Austin Flint Murmur

A 73-year-old man with a history of hypertension was referred to hospital because of a heart murmur and an abnormal electrocardiogram (right bundle branch block and left ventricular [LV] hypertrophy) on medical checkup. On physical examination, a systolic ejection murmur and an early diastolic murmur were heard at the base of the heart, whereas the cardiac apex showed a diastolic rumble (Movie S1). Phonocardiography (Figure A) demonstrated systolic ejection murmurs in the high (H) and higher-middle (M2) frequency ranges (arrowhead) after the first sound (S1); of note, diastolic rumbling was recorded in the low (L) and lower-middle (M1) frequency ranges (arrows) after the second sound (S2). A diagnosis of severe aortic regurgitation, along with mild aortic stenosis, was made on echocardiography (Figure B; Table S1). The low-pitched diastolic rumble at the apex is known as the Austin Flint murmur,¹ a sign of severe aortic regurgitation that needs to be treated. Proposed mechanisms for this condition include vibration of the LV endocardium and turbulence of mitral inflow as a result of the regurgitant flow.² The Austin Flint murmur disappeared after surgical aortic valve replacement.

Figure.

(A) Phonocardiography. (B) Severe aortic regurgitation and mild aortic stenosis on echocardiography. Ao, aorta; H, high frequency; L, low frequency; LV, left ventricle; M1, low-middle; M2, high-middle; RA, right atrium; RV, right ventricle; S1, first sound; S2, second sound.

Disclosures

The authors declare no conflicts of interest.

Supplementary Files

Supplementary File 1

Movie S1. Heart sounds.

Supplementary File 2

Table S1. Echocardiographic variables

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-18-0697

References

• 1.   Flint A. On cardiac murmurs. Am J Med Sci 1862; 44: 29–54.
• 2.   Landzberg JS, Pflugfelder PW, Cassidy MM, Schiller NB, Higgins CB, Cheitlin MD. Etiology of the Austin Flint murmur. J Am Coll Cardiol 1992; 20: 408–413.