Dynamic thromboembolic left ventricular outflow tract obstruction after aggressive procoagulant treatment in hemorrhagic shock: a case report.

BACKGROUND: In cases of hypertrophic obstructive cardiomyopathy (HOCM), the systolic anterior motion of the mitral valve apparatus results in an obstruction of the left ventricular outflow tract (LVOT), which is known as the SAM [systolic anterior motion] phenomenon. Hypothetically, a pathological obstruction of the LVOT of a different etiology would result in a comparable hemodynamic instability, which would be refractory to inotrope therapy, and may be detectable through echocardiography. CASE PRESENTATION: We observed a severely impaired left ventricular function due to a combination of a thrombotic LVOT obstruction and distinctive mitral regurgitation in a 56-year-old Caucasian, female patient after massive transfusion with aggressive procoagulant therapy. Initially, the patient had to be resuscitated due to cardiac arrest after a long-distance flight. The resuscitation attempts in combination with lysis therapy due to suspected pulmonary artery embolism were initially successful but resulted in traumatic liver injury, hemorrhagic shock and subsequent acute respiratory distress syndrome (ARDS). Oxygenation was stabilized with veno-venous extracorporeal membrane oxygenation (ECMO), but the hemodynamic situation deteriorated further. Transesophageal echocardiography (TEE) showed a massive, dynamic LVOT obstruction. Two thrombi were attached to the anterior leaflet of the mitral valve, resulting in a predominantly systolic obstruction. Unfortunately, the patient died of multiple-organ failure despite another round of lysis therapy and escalation of the ECMO circuit to a veno-venoarterial cannulation for hemodynamic support. CONCLUSION: Massive transfusion with aggressive procoagulant therapy resulted in mitral valve leaflet thrombosis with dynamic, predominantly systolic LVOT obstruction, comparable to the SAM phenomenon. The pathology was only detectable with a TEE investigation.

Patterns of cardiac dysfunction coinciding with exertional breathlessness in hypertrophic cardiomyopathy.

OBJECTIVE: The commonest cause of breathlessness in hypertrophic cardiomyopathy (HCM) is left ventricular outflow tract (LVOT) obstruction which improves with its removal. However, in the absence of outflow tract obstruction, as in dilated cardiomyopathy, patients may be limited by similar symptoms, thus suggesting a potential common mechanism for the two conditions. We aimed to assess cardiac function at the time of symptoms in a group of unselected patients with HCM to identify other patterns of cardiac dysfunction which coincide with their breathlessness. METHODS: We studied 37 HCM patients (aged 55 ± 15 years, 13 female) with septal thickness >15 mm and 17 controls (aged 58 ± 12 years, 12 female) using Doppler echocardiography, at rest and at peak dobutamine stress. Stress end points were symptoms, >20 mmHg drop in systolic blood pressure, arrhythmia, or maximum dobutamine dosage of 40 µg/kg/min. RESULTS: At rest: LV systolic function was maintained (EF 68 ± 7 v 76 ± 12%, respectively), LVOT velocity raised (p<0.005), lateral and septal long axis amplitude reduced (p<0.05 and p<0.005, respectively) and dyssynchronous and QRS duration was also broader (p<0.005) in patients compared to controls. At peak stress: Overall LVOT velocities were higher in patients than controls (4.3 ± 1.7 v 1.7 ± 1.0m/s, p<0.005, respectively) due to systolic anterior movement of the mitral valve and mitral regurgitation developing. In the 15 patients who did not develop significant LVOT obstruction (velocity <4m/s), LV ejection time increased and peak systolic amplitude did not increase. In the 10 patients with neither LVOT obstruction nor restrictive filling, QRS duration prolonged by 12 ms (p <0.05), post-ejection shortening worsened and peak systolic amplitude fell (p<0.005). Also, LV ejection time prolonged by 5s/min (p<0.05), filling time failed to increase as it did in controls (p<0.005) and Tei index was higher than controls (p<0.01). CONCLUSION: Exertional breathlessness in HCM is associated with LV outflow tract obstruction and functional mitral regurgitation in almost two thirds of patients. The remaining one third have either resistant restrictive physiology or dyssynchronous cavity at fast heart rate. Despite similar exercise limiting breathlessness in the three groups, means of management should be quite different.

A Case of Transcatheter Alcohol Ablation of the Septum in a Patient of Hypertrophic Obstructive Cardiomyopathy

Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by inappropriate myocardial hypertrophy that occurred in the absence of an obvious cause for the hypertrophy and dynamic left ventricular outflow tract obstruction, caused by asymmetrical septal hypertrophy and systolic anterior motion of the anterior mitral leaflet. The pathophysiological abnormality in HOCM is diastolic dysfunction, abnormal stiffness of the left ventricle with resultant impaired ventricular filling and impaired vasodilator reserve (perhaps related to the thickened and narrowed small intramural coronary arteries found in HOCM). During the early course of this progressive disease, treatment consists of negative inotropic drugs. Surgery has been the only therapeutic option in patients with hypertrophic cardiomyopathy who are resistant to drug treatment and sequential pacemaker therapy. We describe a novel catheter-based technique that may replace surgical myocardial reduction. The technique is interventional infarction of a portion of the interventricular septum by the infusion of alcohol into a selectively catheterized septal artery.