Kanji Iga MD, Hirokazu Kondou MD, Chisato Izumi MD,

Takashi Konishi MD

Key words; continuous murmur, PTMC, echo-Doppler

From Department of Cardiology, Tenri Hospital

200 Mishimacho, Tenri City, 632-8852, Japan

Address correspondence to:

Kanji Iga MD, Department of Cardiology, Tenri Hospital,

200 Mishimacho, Tenri City, 632-8552 Japan

E-mail: igakan@kcn.ne.jp

Fax 81-743-62-1903

A 74-year-old female was admitted to our hospital because of bradycardia due to digitalis intoxication. The patient had undergone percutaneous transvenous mitral commissurotomy 4 years ago. The left atrial pressure decreased to 12 mmHg at the end of the procedure and no continuous murmur was heard. On physical examination a grade 3/6 continuous murmur was heard over the 5th intercostal space at the right sternal border besides an apical diastolic rumbling murmur. The peak intensity of the murmur was around the S2 and was barely heard around the S1.

Transesophageal echocardiography revealed a tiny hole in the atrial septum and a continuous flow signal was seen from left atrium to right atrium through the hole with a peak velocity of 2m/sec (Fig.1). The continuous murmur disappeared when a #7 NIH catheter crossed the hole and was placed in the left atrium during cardiac catheterization. Mean left and right atrial pressures were 24 mmHg and 5mmHg respectively and the calculated mitral valve area was 1.2cm2 (Fig.2).

The maximal echo-Doppler velocity during a cardiac cycle coincided with the maximal intensity of the continuous murmur. The diameter of a #7 Fr catheter was sufficient to stop the left-to-right shunt. Although an uncomplicated atrial septal defect itself does not produce any murmur and the velocity is usually less than 1m/sec, the murmur in this patient was caused by an increased flow velocity through the hole implying increased left atrial pressure.

The long axis view of transesophageal echocardiograms showed a small hole in the atrial septum (right, arrow) and a color flow signal extended to the right atrium through the hole (left). (LA:left atrium, RA:right atrium,)

Fig. 2

A continuous wave Doppler echocardiogram showed increased flow velocity through all of the cardiac cycle. The maximal velocity coincided with the maximal intensity of the murmur (left). Simultaneous pressure recording of both left and right atrium showed a significant pressure gradient through all of the cardiac cycle. A prominent pressure gradient was present around the S2 because of the left atrial V wave peak (right).