Diagnostic accuracy of transesophageal echocardiography during cardiopulmonary resuscitation

Diagnostic value of transoesophageal echocardiography in suspected haemodynamically significant pulmonary embolism

OBJECTIVE

To assess the value of transoesophageal echocardiography (TOE) for diagnosing suspected haemodynamically significant pulmonary embolism and signs of right ventricular overload at standard echocardiography.

METHODS

113 consecutive patients (58 male; 55 female), mean (SD) age 53.6 (13.3) years, in whom there was clinical suspicion of pulmonary embolism and right ventricular overload on transthoracic echocardiography, underwent TOE in addition to routine diagnostic procedures to identify pulmonary artery thrombi.

RESULTS

TOE revealed thrombi in 32 of 51 patients who had suspected acute pulmonary embolism and in 31 of 62 with suspected chronic pulmonary embolism. In one patient a pulmonary angiosarcoma rather than chronic pulmonary embolism was found at surgery. The diagnosis of pulmonary embolism was confirmed in 77 patients by scintigraphy, spiral computed tomography, angiography, or necropsy (reference methods). While TOE failed to provide a diagnosis of pulmonary embolism in 15 of these 77 patients, no false positive findings were reported (sensitivity 80.5%, specificity 97.2%). In 11 and 26 cases, respectively, the thrombi were confined to the left or right pulmonary artery. Bilateral thrombi were found in 25 patients. Mobile thrombi were observed only in acute pulmonary embolism (in 19 of 32 patients). No complications of TOE were noted.

CONCLUSIONS

TOE permits visualisation of pulmonary arterial thrombi, confirming the diagnosis in the majority of patients with pulmonary embolism and right ventricular overload. This may be useful for prompt decision making in patients with haemodynamic compromise considered for thrombolysis or embolectomy.

Outcome in cardiac arrest patients found to have cardiac standstill on the bedside emergency department echocardiogram

Patients presenting in cardiac arrest frequently have poor outcomes despite heroic resuscitative measures in the field. Many emergency medical systems have protocols in place to stop resuscitative measures in the field; however, further predictors need to be developed for cardiac arrest patients brought to the emergency department (ED).

OBJECTIVE

To examine the predictive value of cardiac standstill visualized on bedside ED echocardiograms during the initial presentations of patients receiving cardiopulmonary resuscitation (CPR).

METHODS

The study took place in a large urban community hospital with an emergency medicine residency program and a high volume of cardiac arrest patients. As part of routine care, all patients arriving with CPR in progress were subject to immediate and brief subxiphoid or parasternal cardiac ultrasound examination. This was followed by brief repeat ultrasound examination during the resuscitation when pulses were checked. A 2.5-MHz phased-array probe was used for imaging. Investigators filled out standardized data sheets. Examinations were taped for review. Statistical analysis included descriptive statistics, positive and negative predictive values, and likelihood ratios.

RESULTS

One hundred sixty-nine patients were enrolled in the study. One hundred thirty-six patients had cardiac standstill on the initial echocardiogram. Of these, 71 patients had an identifiable rhythm on monitor. No patient with sonographically identified cardiac standstill survived to leave the ED regardless of his or her initial electrical rhythm. Cardiac standstill on echocardiogram resulted in a positive predictive value of 100% for death in the ED, with a negative predictive value of 58%.

CONCLUSIONS

Patients presenting with cardiac standstill on bedside echocardiogram do not survive to leave the ED regardless of their electrical rhythms. This finding was uniform regardless of downtime. Although larger studies are needed, this may be an additional marker for cessation of resuscitative efforts.

The incidence of pulmonary embolism in unexplained sudden cardiac arrest with pulseless electrical activity

PURPOSE

The cause of many cases of sudden cardiac arrest from pulseless electrical activity is unknown. We hypothesized that pulmonary embolism was responsible for a substantial proportion of these cases and used transesophageal echocardiography to identify pulmonary embolism among patients with sudden cardiac arrest.

SUBJECTS AND METHODS

We performed a prospective study at a tertiary care, university-operated county hospital, with a level 1 trauma center. Consecutive patients (n = 36) who were admitted with (n = 20) or unexpectedly developed (n = 16) sudden cardiac arrest of unknown cause were studied with transesophageal echocardiography during cardiopulmonary resuscitation. We determined the presence of central pulmonary embolism, right ventricular enlargement, and other causes of sudden cardiac arrest (such as myocardial infarction and aortic dissection) using prospectively defined criteria.

RESULTS

Of the 25 patients with pulseless electrical activity as the initial event, 9 (36%) had pulmonary emboli (8 seen with transesophageal echocardiography and 1 diagnosed at autopsy) compared with none of the 11 patients with other rhythms, such as asystole or ventricular tachycardia or fibrillation (P = 0.02). Of the 8 patients who had pulmonary embolism diagnosed by transesophageal echocardiography, 2 survived to hospital discharge.

CONCLUSIONS

Mortality from massive pulmonary embolism is high, particularly if patients present with sudden cardiac arrest. Earlier diagnosis of pulmonary embolus may permit wider use of thrombolytic agents or other interventions and may potentially increase survival.

Comparison of intraoperative transesophageal echocardiographic examinations with the operative findings: prospective review of 1918 cases

The purpose of this study was to prospectively compare the intraoperative transesophageal echocardiographic (IOTEE) findings with the operative findings in 1918 consecutive cardiac cases. Forty-eight discordant findings were found between the IOTEE and operative findings. Of the 48 discordant findings, most were related to valve pathology. Structural abnormalities that were missed by IOTEE included those of the aortic valve, 12 cases (25%), mitral valve, 13 cases (27%), and pulmonic and tricuspid valves, 5 cases (10%). Functional discrepancies occurred in 8% of cases. Overall, incidence of discrepant findings between IOTEE and operative findings was low (2.5%). This resulted in an alteration of the planned surgical procedure in a small number of cases (0.3%).

The Role of Echocardiography Doppler in Pulmonary Embolism

The purpose of this review is to make a critical analysis of selected literature about the role of echo-Doppler in suspected or proved venous thromboembolism and to address some issues about the potential use of echo-Doppler in specific situations in patients with pulmonary embolism (PE). Echo-Doppler is of great value in patients with suspected PE because many conditions that may be clinically mistaken for PE will be diagnosed. Echo-Doppler should not be used alone to rule out the diagnosis of PE because the ability of the technique in proving the diagnosis of PE in a nonselected population is limited. Echo-Doppler may be of value for diagnosis in selected subgroups of PE patients, mostly in scenarios like the emergency department or intensive care unit. Echo-Doppler is valuable in the hemodynamic assessment of patients with PE, making possible a strategy for risk stratification of in-hospital death in relation to the degree of right ventricle dysfunction at the time of diagnosis of acute PE. Echo-Doppler is useful for serial assessment of patients with established diagnosis of chronic thromboembolic pulmonary hypertension. Echo-Doppler may be useful in follow-up of patients after a diagnosis of acute PE to enable early identification of patients with persistent pulmonary hypertension/right ventricle dysfunction.