Left atrial myxoma: a rare nonatherosclerotic cause of acute myocardial infarction

An unusual presentation of atrial myxoma: thromboembolic phenomenon with a recent normal echocardiogram

Atrial myxomas are the most common primary neoplasms of the heart. Clinical presentation varies from asymptomatic incidental masses to serious life-threatening cardiovascular complications. We describe the case of a 37-year-old man who presented with both coronary and cerebral embolisation secondary to an atrial myxoma in the context of a recent normal transthoracic echocardiogram.

Atrial myxoma presenting as a non-ST-segment elevation myocardial infarction

Cardiac myxomas are the most common benign tumors of the heart. We describe the rare phenomenon of myxomatous embolization, resulting in a non-ST-elevation myocardial infarction treated successfully with surgical excision. The routine early use of both transthoracic and transesophageal echocardiography is pivotal in selecting an optimal management strategy for these patients.

Development of a new model for acute myocardial infarction in rabbits

The rabbit left anterior descending coronary artery is not macroscopically apparent; this often leads to failure in creation of an acute myocardial infarction (AMI) model. In order to devise a simple method with good reproducibility and high success rate for use as a rabbit AMI model, a new surgical technique was developed, in which the obtuse marginal (OM) branch of the left circumflex coronary artery was coagulated with an electric knife using a left parasternal approach. Four weeks after OM branch coagulation, an electrocardiogram (ECG), blood biochemistry analysis, echocardiographic measurements and pathologic analysis were performed. The left parasternal approach provided the surgeon clear visualization of the targeted blood vessel to accurately identify the proper site to occlude. The successful development of AMI was confirmed by ST segment elevation on the ECG, by high levels of AMI-related markers in blood samples, by cardiac functional damage reflected on echocardiographic images and by changes in pathological sections. Furthermore, an acceptable success rate and low mortality were achieved. Hence, this surgical technique was suggested to be a highly reliable and reproducible method to induce AMI in rabbits for the assessment of new therapeutic interventions or regenerative approaches.

Metastatic Breast Carcinoma to the Coronaries: A Rare Cause of Acute Myocardial Infarction

A 63-year-old female with a history of invasive ductal breast carcinoma presented to the emergency department with symptoms characteristic of myocardial infarction. Electrocardiography showed sinus tachycardia and ST elevations in leads II, III, and aVF, consistent with inferior wall myocardial infarction. A computed tomography (CT) scan of the chest, abdomen, and pelvis with intravenous contrast demonstrated widespread intrathoracic metastatic disease. Cardiac magnetic resonance imaging (MRI) with contrast revealed obstruction of the left ventricular (LV) outflow tract by an LV mass. Cardiac MRI enabled detection of a rare case of myocardial infarction secondary to tumor emboli and intracavitary LV metastasis. This case report emphasizes the role of cross-sectional imaging including CT and cardiac MRI for unusual causes of myocardial infarction, particularly when associated with neoplastic processes.