J Cardiol 2007 Jun; 49（6）: 367 – 368

Cardiovascular Imaging In-a-Month●Unusual Shunt Disease
Yoshiki

AKAKABE, MD

Tatsuya

KAWASAKI, MD

Michiyo

YAMANO, MD

HirokiSUGIHARA, MD

CASE
A 23-year-old man presented with palpitation. He had undergone surgical closureof an atrial septal defect at age 3 years. A grade Ⅲ ejection murmur was heard bestat the second right sternal border. Electrocardiography showed first-degree atrioventricular block with right bundle branch block. Chest radiography showed no cardiomegaly or pulmonary edema. The level of B-type natriuretic peptide was 9.7
pg/ml. Transthoracic echocardiographic examination was performed（Fig. 1）.

Fig. 1──────────────────────────────────────────────
松下記念病院 循環器科〔赤壁佳樹，川崎達也，山野倫代，杉原洋樹〕 : 〒 570−8540 大阪府守口市外島町 5−55
Department of Cardiology, Matsushita Memorial Hospital, Osaka
Address for correspondence : AKAKABE Y, MD, Department of Cardiology, Matsushita Memorial Hospital, Sotojima 5−55,Moriguchi, Osaka 570−8540 ; E-mail : kabe1024kami0924@gray.plala.or.jp
Manuscript received February 2, 2007 ; revised February 9, 2007 ; accepted March 28, 2007367

368

Akakabe, Kawasaki,Yamano et al

Point of Diagnosis
Transthoracic echocardiography indicated a left
ventricle to right atrium shunt（Fig. 1）. The pulmonary to systemic blood flow ratio was calculated
as 1.1. Subsequent transesophageal echocardiography demonstrated a direct communication from theleft ventricular outflow tract to the right atrium（Fig. 2）, known as the Gerbode defect, which is arare type of ventricular septal defect. 1）Specificmorphology of the defect foramen was not elucidated because surgical closure was not performed.
Holter monitoring showed frequent isolated premature ventricular contractions, which might havecaused his palpitations.
Gerbode defect is generally a congenital heartdisease, but is possibly acquired secondary to endocarditis.2）He had no documented previous historyof endocarditis. The operative procedure for atrial
septal defect remained unclear ; we cannot knowwhether the Gerbode defect was just coincidental toatrial septal defect. In the present case, echocardiography provided useful information in the diagnosisof this unusual shunt disease and in the decision on
therapeutic strategy. He has been doing well without any medication.
Diagnosis : Left ventricular-to-right atrial shunt（Gerbode defect）
Key Words : Heart septal defects ; Echocardiography,transthoracic
References
1）Gerbode F, Hultgren H, Melrose D, Osborn J : Syndromeof left ventricular-right atrial shunt ; successful surgicalrepair of defect in five cases, with observation of bradycardia on closure. Ann Surg 1958 ; 148 : 433−4462）Velebit V, Sch neberger A, Ciaroni S, Bloch A, Maurice J,Christenson JT, Simonet E, Schmuziger M : Acquired left
ventricular-to-right atrial shunt（Gerbode defect）after bacterial endocarditis. Tex Heart Inst J 1995 ; 22 : 100−102

Fig. 2Fig. 1 Transthoracic echocardiogram in the apical fourchamber view
Left : Color Doppler imaging. Right : Continuous
wave Doppler recording of shunt flow.
A high velocity flow is visible from the left ventricle
to the right atrium during systole.
LV ＝ left ventricle ; RA ＝ right atrium : LA ＝ left
atrium.

Fig. 2 Transesophageal echocardiograms
Left : Aorta level. Right : Left ventricular outflow
track level.
A shunt flow originates from the atrioventricular portion of the subaortic membranous septum and isdirected into the right atrium.
Ao ＝ aorta ; LVOT ＝ left ventricular outflow tract ;RV ＝ right ventricle. Other abbreviations as in Fig. 1.

J Cardiol 2007 Jun; 49（6）: 367 – 368