Anomalous Papillary Muscle Attached to Left Ventricle Apex with Parallel Course to Interventricular Septum and Extending to Both Mitral Leaflets Accompanied by Large Ventricular Septal Defect.

Dear Sir,

A 13-year-old female teenager referred to our echocardiography laboratory for preoperative transthoracic echocardiography. The patient had history of pulmonary artery banding in early infancy because of large ventricular septal defect. Patient was asymptomatic except dyspnea on exertion New York Heart Association (NYHA) functional class II. In physical examination, systemic blood pressure was 113/73 mmHg. There was no significant peripheral or central cyanosis at rest and clubbing. Cardiac auscultation showed systolic murmur in left parasternal with V/VI severity. She was candidate for ventricular septal defect repair. Transthoracic echocardiography showed large outlet muscular ventricular septal defect (31 mm) with bidirectional shunt, functional pulmonary artery banding with peak pressure gradient = 95 mmHg, and right ventricular systolic pressure = 110 mmHg. The interesting finding was aberrant muscle bundle originating from apex, with parallel course to interventricular septum, with attachment to both mitral leaflets [Figure 1 and Videos 1–3]. Mitral valve had mild regurgitation and no stenosis. Also, there was no left ventricular outflow tract (LVOT) obstruction. This muscle bundle was posteromedial papillary muscle. Anomalous attachments of papillary muscles have been reported.[12] This abnormal attachment can produce LVOT obstruction,[3] but in the present case there was no LVOT obstruction or mitral regurgitation. Recently, Işılak et al.,[4] have reported a young female with perimembranous ventricular septal defect and accessory mitral papillary muscle, originating from anterolateral papillary muscle; and its chordae was parallel to the interventricular septum attaching to the anterior mitral leaflet. But in our case, ventricular septal defect was in outlet muscular septum and posteromedial papillary muscle originated from apex, with parallel course to interventricular septum, with attachment to both mitral leaflets. In patient with congenital heart disease, any congenital cardiac malformation can occur and any cardiac structure should be meticulously examined.

Figure 1

Anomalous papillary muscle attached to apex in apical two-chamber view (upper) and with parallel course to interventricular septum in parasternal short axis view (lower)