Impact of transesophageal color flow Doppler echocardiography in current cardiology practice

Systemic absorption and toxicity from topically administered lidocaine during transesophageal echocardiography

This report describes the cases of three patients who had central nervous system toxicity from locally administered lidocaine during transesophageal echocardiography. Parenteral sedation was not employed. Serum levels of lidocaine were obtained after the procedure in all three patients, who recovered spontaneously and suffered no permanent ill effects. Medical conditions such as congestive heart failure and diminished hepatic function or concomitant use of lidocaine analogs may predispose patients to the toxic side effects of locally administered lidocaine. Extreme care and close monitoring of patients are warranted when topical lidocaine anesthetic is employed in the setting of delayed lidocaine clearance.

Frequency of bacteremia associated with transesophageal echocardiography in intensive care unit patients: a prospective study of 139 patients

OBJECTIVE

To determine the occurrence rate of bacteremia associated with transesophageal echocardiography in intensive care unit (ICU) patients.

DESIGN

A prospective study of 139 patients undergoing transesophageal echocardiography.

SETTING

The medical ICU of a tertiary referral teaching hospital.

PATIENTS

One hundred thirty-nine ICU patients (mean age 58 yrs) who underwent transesophageal echocardiography.

INTERVENTIONS

Blood samples were systematically drawn for aerobic and anaerobic culture at the following times: before (blood culture 1), at the end of (blood culture 2), and 30 mins after (blood culture 3) transesophageal echocardiography examinations.

MEASUREMENTS AND MAIN RESULTS

The mean duration of transesophageal echocardiography was 35 mins (range 7 to 120). One hundred thirty-four patients received mechanical ventilation; 125 patients had a nasogastric tube. Fifty-one patients had one or more underlying conditions that usually justify antimicrobial prophylaxis of bacterial endocarditis before high-risk procedures. Fifty-six patients did not receive any antibiotic treatment at the time of transesophageal echocardiography. In 114 patients, the three blood cultures were negative. In six patients, transesophageal echocardiography was performed during a preexisting bacteremia. A contamination (only one positive blood culture of the three sampling times) with coagulase-negative staphylococci occurred in four patients at blood culture 1, five patients at blood culture 2, and six patients at blood culture 3. Contamination with Corynebacterium species occurred in two patients at blood culture 2. In one patient receiving cefotaxime and netilmicin, blood culture 1 was sterile and blood cultures 2 and 3 yielded coagulase-negative staphylococci. In one patient receiving no antibiotic treatment, blood culture 1 was sterile and blood cultures 2 and 3 yielded Enterococcus faecalis. None of these two patients received a specific antibiotic treatment or developed any secondary septic focus.

CONCLUSIONS

The overall frequency of bacteremia induced by transesophageal echocardiography in ICU patients was 1.4% (two of 139 patients) (95% confidence interval 0.2% to 5.1%). The frequency did not differ whether patients received antibiotics before transesophageal echocardiography (one [1.2%] of 83 patients) or not (one [1.8%] of 56 patients) (p = .96). Therefore, routine antimicrobial prophylaxis does not appear justified before transesophageal echocardiography in ICU patients.

Endocarditis-associated paravalvular abscesses. Do clinical parameters predict the presence of abscess?

STUDY OBJECTIVE

To determine whether standard clinical and transthoracic echocardiographic criteria considered to be suggestive of the presence of endocarditis-associated paravalvular abscess are predictive of which patients would benefit from reliable but invasive transesophageal echocardiographic investigations for abscess.

DESIGN

Retrospective chart review.

SETTING

A 630-bed university hospital.

PATIENTS

Forty-eight patients with 51 episodes of definite endocarditis and 24 paravalvular abscesses.

MEASUREMENTS AND RESULTS

A comparison of abscess and nonabscess populations revealed that clinical parameters (patient demographics, valvular involvement, presence of a prosthesis, infection with a virulent organism, pericarditis, persistent fever, persistent bacteremia, congestive heart failure, history of intravenous drug use, embolization) and transthoracic echocardiographic parameters were insensitive predictors of the presence of abscess. The only statistically significant correlate was the presence of previously undetected atrioventricular or bundle branch block. Paravalvular abscesses were common in our population and were associated with increased mortality. Improved survival correlated with the absence of mitral valve involvement and the absence of moderate-to-severe congestive heart failure.

CONCLUSIONS

Given the accuracy and safety of transesophageal echocardiography and the unreliability of clinical and transthoracic echocardiographic criteria, we recommend that transesophageal echocardiography be considered in all endocarditis patients with previously unrecognized conduction disturbances, aortic or prosthetic valve involvement, or both, or indications for valve replacement, or all of the foregoing.

Transesophageal echocardiography in the intensive care unit: impact on diagnosis and decision-making

Transesophageal echocardiography (TEE) is widely used in the management of patients in intensive care units. The present study assesses the specific value of this technique in various categories of these patients. We reviewed 113 studies performed in 100 such patients for: suspected aortic dissection (25), suspected endocarditis (33), source of emboli assessment (19), hemodynamic instability (15), and miscellaneous (21). TEE provided diagnostic information in all patients with aortic dissection, in 53% of the cases with hemodynamic instability, in 50% of the cases with septic states with high likelihood of endocarditis, and in 29% of the cases where the question was the source of emboli. When the clinical probability for endocarditis was low, all transesophageal echocardiograms performed in septic patients were negative. The information provided by TEE was considered crucial in one-third of the positive cases; in about one-half of these special cases, the results were instrumental for further surgical management. There were no significant side effects related to the procedure. TEE is easily performed in the intensive care unit setting and yields useful information in almost half of the cases. Special benefit is expected in suspected aortic disease, hemodynamic instability, suspected endocarditis, and embolic events. The overall yield as screening procedure in febrile patients is low.

Aorta: comprehensive evaluation by echocardiography and transesophageal echocardiography

The emergence of transesophageal echocardiography has made echocardiography a nearly ideal technique for evaluating the thoracic aorta. The echocardiographic anatomy of the aorta is reviewed. The role of echocardiography for evaluating aortic dissection, thoracic aortic aneurysm, aortic atherosclerosis, and thoracic aortic trauma is discussed. Comparison of echocardiography with other techniques for imaging the aorta (computed tomographic scan, nuclear magnetic resonance, and aortography) is presented.

Utility of transesophageal echocardiography in the conservative management of prosthetic valve endocarditis

Prosthetic valve endocarditis is a formidable complication following cardiac valve replacement. Surgical intervention has resulted in a significant reduction in mortality when certain complications prevail. We report two such cases of prosthetic valve endocarditis in which the use of transesophageal echocardiography permitted close surveillance during medical therapy and thus avoided the need for surgical intervention. Therefore, with the improved ability to monitor disease progression with transesophageal echocardiography, nonsurgical management of prosthetic valve endocarditis remains an option.

Prospective study of blood culture during transesophageal echocardiography

To ascertain the incidence and significance of bacteremia associated with transesophageal echocardiography (TEE), 132 consecutive patients (aged 17 to 73 years) free of apparent infection who were undergoing 135 transesophageal echocardiographic procedures from October 1990 to August 1991, were prospectively studied. For each procedure, two sets of blood cultures were obtained for culture 30 to 60 minutes before TEE, immediately after, and 180 to 240 minutes after the procedure. For each blood culture, 10 ml of venous blood was evenly inoculated into aerobic and anaerobic culture bottles and inoculated for 7 days using a radiometric system. A throat swab was obtained immediately before each procedure. Three of 270 preprocedure blood cultures were positive for Bacillus cereus, Staphylococcus simulans, and Peptostreptococcus species, respectively. No blood culture was positive in the immediate postprocedure period. Two of 270 late blood samples grew Staphylococcus epidermidis in the same patient. Nevertheless, the microorganisms isolated from blood cultures were different from those isolated from the throat swab. No patients had fever or evidence of infective endocarditis after TEE during the follow-up period. It is concluded that the incidence of TEE-related bacteremia is extremely low, and a general recommendation for antibiotic prophylaxis during TEE is not warranted.

Use of a mouth gag instrument to facilitate bite block insertion and prevent finger and probe bites during transesophageal echocardiography

Transesophageal echocardiography greatly enhances the examination of patients difficult to image transthoracically. While of low patient risk, a potential for harm from human bites to the echocardiography staff and to the transesophageal probe remains, particularly when dealing with uncooperative patients. This risk potential prompted implementation of additional anti-bite protection in our universal precautions policy beyond use of a standard mouth guard. A mouth gag instrument was modified by placing latex rubber tubing over the instrument blades. This instrument was inserted into the mouth and set in an open position giving the operator safe access for probe and mouth bite guard insertion. This technique improved access to the patient's mouth and visualization of probe insertion without the mouth bite guard. The mouth gag instrument provided an insertion of the transesophageal probe in impaired or otherwise uncooperative patients, which was safer for the patient, laboratory staff, and the probe itself.

Transesophageal echocardiographic recognition of subaortic complications in aortic valve endocarditis. Clinical and surgical implications

BACKGROUND

Secondary involvement of the mitral-aortic intervalvular fibrosa and the anterior mitral leaflet (subaortic structures) can occur in patients with aortic valve endocarditis. The secondary involvement of these structures occurs as a result of direct extension of the infection from the aortic valve or as a result of an infected aortic regurgitant jet striking the ventricular surfaces of the mitral-aortic intervalvular fibrosa and the anterior mitral leaflet. The abscess of mitral-aortic intervalvular fibrosa can expand to form an aneurysm. Subsequently, this mitral-aortic intervalvular fibrosa aneurysm can develop a perforation and communicate with the left atrium, resulting in the systolic regurgitation of blood from the left ventricular outflow tract into the left atrium. Secondary infection can also occur on the ventricular surface of the anterior mitral leaflet and result in the formation of an aneurysm or perforation of anterior mitral leaflet.

METHODS AND RESULTS

This study examines the utility of transesophageal echocardiography in the detection of these subaortic complications in 55 consecutive patients with aortic valve endocarditis. A total of 24 patients (44%) had involvement of subaortic structures, including four with an abscess in the mitral-aortic intervalvular fibrosa, four with mitral-aortic intervalvular fibrosa aneurysm, seven with perforation of the mitral-aortic intervalvular fibrosa with communication into the left atrium, two with an aneurysm of the anterior mitral leaflet, and seven with perforation of the anterior mitral leaflet. The transesophageal echocardiographic findings were confirmed at surgery in 20 patients and at necropsy in two. By comparison, transthoracic echocardiography visualized these lesions in five of 24 patients (21%), including none of four with mitral-aortic intervalvular fibrosa abscesses, two of four with mitral-aortic intervalvular fibrosa aneurysms, one of seven with mitral-aortic intervalvular fibrosa perforations, one of two with anterior mitral leaflet aneurysms, and one of seven anterior mitral leaflet perforations. Eccentric mitral regurgitation-type systolic jets were noted in eight additional patients by transthoracic color flow imaging, and this finding suggested the possibility of these unusual subaortic complications. If these patients are included, then transthoracic echocardiography suggested the presence of these subaortic complications in 13 of 24 patients (54%).

CONCLUSIONS

The results indicate that 1) involvement of the subaortic structures in patients with aortic valve endocarditis may be more common than previously recognized, 2) patients with aortic valve endocarditis and eccentric jets of mitral regurgitation on transthoracic echocardiography should undergo further evaluation by transesophageal echocardiography to exclude these unusual complications, 3) precise recognition of these complications is of value in the optimal medical and surgical management of these patients, and 4) these complications may be responsible for unexplained congestive heart failure and hemodynamic deterioration in some patients with aortic valve endocarditis.

Incidence of bacteremia in transesophageal echocardiography: a prospective study of 140 consecutive patients

The incidence of bacteremia related to transesophageal echocardiography was studied in 140 consecutive patients (71 women and 69 men with a mean age of 53.7 +/- 15 years). Thirty-four patients had one or more prosthetic heart valves. Blood cultures were obtained from each patient through separate venipuncture sites immediately before and after transesophageal echocardiography. An additional late blood culture was obtained in 114 patients 1 h later. The skin was cleaned with povidone-iodine and venipunctures were performed with separate butterfly needles with use of sterile gloves and drapes. Blood samples were drawn into separate syringes, transferred to aerobic and anaerobic culture bottles and processed with use of a semiautomated system. The overall incidence of blood cultures positive for bacteremia was 2% (8 of 394 bottles) and all positive cultures grew in a single blood culture bottle. Positive cultures occurred in 4 (1.4%) of 280 bottles before the procedure, in 2 (0.7%) of 280 bottles immediately after the procedure and in 2 (0.9%) of 228 late (1-h) blood culture bottles. Bacterial isolates were coagulase-negative staphylococci (n = 5), Propionibacterium (n = 2) and Moraxella (n = 1). All were considered contaminants. Mean endoscopic time in these patients was not significantly different from that in the other patients. Follow-up of patients with a blood culture positive for bacteremia revealed no clinical evidence of systemic infection. It is concluded that 1) the incidence of bacteremia related to transesophageal echocardiography is very low, and 2) the incidence of blood cultures positive for bacteremia after transesophageal echocardiography is indistinguishable from the anticipated contamination rate.

Transesophageal echocardiography for congenital heart disease

Surface echocardiographic imaging of small children is routinely successful in defining anatomical details and Doppler flow patterns with even the most complex congenital cardiac malformations. However, in larger children or adults, imaging is frequently limited. A recent expansion of the role of echocardiography is intraoperative epicardial imaging. Epicardial and postoperative imaging, however, have significant limitations. To avoid some of these limitations, transesophageal echocardiography has increasingly been used in the arena of congenital heart disease. The more recent development of small sized gastroscopic probes has allowed transesophageal echocardiographic assessment of congenital heart disease in children down to newborn size. As detailed studies of individual lesions are reported, it has become clear that the mere presence of a congenital heart defect is not an indication for transesophageal echocardiography in most children if imaging can be accomplished by surface examination. However, transesophageal echocardiography may be indicated for the intraoperative or postoperative assessment of that defect, particularly when repair has been difficult or is known to be associated with significant residual abnormalities. Cardiac structures encountered with horizontal and vertical imaging plane transducers have been described and should be completely familiar to the examining echocardiographer.

An acquired interatrial fistula secondary to para-aortic abscess documented by transesophageal echocardiography

Para-aortic ring abscess and resulting fistulous communication between adjacent structures frequently occur in prosthetic aortic valve endocarditis but are rarely diagnosed preoperatively. We report a patient who had an abscess involving the aortic-mitral intervalvular fibrosa that eroded into the interatrial septum, causing an interatrial communication with a left-to-right shunt. The abscess was detected by transthoracic echocardiography, but the fistula was only seen by the subsequent transesophageal echocardiogram. To our knowledge, this is the first report of an interatrial fistula secondary to a para-aortic valve abscess and its diagnosis preoperatively. Transesophageal echocardiography should be performed in any patient suspected to have complicated aortic endocarditis.

Recognition and embolic potential of intraaortic atherosclerotic debris

Atherosclerotic disease of the thoracic aorta is common in the elderly and patients with clinical coronary artery disease. Although embolization can occur from atherosclerotic debris within the thoracic aorta, it is not commonly considered in the differential diagnosis of the source of a systemic embolism. In the current study, the prevalence, clinical significance and embolic potential of intraaortic atherosclerotic debris as detected by transesophageal echocardiography was determined. Intraaortic atherosclerotic debris was identified in 38 (7%) of 556 patients undergoing transesophageal echocardiography. An embolic event occurred among 11 (31%) of the 36 study patients with intraaortic atherosclerotic debris. The incidence of an embolic event was higher when the debris was pedunculated and highly mobile (8 [73%] of 11 patients) than when it was layered and immobile (3 [12%] of 25 patients) (p less than 0.002). Among 15 patients undergoing an invasive procedure of the aorta, the incidence of embolism was 27%. In conclusion, in a patient with an embolic event, the thoracic aorta should be considered as a potential source. Transesophageal echocardiography can reliably detect intraaortic atherosclerotic debris, and when it is identified, an invasive aortic procedure should be avoided if possible.

Streptococcal endocarditis temporally related to transesophageal echocardiography

A case of streptococcal sanguis endocarditis temporally related to a transesophageal echocardiogram is reported; and the literature on the incidence of bacteremia occurring during transesophageal echocardiography is reviewed. On the basis of this case and review of the literature, a reevaluation of the current guidelines for endocarditis prophylaxis during this procedure is recommended.

Enhancement of hypoxemia by atrial shunting in cystic fibrosis

Patients with CF may develop hypoxemia which seems disproportionate to the degree of pulmonary disease. In a series of patients with CF and advanced pulmonary disease undergoing transesophageal echocardiography for the evaluation of cor pulmonale, eight of 15 patients were found to have atrial shunts through a stretched foramen ovale. To our knowledge, this is the first observation of intracardiac shunting in CF. This phenomenon may account for unexplained levels of cyanosis and worsening of hypoxemia with exercise, vasodilators, or PEEP and poses the threat of paradoxic emboli when central venous lines are used in these patients.