Echocardiography and CMRI consistently revealed right heart dilation but correlated poorly for right heart function, and a holistic approach incorporating multiple modalities and clinical assessment is recommended as the pathophysiology of PH may differ in patients with left-to-right shunts.
Key Findings
Results
Right-heart dilation was observed in all patients with pulmonary hypertension secondary to left-to-right shunts.
75 patients were included with a median age of 9.98 years (IQ1-IQ3: 6.01-40.9 years)
All patients had mean pulmonary artery pressure ≥ 25 mmHg confirmed by right heart catheterisation
Increased tricuspid valve annular diameter was observed on echocardiography with a median z-score of 2.44
RV end-diastolic indexed volumes were at least double the normal reference ranges in most patients, with a median of 240 mL/m2 (IQ1-IQ3: 165-268 mL/m2) on CMRI
Results
There was a statistically significant sex difference in RV systolic function, with more males having normal RV systolic function compared to females.
70% of males had normal RV systolic function compared to only 45% of females (p < 0.05)
The median normal RV systolic function was 49% for males (IQ1-IQ3: 48.0-50.0%) and 49% for females (IQ1-IQ3: 47.3-49.8%)
RV systolic function was assessed by CMRI
Results
Echocardiographic markers of RV function correlated poorly with CMRI RV ejection fraction.
Three echocardiographic markers of RV function were compared to CMRI RV ejection fraction
Correlation coefficients were r = -0.28, r = -0.10, and r = -0.04 for the respective echocardiographic markers
All correlation coefficients were negative and near zero, indicating very weak or no meaningful correlation
Both echocardiography and CMRI consistently revealed right heart dilation despite poor functional correlation
Results
A substantial proportion of patients demonstrated left heart dilation and impaired left ventricular ejection fraction.
80% of patients demonstrated left heart dilation
35% of patients had impaired left ventricular (LV) ejection fraction
LV impairment was identified across echocardiography, radionuclide ventriculography, and CMRI
The authors conclude that evaluation of LV function should not be neglected in patients with PH secondary to left-to-right shunts
Methods
Three imaging modalities — transthoracic echocardiography, cardiac MRI, and nuclear ventriculography — were used to assess right and left heart dimensions and function in patients with pulmonary hypertension secondary to congenital left-to-right shunts.
All patients had mean pulmonary artery pressure ≥ 25 mmHg confirmed during right heart catheterisation prior to imaging
The study was conducted in a sub-Saharan African patient population
75 patients were included with a wide age range (median 9.98 years, IQ1-IQ3: 6.01-40.9 years), suggesting a predominantly pediatric but mixed-age cohort
A holistic approach incorporating multiple modalities and clinical assessment is recommended by the authors
What This Means
This research studied 75 patients in sub-Saharan Africa who had high blood pressure in the lungs (pulmonary hypertension) caused by congenital heart defects that allow blood to flow abnormally from the left side of the heart to the right side. The researchers used three different heart imaging tests — ultrasound (echocardiography), cardiac MRI, and a nuclear imaging scan — to measure the size and pumping function of both sides of the heart. They found that the right side of the heart was enlarged in every single patient, with the heart chambers measuring at least twice the normal size on MRI. Interestingly, more male patients (70%) had normal right heart pumping function compared to female patients (45%), a statistically significant difference. They also found that the ultrasound measurements of right heart function did not reliably match what the MRI showed, with very low correlation scores, meaning the two tests often gave different impressions of how well the right heart was working.
A notable and perhaps unexpected finding was that the left side of the heart was also affected: 80% of patients showed left heart enlargement, and 35% had weakened left heart pumping function. This is significant because pulmonary hypertension from these types of defects is often thought of primarily as a right heart problem, but this study highlights that left heart function can also be compromised and should not be overlooked during evaluation.
This research suggests that no single imaging test is sufficient to fully assess heart health in these patients, and that using multiple imaging methods together gives a more complete picture. It also raises awareness that both sides of the heart need to be evaluated in patients with this condition. The findings are particularly relevant for healthcare settings in sub-Saharan Africa, where congenital heart defects causing pulmonary hypertension carry serious consequences, and where choosing the right combination of diagnostic tools matters for patient care.
Henema M, Brown S, Smit F, Botes L. (2026). An analysis of imaging modalities to assess the right and left heart in pulmonary hypertension with left-to-right shunts.. Cardiovascular journal of Africa. https://doi.org/10.5830/CVJA-2026-033