Pentalogy of Fallot: A case report

Abstract

We report the case of a 45-year-old woman with pentalogy of Fallot, a severe and complicated cyanotic congenital heart disease. Congenital anomalies of pentalogy of Fallot include ventricular septal defect, right ventricular hypertrophy, saddle aorta, pulmonary ostium stenosis, atrial septal defect, and patent foramen ovale. Pentalogy of Fallot is less common than triplet and tetralogy of Fallot and can affect children’s physical development. Approximately 95% of patients with pentalogy of Fallot die before the age of 40 years, and early surgical radical surgery is recommended. However, the patient in the current case did not undergo surgery.

Introduction

Most infants with pentalogy of Fallot exhibit dyspnea, progressive cyanosis, and poor exercise tolerance compared with their peers. Severe hypoxia may cause sudden dyspnea and severe cyanosis and can even be life-threatening. Overall, 95% of patients with pentalogy of Fallot die before the age of 40 years, and early surgical radical surgery is recommended for these patients. ¹ Pentalogy of Fallot is caused by abnormal embryonic development, which may be related to genetic or maternal factors. Genetic factors involve chromosome aberrations in parents, whereas maternal factors are often due to viral and bacterial infections in the first trimester, especially those caused by rubella virus and coxsackievirus. Right ventricular hypertrophy occurs usually due to structural cardiac changes secondary to pulmonary artery stenosis. The prognosis of patients mainly depends on the extent of pulmonary artery stenosis and collateral circulation. Overall, 25%–35% of children die by the age of 1 year and 70%–75% by the age of 10 years. The main causes of mortality include chronic hypoxia, polycythemia, secondary myocardial hypertrophy and heart failure, and malignant arrhythmia. The malformation of pentalogy of Fallot develops due to dysplasia of the infundibulum or conus of the right ventricle. The reverse rotation of the truncus arteriosus was not observed at 4 weeks of embryonic development. The aorta (AO) is located on the right side of the pulmonary artery, and the conic septum is displaced from the sinus septum, resulting in perimembranous ventricular septal defect or subtruncal ventricular septal defect.

Case report

The patient was a 45-year-old woman who was unmarried and childless. She was admitted to the hospital because of “recurrent dyspnea for more than 40 years, aggravated with cyanosis and dizziness for 1 day.” At the age of 5 years, she experienced recurrent dyspnea after exercise without obvious cause, and the symptoms were gradually relieved after rest. She usually performed squatting and had occasional chest pain attacks. One day prior to hospitalization, she developed worsening dyspnea with cyanosis and dizziness. Physical examination revealed dysplasia, microsomia, cyanosis of the lips and nails, and clubbing of both upper limbs; moreover, a grade 5/6 pansystolic murmur with systolic tremor could be heard between the second and fourth intercostal spaces at the left sternal border. On 24 June 2024, the pro B-type natriuretic peptide (pro-BNP):N-terminal-proBNP level was 321 pg/mL, and the D-dimer level was 0.72 mg/L. Routine blood test revealed a hemoglobin level of 90 g/L. The electrocardiogram findings were as follows: (a) sinus tachycardia; (b) widened P wave; (c) 1° atrioventricular block; (d) abnormal Q waves (I, II, aVL, and aVF) and poor R-wave progression; and (e) right ventricular hypertrophy. The electrical axis was extremely right-skewed.

Chest CT (Figure 1) showed that the chest was deformed, the sternum was depressed, and the shape was irregular. The ratio of the anteroposterior diameter of the chest to the left diameter was approximately 0.27, and the heart was obviously compressed and flattened to the left side. Chest CT findings were as follows: (a) cardiac enlargement with a small amount of pericardial effusion and obvious enlargement of the pulmonary artery trunk (considered as aneurysm; based on the medical history, the diagnosis was congenital heart disease) and (b) straight back syndrome.

Figure 1.

Patient’s chest CT. (a) The aorta rides on the septum; (b) chest CT revealed ventricular septal defect and (c) chest CT showed pulmonary artery ostium stenosis. CT: computed tomography.

Echocardiographic description of the heart is presented in Figures 2–3. Cardiac measurements based on Doppler examination were as follows (normal values in parentheses): (a) left ventricular function AO, 23  (<35) mm; (b) left atrium (LA), 27 (25–35) mm; (c) main pulmonary artery (MPA), 38 mm (less than AO inner diameter); (d) left ventricular end diastolic dimension, 33 (35–55) mm; (e) interventricular septum thickness, 9 (8–11) mm; (f) left ventricular posterior wall thickness, 11 (8–11) mm; (g) ejection fraction, 68% (50%–75%); and (h) fractional shortening, 37% (>25%). The diameter of the MPA was dilated similar to a tumor, with a large diameter of approximately 38 mm. Four-chamber view scan showed an anechoic area on the left atrial side, with an area of approximately 57.8 × 26.7 mm (length × diameter), and blood flow signals were observed in the area. The anechoic area was connected to the left atrial side, with an inner diameter of approximately 8.0 mm, peak velocity of approximately 1.18 m/s, and pressure gradient of approximately 5.5 mmHg. The heart valves were not thick, opened well, and closed poorly. The septum and the posterior wall of the left ventricle were not thick and showed retrograde motion. The peak velocity was 2.7 m/s, and the pressure gradient was 30 mmHg. There was a bidirectional shunt at the ventricular level (right-to-left shunt was more obvious). The AO appeared to be saddle-shaped. The diameter of the atrial septum was approximately 5.1 mm, peak velocity was approximately 1.3 m/s, and pressure gradient was approximately 6.7 mmHg. The atrial level was shunted from left-to-right. Color Doppler showed red blood flow in the inflow tract and blue blood flow in the outflow tract. A mild mitral regurgitation bundle was detected in the LA. A mild tricuspid regurgitation bundle was observed in the right atrium. A mild aortic regurgitation bundle was noted in the left ventricular outflow tract. Spectral Doppler showed that the flow spectrum of each valve orifice was laminar, and the flow spectrum of the mitral valve was as follows: peak E was lower than peak A. The velocity of blood flow in the MPA was approximately 1.3 m/s, and that over the pulmonary valve was approximately 1.85 m/s. There were irregular fluid echo areas in the pericardium: (a) the anteroposterior diameter of the left ventricular posterior wall was 3.3 mm; (b) the anteroposterior diameter of the right ventricular anterior wall was 4.6 mm; and (c) the anteroposterior diameter of the right ventricular lateral wall and apex was 6.4 mm. Perimembranous ventricular septal defect with bidirectional shunt was noted. The pulmonary valve blood flow velocity increased, indicating stenosis (pulmonary stenosis of the right ventricular outflow tract). Furthermore, AO-like straddling-like atrial septal aneurysm with atrial septal defect was observed (central type, left-to-right shunt). There was mild mitral regurgitation, mild tricuspid insufficiency, and mild aortic insufficiency, and a small amount of pericardial fluid was collected.

Figure 2.

Patient’s cardiac ultrasound. (a) Color Doppler echocardiography showed ventricular septal defect; (b) ventricular septal defect (perimembranous, bidirectional shunt) and (c) color Doppler ultrasound showed congenital patent foramen ovale: AO, 23  (<35) mm; LA, 27 (25–35) mm; MPA, 38 mm; LVDd, 33 (35–55) mm; IVST, 9 (8–11) mm; LVPW, 11 (8–11) mm; EF, 68% (50%–75%); and Fs, 37% (>25%). AO: aorta; LA: left atrium; MPA: main pulmonary artery; LVDd: left ventricular end diastolic dimension; IVST: interventricular septum thickness; LVPW: left ventricular posterior wall thickness; EF: ejection fraction; Fs: fractional shortening.

Figure 3.

PLAX (long axis of the parasternal left ventricle) view image of echocardiographic and tissue Doppler images.(a) The aorta rides on the septum; (b) pulmonary artery stenosis; (c) ventricular septal defect and (d) ventricular septal defect.

Further testing is recommended. The patient refused surgical treatment and was treated conservatively with drugs. She was discharged after oxygen inhalation and other symptomatic treatments.

Discussion

Tetralogy of Fallot (TOF) is a cyanotic congenital heart disease. The incidence of TOF is approximately 1/3000, and approximately 2% of the untreated patients can survive until the age of 40 years. ² Pentalogy of Fallot is even more rare, and its occurrence is related to various gene mutations. Mutations in GATA-4 and GATA-6 can cause TOF. Mutations in GATA-4 can also cause atrial septal defect and ventricular septal defect. In addition, mutations in TBX5 can cause cardiac septal defects. ³ Gene methylation may cause abnormal cardiac development.

In some remote mountainous areas of China, the economic and medical conditions have not yet been developed, and some patients are diagnosed with pentalogy of Fallot at a later stage, even in adulthood. Echocardiography, computed tomography angiography, and angiocardiography are common diagnostic methods for TOF. Cardiovascular angiography is the gold standard technique for the diagnosis of congenital heart disease, which is invasive, susceptible to receptors, and not suitable for routine examination. Echocardiography is a noninvasive, convenient, and rapid examination, which is the first choice for TOF examination. It can provide imaging support during the formulation of a surgical plan. Adult patients with a long history of pentalogy of Fallot have established abundant collateral circulation in their vital organs due to the influence of long-term hypoxia. ⁴ Although the patient in the current case was diagnosed with pentalogy of Fallot, he could live to middle age, which may be related to the establishment of abundant collateral circulation in the body due to the function of a long-term hypoxic environment. Sun and Li ⁵ reported a case of pentalogy of Fallot combined with coronary artery malformation and left main artery–left atrial fistula.

Conclusion

Patients with pentalogy of Fallot are usually required to control the intake of water and sodium, have a light diet, and supplement adequate protein and energy. The treatment methods include surgical correction and palliative surgery. Palliative procedures include subclavian artery–pulmonary anastomosis or patch widening of the right ventricular outflow tract in older patients. Ascending aortopulmonary anastomosis or central shunt was performed in patients younger than 3 months. Propranolol and sodium bicarbonate can be used for the treatment of hypoxic episodes with sedation and decreased pulmonary circulation due to syncope and right ventricular infundibulum spasm.

The timing of surgery for pentalogy of Fallot is currently controversial, and it is generally believed that 6 months is an appropriate timing for surgery because the valve condition is acceptable and the foundation for repair is optimal. ⁶ Early surgery can not only reduce the natural mortality of patients but also avoid potential damage to important organs such as the heart, brain, lungs, and kidneys caused by long-term chronic hypoxia. ⁷ Patients with pentalogy of Fallot can survive to adulthood, with generally good pulmonary artery and left ventricle development and even patent ductus arteriosus compensation mechanism. ⁸ In this case, the patient could survive into adulthood, probably because the right-to-left shunt from the atrial septal defect reduced pulmonary hypertension. In addition, the left ventricle was well-developed in this patient. Survival to adulthood indicates that the development of the left ventricle and pulmonary artery is not very poor, the indication for radical resection is stronger than that among children, and the operative mortality is significantly reduced. Therefore, once the diagnosis is established, radical surgery should be performed immediately.

Radical resection of pentalogy of Fallot through median sternotomy is the most common surgical treatment. Long-term hypoxia leads to abundant collateral circulation and decreased coagulation factors. Secondary bleeding or massive bleeding after the operation is likely to occur; hence, it is necessary to strictly stop bleeding to avoid reopening. Blood products such as red blood cells, plasma, platelets, coagulation factors, and cryoprecipitate should be prepared before operation. Open surgery, including repair of atrial septal defect and ventricular septal defect, repair of stenosis in the infundibulum of the right ventricle, or incision of the stenotic pulmonary valve, can completely correct this malformation. Adequate relief of the right ventricular outflow tract obstruction is the key to successful operation and postoperative recovery. Liver function and albumin levels were monitored dynamically after the operation, and treatment and supplement were adjusted within appropriate time. Low cardiac output and respiratory dysfunction were closely monitored after the operation. It is generally believed that the factors affecting postoperative prognosis and mortality include pulmonary regurgitation, ventricular residual leakage, left ventricular outflow tract obstruction, and right ventricular outflow tract obstruction.