Best management in isolated right ventricular hypoplasia with septal defects in adults

Isolated right ventricular hypoplasia associated with cyanotic atrial septal defect: a case report

Background

Hypoxaemia in isolated right ventricular (RV) hypoplasia (IRVH) is primarily caused by a right-to-left shunt (RLS) at the atrial level, such as an atrial septal defect (ASD). When considering closure of the RLS, it should be closed only after ensuring that it will not cause right-sided heart failure (HF).

Case summary

A 21-year-old woman had been experiencing shortness of breath during exertion since childhood. Transthoracic and transoesophageal echocardiography revealed an ASD with bidirectional shunting, and microbubble test revealed a marked RLS. Cardiac magnetic resonance imaging revealed a hypoplastic RV end-diastolic volume corrected for body surface area of 47 mL/m2 (70% of normal range). Right heart catheterization revealed a decreased Qp/Qs ratio of 0.89 and a pressure waveform with a clear increase in the 'A'-wave, although the mean right atrial pressure was not high (4 mmHg). Therefore, the patient was diagnosed with cyanotic ASD and IRVH. A temporary balloon occlusion test was performed to evaluate the right-sided heart response to capacitive loading prior to ASD closure. After treatment, the patient's improved markedly. The pre-operative brain natriuretic peptide (BNP) level was normal; however, 6 months after ASD closure, the BNP level was elevated, and the continuous-wave Doppler waveform of pulmonary regurgitation at the time of transthoracic echocardiography changed, suggesting an increase in diastolic RV pressure.

Discussion

When ASD is complicated by hypoxaemia, the possibility of IRVH, although rare, should be considered. Another difficult point is determining whether the ASD can be closed, considering its immature RV compliance.

Percutaneous Modified Blalock-Taussig Shunt Closure in a Patient with Isolated Right Ventricular Hypoplasia

Clinical presentation, course, and treatment for patients with isolated right ventricular (RV) hypoplasia (IRVH) depends on the degree of hypoplasia that is present-this is a spectrum from spontaneous maturation to Fontan circulation over time. An 8-month-old infant presented with IRVH; in the patient, a modified Blalock-Taussig (MBTS) shunt was closed percutaneously after spontaneous RV function recovery. A female newborn was diagnosed with differential cyanosis at birth. The echocardiography showed a hypertrophic RV with a small cavity, a right-left shunt on the atrial septal defect, an almost closed ductus arteriosus (DA), and a small tricuspid valve ring (Z-score-2) with mild regurgitation (pressure gradient 30 mmHg). On the 4th day of life, the patient showed deepened cyanosis and hyperlactatemia was registered. The echocardiography examination revealed a closed DA. Right ventriculography performed on the 5th day of life evidenced the presence of a small hypertrabeculated RV. The pressure in the RV increased. A right-side MBTS was created on the 6th day of life. Further echocardiographic findings indicated a gradual development of the RV and a decrease in RV pressure. MBTS occlusion was performed when the patient was 8 months old. Vital parameters were monitored invasively and noninvasively after the balloon occlusion of MBTS. Percutaneous MBTS occlusion was successfully performed using an Amplatzer vascular plug 2 (AVP2). During the follow-up period, the patient was found to have maintained a normal percutaneous oxyhaemoglobin blood saturation.

Clinical Status and Outcome of Isolated Right Ventricular Hypoplasia: A Systematic Review and Pooled Analysis of Case Reports

Background

Isolated right ventricular hypoplasia (IRVH), not associated with severe pulmonary or tricuspid valve malformation, is a rare congenital myocardial disease. This study aims to evaluate the clinical status and outcome of IRVH.

Methods

A systematic search of keywords on IRVH was conducted. Studies were searched from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi (Ichushi) published between January 1950 and August 2021.

Results

Thirty studies met the inclusion criteria. All of these studies were case reports and included 54 patients (25 males and 29 females). The median age of the patients was 2.5 years old (0-15.3 years). Of the 54 patients, 13 (24.1%) reported a family history of cardiomyopathy. Moreover, 50 (92.6%), 19 (35.2%), and 17 (31.5%) patients were diagnosed with cyanosis, finger clubbing, and dyspnea, respectively. Furthermore, 53 (98.2%) patients had a patent foramen ovale or an atrial septal defect (ASD). Z-score of the tricuspid valve diameter on echocardiogram was -2.16 ± 1.53, concomitant with small right ventricular end-diastolic volume. In addition, 29 (53.7%), 21 (38.9%), 7 (13.0%), and 2 (3.7%) patients underwent surgery, ASD closure, Glenn operation, and one and a half ventricular repair, respectively. Among them, nine (20.4%) patients expired, and the multivariable logistic regression analysis showed that infancy, heart failure, and higher right ventricular end-diastolic pressure were risk factors for death.

Conclusions

IRVH was diagnosed early in children with cyanosis and was associated with high mortality. This systematic review and pooled analysis provided evidence to assess the of IRVH degree in order to evaluate the clinical status and outcome of IRVH.

Isolated hypoplastic right ventricle - a challenge in medical practice

Isolated right ventricle hypoplasia (IRVH) is a disease characterized by an underdeveloped right ventricle. It is a congenital heart disease than can associate heterogeneous structural defects and nonspecific clinical features, which can often present a challenging therapeutic management. In this article, there are presented diagnostic methods and treatment options for right ventricle hypoplasia (RVH) according to clinical features, patients age and associated structural heart defects. RVH has a different prognosis in accordance with the severity of the heart defects and the patient's age at which the diagnosis is established. Thus, isolated forms of RVH generally present mild structural and functional defects that can be associated with the onset of symptoms in adolescence or even in adulthood. In these cases, atrial septal defect closure with or without superior cavo-pulmonary anastomosis can be the only procedures needed to correct the hemodynamic abnormalities and relief the symptomatology. Patients with severe form of RVH associated with complex cardiac malformations and onset of the symptoms in the neonatal period require prompt intervention and necessitate palliative procedures. In the long term, these patients could need multiple reinterventions. The family physician should be aware of the cardiac origin of isolated symptoms or clinical signs, such as exertional dyspnea or clubbing fingers, and send the patient for pediatric cardiological evaluation.