Hypoplastic Left Heart Syndrome: Prognostic Significance of Morphological Variants of the Heart in the Choice of Treatment Approach
Abstract
Hypoplastic left heart syndrome (HLHS) is one of the most complicated congenital heart defects which leads to the inevitable fatal outcome in the natural course of the disease. Currently, Norwood procedure and fetal aortic valvuloplasty are considered the major approaches for surgical treatment of HLHS. However, the prognosis of such surgeries is often unpredictable.
The aim. To study morphological variations of the left ventricle (LV) in HLHS and evaluate the prognostic significance of each of them in the choice of surgical approach.
Materials. The main group included 63 hearts of newborns with HLHS, the comparison group included 53 hearts of newborns without cardiac pathology.
Methods. The methods used were survey microscopy, as well as macro- and micromorphometry of various parameters of the heart, calculation of the ratio of their absolute values (indices) with subsequent statistical data processing.
Results. Five types of LV were identified in HLHS patients based on the size and shape of the cavity, wall thickness, presence or absence of fibroelastosis: slit-like hypoplastic (Type I) (n = 10; 15.9%); slit-like hypertrophic (Type II) (n = 19; 30.2%); cylindrical (Type III) (n = 22; 34.9%); lacunar (Type IV) (n = 6; 9.5% ); lacunar-cylindrical (Type V) (n = 6; 9.5%). In Type I left ventricles, the interventricular index (IVI) (the ratio of the areas of the free walls of the left and right ventricles on the cross sections of the heart) was the smallest: 0.13 ± 0.03 units versus normal 1.96 ± 0.31 units. In Type II left ventricles, the value was equal to 1.69 ± 0.23 units; in Type III it was 1.59 ± 0.64 units; in Type IV it was 1.31 ± 0.03 units; in Type V it was 1.05 ± 0.52 units. The index of the working area of the right ventricular myocardium (RVI) (the ratio of the area of the free wall of the right ventricle to the sum of the areas of the free wall and interventricular septum) in Type I LV was the highest: 81.3 ± 5.7% versus normal 57.1 ± 2.02%; in Type II it was 49.7 ± 6.4%; in Type III it was 39.8 ± 2.9%; in Type IV it was 69.7 ± 16.1%; in Type V it was 41.3 ± 24.4%.Type III–V LVs have always been associated with fibroelastosis, in contrast to Type I and II LVs.
Conclusions. In HLHS, Type I hearts are the most eligible for the Norwood procedure, since the LV, due to its minimal size, is not an excess ballast for the working right ventricle. Type II LV is optimal for the fetal aortic valvuloplasty, since during the II-III trimesters of gestation they can join the circulatory system due to remodeling. HLHS with LV fibroelastosis (Types III, IV, V) seem to be the least favorable for both pre- and postnatal surgery, especially in the presence of fibroelastosis of the right ventricle.
References
- Vogel M, McElhinney DB, Wilkins-Haug LE, Marshall AC, Benson CB, Juraszek AL, et al. Aortic stenosis and severe mitral regurgitation in the fetus resulting in giant left atrium and hydrops: pathophysiology, outcomes, and preliminary experience with pre-natal cardiac interven-tion. J Am. Coll. Cardiol. 2011;57:348-355. https://doi.org/10.1016/j.jacc.2010.08.636
- Allan LD, Sharland G, Tynan MJ. The natural history of the hypoplastic left heart syndrome. Int. J. Cardiol. 1989;25(3):341-343. https://doi.org/10.1016/0167-5273(89)90226-x
- Cole CR, Yutzey KE, Brar AK, Goessling LS, Van Vickle-Chavez SJ, Cunningham MW, et al. Congenital Heart Dis-ease Linked to Maternal Autoimmunity against Cardiac Myosin. The Journal of Immunology. 2014;192(9):4074-4082. https://doi.org/10.4049/jimmunol.1301264
- Hoffman J, Kaplan S, Liberthson R. Prevalence of con-genital heart disease. Am Heart J. 2004;147(3):425-439. https://doi.org/10.1016/j.ahj.2003.05.003
- Lee MG, Brizard CP, Galati JC, Iyengar AJ, Rakhra SS, Kon-stantinov IE, et al. Outcomes of patients born with sin-gle-ventricle physiology and aortic arch obstruction: the 26-year Melbourne experience. J. Thorac. Cardiovasc. Surg. 2014;148(1):194-201. https://doi.org/10.1016/j.jtcvs.2013.07.076
- Ahmed B, Stanojevic M, Kopjar T. Accuracy of the fetal echocardiography in the high risk pregnancies. Donald School. J. Obstetr. Gynecol. 2007;1(1):86-95. https://doi.org/10.5005/jp-journals-10009-1088
- Chew C, Halliday JL, Riley MM, Penny DJ. Population-based study of antenatal detection of congenital heart disease by ultrasound examination. Ultrasound Obstet. Gynecol. 2007;29(6):619-624. https://doi.org/10.1002/uog.4023
- Honjo O, Caldarone CA. Hybrid palliation for neonates with hypoplastic left heart syndrome: current strate-gies and outcomes. Korean Circ J. 2010;40(3):103-111. https://doi.org/10.4070/kcj.2010.40.3.103
- Grossfeld P. Hypoplastic left heart syndrome: new in-sights. Circulation Research. 2007;100(9):1246-1248. https://doi.org/10.1161/01.RES.0000268192.20525.c2
- Hasan BS, Keane JF, Tworetzky W, Lock JE, Marshall AC. Postnatal angiographic appearance of left ventricu-lar myocardium in fetal patients with aortic steno-sis having in-utero aortic valvuloplasty. Am. J. Cardiol. 2009;104(9):1271-1275. https://doi.org/10.1016/j.amjcard.2009.06.044
- Wilkins-Haug LE, Tworetzky W, Benson CB, Marshall AC, Jennings RW, Lock JE. Factors affecting technical success of fetal aortic valve dilation. Ultrasound Obstet. Gynecol. 2006;28(1):47-52. https://doi.org/10.1002/uog.2732
- Pedra SR, Peralta CF, Crema L, Jatene IB, da Costa RN, Pedra CA. Fetal interventions for congenital heart disease in Brazil. Pediatr Cardiol. 2014;35(3):399-405. https://doi.org/10.1007/s00246-013-0792-3
- Hraška V, Sinzobahamvya N, Haun C, Photiadis J, Arenz C, Schneider M, et al. The long-term outcome of open val-votomy for critical aortic stenosis in neonates. The Annals of Thoracic Surgery. 2012;94(5):1519-1526. https://doi.org/10.1016/j.athoracsur.2012.03.056
- Simpson JM, Sharland GK. Natural history and out-come of aortic stenosis diagnosed prenatally. Heart. 1997;77(3):205-210. https://doi.org/10.1136/hrt.77.3.205
- Axt-Fliedner R, Kreiselmaier P, Schwarze A, Krapp M, Gembruch U. Development of hypoplastic left heart syn-drome after diagnosis of aortic stenosis in the first tri-mester by early echocardiography. Ultrasound Obstet. Gynecol. 2006;28(1):106-109. https://doi.org/10.1002/uog.2824
- Zakharova V, Savchuk T, Rudenko O. Hypoplastic left heart syndrome: Structural changes of the left ventricular myo-cardium. Virchows Arch. 2013;463(2):198.
- Savchuk T. [Hypoplastic left heart syndrome: Morpho-genesis of patomorphological types of the left ventricle]. Georgian Medical News. 2020;2(229):55-61. Russian. PMID: 32242845
- Trembovetska OM, Knyshov GV, Zakharova VP, Rudenko OV, Moroz MM. [Dynamic characteristics morphological background of the heart left ventricle myocardium]. Heart and vessels. 2015;(3):51-60. Russian.
- Zakharova VP, Trembovetskaya TV, Savchuk TV, Batsak BV, Rudenko KV, Rudenko OV. [New aspects of the heart ventricular myocardium structure]. Heart and vessels. 2014;3:35-43. Russian.