Faculty Bibliography

BACKGROUND: We have developed a novel and practical cardiovascular magnetic resonance (CMR) technique to evaluate left ventricular (LV) mitral annular motion by tracking the atrioventricular junction (AVJ). To test AVJ motion analysis as a metric for LV function, we compared AVJ motion variables between patients with hypertrophic cardiomyopathy (HCM), a group with recognized systolic and diastolic dysfunction, and healthy volunteers. METHODS: We retrospectively evaluated 24 HCM patients with normal ejection fractions (EF) and 14 healthy volunteers. Using the 4-chamber view cine images, we tracked the longitudinal motion of the lateral and septal AVJ at 25 time points during the cardiac cycle. Based on AVJ displacement versus time, we calculated maximum AVJ displacement (MD) and velocity in early diastole (MVED), velocity in diastasis (VDS) and the composite index VDS/MVED. RESULTS: Patients with HCM showed significantly slower median lateral and septal AVJ recoil velocities during early diastole, but faster velocities in diastasis. We observed a 16-fold difference in VDS/MVED at the lateral AVJ [median 0.141, interquartile range (IQR) 0.073, 0.166 versus 0.009 IQR -0.006, 0.037, P < 0.001]. Patients with HCM also demonstrated significantly less mitral annular excursion at both the septal and lateral AVJ. Performed offline, AVJ motion analysis took approximately 10 minutes per subject. CONCLUSIONS: Atrioventricular junction motion analysis provides a practical and novel CMR method to assess mitral annular motion. In this proof of concept study we found highly statistically significant differences in mitral annular excursion and recoil between HCM patients and healthy volunteers.

Anomalies of the membranous portion of the interventricular septum include perimembranous ventricular septal defect and/or membranous septal aneurysm (MSA). In congenitally corrected transposition of the great arteries (L-TGA in sinus solitus), the combination of ventricular inversion and arterial transposition creates a unique anatomic substrate that fosters subpulmonic left ventricular outflow tract obstruction by an MSA. The combination of an L-TGA with subpulmonic obstruction by an MSA is referred to as the windsock syndrome. We report a case of windsock syndrome in a 25-year-old man which is to our knowledge the first three-dimensional echocardiographic description of this congenital entity.

A 55-year-old woman was diagnosed with endocarditis involving the aortic valve and resulting in moderate aortic insufficiency. Transesophageal and transthoracic echocardiography demonstrated an unusually accentuated diastolic anterior motion of the anterior mitral valve leaflet toward the interventricular septum. The anterior leaflet remained within a few millimeters of the septum throughout diastole, with a narrow jet of aortic insufficiency separating the anterior leaflet from the septum. We hypothesize that the particularly long anterior mitral leaflet was drawn toward the septum during diastole due to the Venturi effect of the aortic insufficiency jet within a narrow ventricular outflow tract. This accentuated diastolic anterior motion may be a diastolic correlate of systolic anterior motion of the mitral valve. (c) 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012.

Cholesterol emboli syndrome is a relatively rare, but potentially devastating, manifestation of atherosclerotic disease. Cholesterol emboli syndrome is characterized by waves of arterio-arterial embolization of cholesterol crystals and atheroma debris from atherosclerotic plaques in the aorta or its large branches to small or medium caliber arteries (100-200 mum in diameter) that frequently occur after invasive arterial procedures. End-organ damage is due to mechanical occlusion and inflammatory response in the destination arteries. Clinical manifestations may include renal failure, blue toe syndrome, global neurologic deficits and a variety of gastrointestinal, ocular and constitutional signs and symptoms. There is no specific therapy for cholesterol emboli syndrome. Supportive measures include modifications of risk factors, use of statins and antiplatelet agents, avoidance of anticoagulation and thrombolytic agents, and utilization of surgical and endovascular techniques to exclude sources of cholesterol emboli.

Intravenous microbubble contrast agents are frequently used during ultrasound imaging to improve endocardial border detection, enhance Doppler signals, differentiate thrombi from tumors or define vascular anatomy. Dobutamine stress echocardiography (DSE) with or without addition of atropine is a standard technique for evaluation of coronary artery disease. Noncontrast or contrast-enhanced DSE is generally considered a safe procedure. We report what appears to be the first case of new-onset seizure activity following perflutren microbubble contrast injection during dobutamine-atropine stress echocardiography. On the basis of this single occurrence, we are only able to demonstrate a temporal, but not a causal relationship between the administration of microbubble echo contrast and onset of seizure. We do not suggest withholding administration of microbubble contrast when clinically indicated. However, increased vigilance in monitoring for seizure development in patients receiving microbubble contrast seems warranted.