Acute rupture of anterior papillary muscle of mitral valve – emergency institution of cardiopulmonary bypass in the ICU

History

A 51-year-old male patient, known case of hypertension, hyperlipidemia, and diabetes mellitus type II (not on regular medication), presented to another hospital after collapse at work. He was having chest pain for previous 3 days, had not sought any help, till he collapsed. In the Emergency room he was having acute shortness of breath and hypoxia. He was intubated in the Emergency Room. He had a massive pulmonary edema. His investigations showed highly elevated cardiac markers (Tro-ponin T > 3000 pg/mL and Pro BNP > 3000 pg/mL). He was taken up for coronary angiogram, which showed triple vessel disease with acute thrombosis of RCA. Balloon Angioplasty was done to RCA. In view of his cardiogenic shock and severe hypo-tension, despite heavy inotropic support (Nor Adrenaline and Adrenaline), he was put on IABP. As his condition did not improve, cardiac surgery team at Burjeel was consulted and immediate transfer was advised. On arrival, he was in renal shut-down and was developing hepatic dysfunction. Acidosis persisted and despite corrective measures and adjusting ventilator parameters, his condition deteriorated. He was given multiple doses of Phe-nylephrine injection and a Methyl-ene Blue infusion was started. His heart rate remained above 140/min. Transthoracic echocardiogram showed fair right and left ventricular contractility. Despite very poor prognosis for any intervention, the relatives granted permission and requested to go ahead with any procedures. A bedside VA ECMO was instituted with centrifugal pump through femoral cannulation. He developed VT & VF, during the procedure, needing defibrillation. Gradually he got stabilized with ECMO, the heavy dose of inotropic support could be reduced with mean pressure of 60-65 mmHg. His heart rate came down to 70-80/min in normal sinus rhythm. TEE was done. Severe Mitral Regurgitation was observed with anterior papillary muscle rupture. His condition was explained to the relatives. In view of the refractory cardiogenic shock, unstable hemodynamics, despite IABP and ECMO, it was decided to proceed for Emergency CABG + MVR as a desperate life-saving measure.

Surgical Procedure

Intra Operatively ECMO was converted to Cardio Pulmonary Bypass. CABG x 3 and Mitral Valve was replaced with 25mm size CE bioprosthetic valve. As anticipated, he had difficulty in coming off cardiopulmonary bypass; hence, VA ECMO was reinstituted through the same femoral access, which was used for CPB.

He had significant bleeding for the next 24 hours on ECMO. He had persistent refractory hyperkalemia (serum potassium above 8 mmol/L). It did not respond to conventional measures to lower the potassium. CRRT was started in the ICU. Patient gradually worsened despite ECMO, IABP and heavy inotropes and expired on the 4th post-operative day.

Conclusion

1) Quick action is needed in saving patients with post infarct papillary muscle rupture and cardiogenic shock. In this patient, papillary muscle rupture and resultant acute severe MR could, unfortunately, be recognized only afer the patient was stabilized on ECMO, with his heart rate settling and with the help of TEE.

2) Multi-organ failure sets in very fast worsening the outcome and hence timely intervention is essential to salvage the myocardium and the patient.

3) The team should be prepared to take care of the very sick patient in the post-op period.

4) Family should be briefed about the situation and possible worst outcome.

In this patient, earlier ECMO might have helped to save the patient. In its absence at the referral unit, a mobile retrieval ECMO unit from our institution could have made it possible. Unfortunately such a mobile team was not existent at that time. Since then we have instituted the same.

Cardiogenic shock