Case presentation
A 63 years-old woman was admitted at our institution in March 2020, with diagnosis of severe myxomatous mitral regurgitation. Pre-operative echocardiography showed a prolapse of both mitral leaflets and annular dilatation, preserved systolic function and normal kinesis. Coronary angiography was normal.
A mitral valve repair through a minimally invasive approach at the right fourth intercostal space was performed. Valve repair was achieved by posterior leaflet resection and annuloplasty with an open band (Futureband, Medtronic Inc.). Custodiol cardioplegia was used. No aortic insufficiency and good delivery of cardioplegia was assured. Cardiopulmonary bypass time was 114 minutes, and cross-clamp time was 82 minutes. Conversion to a full sternotomy was required due to a sudden bleeding caused by ruptured left atriotomy. No re-clamping was needed. Post-op transesophageal echocardiogram (TEE) showed good repair with only trivial mitral regurgitation and good cardiac function.
On the first post-operative day (POD), the patient suffered generalized tonic–clonic seizures. Haemodinamic instability occured and inotropic support was required (norepinephrine 0,08 mcg/Kg/min, epinephrine 0,04 mcg/Kg/min)
TEE showed a severely reduced left ventricle ejection fraction (30%). Basal segments appeared hyperkinetic while apical segments were hypo/akinetic with typical ballooning aspect, no SAM was reported. EKG showed diffuse ST elevation. Due to an increase of myocardionecrosis markers, coronary angiography was repeated, with no new findings. Then, Takotsubo Syndrome was suspected, and pharmacological hemodynamic support was continued, adding levosimendan at 0,1 mcg/Kg/min.
On the 6th POD severe hypotension re-occurred. TEE showed slight improvement in systolic function (LVEF 44%) with persistent apical akinesis but this time with persistent hyperkinesis of the base of the left ventricle causing a new onset of SAM of the anterior mitral leaflet with left ventricle outflow tract obstruction and severe mitral regurgitation [Figure 1]. Consequent pulmonary artery hypertension and right ventricle dysfunction complicated the clinical condition. No lung injury or pulmonary oedema were present.
Inhaled nitric oxide (NO) at 20 parts per million (ppm) and sildenafil IV were immediately added.
No extracorporeal membrane oxygenation (ECMO) was needed. Aggressive fluid administration was started despite the right ventricle dysfunction and IV Esmolol was titrated as soon as the hemodynamic condition allowed a progressive reduction of inotropes (norepinephrine 0,02 mcg/Kg/min, epinephrine 0,02 mcg/Kg/min). After slow iNO weaning the patient was maintained on Sildenafil infusion until the tenth POD and oral beta-blocker therapy with bisoprolol until discharge.
The patient gradually improved, and the 21st POD echocardiogram showed a recovered LVEF (55%), no SAM and only slight apical hypokinesia with mild mitral regurgitation [Figure 2]. After 5 days the patient was discharged for rehabilitation in good conditions.