Impaired left ventricular function after arterial switch operation: exclusion of significant coronary artery stenosis with an intravascular Doppler guidewire

Coronary Microvascular Dysfunction in Patients with Congenital Heart Disease

Congenital heart diseases represent a wide range of cardiac malformations. Medical and surgical advances have dramatically increased the survival of patients with congenital heart disease, leading to a continuously growing number of children, adolescents, and adults with congenital heart disease. Nevertheless, congenital heart disease patients have a worse prognosis compared to healthy individuals of similar age. There is substantial overlap in the pathophysiology of congenital heart disease and heart failure induced by other etiologies. Among the pathophysiological changes in heart failure, coronary microvascular dysfunction has recently emerged as a crucial modulator of disease initiation and progression. Similarly, coronary microvascular dysfunction could be important in the pathophysiology of congenital heart diseases as well. For this systematic review, studies on maximal vasodilatory capacity in the coronary microvascular bed in patients with congenital heart disease were searched using the PubMed database. To date, coronary microvascular dysfunction in congenital heart disease patients is incompletely understood because studies on this topic are rare and heterogeneous. The prevalence, extent, and pathophysiological relevance of coronary microvascular dysfunction in congenital heart diseases remain to be elucidated. Herein, we discuss what is currently known about coronary microvascular dysfunction in congenital heart disease and future directions.

Site of coronary sinus drainage does not significantly affect coronary flow reserve in patients long term after Fontan operation

This study was designed to investigate the impact of postoperative coronary sinus drainage pressure on coronary flow reserve (CFR) assessed by Doppler guidewire in patients long term after Fontan operation. Twenty-nine patients (median age, 17.4 years female, 11) at a median of 10.6 years after Fontan operation were examined with intracoronary Doppler guidewire during cardiac catheterization. Fourteen patients had coronary sinus (CS) drainage to the systemic venous atrium and 15 patients had CS drainage to the pulmonary venous atrium after Fontan operation. Median CS drainage pressure was significantly higher in systemic venous CS drainage compared to pulmonary venous CS drainage (11 vs 5 mmHg, p < 0.0001). Median CFR values for the right and left coronary artery did not differ significantly with respect to CS drainage. There was a positive correlation between coronary flow reserve and pulmonary arteriolar resistance (p < 0.05) in multivariate regression analysis. The site of coronary drainage into the systemic atrium or the pulmonary venous atrium did not significantly affect CFR. Our data do not support a surgical strategy of elective redirection of coronary sinus blood to a low-pressure compartment but support an early staged approach. The positive correlation between CFR and pulmonary resistance demands further evaluation.