Double Outlet Right Ventricle (DORV) — #1 Anatomy
A conal–septal malalignment spectrum in which LV egress is VSD-dependent and the VSD–great artery relationship becomes the “anatomic steering wheel.”
Double outlet right ventricle (DORV) is best approached as a family of ventriculo-arterial connection patterns, unified by predominant RV commitment of both arterial valves and a VSD that serves as the obligate LV exit [1–3]. Modern anatomic thinking emphasizes that DORV is, at its core, a disorder of conal (infundibular) development and alignment, and that many “borderline” phenotypes are best explained by the presence, distribution, and geometry of conal muscle rather than by a single numeric rule alone [4,5].
1) Core morphologic definition
DORV is diagnosed when both great arteries arise entirely or predominantly from the morphologic RV, commonly operationalized as >50% of each semilunar valve committed to the RV (“50% rule”) [1–3].
- Diagnosis type: a ventriculo-arterial connection diagnosis (where the arterial valves “sit”), not a physiologic diagnosis by itself [2].
- Practical implication: because the LV lacks direct continuity to a semilunar valve, LV egress becomes VSD-dependent [2,3].
2) Segmental description (make it reproducible)
A clean DORV description begins with a segmental set-up:
- Atrial situs (S / I)
- Ventricular loop (D / L)
- Great-artery relationship (normally related vs malposed; anterior–posterior and right–left relationships) [1,2].
This is why phenotypes such as [S, D, N] DORV are clinically useful: they “fix” the segmental framework first, then allow the conal/VSD anatomy to explain physiology and repair strategy [1,2].
3) The conal explanation
Normal reference (why the LV normally has a “direct” outlet)
In the normal heart, the aortic and mitral annuli are in fibrous continuity (aorto–mitral continuity), minimizing muscular interposition between LV inflow and outflow [2].
DORV principle (why LV outflow becomes VSD-dependent)
In DORV, there is often aorto–mitral discontinuity with muscular interposition—a reflection of abnormal conal development—creating an anatomic setting in which the LV cannot access a semilunar valve directly [2,4,5]. This is one reason the “conus” (infundibulum) concept remains central to understanding DORV variability and the feasibility of specific repairs [4,5].
Contemporary insight: cross-sectional imaging and patient-specific 3D/VR planning are increasingly used to evaluate baffle feasibility (“routability”) in complex conal geometries [4].
4) The obligate VSD: the LV “exit door”
Because LV egress is not directly to a semilunar valve, the VSD is obligatory and functions as the functional LV outflow tract [2,3].
Accordingly, classification starts with the VSD–great artery relationship:
- Subaortic VSD (VSD primarily aligned to the aortic valve) [2,8]
- Subpulmonary VSD (Taussig–Bing physiology) (VSD primarily aligned to the pulmonary valve) [2,7,10]
- Doubly committed VSD (VSD adjacent to both semilunar valves) [2,6]
- Remote / non-committed VSD (VSD distant from both semilunar valves; longer, more complex LV routing) [2,6,10]
One-liner: in DORV, the VSD is not “associated”—it is the anatomic determinant of LV egress and the primary map for physiology and repair [2,3].
5) Why anatomy predicts the operation (anatomy-to-repair logic)
DORV repair planning can be framed as two sequential, anatomy-first questions:
A) Can the LV be routed to the systemic outlet without obstruction?
- Committed VSD (subaortic/subpulmonary/doubly committed): often amenable to intraventricular tunneling to a target semilunar valve, depending on conal septum prominence and valve/chordal relationships [2,7,8].
- Remote/non-committed VSD: feasibility hinges on routability—path length, turns, potential LVOTO, and interference from AV valve tissue/chordae [2,6,10].
- Current practice trend: preoperative 3D evaluation is increasingly used to anticipate baffle geometry and obstruction risk in complex forms [4].
B) What must be done about RV outflow / pulmonary blood flow?
- Presence/absence of RVOT obstruction, need for RVOT reconstruction, or alternative outflow strategies substantially shifts the operation even within the same “DORV” label [6,7,9,10].
6) High-yield anatomic checklist (echo/CT/MRI + OR planning)
When documenting DORV in a “textbook-complete” way, include:
- VSD type: subaortic / subpulmonary / doubly committed / remote [2,3,6]
- Great-artery relationship: normally related vs malposed; relative positions [1,2,6]
- Outflow tract geometry: subaortic narrowing, RVOT/PS, arch anomalies [2,7,10]
- AV valve anatomy: straddling/overriding, chordal attachments that may block a tunnel [2,7]
- Ventricular adequacy: balance, hypoplasia, suitability for biventricular routing vs alternative pathways [7,9,10]
- Coronary anatomy: essential when strategies resemble arterial switch/double-root translocation concepts [2,6,10]
Closing concept
DORV is a conotruncal alignment spectrum: the “50% rule” defines the ventriculo-arterial commitment, but conal muscle development and its discontinuities explain the wide anatomic variability and the practical boundaries of biventricular repair [1,4,5]. The obligate VSD is the LV exit, and the VSD–great artery relationship remains the most reliable “steering wheel” for physiology and surgical strategy [2,3,6,7,10].
References (PubMed-verified)
[1] Anderson RH, Becker AE, Wilcox BR, Macartney FJ, Wilkinson JL. Surgical anatomy of double-outlet right ventricle--a reappraisal. Am J Cardiol. 1983;52(5):555-559. doi:10.1016/0002-9149(83)90025-5. (PubMed)
[2] Walters HL 3rd, Mavroudis C, Tchervenkov CI, Jacobs JP, Lacour-Gayet F, Jacobs ML. Congenital Heart Surgery Nomenclature and Database Project: double outlet right ventricle. Ann Thorac Surg. 2000;69(4 Suppl):S249-S263. doi:10.1016/S0003-4975(99)01247-3. (PubMed)
[3] Urbina T, Graham B, Tang R, Wilson SD, Sanchez Mejia AA, Gowda SH. Congenital Conundrum: Unraveling the Puzzle of Double Outlet Right Ventricle for the Neonatologist. Neoreviews. 2025;26(7):e477-e489. doi:10.1542/neo.26-7-034. (PubMed)
[4] Josowitz R, Rogers LS. Double outlet right ventricle - the 50% rule has always been about the conus. Curr Opin Cardiol. 2024;39(4):348-355. doi:10.1097/HCO.0000000000001131. (PubMed)
[5] Walters HL 3rd. Conuses and discontinuities: To be or not to be in double-outlet right ventricle. J Thorac Cardiovasc Surg. 2017;154(2):605-606. doi:10.1016/j.jtcvs.2017.04.006. (PubMed)
[6] Pang KJ, Meng H, Hu SS, Wang H, Hsi D, Hua ZD, Pan XB, Li SJ. Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle. Tex Heart Inst J. 2017;44(4):245-251. doi:10.14503/THIJ-16-5759. (PubMed)
[7] Kleinert S, Sano T, Weintraub RG, Mee RB, Karl TR, Wilkinson JL. Anatomic features and surgical strategies in double-outlet right ventricle. Circulation. 1997;96(4):1233-1239. doi:10.1161/01.CIR.96.4.1233. (PubMed)
[8] Takeuchi K, Del Nido PJ. Surgical management of double-outlet right ventricle with subaortic ventricular septal defect. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2000;3:34-42. doi:10.1053/tc.2000.6042. (PubMed)
[9] Artrip JH, Sauer H, Campbell DN, Mitchell MB, Haun C, Almodovar MC, Hraska V, Lacour-Gayet F. Biventricular repair in double outlet right ventricle: surgical results based on the STS-EACTS International Nomenclature classification. Eur J Cardiothorac Surg. 2006;29(4):545-550. doi:10.1016/j.ejcts.2005.12.038. (PubMed)
[10] Villemain O, Belli E, Ladouceur M, Houyel L, Jalal Z, Lambert V, Ly M, Vouhé P, Bonnet D. Impact of anatomic characteristics and initial biventricular surgical strategy on outcomes in various forms of double-outlet right ventricle. J Thorac Cardiovasc Surg. 2016;152(3):698-706.e3. doi:10.1016/j.jtcvs.2016.05.019. (PubMed)