Noninfectious Mitral Annular Disruption
An Unusual Complication of a 25-Meter Fall
A previously healthy 35-year-old man fell from a height of 25 meters while pruning a tree. His fall was somewhat slowed by the untrimmed tree branches. The ground impact focused on the right thorax and axilla, with resultant closed head injury, right clavicular fracture, and multiple right-sided rib fractures with pneumo- and hemothorax. Emergent tube thoracotomy, tracheotomy, and orthopedic interventions were conducted. The patient’s 10-day hospital course was notable for steady improvement, and, other than for a mild traumatic brain injury, he felt well on discharge. Prior to discharge, a loud holosystolic murmur, consistent with mitral regurgitation, was auscultated. The patient remained afebrile and there was no evidence of heart failure or systemic embolic phenomena. A transthoracic echocardiogram done during the admission was suggestive of severe mitral regurgitation, but images were technically suboptimal. The patient was eventually referred to our facility for transesophageal imaging and a consultation for the question of mitral valve repair. At the time of our evaluation, 6 months after the accident, he reported no cardiopulmonary symptoms and was able to hike 5 to 7 miles without dyspnea or fatigue. A screening transthoracic echocardiogram had been done 5 years before the accident because of a family history of cardiomyopathy, and was normal, without evidence of valvular pathology.
A transesophageal echocardiogram showed intact mitral leaflets, without evidence of endocarditis or paravalvular abscess (Movie I in the online-only Data Supplement). However, there was marked disruption and fistulization of the anterior mitral annulus with a 9 × 7 mm irregularly shaped opening at the base of the A2/A3 mitral valve scallops (Figure A and B, Movies II and III in the online-only Data Supplement). There was systolic left ventricular-to-left atrial flow through the fistula (Figure C, Movie IV in the online-only Data Supplement); its Doppler signal was characteristic of mitral regurgitation (Figure D). Biventricular cavity size, systolic function, and estimated pulmonary artery systolic pressure were within normal limits.
In summary, these findings demonstrated a left ventricular to left atrial fistula through the anterior mitral annulus, acquired as a result of rapid deceleration injury from a fall. Because the patient was free of cardiovascular symptoms, and the probability of the need for valve replacement during repair was high, the recommendation was made to delay primary repair of the defect until the onset of symptoms or standard echocardiographic signs of left ventricular decompensation. Frequent clinical and echocardiographic follow-up was scheduled.
Disruption of the mitral annulus is well described as a consequence of (1) infective mitral endocarditis with paravalvular abscess formation1 and (2) cardiac surgery, usually, mitral or aortic valve replacement.2 Cardiac trauma as a result of a fall from heights is likewise well described and is frequently fatal, because it typically involves rupture of the atrial or ventricular free wall with rapid exsanguination. In other types of cardiovascular deceleration injury, such as that resulting from motor vehicle accidents, disruption of the most anterior cardiac structures is most frequently seen: avulsion of the tricuspid valve, aortic disruption, and right ventricular contusion.3,4 In case of aortic disruption, the ligamentum arteriosum is thought to serve as a rigid anchor, while the surrounding tissues continue in motion on impact, thus shearing the aorta. Likewise, in our patient, the fibrous skeleton of the heart at the confluence of the aortic and mitral valves presumably served as an anchor, while the valve apparatus itself continued motion. This discrepancy resulted in shear injury and fistulization of the anterior mitral annulus. To our knowledge, we describe the first case of survivable traumatic disruption of the mitral annulus.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.115.016737/-/DC1.
- © 2015 American Heart Association, Inc.