1Vivantes Klinikum im Friedrichshain Klinik für Innere Medizin - Kardiologie und konserv. Intensivmedizin Berlin, Deutschland
A 23 year old man was admitted to the intensive care department following out of hospital cardiac arrest. The initial rhythm was ventricular fibrillation. Following 15 minutes of reanimation including multiple defibrillations and iv adrenalin, the patient had return of spontaneous circulation and a stable sinus rhythm. The patient did not have any relevant medical or family history. ECG was unremarkable, initial echocardiography revealed mildly imparied left ventricular (LV) function with mild mitral regurgitation. The patient was intubated, cooled, and made a rapid neuroloical recovery following warming.
The patient underwent cardiac magnetic resonance imaging (CMR), which demonstrated mild LV dilatation, mildly impaired LV function, bileaflet mitral valve prolapse with mild regurgitation, and mitral annulus dysjunction (MAD) - typically defined as "the absence of myocardium during systole between the MV annulus and the adjacent segment of the left ventricular wall". T1, T2 mapping were normal, and there was no evidence of scarring or fibrosis on late gadolinium enhancement imaging. Trans-esophageal echocardiography (TEE) confirmed the bileaflet mitral prolapse and mild-moderate regurgitation. Coronary angiography was normal.
MAD is an increasingly recognised condition, and is associated with malignant cardiac arrythmia. In the absence of additional mitral valve disease, it can be easily overlooked. Techniques with increased spatial resolution, including CMR or cardiac computed tomography (CT) are more sensitive to detect the anomaly. In addition, CMR can be used to detect scarring, which is associated with a higher risk of life threatening arrythmia. CMR can also be used to measure LV volumes and quantify the degree of mitral regurgitation.
The natural history of mitral valve prolapse is variable, with a low risk of malignant arrythmia. MAD has been shown to increase this risk, particularly in patients with papillary muscle fibrosis on CMR. MAD is also associated with more severe mitral leaflet deformity and increased LV enlargement.
As the mitral regurgitation was mild in this patient, no intervention on the valve was required. The patient was commenced on heart failure therapy, and an cardiac defibrillator was implanted for secondary prevention. The patient will return for annual echocardigraphy to assess the progress of the mitral valve prolapse.