless it is large.

• PrimumPrimum. This defect is in the lower part of the septum. It also involves an incomplete or partial atrioventricular septal defect, and the valves that separate the upper and lower heart chambers are not normal. About 2 out of every 10 babies born with ASD have primum defects. This type of defect does not close on its own.

• Sinus venosusSinus venosus. This defect is in the upper part of the septum near where a large vein (the superior vena cava) brings blue blood from the upper body to the right atrium. It is rare, accounting for only about 1 out of every 10 cases of ASD. Children with sinus venosus defects usually have an associated condition called partial anomalous pulmonary venous return, in which one or more of the veins carrying red blood from the lungs return to the wrong chamber of the heart. This type of defect does not close on its own.

Effects of atrial septal defect

• Over time, the extra blood flow to the right side of the heart and the lungs can cause: • Enlargement of the right atrium and

the right ventricle.

• Right heart overload. The right side of the heart has to work harder to pump extra blood to the lungs, especially as resistance in the pulmonary artery increases. Over time, the heart may become overworked, and function may become impaired. This is exceedingly rare with modern methods of diagnosis and treatment.

• Arrhythmias (irregular heartbeats or Arrhythmias (irregular heartbeats or rhythms). rhythms). Extra blood flowing into the right atrium through the ASD can cause the atrium to stretch and enlarge. When this occurs, a fast heartbeat can develop with symptoms such as dizziness, fainting, or chest discomfort.

• StrokeStroke. Occasionally a blood clot in a vein or in the right side of the heart can pass through the ASD and enter the blood stream, where it can block an artery supplying the brain and cause a stroke.

• Pulmonary arterial hypertension.Pulmonary arterial hypertension. This is when high blood pressure exists in the arteries that carry blood to the lungs. The extra blood being pumped to the lungs can increase the pressure in the pulmonary arteries. Over time, high pressure can damage the arteries and the small blood vessels in the lungs. They thicken and become stiff, making it harder for blood to flow through them (pulmonary vascular disease).

• Usually, most of these effects don't Usually, most of these effects don't show up until adulthood, often around show up until adulthood, often around age 30 or later. age 30 or later. They are rare in infants and children.They are rare in infants and children.

Coarctation of the Aorta

• Common in patients with some chromosomal anomalies (Turner’s syndrome)

• Due to narrowing of the aorta• Left ventricle has to work harder to

force blood through narrow aorta

Coarctation of the aorta: Signs

• Depends on degree of narrowing

• Severe – possible heart failure in first days of life• Mild – progressive left ventricular hypertrophy

(thickening of the muscle)

• Weak pulses in the legs of the infant Weak pulses in the legs of the infant (femoral artery pulse) and increased (femoral artery pulse) and increased pressure in upper extremitiespressure in upper extremities

Tetralogy of Fallot

• Combination of four heart defects

1. Pulmonary stenosis – narrowing of pulmonic valve that impedes blood flow from right ventricle to pulmonary artery

2. VSD

3. Overriding aorta –Aorta is enlarged and appears to arise from both right and left ventricles

4. Right ventricular hypertrophy – due to pumping at high pressure

Tetralogy of Fallot

Tetralogy of Fallot: Signs andSymptoms

• Usually diagnosed in the first few weeks of life

• Loud murmur• Cyanosis due to pulmonary stenosis• Rapid breathing in response to low oxygen

Transposition of the Great Arteries• The aorta and pulmonary artery arise from the wrong

• ventricle• Oxygen poor blood from body to the RA and RV is

pumped out of the aorta to the body• Oxygen rich blood from the lungs to the LA and LV is

sent back to the lungs through the pulmonary artery• VSD is common with Transposition of Great Arteries

and allows for some blood mixing but not enough to give adequate oxygen to all organs

Signs and Symptoms• Cyanosis during first hours/days of life

• Rapid breathing due to lack of oxygen• If untreated, 50% will die in the first months of life,

and 90% in the first year

SIGNS AND SIGNS AND SYMPTOMS OF SYMPTOMS OF

CLINICAL CLINICAL CARDIOLOGYCARDIOLOGY

Bradycardia• The heart is beating at an abnormally

slow rate of less that 60 beats per minute.• It may be caused by a low body

temperature, certain drugs, the parasympathetic nervous system or excellent physical conditioning.

• For instance, marathon runners frequently experience bradycardia.

• Chronic bradycardia in individuals other than athletes who are well conditioned may cause inadequate circulation of blood to the body.

Tachycardia• The opposite of bradycardia.

• In tachycardia the heart rate is abnormally fast ( above 100 beats per minute).

• Tachycardia may be caused by stress, elevated body temperature, certain drugs or heart disease.

• Chronic tachycardia is considered pathological because it may contribute to fibrillation or heart arrhythmias

• Angina pectoris Angina pectoris

• is the medical term for chest pain due to coronary heart disease.

• It occurs when the myocardium isn’t getting sufficient blood carrying O2 and nutrients.

• Ischemia

• is the term used to indicate an insufficient supply of blood to the myocardium.

• It may occur initially during physical exercise, stress or extreme temperatures.

• It is a sign of increased risk of a It is a sign of increased risk of a heart attack.heart attack.

• Describe the histological similarities and differences of the blood vessels

• Explain the pattern and names of the major arteries and veins of the pulmonary & systemic circulations

• Describe the circulatory changes that occur at birth.