J Korean Soc Radiol.  2016 Mar;74(3):195-198. 10.3348/jksr.2016.74.3.195.

Incidental Finding on Cardiac CT of Anomalous Anterior Papillary Muscle without Left Ventricular Outflow Obstruction: A Case Report

• Kang EJ
• Lee J
• Lee KN

• KMID: 2155280
• DOI: http://doi.org/10.3348/jksr.2016.74.3.195

Abstract

Abnormal insertion of the papillary muscles is rare and has been described only in patients with hypertrophic cardiomyopathy based on findings of echocardiography or autopsy. Herein, we reported a rare case of abnormal insertion of the papillary muscle in a 64-year-old man without cardiomyopathy, incidentally detected by cardiac computed tomography (CT). Multiplanar long-axis and three-dimensional volume-rendered reconstructed images revealed an abnormally inserted papillary muscle, which did not provoke left ventricular outflow tract obstruction. This is the first report of the anomaly in a healthy individual who was initially assessed by cardiac CT.

MeSH Terms

Autopsy
Cardiomyopathies
Cardiomyopathy, Hypertrophic
Echocardiography
Heart
Humans
Incidental Findings*
Middle Aged
Papillary Muscles*
Ventricular Outflow Obstruction*

Figure

• 

  Fig. 1 A 64-year-old man with anomalous insertion of the anterior papillary muscle that is incidentally detected on cardiac CT. A. Short-axis view acquired during the systolic phase shows elongated anterior papillary muscle (arrowhead) in close proximity to the left ventricular outflow tract (LVOT). B, C. Long-axis images acquired during the systolic phase reconstructed perpendicular to the short axis plane with passes through the anterior papillary muscle (broken lines B and C in A). The elongated anterior papillary muscle inserts directly into the basal portion of the anterior mitral leaflet without interposed chordae tendineae (white arrows), producing LVOT narrowing. There are several chordae tendineae normally attached to the anterior mitral leaflet and lateral free wall of the left ventricle (white arrowheads). D. Long-axis image acquired during the systolic phase reconstructed perpendicular to the short axis plane in the midcavity without traversing the anterior papillary muscle (broken line D in A) shows a wide-open LVOT without narrowing. E, F. Three-dimensional volume-rendered long-axis views of the midcavity at diastole (E) and systole (F). The anterior papillary muscle is displaced anteriorly within the left ventricular cavity at diastole (E). However, there is no evidence of LVOT obstruction at systole (F). Ao = aorta, CT = computed tomography, LA = left atrium, P = anterior papillary muscle

Reference

1. Klues HG, Roberts WC, Maron BJ. Anomalous insertion of papillary muscle directly into anterior mitral leaflet in hypertrophic cardiomyopathy. Significance in producing left ventricular outflow obstruction. Circulation. 1991; 84:1188–1197.

2. Zimbarra Cabrita I, Grapsa J, Dawson D, Pinto FJ, Gibbs JS, Nihoyannopoulos P. Anomalous insertion of the papillary muscle in a patient with sickle cell disease: a normal variant with no left ventricular outflow obstruction. Rev Port Cardiol. 2012; 31:683–684.

3. Strajina V, Živković V, Nikolić S. Anomalous anterior papillary muscle as an autopsy finding in two cases. J Forensic Sci. 2013; 58:544–547.

4. Christner JA, Kofler JM, McCollough CH. Estimating effective dose for CT using dose-length product compared with using organ doses: consequences of adopting International Commission on Radiological Protection publication 103 or dual-energy scanning. AJR Am J Roentgenol. 2010; 194:881–889.

5. Wenink AC, Gittenberger-de Groot AC, Brom AG. Developmental considerations of mitral valve anomalies. Int J Cardiol. 1986; 11:85–101.

6. Teal SI, Moore GW, Hutchins GM. Development of aortic and mitral valve continuity in the human embryonic heart. Am J Anat. 1986; 176:447–460.

7. Del Guzzo L, Sherrid MV. Anomalous papillary muscle insertion contributing to obstruction in discrete subaortic stenosis. J Am Coll Cardiol. 1983; 2:379–382.

8. Chen JJ, Manning MA, Frazier AA, Jeudy J, White CS. CT angiography of the cardiac valves: normal, diseased, and postoperative appearances. Radiographics. 2009; 29:1393–1412.

9. Yamamuro M, Tadamura E, Kubo S, Toyoda H, Nishina T, Ohba M, et al. Cardiac functional analysis with multi-detector row CT and segmental reconstruction algorithm: comparison with echocardiography, SPECT, and MR imaging. Radiology. 2005; 234:381–390.