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Natural and post-operative history of pulmonary vascular obstruction associated with ventricular septal defect
Insights
Pulmonary vascular obstruction progresses with age in VSD with PH. Early surgical repair is crucial to prevent irreversible changes and improve outcomes in children with VSD and pulmonary hypertension.
Area of Science:
- Pediatric Cardiology
- Pulmonary Hypertension
- Congenital Heart Disease
Background:
- Ventricular Septal Defect (VSD) with Pulmonary Hypertension (PH) can lead to progressive pulmonary vascular obstruction (PVO).
- Understanding the natural history of PVO is critical for timely intervention.
Purpose of the Study:
- To investigate the progression of PVO in VSD associated with PH.
- To determine the impact of age on PVO development.
- To identify predictors of poor outcomes in post-operative cases.
Main Methods:
- Pulmonary Vascular Resistance (PVR) was measured before and after tolazoline administration (1 mg/kg).
- Longitudinal study assessing PVR changes with age.
- Analysis of post-operative outcomes in relation to pre-operative PVR and age.
Main Results:
- Organic PVO was minimal in infancy but increased linearly with age.
- Average PVR increase post-tolazoline was 1 unit.m²/year.
- In Eisenmenger complex, PVR increase ranged from 0.7 to 4 unit.m²/year.
- Late post-operative deaths occurred in patients >5 years old with pre-operative PVR >12 unit.m².
- Successful PVR reduction was noted in patients with pre-operative PVR <8 unit.m² (pre-tolazoline) and <7 unit.m² (post-tolazoline).
Conclusions:
- Pulmonary vascular obstruction in VSD with PH progresses with age.
- Early surgical intervention is indicated to prevent irreversible PVO.
- Pre-operative PVR and age are critical factors in surgical outcomes.
Abstract:
The natural history of pulmonary vascular obstruction in VSD associated with PH was studied by measuring PVR before and after injection of tolazoline 1 mg/kg. Organic pulmonary vascular obstruction (PVO) was minimal in infancy, but increased linearly progressively with advancing age, and average rate of increase in PVR after tolazoline was 1 unit.m2/year. The rate of increase in PVR after tolazoline in Eisenmenger complex was variable and ranged between 0.7 to 4 unit.m2/year in most cases. Analysis of 7 cases of post-operative late death due to PVO revealed that usually these cases were over 5 years of age at operation, and pre-operative PVR was more than 12 unit.m2. Reduction of PVR was confirmed post-operatively in most of these cases whose pre-operative PVR before and after tolazoline were les than 8 unit.m2 and 7 unit.m2 respectively. Early surgical repair is indicated in VSD and PH to prevent progress of PVO.