Palpable cardiac impulse predicts adequate acoustic windows.

In this study, we sought to determine the usefulness of palpating an apical cardiac impulse on physical examination in predicting adequate echocardiographic images for stress echocardiography. A variety of stress tests using either echocardiographic imaging or nuclear imaging are available to referring physicians. Deciding which test is best for a given patient is often difficult. In the case of stress echocardiography, the most significant limitation is poor image quality in a small portion of patients. We enrolled 136 consecutive outpatients referred for echocardiography. The presence or absence of a palpable cardiac apex on physical examination was recorded by two independent and blinded examiners. Data, including age, sex, weight, prior chest surgery, and smoking, were also collected. Echocardiographic imaging of the left ventricle was scored according to the number of adequately visualized wall segments in a standard 16-segment model. One hundred eleven patients (82%) had adequate visualization of at least 14 of 16 wall segments. Ninety-eight patients (72%) had a palpable cardiac impulse, of whom 90 (92%) also had adequate acoustic image quality versus only 21 (55%) of the 38 patients in whom an apex was not palpable (P<0.0001). Other variables that were measured were not significantly related to image quality, with the exception of weight; patients with adequate images weighed a mean of 75 kg versus 91 kg in those with inadequate images (P<0.0006). However, multivariate analysis showed a palpable apex to be the only independent predictor after controlling for other variables. A physical examination assessment for a palpable apical impulse is useful to predict adequate echocardiographic image quality for stress echocardiography. When used in conjunction with other parameters, this may lead to more appropriate referral to augmented stress testing.

Transformation of mitral valve prolapse to dynamic left ventricular outflow tract obstruction and back again in a patient with acute transient myocardial depression.

We describe an unusual case of transient resolution of preexisting mitral valve (MV) prolapse during acute cardiac dysfunction and the development of dynamic left ventricular (LV) outflow tract obstruction. The patient presented with lightheadedness, chest pain, and compromised hemodynamic status. Echocardiography revealed akinesis and deformation of the LV anterior wall and apex, hyperdynamic activity in the bases, anterior MV leaflet systolic anterior motion without prolapse, and a dynamic outflow tract gradient. Myocardial function fully recovered over 1 month. Repeat ultrasonography showed posterior MV leaflet prolapse and no anterior MV leaflet systolic anterior motion. Elongated MV leaflets may have contributed to dynamic outflow tract obstruction and life-threatening hemodynamic compromise during LV conformational change.

The development of valvular strands during thrombolytic therapy detected by transesophageal echocardiography.

A case report of a patient who had valvular strands while undergoing treatment with thrombolytic therapy for prosthetic mitral valve thrombosis is presented. The development of valvular strands during thrombolytic therapy provides unique evidence supporting a thrombotic/fibrotic origin to this relatively common finding on transesophageal echocardiography.

Echocardiographic assessment of epicardial defibrillator patch electrodes.

We performed a blinded controlled analysis of transthoracic echocardiograms on 18 patients before and after epicardial defibrillator patch electrode placement to determine the accuracy of echocardiography in identifying defibrillator patches and to determine possible echocardiographic findings that may correlate with defibrillator function or perioperative complications. The sensitivity of two-dimensional echocardiography in detecting defibrillator electrodes was 72% by one observer and 39% by a second observer. Corresponding specificities were 67% and 83%, respectively. The discordance rate was 27%. The echocardiographic finding of patch buckling was not observed and echocardiographic estimates of the distance from patch to epicardium did not correlate with defibrillator threshold at the time of surgery. We conclude that: echocardiography is only moderately sensitive and specific in identifying epicardial defibrillator electrodes; significant interobserver variability does exist; and echocardiography therefore cannot be used reliably to assess for pericardial changes or possible complications of patch electrode placement.

Right-sided valvular pathology and rheumatic fever.

This paper discusses some of the recent advances in the evaluation and treatment of right-sided cardiac pathology, and reviews the more general subject of rheumatic fever, with particular emphasis on diagnosis and possible genetic influences. A comprehensive assessment of these topics is not intended; rather, interesting features and recently published long-term outcome data of more common right heart abnormalities are summarized.

Aortic dissection without intimal tear: case report and findings on transesophageal echocardiography.

Transesophageal echocardiography (TEE) relies on the presence of an intimal flap for diagnosing aortic dissection; however, a small percentage of cases of dissection can occur without apparent intimal disruption. This case reviews unusual echocardiographic features of aortic dissection and previously undescribed echocardiographic findings in a patient with aortic dissection without intimal flap.

Predictive value of dobutamine echocardiography just before noncardiac vascular surgery.

This study prospectively evaluated 75 consecutive patients (mean age 69 +/- 9 years) undergoing major vascular surgery to test the hypothesis that dobutamine stress echocardiography can be used to predict perioperative cardiac events. A positive test was defined as a new or worsening wall motion abnormality in at least 2 of 18 wall segments. Up to 40 micrograms/kg/min of dobutamine was administered. All readings were done by physicians unaware of the patients' symptoms and electrocardiographic response. In addition, physicians caring for the patients were unaware of the test result. End points of the study were unstable angina with documented electrocardiographic changes, nonfatal myocardial infarction or cardiac death. The perioperative ischemic event rate was 7% (5 of 75 patients). Three patients developed unstable angina and 2 sustained nonfatal myocardial infarctions. All of these patients had positive results on dobutamine stress echocardiography (sensitivity 100%). However, 22 patients who also had positive results on dobutamine stress echocardiography did not have perioperative events (specificity 69%). The corresponding positive predictive value was 19%. None of the 48 patients who had negative results on dobutamine stress echocardiography had events (negative predictive value 100%). In conclusion, dobutamine stress echocardiography can be used to predict perioperative events with great sensitivity, but its positive predictive value in this patient population in low, likely due to the low incidence of perioperative events in patients with known coronary artery disease and the imperfect specificity of dobutamine stress echocardiography in identifying significant coronary stenosis. Dobutamine stress echocardiography is most useful in this setting when negative, because it predicts safety from complications with confidence.