Left ventricular dysfunction due to chronic right ventricular pressure overload. Resolution following percutaneous balloon valvuloplasty for pulmonic stenosis

Left ventricle dysfunction in patients with critical neonatal pulmonary stenosis: echocardiographic predictors. A single-center retrospective study

Background

The aim of this study is to identify echocardiographic predictors of transient left ventricle dysfunction after pulmonary valve balloon dilatation (PVBD), in neonates with pulmonary valve stenosis (PVS) and atresia with intact septum (PAIVS) at birth.

Methods

The study includes patients admitted at the Bambino Gesù Children Hospital from January 2012 to January 2017. Clinical, echocardiographic and cardiac catheterization data before and after PVBD were retrospectively analyzed.

Results

Twenty-nine infants were included in the study (21 male and eight female). The median age was 5.8 ± 7.1 days. Eight patients developed transient LV dysfunction (three PAIVS and five PVS) and comparing data before and after the procedure, there was no difference in right ventricle geometrical and functional parameters except for evidence of at least moderate pulmonary valve regurgitation after PVBD.

Conclusion

Moderate to severe degree pulmonary valve regurgitation was significant associated to LV dysfunction (p < 0.05) in PVS and PAIVS patients.

Characterization of Left Ventricular Dysfunction by Myocardial Strain in Critical Pulmonary Stenosis and Pulmonary Atresia After Neonatal Pulmonary Valve Balloon Dilation

Transient left ventricular (LV) dysfunction occurs in some infants born with critical pulmonary stenosis (PS) or membranous pulmonary atresia with intact ventricular septum (PAIVS) after pulmonary valve (PV) balloon dilation (BD). The cause for this is not well understood. We sought to characterize this LV dysfunction by investigating regional differences in this cohort using myocardial strain imaging. Patients who underwent neonatal (<2 weeks age) PV BD for critical PS or PAIVS from Jan, 2007 to March, 2014 with echocardiographic images suitable for strain analysis were identified; infants with ≥moderate post-BD LV dysfunction (ejection fraction <40%, n = 8) were matched 1:1 with controls who underwent PV BD but did not develop LV dysfunction. Longitudinal and circumferential global and segmental strain were analyzed before and after PV BD. For the 8 LV dysfunction cases, LV global longitudinal strain worsened after PV BD (-16% pre- vs -8% post-PV BD, p = 0.008) with similar impairment in global LV circumferential strain (-17% vs -8%, p = 0.008); there was no significant change in RV global or segmental longitudinal strain pre- vs post-PVBD. No significant pre/post-BD differences in global or circumferential strain were found in control pts. Segmental analysis of longitudinal and circumferential LV strain before and after balloon dilation in cases demonstrated decreased strain in all segments, but more pronounced and statistically significant in septal segments as compared with the free wall. In conclusion, transient LV dysfunction post-PV BD for critical PS/PAIVS is characterized by impaired global longitudinal and circumferential LV strain, with the most significant reductions in strain at the interventricular septum; longitudinal RV strain remains unchanged. These findings suggest that the mechanism of LV dysfunction post-PV BD is adverse ventricular-ventricular interactions specifically involving the interventricular septum.

Limitations of radionuclide angiographic assessment of left ventricular systolic function before lung transplantation

To evaluate the influence of increased right ventricular afterload on radionuclide assessment of the left ventricular ejection fraction (LVEF), we compared the preoperative and postoperative value of isotopic LVEF in 11 patients who underwent lung transplantation and had a preoperative LVEF value below 55% (normal value: 68 +/- 8%). The underlying disease conditions were obstructive lung disease (n = 7) and pulmonary fibrosis (n = 4). The transplantation procedure was unilateral in 10 patients and bilateral in one. The mean value of isotopic LVEF prior to transplantation was 51 +/- 3% (range: 49% to 55%). At 42 +/- 13 mo postoperatively, isotopic LVEF increased significantly, to 65 +/- 10% (p = 0.001), suggesting that intrinsic left ventricular systolic function was in fact normal in these patients. We hypothesize that the low preoperative isotopic LEVF was not related to intrinsic dysfunction of the left ventricle, but rather to right ventricular pressure overload, leading to bulging of the interventricular septum into the left ventricle and to subsequent geometric distortion of the left ventricle. We conclude that isotopic LVEF may underestimate intrinsic left-ventricular systolic function in patients with severe chronic lung disease. Candidates for lung transplantation should not be rejected on the basis of a low isotopic LVEF, provided echocardiographic examination does show apparently normal left ventricular contraction.

Changes in patterns of left ventricular diastolic filling revealed by Doppler echocardiography in infants with ventricular septal defect

To evaluate left ventricular diastolic filling in infants with ventricular septal defect, which has yet to be documented, we measured various Doppler echocardiographic indexes from transmitral flow in the following groups: 10 infants with ventricular septal defect without pulmonary hypertension; 10 infants with ventricular septal defect with pulmonary hypertension; and 9 normal infants to serve as controls. The peak A, total velocity time integral, E area, and A area in patients without pulmonary hypertension were all significantly larger than those in controls. The peak ratio E/A, and 1/3 filling fraction, in patients without pulmonary hypertension were significantly lower than in controls. The peak A, A area, and deceleration time in patients with pulmonary hypertension were significantly larger than in patients without pulmonary hypertension and controls. The peak E/A, area E/A, and 1/3 filling fraction in patients with pulmonary hypertension were significantly lower than in those without pulmonary hypertension and controls. The index of left ventricular mass, as well as the index of end-diastolic left ventricular wall thickness, correlated strongly with peak A, A area, and deceleration time. The ratio between the systolic pulmonary and systemic pressures correlated strongly with peak A, A area, peak E/A, area E/A, and 1/3 filling fraction. These results demonstrated that the patterns of left ventricular filling in infants with ventricular septal defect were different from those in normal infants, and suggested that the abnormal patterns may indicate the insufficiency of adaptation of left ventricle (increase of left ventricular compliance) for volume overload in the presence of a ventricular septal defect.

Effects of chronic right ventricular pressure overload on left ventricular diastolic function

Right ventricular (RV) function influences left ventricular (LV) diastolic filling in various clinical and experimental models. The influence of RV systolic function on LV diastolic performance was examined in patients with severe RV pressure overload. Eighty-two patients with pulmonary vascular or parenchymal disease who were referred for heart-lung or lung transplant evaluation were studied. All patients had radionuclide angiography from which RV ejection fraction and LV peak filling rate were measured. Most patients (n = 51) had right-sided cardiac catheterization. In 24 patients (group 1), RV ejection fraction was < 30%, whereas in 58 (group 2), it was > 30%. Mean pulmonary artery pressure was greater in group 1 than in 2 (57 +/- 16 vs 34 +/- 20 mm Hg; p < 0.0001). Pulmonary artery wedge pressure was also greater in group 1 than in 2 (14 +/- 9 vs 7 +/- 2 mm Hg; p < 0.0001), whereas peak filling rate was decreased (2.16 +/- 0.88 vs 2.97 +/- 0.79 end-diastolic volumes/s; p < 0.0001). LV ejection fraction was normal in all patients. There was an inverse relation between RV ejection fraction and pulmonary artery wedge pressure (r = 0.45; p < 0.001; SEE 5.3). There was a direct relation between RV ejection fraction and LV peak filling rate (r = 0.49; p < 0.0001; SEE 1.34). In patients with RV pressure overload, RV systolic function is related to LV diastolic performance. This effect is most likely mediated by ventricular interdependence.

Management of typical and dysplastic pulmonic stenosis, uncomplicated or associated with complex intracardiac defects, in juveniles and adults: use of percutaneous balloon pulmonary valvuloplasty with eight-month hemodynamic follow-up

To alleviate large fixed right ventricular (RV) outflow gradients, percutaneous balloon dilatation of pulmonic stenosis (PS) was performed in 38 patients with mean age of 14 +/- 14 years (median: 9 years, age range: 9 months to 63 years). There were 21 males and 17 females. Thirty-four patients had typical PS (5 of them also having other complex congenital cardiac anomalies, while 13 additional patients had a patent foramen ovale); 2 further subjects had subpulmonic, and 2 dysplastic pulmonary valvular obstructions. Sixteen patients were in the New York Heart Association (NYHA) Class I, 15 in Class II, 6 in Class III, and 1 in Class IV. Electrocardiographic (ECG) evidence of right ventricular hypertrophy (RVH) was present in 29 patients (76%); 3 patients had right bundle branch block (RBBB). For the entire group, there was a marked decrease in the mean systolic transpulmonic gradient in the immediate post-valvuloplasty period (from 97 +/- 43 to 26 +/- 17 mmHg; P < 0.0001). One patient expired 8 hours post-valvuloplasty (he was in the NYHA Class IV, and had severe RV failure). No other cardiovascular complications were encountered; the median hospital stay was 3 days (range: 1-10 days). At an 8-month follow-up, 12 patients who were reevaluated invasively had a median transpulmonic gradient of 27 mmHg (range: 5-92 mmHg) as compared to their pre-valvuloplasty values of 84 mmHg (range: 49-142 mmHg; P < 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Transcatheter treatment of pulmonary outflow tract obstruction: a review

The role of transcatheter methods in the management of pulmonary outflow tract obstruction are discussed in this review. Balloon pulmonary valvuloplasty for relief of isolated pulmonary valve stenosis has been successfully used by many investigators and is the procedure of choice for the management of these lesions. Supravalvar pulmonic stenosis, if discrete, can be relieved by balloon dilatation. Cyanotic children with interatrial right-to-left shunts secondary to severe valvar pulmonary stenosis respond in a manner similar to that observed with isolated pulmonary valve stenosis. In these patients, balloon valvuloplasty is the treatment of choice and may be corrective in most patients. In patients with interventricular right-to-left shunting secondary to pulmonary outflow tract obstruction and in patients with narrowed BT shunts, balloon dilatation may be an effective palliative procedure in a substantial proportion of patients obviating the need for an initial or second palliative shunt. Balloon dilatation is recommended if the patient's size or cardiac anatomy make them unsuitable for safe total surgical correction. In patients with pulmonary atresia, either initial opening of the atretic pulmonary valve by laser or by surgery with subsequent balloon dilatation are potentially beneficial in reducing the total number of surgical procedures that these children are likely to require. However, further clinical trials are needed before their general use.

Early improvement in left ventricular diastolic function after relief of chronic right ventricular pressure overload

Chronic right ventricular pressure overload is associated with left ventricular diastolic dysfunction. Whether or not an abrupt reduction in pulmonary artery pressure in patients with chronic pulmonary hypertension results in early improvement of left ventricular diastolic function is unknown. To assess this, the Doppler indexes of left ventricular diastolic function and echocardiographic measures of left ventricular volume were analyzed in 22 patients (age, 41 +/- 14 years, mean +/- SD) before and within 1 week after pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension. Mean duration of cardiopulmonary symptoms was 37 months (range, 4 months to 9 years). After operation, mean pulmonary artery pressure and pulmonary vascular resistance decreased (50 +/- 13 to 29 +/- 9 mm Hg and 904 +/- 654 to 283 +/- 243 dynes.sec/cm5, respectively, both p less than 0.001), pulmonary artery wedge pressure was unchanged (11 +/- 5 to 12 +/- 5 mm Hg), and cardiac index increased (2.0 +/- 0.5 to 2.8 +/- 0.7 l/min/m2 p less than 0.001). Left ventricular end-diastolic volume and stroke volume increased significantly (58.5 +/- 18.0 to 76.6 +/- 25.0 ml and 30.3 +/- 12.3 to 41.8 +/- 12.5 ml, respectively, both p less than 0.001) after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)