What is Double Inlet Left Ventricle?

The Double Inlet Left Ventricle (DILV) defect is congenital and affects the valves and chambers of the heart. In a normal heart, the mitral valve leads into the left ventricle and the tricuspid valve leads into the right ventricle. However, in hearts with DILV, both the mitral valve and the tricuspid valve lead into the left ventricle.1 Therefore, only the left ventricle works and the right ventricle becomes small and underdeveloped, unable to pump blood to the lungs as it typically would.2 So, oxygen-rich and oxygen-poor blood mix together in the heart and it is pumped throughout the body. Patients with DILV often have other heart problems as well.2, 3

These can include:2, 3

  • Narrowing of the aorta, the main vessel delivering oxygenated blood to the body (Coarctation of the aorta)

  • Pulmonary valve of the heart is not formed properly (Pulmonary atresia)

  • Narrowing of the pulmonary valve (Pulmonary valve stenosis)

Underdeveloped right ventricle, that is hypoplastic and does not pump blood through the heart well. 

Double Inlet: both the mitral valve and the tricuspid valve lead into the left ventricle

Symptoms

  • Tires easily (fatigue)

  • Blue or purple tinted skin, lips, or fingernails (cyanosis)

  • Difficulty feeding

  • Difficulty gaining weight

  • Fast breathing (tachypnea)

  • Swelling in the legs and abdomen (edema)

  • Heart murmur

  • Heart failure

  • Fast heartbeat (tachycardia)

  • Sweating

Diagnosis

Doctors typically diagnose this defect using a fetal echocardiogram while the baby is still in the womb.1 This ultrasound uses sound waves to view and make pictures of a baby’s developing heart. In newborns, diagnosis is usually by:1-4

Echocardiogram (Echo)

Cardiac MRI

Chest X-ray (CXR)

Electrocardiogram (EKG)

Cardiac Catheterization

Treatments

Surgery is required to improve blood circulation through the body and into the lungs.3 The most common surgeries used are similar to the ones used to treat HLHS and TA. While these surgeries happen typically at the time frames indicated, the exact timing of each surgery is dependent on the patient, their symptoms, and the severity of SVD. The patient will typically receive the Norwood procedure (within the first few weeks), the Hemi-Fontan/Glenn procedure (4-6 months range), and the Fontan procedure (2-3 years old). 1-3

Additional Resources

References

  1. Seattle Children’s Hospital. Double-Inlet Left Ventricle. Seattle Children’s Hospital. Accessed December 15, 2024. https://www.seattlechildrens.org/conditions/double-inlet-left-ventricle/

  2. Cleveland Clinic. Double Inlet Left Ventricle. Cleveland Clinic. October 27, 2022. Accessed December 15, 2024. https://my.clevelandclinic.org/health/diseases/14786-double-inlet-left-ventricle

  3. Medline Plus. Double inlet left ventricle. Medline Plus. Accessed December 15, 2024. https://medlineplus.gov/ency/article/007327.htm

  4. P Syamasundar Rao. Double-Inlet Left Ventricle. National Library of Medicine. August 24, 2022. Accessed December 15, 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC9497213/