Stunned Myocardium due to Decompensation from Hypovolemic Shock in a Pregnant Woman with Uterine Atony Following Cesarean Section

Abstract

Transient post ischemic left ventricular dysfunction has been called stunned myocardium. The stunned myocardium can lead cardiac problems such as arrhythmias, left ventricular dysfunction, and a myocardial infarction. Stunned myocardium is a reversible condition. In this case, a 25 year old female patient with a history of mild intermittent asthma became hypovolemic and got into shock after developing uterine atony following a cesarean section. The patient did not respond to rapid volume replacement therapy. Subsequently, the patient had acute pulmonary edema, hypotension, and tachycardia developed. Echocardiogram was done showing severe left ventricular dysfunction (ejection fraction (EF), 25-35%) with left inferobasal wall hypokinesis and no right ventricular dysfunction or severe tricuspid regurgitation or right ventricular hypertrophy. Chest x-ray showed newly diagnosed cardiomegaly and bilateral pulmonary congestion. Initial troponin I was elevated, however, the level of troponin I remained stable with the same baseline value. Patient was at high risk for pulmonary embolism (PE) based on risk assessment, therefore, anticoagulation was started. Chest CT for pulmonary embolism was performed, and the result was negative. Two days after, repeated echocardiogram showed improved EF was 35%. Patient was discharged with beta -blocker to reduce oxygen demand of myocardium. This case supports hypovolemic shock not responding to volume replacement therapy can cause myocardium damage which is able to be diagnosed with stunned myocardium. Keywords: Hypovolemic shock; Stunned myocardium; Pulmonary embolism Case ReportA 25 year old Hispanic female with history mild intermittent asthma was admitted for normal vaginal delivery. Obstetrician converted it to cesarean section due to severe bleeding secondary to uterine atony and inversion. Patient was already intubated for the cesarean section. Heart rate were 150/ min , O 2 saturation was 81% on FIO 2 100% , and systolic blood pressure was checked at 84 mmHg and diastolic was 40 mmHg, therefore, 2 units of packed red blood cell and 4 liters of Ringer lactate were given for hypovolemic shock secondary to bleeding. Blood pressure was not returned to normal range even if transfusion and intravenous fluid were given. Endotracheal tube position was checked by laryngoscopy, glydescope and fiber optic bronchoscopy. After completion of cesarean section in the operation room, patient was transferred to surgical intensive care unit (SICU) for post-surgical care. Patient was still tachycardic and hypotensive, therefore, patient was transferred to medical intensive care unit (MICU) for acute respiratory distress syndrome (ARDS) and presumed diagnosis of PE, which might be developed during cesarean section. Chest x-ray at that time showed bilateral pulmonary edema with cardiomegaly. Electrocardiogram (EKG) showed sinus tachycardia without specific ischemic changes (Figure 2). Initial troponin I was elevated up to 0.21, however, it was post-operative, moreover, the peak of troponin...