26 Hearts with Single-Ventricle Physiology
Definition and Classification
- So-called single-ventricle physiology refers to a situation in which both pulmonary and systemic circulations are maintained entirely or mainly by the work of one ventricle. Despite morphologic variations, fundamental hemodynamic physiology is similar and requires univentricular repair.
- Pathologic conditions that cause single-ventricle physiology (Fig. 26.1):
- • Double-inlet left ventricle (so-called single left ventricle)
- • Double-inlet right ventricle (so-called single right ventricle)
- • Double-inlet indeterminate ventricle (so-called common ventricle)
- • Absent right atrioventricular connection is synonymous with tricuspid atresia when the absent connection involves the morphologic right ventricle.
- • Absent left atrioventricular connection
- • Also included are the following:
- – Hypoplastic right heart with pulmonary atresia or critical stenosis (Chapter 17)
- – Hypoplastic left heart syndrome (Chapter 22)
- – Unbalanced atrioventricular septal defects
- In most cases there are two ventricular chambers present, with one well formed and a second rudimentary, although on occasion there are two equally dominant ventricles.
- Atrioventricular valves guarding the inlet can be two separate valves, one patent valve with one atretic valve or a common valve.
- Tricuspid atresia: often associated with left juxtaposition of the atrial appendages
- Great artery origins vary and may be concordant, discordant, or double outlet from the main or rudimentary chamber
- Great artery connections may be patent or obstructed
Fig. 26.1 Types of univentricular atrioventricular connections. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.