Right ventricular hypertrophy after atrial switch operation: normal adaptation process or risk factor? A cardiac magnetic resonance study

Abstract

BackgroundSystemic right ventricle (RV) hypertrophy and impaired function occur after atrial switch for dextro-transposition of the great arteries (d-TGA). Echocardiography is limited in its ability to assess the RV. We sought to evaluate systemic RV myocardial-mass index (MMI) and function after atrial switch and to analyse the role of hypertrophy for ventricular function with special consideration of the interventricular septal (IVS) movement.MethodsThirty-seven consecutive patients (median age 22.9 years) after atrial switch were studied using cardiac magnetic resonance imaging (1.5T Intera, Philips) with a dedicated 5-channel phased-array surface cardiac coil. Cine steady-state free-precession sequences were acquired to obtain myocardial masses and function. The systolic movement of the IVS was defined as positive when moving towards the centroid of the RV and was defined as non-positive otherwise. Patient parameters were compared to controls.ResultsThe systemic RVs were significantly larger (p < 0.001) than the left ventricles of the control group, systolic function was significantly impaired (p < 0.001) and MMI including the IVS was comparable (p = n.s.). RV-MMI excluding the IVS and RV ejection fraction (EF) demonstrated a quadratic correlation (r = 0.6, p < 0.001), meaning that patients with RV-MMI ≤29 g/m2 and >68 g/m2 had a reduced level of systolic function. Positive septal movement improved RV function compared with non-positive septal movement (p = 0.024).ConclusionsThere seems to be a range of beneficial RV hypertrophy after atrial switch in which a sufficient RV-EF can be expected. A positive septal movement, probably the result of hypertrophic septal RV fibres, improves RV function and might be regarded as a beneficial contraction pattern.

The clinical anatomy of the right ventricle

“…The fate and the results depend on associated lesions, shunts, status of the LV and pulmonary vasculature. The distinction between RV hypertrophy as a normal adaptation process versus a risk factor in the post‐switch operation period requires precise quantification of structural and functional RV parameters and is better established using cardiac MRI (Grothoff et al, ).…”

MicroRNA-183-3p Is a Predictor of Worsening Heart Failure in Adult Patients With Transposition of the Great Arteries and a Systemic Right Ventricle

“…The present study aimed to analyze miRNA signatures in patients with TGA and a systemic right ventricle in order to identify those miRNAs that were associated with worsening HF. It is known that a right ventricle in the systemic position is prone to maladaptive remodeling and heart failure ( 5 , 29 , 30 ). Thus, it is important to identify those patients who are at risk for worsening or overt HF since it has tremendous implications on prognosis ( 3 , 8 ).…”

Pathophysiologic Principles in the Management of Severe PAH

“…Early in life, the fetal RV is well adapted to high afterload, making it well suited to situations where it may assume the role as the systemic ventricle. [13][14][15] Indeed, persistence of the fetal phenotype may impart the improved prognosis in patients with post-tricuspid valve septal cardiac defects (eg, ventricular septal defect or patent ductus arteriosis). The cause(s) of the increase in afterload, and in a related manner, the location of the pulmonary arterial occlusion (proximal vs distal) may also affect the ability of the RV to adapt chronically.…”