Age: 30 years
Gender: Female
Occupation: Unemployed
Working diagnosis: Tricuspid atresia, pulmonary atresia, functionally single ventricle
HISTORY
The patient’s cardiac status became known when she was admitted to the hospital at 6 weeks of age with cyanosis and failure to thrive. A catheterization confirmed the absence of a right AV connection, a hypoplastic RV, and a single great artery.
At 6 months a Waterston shunt operation was performed. She recovered uneventfully. However, this became inadequate, as evidenced by worsening cyanosis. Consideration was given to the feasibility of a Fontan-type operation. However, the native pulmonary arteries were judged to be too hypoplastic and the pulmonary circulation was too dependent on collateral arteries to permit a Fontan approach. Subsequently, at age 7 years a left BT shunt was placed to improve pulmonary blood flow.
The remainder of her childhood was uneventful, though she remained cyanotic and was frequently treated with venesection.
When she was 20 years old, the patient had a spontaneous abortion (around 6 weeks of gestation) following an unplanned pregnancy.
She reattended the clinic after several years of being lost to follow-up and asked if anything could be done to improve her restricted physical capacity. She partially attributed her nonattendance to a fear of needles that developed in her teens from frequent venesection.
Comments: The patient has a form of univentricular heart of LV type with pulmonary atresia and cyanosis. The degree of cyanosis in patients with pulmonary atresia is determined by the amount of pulmonary flow, which may be supplied by the arterial duct, multiple aortopulmonary collaterals, and/or the bronchial circulation.
The rationale for considering a Fontan-style palliation is that it allows separation of the systemic and pulmonary circulations in patients with a functionally single ventricle, thus avoiding the potentially deleterious effects of long-standing ventricular volume overload and cyanosis. However, this requires a pulmonary vascular bed of adequate size with low resistance.
Venesection, or therapeutic phlebotomy, was commonly performed in the past on the assumption that the practice reduced the risk of stroke and improved the patient’s symptoms. Recent data, however, challenge both these alleged benefits, and venesections have now been limited to very few selected patients and indications.
The risk of fetal death increases with the degree of maternal cyanosis (see Case 75 ). Counseling and education of all women with ACHD is a vital component of their management so that they can make informed and planned choices about having children.
Although many patients with ACHD face major employment and psychosocial challenges they generally have quality-of-life scores that are remarkably comparable to those of the general population. Nevertheless, those with persistent cyanosis do have a poorer perception of their physical health.
Unfortunately, it is not uncommon for patients with complex congenital heart disease to be lost to clinical follow-up from adolescence to adulthood, and to reappear when problems develop. It is important that strenuous efforts are made to maintain good lines of communication between the patient, his or her family doctor, and the congenital heart specialist, and that the need for lifelong follow-up is emphasized to patients and their families from a young age.
CURRENT SYMPTOMS
The patient now has shortness of breath on minimal exertion. She has noted progressive deterioration in her exercise capacity over several years. She has not had hemoptysis, palpitations, syncope, or gout.
NYHA class: III
Comments: The patient’s functional status was assessed using the NYHA classification although some leaders in the field have recommended using functional classifications specifically designed for patients with congenital heart disease, such as the Warnes-Somerville Ability Index.
Patients with cyanotic ACHD have a substantially greater increase in ventilation during exercise than do normal subjects, and dyspnea is often a prominent symptom. Some of the stimuli for this include hypoxemia, metabolic acidosis, and shunting of carbon dioxide into the systemic arterial circulation.
This patient reports a severe and progressive decline in functional capacity. It is imperative to thoroughly investigate the causes for this decline.
PHYSICAL EXAMINATION
BP 92/60 mm Hg (right arm), HR 80 bpm (regular), oxygen saturation (finger) 71%
Height 159 cm, weight 54 kg, BSA 1.54 m 2
Surgical scars: Right and left thoracotomy scars were present.
Neck veins: JVP was not elevated.
Lungs/chest: Breath sounds were within normal limits.
Heart: The apical impulse was displaced leftward. There was a normal first heart sound and single second heart sound. A continuous murmur was audible over the anterior and posterior aspect of the thorax (mainly in the midline and to the right).
Abdomen: Normal
Extremities: There were weak left radial and brachial pulses and normal femoral and pedal pulses bilaterally. She was cyanosed with marked clubbing of the fingers and toes. There was no peripheral edema.
Comments: In patients with ACHD cyanosis is a manifestation of either right-to-left shunting or inadequate pulmonary blood flow. In this case, it reflects both.
The patient is cachectic, which is common in cyanotic heart disease.
A single second heart sound is often a feature of pulmonary stenosis or atresia. A continuous murmur in this patient could be due to the Waterston shunt, the BT shunt, MAPCAs, or all of the above. The observation that the murmur is not heard on the left side of the chest raises the suspicion that the left BT shunt is occluded and that, perhaps, MAPCAs may be supplying the left lung.
There is reduced arterial flow ipsilateral to a classic BT shunt (with end-to-side anastomoses of the subclavian and branch pulmonary arteries) as manifest by weak or absent upper limb pulses.
Finger clubbing is a manifestation of chronic cyanotic heart disease. It is postulated that platelet-derived growth factor is released from clumps of platelets and megakaryocytes (shunted from right to left) as they impact in the capillary beds of the digits and periosteum, causing increased capillary permeability, fibroblastic activity, and arterial smooth muscle hyperplasia.
LABORATORY DATA
| Hemoglobin | 22.5 g/dL (11.5–15.0) |
| Hematocrit/PCV | 63% (36–46) |
| MCV | 89 fL (83–99) |
| Platelet count | 161 × 10 9 /L (150–400) |
| Sodium | 140 mmol/L (134–145) |
| Potassium | 5.1 mmol/L (3.5–5.2) |
| Creatinine | 0.9 mg/dL (0.6–1.2) |
| Blood urea nitrogen | 8.4 mmol/L (2.5–6.5) |
| Total bilirubin | 28 µmol/L (3–24) |
| ALP | 64 U/L (38–126) |
| ALT | 10 IU/L (8–40) |
| Total protein | 82 g/L (62–82) |
| Albumin | 43 g/L (37–53) |
| Uric acid | 656 µmol/L (210–440) |
| Iron | 7.8 µmol/L (12.6–26) |
| Ferritin | 11 µg/L (20–186) |
| Total iron binding capacity | 65 µmol/L (50–80) |
| Transferrin | 2.6 g/L (2.0–3.2) |
| Transferrin saturation | 12% (20–45) |
| Vitamin B 12 | 151 ng/L (180–914) |
| Folate | 4.0 µg/L (2.5–20) |
Comments: There is evidence of iron depletion. This reduces systemic oxygen transport and may contribute to poorer exercise function. Iron supplementation—and not venesection—is advised here (see Case 72 ). There is also deficiency of vitamin B 12 , which requires investigation and replacement. Even though her hemoglobin is severely elevated, it may not be high enough for her severe cyanosis.
The erythrocytosis results in an increase in unconjugated bilirubin and places these patients at greater risk of calcium bilirubinate (pigment) gallstones.
The elevated uric acid level is typical of chronic cyanosis and is due to inappropriately low renal fractional uric acid excretion rather than overproduction.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 71 bpm
QRS axis: +26°
QRS duration: 100 msec
Sinus rhythm, RA and LA overload, and voltage evidence of LV hypertrophy with nonspecific repolarization abnormalities.
Comments: This ECG is recorded at standard calibration of 10 mm/mV, although half-standard would have separated the overlapping R- and S-waves in the precordial leads.
A marked increase in R- and S-wave voltages in both the limb and precordial leads is typical of univentricular hearts of the LV type. In this case the limb leads did not show this pattern.
The patient is in sinus rhythm, importantly, since the development of arrhythmias (atrial flutter/fibrillation or occasionally ventricular tachycardia) is a common cause of deterioration in these patients.
CHEST X-RAY
FINDINGS
Cardiothoracic ratio: 60%
Situs solitus, levocardia with a left aortic arch. Enlarged cardiac silhouette, with a prominent bulge from the left heart border. Large RA. Pulmonary vascular markings are at the lower limit of normal. There was disruption of the right-sided and, to a lesser extent, the left-sided ribs suggesting prior thoracotomies.
Comments: Cardiomegaly reflects the volume loading of the heart in a single-ventricle type of circulation, further exaggerated by the surgical aortopulmonary shunts and potentially large multiple aortopulmonary collateral arteries, when the latter are present (here, there is no such evidence for the latter in the chest radiograph, i.e., there is no rib notching, differential/segmental pulmonary vascular markings, etc).
The bulge from the left heart border is unlikely due to the pulmonary artery, as there is pulmonary atresia and hypoplastic native pulmonary arteries. It seems likely to be due to enlargement of the LA appendage, which is clearly appreciated on the MRI images.
Rib disruption on an adult’s CXR provides evidence of thoracotomy in childhood, as there is continued somatic growth while the ribs are healing. Unilateral rib notching may be seen in patients who have had a classic BT shunt.
EXERCISE TESTING
Type of protocol: 6-minute walk test (6MWT)
No supplemental oxygen
Baseline
End
Heart rate
60
90
Dyspnea
2
8 (Borg Scale)
Fatigue
1
7 (Borg Scale)
Saturation
67%
45% 
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