Failure of digital echocardiography to accurately diagnose intracardiac shunts.

BACKGROUND: Intravenous agitated saline injection during transthoracic echocardiography assists in the detection of right to left intracardiac and intrapulmonary shunts. Whether digital echocardiography offers comparable sensitivity and specificity to analog tape recording to assess shunts is unknown. Technical differences between methods could lead to significant differences in shunt detection. METHODS: Agitated saline was injected intravenously at rest and with Valsalva in 189 consecutive patient studies (406 injections). Echocardiographers assessed presence and degree of left ventricle contrast on simultaneously recorded analog tape and digital echocardiography images in blinded fashion. RESULTS: Digital echocardiography had low overall sensitivity (rest 0.50, valsalva 0.63, late 0.39) compared to analog tape. Longer clip lengths improved sensitivity for detection of late contrast passage (rest 0.50, valsalva 0.67, late 0.46). CONCLUSION: Digital echocardiography saline contrast studies have poor sensitivity for assessment of intracardiac shunts versus analog tape, and increasing clip length only modestly increases sensitivity. Joint Photographic Experts Group digital compression losses may be an important cause of failure to detect intracardiac shunts, including patent foramen ovale.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy is recognized as an important cause of death in young patients, particularly athletes. In the past 5 years, cardiac MRI techniques have evolved rapidly in an attempt to improve the noninvasive diagnosis of this disorder. Steady-state free precession sequences and more rapid fat saturation techniques have permitted a comprehensive and well-tolerated examination. The first formal testing of diagnostic accuracy among a broad range of readers has recently been completed. Despite these advances, limited spatial resolution and interobserver variability have prevented successful implementation of these methods. Future approaches may include high-field imaging at 3 Tesla, and viability imaging to improve diagnostic accuracy.

Assessment of global and regional myocardial function in the mouse using cine and tagged MRI.

Mouse models are expected to play an important role in future investigations of human cardiac diseases. In the present report, MRI methods for determining global and regional cardiac function in the mouse are demonstrated. ECG-gated cine images were acquired in five C57BL/6 mice at physiological temperatures (37 degrees C) and heart rates of 500 +/- 50 beats per minute. Left ventricular mass, ejection fraction, and cardiac output were estimated from the resulting images. Regional myocardial function was also determined in three animals by application of 2D SPAtial Modulation of Magnetization (SPAMM) in combination with the cine protocol. The quality of the tagged images was sufficient to allow mapping of myocardial strains and displacements. The results of the regional strain analysis were consistent with similar studies in larger animals. This work demonstrates the first characterization of regional myocardial function in the mouse via SPAMM techniques.

Hypereosinophilia associated with cardiac rhabdomyosarcoma.

Hypereosinophilia, defined as an absolute eosinophil count exceeding 1,500/mm(3), is caused by a limited number of disorders. Its association with malignancy is a rare occurrence that typically denotes extensive metastasis and a poor prognosis. Several theories have been proposed to explain the hypereosinophilia associated with malignancy, focusing on the production of eosinophilopoietic cytokines by tumors. We describe a patient with hypereosinophilia associated with a cardiac rhabdomyosarcoma, review the etiologies of hypereosinophilia, and discuss the possible mechanisms.