This is a left-to-right (acyanotic) heart defect – Symptoms are typically mild or absent altogether. Most anesthetic plans will not change with these defects unless the patient is demonstrating congestive heart failure. However, caution should always be taken. Broad anesthetic implications of acyanotic congenital heart defects (CHD) include:

Get a detailed medical history – understand all you can about what defect the patient has and how severe the symptoms are. Get surgical history, daily medications, hemodynamic status, and cardiac and lung function.

Reduce left-to-right shunt – Increases in SVR will worsen left-to-right shunting. Sudden increases or decreases in pulmonary vascular resistance or SVR will also be tolerated poorly. Volatile anesthetics, propofol, etomidate, and barbiturates all decrease SVR – so use cautiously.

Limit stress – or anything that would stimulate sympathetic response. Opioids are often used to reduce/eliminate sympathetic responses to pain, laryngoscopy, etc. Use a slow/cautious induction.

Maintain MAP and SVR – Arterial lines and/or central lines are ideally employed to keep tight controls. These patients will not have optimal cardiac reserve.

Avoid shunt reversal – Airway obstruction, hypoventilation, hypoxia, and pulmonary hypertension create greater pressures on the right side of the heart and can reverse the shunt (making it a cyanotic shunt). This is otherwise called Eisenmenger Syndrome.

Debubble – avoid any bubbles in venous lines. These can lead to a paradoxical embolus.

Cardiac bypass – complex congenital defects sometimes require this. Be aware that this may result in hemodilution!

Endocarditis prophylaxis – for 6 months post-surgical repair of the cardiac defect.

ASDs are a common acyanotic congenital heart defect (CHD). They account for 8-13% of all CHDs.

An ASD is a defect where blood abnormally flows from one atrium to the other atrium and/or unanticipated vessels. This left to right shunt sends oxygenated blood to the right side of the heart. In essence, the problem is that the body is getting less volume of the oxygenated blood. Shifts in flows and pressures to the right compartments of the heart, and then to the lungs, can also create problems.

There are 3 types of ASDs. These are in order of most common to least common: ostium secundum, primum, and sinus venosus.

Characteristic of these kinds of CHDs is a systolic murmur and a widely split S2. Otherwise, these CHDs are typically asymptomatic or minimally symptomatic.

Significant defects require closure by 4-5 years of age to prevent pulmonary vascular disease.