Systematic Approach to Adult Congenital Heart Disease

History and Natural History

Lack of awareness of their CHD and the anatomic diagnosis is common among adult patients for whom diagnosis and possible intervention occurred early in life. Information about procedures was provided to the parents, not to the current adult patient, whose understanding will be modified by time and the second telling. If the patient knows the diagnosis, this provides important information to the sonographer that can be beneficial while performing an echocardiogram. Patients without the particulars of diagnosis might use statements such as, “My arteries were backwards,” which might mean transposition of great arteries, or “I was born with half a heart,” which might mean a single ventricle of some sort. The statement “I had a hole in my heart” can have many meanings ranging from simple to complex problems. Patients may refer to their defect as a “heart murmur,” with no understanding of the implications.

If medical records are available, it is worth spending time reviewing this information before initiating an echocardiographic study. If records are not available, clinicians should make every attempt to procure them from the treatment facility (an important historical question), which is often known. Specific knowledge of surgical procedures is vital to understanding the patient and interpreting the echocardiogram. Subtle, but important, details such as an absent pulmonary artery or a right-sided aortic arch will make the echocardiographic examination much smoother and less time consuming.

The natural history of CHD varies tremendously depending on the defect. Not all CHD is lethal. CHD occurs in about 0.8% of live births. In the current era of significantly improved survival, ^, adults with complex CHDs have outnumbered children. ^, The total number of adults with CHD is estimated to be more than 1 million. Patients who claim to have CHD will be more likely to have a defect that is more prevalent. The actual prevalence of various forms of CHD varies depending on the study cited or methodology used for diagnosis. Bicuspid aortic valve is likely the most common “defect” but is often left out of many lists of CHD as a normal variation. Ventricular septal defect is the next most common CHD, comprising 18% to 28% of the total. A list of the rough incidence percentages of CHD is shown in Table 140.1 . ^, When performing an echocardiogram on an uninformed adult with CHD, knowledge of commonly found CHD and its natural history is helpful.

Details such as the year of surgery and the total number of surgeries a patient has gone through may help to define the type of surgical repair the patient might have had. A detailed listing of timeline for various surgical procedures is provided in another chapter. Gathering all of this information may take some detective work on the part of the sonographer or cardiologist. A good example is the case of d-transposition of great arteries, which was repaired by performing an atrial switch operation (also referred to as Mustard/Senning procedure) for the first time in 1954. With advancement in surgical techniques, the approach of switching the atria was changed to performing the arterial switch operation (also referred to as Jatene procedure) for the first time in 1976. However, acceptance of this newer procedure was not immediate everywhere, implying that patients born before 1976 most likely had atrial switch operations, and those born after early 1980s very likely had arterial switch operations. It is also important to know if the patient had any form of catheter-based intervention such as a device or a stent, which were not common before the mid-1990s. Many patients may also confuse a catheter-based intervention or even a diagnostic catheterization with a “surgery.”

Location of the Scar: “The Scar is the Clue”

Optimal timing for repairing a particular CHD has evolved with time and advancement in surgical technique. We are now increasingly performing complete repairs for several CHDs in the neonatal period and fewer palliative operations ( Table 140.2 ). Primary open-heart repair using cardiopulmonary bypass is most frequently performed through a median sternotomy and a midline chest incision. By contrast, in earlier years, palliative operations were frequently performed using lateral or posterolateral thoracotomies. A midline sternotomy scar versus a right or left lateral thoracotomy scar can help discern the probable surgical repair and, in some cases, the possible diagnosis. Some of the operations that could be performed without opening the heart were performed via a lateral thoracotomy ( Fig. 140.1 ).

Segmental Analysis

An echocardiographic strategy, which encompasses identification of the blood flow in and out of the heart and the connection of the various segments of the heart, is called segmental analysis . This includes systematic determination of the position of the cardiac apex, situs of the atrium, the atrioventricular (AV) relationship, and the ventriculoarterial relationship. In CHD, the pathway that the blood takes and the connections between the cardiac segments are the focus, particularly in those with complex CHD. Standard American Society of Echocardiography (ASE) imaging protocols ^, allow the examiner to identify these points of anatomic interest and recognize the deviation from normal. It is the thinking, not just the protocol, that needs emphasis in terms of segmental analysis. Segmental thinking includes:

• 1.

  Cardiac position and position of the visceral organs (visceral situs)

  • a.

    Position of the heart in the chest and the visceral organs in the abdomen

  • b.

    Relative position of the atria, identified morphologically

  • c.

    Relative position of the ventricles, identified morphologically

• 2.

  Blood flow into the heart

  • a.

    Identification of systemic veins and its drainage

  • b.

    Identification of pulmonary veins and its drainage

  • c.

    Identification of additional venous anomalies

• 3.

  Blood flow through the heart

  • a.

    Atrioventricular connections, identified morphologically

  • b.

    Ventriculoarterial connections, identified morphologically

  • c.

    Shunts

  • d.

    Obstructions

• 4.

  Blood flow out of the heart

  • a.

    Aortic arch patency and branching pattern

  • b.

    Pulmonary artery patency, bifurcation, and size

  • c.

    Presence and size of the ductus arteriosus

• 5.

  Coronary artery anatomy