Unusual Case of Interventricular Septal Dissection with Defects Following Anterior Myocardial Infarction.

A 58-year-old man complaining of squeezing chest pain over the last 12 h was referred to our emergency department. An initial 12-lead electrocardiography revealed a Q wave and ST elevation in leads V1 to V4 (Fig. 1). Cardiac enzymes (e.g., troponin I 50 ng/mL [0.000-0.016]) were elevated. An emergent coronary angiogram revealed total occlusion of the proximal left anterior descending (LAD) coronary artery, and percutaneous coronary intervention (PCI) with drug-eluting stent implantation in the proximal LAD was performed (Fig. 2).

FIG. 1

Initial 12-lead electrocardiography shows ST elevation and a Q wave in leads V1-V4, as well as a premature ventricular beat.

FIG. 2

Coronary angiography reveals total occlusion of proximal left anterior descending coronary artery (LAD) (arrow) (A) and a normal right coronary artery (B). Percutaneous coronary intervention with everolimus-eluting stent implantation (3.0×38 mm, Synergy XD™, Boston Scientific, Marlborough, MA) in the proximal LAD is performed (triangle) (C).

The patient suddenly collapsed 6 h after PCI. He complained of chest pain, and diaphoresis and resting dyspnea were noted. His blood pressure was 70/40 mmHg, and a loud pansystolic murmur at the lower sternal border was auscultated. Portable echocardiography revealed akinesis of the apex with a dissecting interventricular septum and an apical septal defect with left-to-right shunting on color Doppler (Fig. 3). The patient subsequently underwent a successful bovine pericardial patch repair of the ventricular septum defect. He followed an uneventful postoperative course and was discharged on the 14th hospital day.

FIG. 3

Transthoracic echocardiogram with color Doppler showing a clear jet flow entering the dissecting interventricular septum (asterisk) (A) in apical four-chamber view (B) and subcostal view (C). A shunt flow from LV to RV through the dissected septum (white arrow) is shown in modified apical four-chamber view. LA: left agrium, LV: left ventricle, RA: right atrium, RV: right ventricle.

Interventricular septal dissection complicated by left-to-right shunting is an extremely rare complication of acute myocardial infarction.1 Shunt flow was not seen in the standard view (Fig. 3A, B), but visualized when the probe was tilted slightly (Fig. 3C). Short time-delays between symptom onset, echocardiographic diagnosis, hemodynamic support, and definitive surgery were associated with survival.2 Early diagnosis and prompt surgical intervention are critical for improving prognosis.3