Pulmonary insufficiency: preparing the patient with ventricular dysfunction for surgery

Serum Bile Acids in Repaired Tetralogy of Fallot: A Marker for Liver and Heart?

Background and Aims

Patients with repaired tetralogy of Fallot may develop chronic right ventricular dysfunction and hepatic congestion over time. We hypothesized that bile acid metabolism is altered in repaired tetralogy of Fallot patients and therefore sought to correlate right ventricular indices with serum bile acid levels.

Methods

Indexed right ventricular end diastolic volume, as assessed by cardiac magnetic-resonance imaging, was classified as <100ml/m² (Group 1, n = 5), 100–150ml/m² (Group 2, n = 18), and >150ml/m² (Group 3, n = 6) in 29 patients with repaired tetralogy of Fallot. Pulmonary regurgitation fraction and right ventricular ejection fraction were calculated. The serum bile acid profile, including 15 species, in these patients was determined by liquid chromatography coupled with mass spectrometry.

Results

Serum bile acid levels increased from Group 1 to Group 3 (2.5 ± 0.7; 4.1 ± 2.5; 6.0 ± 2.8 μmol/l, respectively) with significantly increased bile acid values in Group 3 compared to Group 1 (p≤0.05). In Group 3, but not in Group 1 and 2, a significant increase in glycine-conjugated bile acids was observed. Pulmonary regurgitation fraction increased (12 ± 1; 28 ± 16; 43 ± 3%, Groups 1–3, respectively) and right ventricular ejection fraction decreased (48.4 ± 6.4; 48.5 ± 6.5; 42.1 ± 5.3%, Groups 1–3, respectively) with rising indexed right ventricular end diastolic volume.

Conclusions

These preliminary results suggest that serum bile acid levels are positively correlated with indexed right ventricular end-diastolic volume in patients with repaired tetralogy of Fallot; however, this needs to be confirmed in a larger patient cohort.

Morphologic and functional remodeling of the right ventricle in pulmonary hypertension by real time three dimensional echocardiography

The aims of this study were to assess the right ventricle in different causes of pulmonary hypertension (PH) and to assess the changes of the tricuspid apparatus during this remodeling. The functional and morphologic changes of the right ventricle and the tricuspid apparatus in relation to different causes of PH remain elusive. A total of 141 consecutive patients were prospectively recruited, of whom 55 had pulmonary arterial hypertension (PAH), 32 had chronic thromboembolic disease (CTED), and 34 had PH secondary to mitral regurgitation (MR). Twenty age- and gender-matched healthy volunteers were also studied to serve as controls. Real-time 3-dimensional echocardiography was used to assess right ventricular (RV) volumes and tricuspid valve mobility. Overall, RV diastolic volumes were greater and RV ejection fractions lower in patients with PAH compared to those with CTED and MR (186.4 ± 48.8 vs 113.5 vs 109.4 ml, p < 0.001, and 33.2% vs 36.8% vs 66.8%, p < 0.001, respectively). Among the 3 PH groups, tricuspid valve mobility was most restricted in the CTED group and least restricted in the MR group. Tricuspid tenting volume was greater in the CTED and PAH groups than in the MR group (p < 0.01). Most patients with PAH (54.6%) had at least moderate tricuspid regurgitation, while in the CTED group, most (59.4%) had mild and only 37.5% had moderate tricuspid regurgitation (p < 0.01). Conversely, patients with MR (85%) had only mild tricuspid regurgitation. There was no correlation between RV systolic pressures and the RV ejection fraction or tenting volume. In conclusion, this study demonstrates that different causes of PH may lead to diverse RV remodeling, with the most adverse remodeling being in patients with PAH. In addition, changes of the tricuspid apparatus also differed, with the most adverse effects seen in patients with CTED.