MR imaging and heart function in patients pre- and post-Fontan surgery

The assessment of atrial function in single ventricle hearts from birth to Fontan: a speckle-tracking study by using strain and strain rate

BACKGROUND

Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques.

METHODS

A cross-sectional study of 81 patients with SV (1 day to 6.5 years) at 4 stages of surgical palliation (presurgery, 22; prebidirectional cavopulmonary anastomosis, 23; pre-Fontan, 22; post-Fontan, 14). The dominant atrium was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; strain rate (SR); and εact/εres ratio before each stage of surgical palliation. Findings were compared with the left atrium of 51 healthy children (1 day to 5.5 years).

RESULTS

Single ventricle atrial size was increased (P < .01), and atrial εres was decreased (P < .01) compared with healthy controls. SV atrial εcon (P < .01) and SRcon (P < .0001) was decreased, increased εact persisted (P < .05), and εact/εres was increased (P < .001) between surgical stages. Although the expected maturational trend of increasing εcon, decreasing εact, and εact/εres occurred in SV, they lagged behind healthy maturational changes (P < .0001).

CONCLUSION

Single ventricle atrium is dilated, has deceased compliance, decreased early diastolic emptying, and increased reliance on active atrial contraction for ventricular filling. This deviates from normal early childhood maturational changes and appears to parallel those of an atrium facing early ventricular diastolic dysfunction.

Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children

Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children.

Hearts late after fontan operation have normal mass, normal volume, and reduced systolic function

OBJECTIVES

The purpose of this study was to assess ventricular mass, volume, and systolic function in patients late after Fontan operation by cardiac magnetic resonance imaging.

BACKGROUND

An assessment of determinants for ventricular function in post-Fontan patients was intended.

METHODS

Twenty-three unselected patients (9 female, 14 male) at a median age of 19.4 years (range, 7.8 to 31.3 years), at a median time of 10.5 years (range, 4.1 to 18 years) after Fontan operation were studied. A standard 1.5-T scanner was used, and analysis was performed using dedicated software. Ten healthy volunteers (median age 26.4, range 18 to 39.3 years) served as the control group.

RESULTS

Median end-systolic mass index was 72.2 g/m(2) (range, 43 to 138 g/m(2)) and 86.6 g/m(2) (range, 52 to 123 g/m(2)) in the control group (p = NS). Median end-diastolic ventricular volume was 64 ml/m(2) (range, 32 to 117 ml/m(2)) compared with 67.7 ml/m(2) (range, 59 to 75 ml/m(2)) in the control group (p = NS). Median ejection fraction was 49.3% (range, 20% to 63%) compared with 64.8% (range, 57% to 79%) in normals (p = 0.00001).

CONCLUSIONS

We conclude that long-term survivors of a Fontan operation have normal ventricular mass, normal volume, but reduced systolic ventricular function.