4D Flow in evaluation of transitional atrioventricular septal defect. A Case Report.

Presenting Author(s)

• FF

  Felipe Sebastian Figueroa, MD

  Research Intern
  National Institute of Cardiology "Ignacio Chavez"
  Mexico City, Mexico City, Mexico

Primary Author(s)

• MG

  Maria Fernanda Gonzalez

  Research Intern
  Instituto Nacional de Cardiología, Mexico

Co-Author(s)

• SP

  Sergio Alfonso Patron-Chi, MD

  Pediatric Cardiology and Cardiovascular Imaging
  National Institute of Cardiology, Distrito Federal, Mexico
• AM

  Aloha Meave gonzalez, MD

  Chair cardiac magnetic resonance
  Instituto Nacional de Cardiología Ignacio Chávez
  Mexico city, Distrito Federal, Mexico
• MC

  Miguel Cruz, MD

  Medical physician of cardiac magnetic resonance
  National Institute of Cardiology "Ignacio Chávez"
  CDMX, Distrito Federal, Mexico

Description of Clinical Presentation: A 42 y/o male, with a history of shortness of breath and cyanosis was evaluated for diagnosis. Physical examination with splitting of S1, and S2 with increased P2 component, with presence of a murmur due to pulmonary hyperflow. Mitral murmur was found.

History of atrioventricular defect and systemic hypertension for 7 years under treatment. Referred for preconsultation due to presumable ostium primum atrial septal defect (ASD) with bidirectional defect with high probability of pulmonary hypertension. Currently under prophylactic antiarrhythmic treatment without evidence of flutter or atrial fibrillation.

Diagnostic Techniques and Their Most Important Findings: ECG findings were: Complete right bundle branch block (RBBB) with horizontal orientation, rightward deviation, ST-segment and T-wave alterations expected due to RBBB.

Echocardiogram was performed showing a partial AVSD with mild right AV valve regurgitation, biatrial dilation, and a primum-type atrial septal defect, with bidirectional shunt.

Cardiac Magnetic Resonance (CMR) was performed showing an AVSD-transitional type, with a common AV valve with severe regurgitation of the right portion. Also a ostium-primum ASD and a large VSD almost occluded with subvalvular tissue of the common valve, and dilation of the trunk and branches of the pulmonary artery. 4D flow was an excellent tool for evaluation of the shunt at all levels and helped to identify the flow dynamics in this complex congenital heart disease.

Learning Points from this Case:

• 
  The presence of RBBB and the deviation of the axis are classic electrocardiographic findings in the context of congenital heart disease, which may indicate possible overload.
  
  


• 
  The use of echocardiography as an initial diagnostic method, while helpful in documenting the presence of septal defects and AV valve regurgitation. Nevertheless it is limited to providing a detailed structural description of the defect.
  
  


• 
  4D flow not only indicated that the VSD was partially occluded by subvalvular tissue, but also demostrated the presence of residual flow through it, which would have gone unnoticed during the echocardiogram. It also allows the measurement of the regurgitant volume of the left AV valve, and mapping of the flow jet shunt through the ASD and residual VSD, revealing a bidirectional shunt. Without it, the transitional AVSD might have been misclassified as “partial” AVSD.
  
  

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