Abstract 10259: A Case of Mitral Annulus Disjunction Highlighting a Disjunction in Our Knowledge

A 56-year-old female patient was brought to our hospital after she suffered a witnessed cardiac arrest while flying on an airplane. She underwent bystander (in the aisle) CPR for about 20 minutes while forcing the plane to land. Altogether, she received seven shocks via AED. At the time of our evaluation, she was alert and in no distress. She did not carry a family history of SCD but reported “she had an issue with heart valve”. Her initial ECG showed atrial fibrillation with a heart rate of 135 bpm, QTc of 515 ms and no findings suggestive of myocardial injury. Her initial workup showed a potassium level of 3.2 mmol/L and no other significant laboratory abnormalities. Her TTE revealed thickened mitral valve leaflets with bileaflet prolapse and severe (4+) central MR. In addition, mitral annular disjunction (MAD) was noted. Her LVEF was 65% with normal wall motion. A left heart catheterization demonstrated normal coronary arteries. Following, a cardiac MRI confirmed MAD at the P3 scallop only, dilated mitral annulus and with a disjunction gap of 7 mm. Furthermore, there was no intramyocardial or annular late gadolinium enhancement (LGE) noted. An ICD was implanted for secondary prevention and she was then referred for mitral valve repair. With this case, we aim at increasing awareness of MAD and SCD. Currently, clinicians rely mostly on anecdotal evidence. While there is increasing literature suggesting the arrhythmogenic nature of MAD, the pathophysiology and implications are still debated. Interestingly, a subject of recent debate, our patient did not have any LGE suggesting no scar/fibrosis that would serve as a nidus for ventricular arrhythmias. Further, a threshold disjunction gap distance of clinical significance has yet to be determined. The benefit of surgical correction remains unclear. Indeed, further prospective studies are required to delineate MAD and help guide early management and its’ ultimate impact on prognosis