Author + information
- Received April 17, 2017
- Revision received May 11, 2017
- Accepted May 23, 2017
- Published online July 21, 2017.
- aDepartment of Cardiovascular Medicine, Hartford Hospital, Hartford, Connecticut
- bUniversity of Connecticut School of Medicine, Farmington, Connecticut
- ↵∗Address for correspondence:
Dr. Musa A. Sharkawi, Department of Cardiovascular Medicine, Hartford Hospital, University of Connecticut School of Medicine, 80 Seymour Street, Hartford, Connecticut 06102.
Obstruction of the left ventricular outflow can be caused by several lesions. These are classified by location as subvalvular, valvular, or supravalvular. Subvalvular aortic stenosis, which may have a dynamic component, may be due to a fibrous membrane, muscular obstruction, or a combination of the 2 (1,2).
A 61-year-old Caucasian woman with a background medical history significant for hypertension and anxiety presented with worsening dyspnea on exertion, chest tightness, and palpitations. An echocardiogram revealed left ventricular (LV) hypertrophy with asymmetric septal hypertrophy (20 mm), systolic anterior motion of the anterior mitral leaflet, LV ejection fraction of 70%, along with evidence to suggest a subaortic membrane. Dynamic LV outflow tract (LVOT) obstruction with a peak gradient at rest of 73 mm Hg was observed that worsened with Valsalva to 123 mm Hg. There was no aortic valve stenosis (Figure 1, Online Videos 1 and 2).
She was referred for cardiac catheterization, which revealed normal coronary arteries. Left ventriculography suggested a subaortic membrane as well as a hyperdynamic LV (Figure 2, Online Video 3). Simultaneous hemodynamic tracings between the LV and aorta were measured using a Langston dual-lumen pigtail catheter (Vascular Solutions, Minneapolis, Minnesota). This revealed 2 distinct sites of obstruction within the LV: the first, in the LV cavity proximal to the LVOT, resulting in a peak-to-peak gradient of 173 mm Hg between the LV cavity and the aorta (Figure 3), and the second within the LVOT with a peak-to-peak gradient of 37 mm Hg between the aorta and LVOT (Figure 4). Further dynamic increase in gradient >200 mm Hg was observed between the proximal LV and aorta after premature ventricle contractions consistent with the Brockenbrough-Braunwald-Morrow Sign (Figure 3) (3). In this case, a dual diagnosis of hypertrophic obstructive cardiomyopathy and subaortic membrane was confirmed. The patient was referred for surgical correction.
As a technical note, although a dual-lumen multipurpose (MPA2) catheter (2 distal side holes) may be more precise than a pigtail catheter (5 distal side holes) in localizing the sites of pressure differences when measuring an intracavitary gradient in the LV, as well as reducing the likelihood of causing ventricular ectopy from contact with the endocardium, the latter is safer when performing a left ventriculogram.
For supplemental videos and their legends, please see the online version of this article.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received April 17, 2017.
- Revision received May 11, 2017.
- Accepted May 23, 2017.
- 2017 American College of Cardiology Foundation
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