Quantitation of left-to-right shunts in secundum atrial septal defect by two-dimensional contrast echocardiography with use of Albunex

Echo contrast-enhanced diagnosis of atrial septal defect

Pulsed wave, continuous wave, and color flow Doppler imaging as well as intravenously administered agitated saline solution can detect intracardiac shunts during transthoracic echocardiography. Ultrasonographic contrast agents have greatly improved the visualization of left heart chambers and can enhance signals from blood flow within chambers and across valves, increasing the sensitivity of Doppler techniques. We describe a patient in whom the use of echo contrast media during transthoracic echocardiography allowed the detection of a previously unseen atrial septal defect. Combining such modalities may help to increase the sensitivity of transthoracic echocardiography and may eliminate the need for transesophageal echocardiography in selected patients.

Contrast echocardiography clarifies uninterpretable wall motion in intensive care unit patients

OBJECTIVES

The study examined the value of contrast echocardiography in the assessment of left ventricular (LV) wall motion in intensive care unit (ICU) patients.

BACKGROUND

Echocardiograms done in the ICU are often suboptimal. The most common indication is the evaluation of LV wall motion and ejection fraction (EF).

METHODS

Transthoracic echocardiograms were done in 70 unselected ICU patients. Wall motion was evaluated on standard echocardiography (SE), harmonic echocardiography (HE), and after intravenous (IV) contrast echocardiography (CE) using a score for each of 16 segments. A confidence score was also given for each segment with each technique (unable to judge; not sure; sure). The EF was estimated visually for each technique, and a confidence score was applied to the EF.

RESULTS

Uninterpretable wall motion was present in 5.4 segments/patient on SE, 4.4 on HE (p = 0.2), and 1.1 on CE (p < 0.0001). An average of 7.8 segments were read with surety on SE, 9.2 on HE (p = 0.1), and 13.7 on CE (p < 0.0001). Ejection fraction was uninterpretable in 23% on SE, 13% on HE (p = 0.14), and 0% on CE (p = 0.002 vs. HE; p < 0.0001 vs. SE). The EF was read with surety in 56% of patients on SE, 62% on HE (p = 0.47), and 91% on CE (p < 0.0001). Thus, wall motion was seen with more confidence on CE. More importantly, the actual readings of segmental wall motion and EF significantly differed using CE.

CONCLUSIONS

CE should be used in all ICU patients with suboptimal transthoracic echocardiograms.

MRI and echocardiography: how do they compare in adults?

TTE with color flow imaging remains the most appropriate initial method for imaging CHD in adults. In many patients with minor abnormalities, this will be the only imaging required. For complicated intracardiac anomalies not well shown by TTE, TEE or MRI are usually adequate with the choice of technique being dependent on the availability of appropriate equipment and expertise. For great vessel abnormalities, further evaluation with MRI and MRA is most appropriate. In patients suspected of having significant systemic or pulmonary venous abnormalities or abnormalities of the aortic arch, MRI and MRA should be regarded as the definitive imaging technique. MRI and MRA are robust methods for evaluating intracardiac disease and can provide accurate information on cardiac chamber anatomy relationships, valvar lesions, and shunts. However, in most patients, this information is provided more rapidly and cost effectively by color Doppler echocardiography.