Approaching atrial septal defects in pulmonary hypertension

Abstract

Atrial septal defects (ASDs) are one of the most frequent congenital cardiac malformations, accounting for about 8-10% of all congenital heart defects. The prevalence of pulmonary arterial hypertension (PAH) in adults with an ASD is 8-10%. Different clinical PAH scenarios can be encountered. At one end of the spectrum are adults with no or only mild pulmonary vascular disease and a large shunt. These are patients who can safely undergo shunt closure. In the elderly, mild residual pulmonary hypertension after shunt closure is the rule. At the other end of the spectrum are adults with severe, irreversible pulmonary vascular disease, shunt reversal and chronic cyanosis, that is, Eisenmenger syndrome. These are patients who need to be managed medically. The challenge is to properly classify ASD patients with PAH falling in between the two ends of the spectrum as the ones with advanced, but reversible pulmonary vascular disease amenable to repair, versus the ones with progressive pulmonary vascular disease not responding to shunt closure. There are concerns that adults with progressive pulmonary vascular disease have worse outcomes after shunt closure than patients not undergoing shunt closure. Due to the correlation of pulmonary vascular changes and pulmonary hemodynamics, cardiac catheterization is used in the decision-making process. It is important to consider the hemodynamic data in the context of the clinical picture, the defect anatomy and further noninvasive tests when evaluating the option of shunt closure in these patients.

Early characteristics of infants with pulmonary hypertension in a referral neonatal intensive care unit

“…Animal models of chronic left-to-right shunting have increased pulmonary vascular resistance and arteriolar medial thickness, implying biologic plausibility to the association between ASD and PH [24, 25]. Epidemiologically, ASDs account for 8–10% of congenital heart defects, though the majority of these close spontaneously in the first year of life [26]. For those with persistent defects, small studies have suggested that infants with BPD may have improved respiratory outcome following transcatheter closure of left-to-right shunts at approximately 6 months of age [27, 28].…”

Atrial Septal Defects Accelerate Pulmonary Hypertension Diagnoses in Premature Infants

“…Retrospective studies of infants born before 32 weeks' gestation have demonstrated that a higher proportion of infants with PH have ASD, than infants without PH ( 23 ). Although small left-to-right shunts will often close spontaneously after birth, larger and persistent ASDs may ultimately require interventional closure or surgery ( 24 , 25 ). Small studies that have evaluated percutaneous transcatheter device closure of ASD in sick neonates have shown some improvements in respiratory status and medication use post-procedure, suggesting that, in some patients, treatment may improve outcomes ( 17 , 18 , 26 ).…”

Cyanosis due to an isolated atrial septal defect: case report and review of the literature

“…14 Shunt reversion in Eisenmenger's syndrome can lead to rightto-left shunt, too, but here the underlying are changes in pulmonary vascular resistance with impaired right ventricular filling and subsequent high right atrial pressures. 15 Persistent hypertension of the newborn can be a potentially fatal course of cyanosis with an isolated atrial septal defect. 16 The mechanism in both these diseases lies in high pulmonary vascular resistance, even if the cause is different.…”