Role of echocardiography in aortic atherosclerotic disease and stroke.

Patients with severe aortic atherosclerosis are at high risk for stroke. The risk is highest for those with atherosclerotic plaque measuring = or >4 mm in thickness. There is currently no proven medical therapy to reduce embolic risk in patients with aortic plaque. Antiplatelet therapy, smoking cessation, and management of diabetes and hypertension are important. Retrospective data support the use of statins to prevent stroke in patients with severe aortic plaque. Embolism from aortic atherosclerosis may occur spontaneously, or less commonly, as a complication of invasive or surgical cardiovascular procedures. Transesophageal echocardiography (TEE) is the procedure of choice for the characterization of plaque and the detection of superimposed mobile thrombi. Therefore, TEE is a useful tool to identify patients at high risk for stroke. For patients who are being evaluated for coronary artery bypass graft (CABG) surgery or coronary angiography, the risks and benefits of these procedures must be carefully weighed and alternate approaches should be considered in patients with severe plaque. Options include off-pump CABG or coronary angiography via a brachial (rather than femoral) approach.

Abdominal aortic aneurysms and thoracic aortic atheromas.

BACKGROUND: Abdominal aortic aneurysm (AAA) is associated with atherosclerosis elsewhere. Thoracic aortic atheromas (ATHs) seen on transesophageal echocardiography (TEE) are an important cause of stroke and peripheral embolization. The purposes of this study were to determine whether an association exists between AAA and ATHs and to assess the importance of screening patients with ATHs for AAA. METHODS: For the retrospective analysis, 109 patients with AAA and 109 matched controls were compared for the prevalence of ATHs on TEE and for historical variables. For the prospective analysis, screening for AAA on ultrasonography was performed in 364 patients at the time of TEE. RESULTS: Results of the retrospective analysis showed that ATHs were present in 52% of patients with AAA and in 25% of controls (odds ratio [OR] = 3.3; P =.00003). There was a significantly higher prevalence of hypertension, myocardial infarction, heart failure, smoking, and carotid or peripheral arterial disease in patients with AAA. However, only ATHs were independently associated with AAA on multivariate analysis (P =.001). Results of the prospective analysis showed that screening at the time of TEE in 364 patients revealed AAA in 13.9% of those with ATHs and in 1.4% of those without ATHs (P <.0001; OR = 11.4). CONCLUSIONS: (1) There is a strong, highly significant association between abdominal aneurysm and thoracic atheromas. (2) Patients with AAA may be at high risk for stroke because of the concomitance of thoracic aortic atheromas. (3) The high prevalence of abdominal aneurysm in patients with thoracic atheromas suggests that screening for abdominal aneurysm should be carried out in all patients with thoracic atheromas identified by TEE.

Diagnosis of esophageal carcinoma because of findings on transesophageal echocardiography.

A patient in whom transesophageal echocardiography was performed to evaluate a possible source of cerebral embolization. The fact that the probe could not be passed easily beyond 35 cm from the incisors suggested esophageal obstruction or compression. A mass was seen posterior to the left atrium that was heterogenous and contained blood vessels, suggesting a malignancy. There were no complications of the procedure. Esophageal adenocarcinoma was confirmed on biopsy. Transesophageal echocardiography may be diagnostic of paracardiac mediastinal masses, both benign and malignant. Great care must be taken if passage of the probe through the esophagus is met with resistance, to avoid serious complications.

Unusual echocardiographic views of bicuspid and tricuspid pulmonic valves.

The pulmonary artery is typically seen on transthoracic echocardiography in its longitudinal axis. Therefore, short axis views of the pulmonic valve leaflets are not generally obtained, and the distinction between tricuspid and bicuspid pulmonic valves is difficult or impossible. Bicuspid pulmonic valve is one cause of pulmonic stenosis, which is especially common in tetralogy of Fallot. Presented here are 2 patients in whom the orientation of the pulmonary artery was unusual, and the pulmonic valve was seen en face. The first patient had tetralogy of Fallot and a bicuspid pulmonic valve. The severe obstruction to right ventricular outflow was infundibular. The second patient had severe stenosis of a tricuspid pulmonic valve, which was treated with balloon valvuloplasty. These unusual views of the pulmonic valve leaflets were obtained because of anterior displacement of the pulmonary artery, and precise anatomic delineation of the problem in each case was possible with transthoracic echocardiography.

Transesophageal echocardiography in intimal flap fenestration.

In selected patients with descending aortic dissection, percutaneous intimal flap fenestration is a less-invasive alternative to surgery. We describe a patient with decreased renal and mesenteric blood flow as a result of descending aortic dissection. Percutaneous balloon intimal fenestration was performed under guidance of transesophageal echocardiography. Transesophageal echocardiography provided crucial information about the intimal flap puncture site and true- and false-lumen blood flow. After the flap fenestration, false-lumen blood flow increased, and the patient improved clinically.

Unusually located left atrial papillary fibroelastoma with probable embolization to the spinal cord.

This report presents a patient with flaccid paraplegia, most probably secondary to embolization from a left atrial papillary fibroelastoma. The unique location of the tumor, attached to the ridge in the left atrium between the left atrial appendage and pulmonary vein, was well documented on transesophageal echocardiography, and the diagnosis was confirmed by histopathology. Although benign, these tumors may develop in all four cardiac chambers and result in pulmonary or systemic embolization. Paraplegia is a rare embolic complication.

Innominate artery atheroma: a lesion seen with gadolinium-enhanced MR angiography and often missed by transesophageal echocardiography.

Transesophageal echocardiography (TEE) is the procedure of choice for identifying aortic atheromas, which may result in stroke, transient ischemic attack and peripheral embolization. However, because of anatomic constraints, the innominate artery may not be visualized. We investigated gadolinium-enhanced MR angiography (MRA) as an alternative technique for evaluation of suspected atheromas of the innominate artery. From a retrospective review of 520 examinations, we identified five patients who had innominate artery atheromas diagnosed prospectively with gadolinium-enhanced MRA who also underwent TEE within 1 month. A total of 10 innominate artery atheromas were demonstrated on MRA; none of these were visualized on TEE. One patient had three atheromas, two patients had two atheromas and three patients had one atheroma. They ranged in size from 3 mm to 1.5 cm (mean 6.5 mm). One atheroma was flat, two were filiform, and seven were protruding. Gadolinium-enhanced MRA is superior to TEE for the diagnosis of atheromas of the innominate artery. In the setting of right cerebral or right arm embolization, when no source is seen in the arch on TEE, gadolinium-enhanced MRA should be considered.

Minimally invasive aortic valve replacement: echocardiographic and clinical results.

BACKGROUND: Port access has been described for mitral and bypass surgery. The purpose of this study was to review the clinical and echocardiographic outcomes of aortic valve replacement by use of port access. METHODS: Between 1996 and 1999, 153 port-access aortic valve replacements were performed at our institution. The mean age was 63 years (range 16-91 years); 58% were male. The New York Heart Association mean class was III; 18% were in class IV. Thirteen percent had diabetes, 42% hypertension, 7% prior transient ischemic episode or stroke, 7% lung disease, 3% renal failure, and 13% previous surgery. Echocardiograms were obtained after valve replacement in 125 patients (96 intraoperative transesophageal and 97 transthoracic echoes). RESULTS: Median length of stay was 8 days. There were no intraoperative deaths; 10 patients (6.5%) died in the postoperative period. Stroke occurred in 4 (2.6%), sepsis in 5 (3.3%), renal failure in 5 (3.3%), pneumonia in 3 (2%), and wound infection in 1 (0.7%). Tissue prosthesis was present in 83 and a mechanical prosthesis in 42. No or trace regurgitation was seen on 94 of 96 (98%) postbypass intraoperative echocardiograms and mild on 2. On follow-up echocardiograms, moderate regurgitation was seen in 4 of 97 (4.1%), mild-to-moderate in 2 (2.1%), mild in 18 (18.6%), and no or trace in 71 (73.2%). Of those who had aortic regurgitation on intraoperative or follow-up echocardiograms, it was paravalvular in 8. CONCLUSIONS: Minimally invasive aortic valve replacement with a port-access approach is feasible, even in high-risk patients. Small incisions, a low infection rate, and a short length of stay are attainable. However, the complications associated with traditional aortic valve replacement still occur. Echocardiography is valuable both for intraoperative monitoring and follow-up of this new procedure.

Acquired aorta-pulmonary artery fistula: diagnosis by multiple imaging modalities.

Acquired communication between the aorta and the pulmonary artery is a rare phenomenon. We describe two patients with a thoracic aortic aneurysm in whom the diagnosis of a communication with the pulmonary artery was first made on transthoracic echocardiography and then more completely elucidated by means of multiple imaging modalities: transesophageal echocardiography, epiaortic ultrasound, computed tomography, and magnetic resonance imaging. Representative images from these complementary studies are presented. A successful repair of the fistula was subsequently accomplished in both patients.

How useful is hand-carried bedside echocardiography in critically ill patients?

OBJECTIVES: The study compared a hand-carried echocardiography (HC) device with standard echocardiography (SE) in critically ill patients. BACKGROUND: Recently, small HC devices have been introduced, and early reports showed a good correlation with SE. METHODS: We used HC (SonoSite, Bothell, Washington) echocardiography to evaluate critically ill patients, and we compared the results with SE obtained with state-of-the-art equipment (Sonos 5500, Hewlett-Packard, Andover, Massachusetts). Each of 80 critically ill patients was studied twice (HC and SE). The studies were done and interpreted separately in blinded fashion. RESULTS: The HC device missed a clinical finding related to the reason for referral in 31% of patients. In 19% of patients a clinically important finding separate from the indication for echocardiography was also missed. The total number of patients with one or more missed findings was 36 (45%). Findings were missed by HC for several reasons. First, HC does not contain spectral Doppler, electrocardiographic, or M-mode capabilities. Two-dimensional imaging is superior on SE, with improved image processing. In addition, although HC does contain color power Doppler, it does not have true color flow Doppler imaging. Therefore, HC often failed to detect or accurately quantify valvular regurgitation. CONCLUSIONS: Although the HC device was able to provide important anatomic information, the device falls far short of SE in the evaluation of critically ill patients.

Pulmonary venous flow in large, uncomplicated atrial septal defect.

BACKGROUND: The pulmonary venous flow velocity pattern (PVFVP) in atrial septal defect (ASD) has not been previously studied in detail. Normally, PVFVP is primarily determined by the left heart performance. We hypothesized that the impact of left-sided heart dynamics on PVFVP is diminished in patients with ASD because of the presence of a left-to-right shunt into the low-resistance right side of the heart. METHODS AND RESULTS: Transesophageal echocardiography was performed in 19 adults and 3 children with a large, uncomplicated secundum ASD (maximum diameter 0.6 to 3.0 cm). All patients were in normal sinus rhythm with an average heart rate of 78 bpm in adults and 116 bpm in children. In 21 subjects the antegrade PVFVP lacked distinct systolic (S) and diastolic (D) waves. Instead, we observed a single continuous antegrade wave extending from the beginning of systole to the onset of atrial contraction. Furthermore, the amplitude of the atrial reversal (AR) wave was smaller than in historical controls. In 3 patients in whom ASD was surgically repaired, we observed an immediate return of distinct S and D waves postoperatively. This confirmed that PVFVP abnormality was indeed the result of the ASD. Also a large increase in the AR wave amplitude (46 + 15 cm/s) was noted postoperatively. CONCLUSIONS: This previously unrecognized PVFVP comprising a single continuous antegrade wave and a diminished AR wave sheds new light on the hemodynamics of ASDs. Its presence may also alert the echocardiographer to the possibility of an ASD when the septal defect cannot be visualized directly.

Homograft pulmonic stenosis after the Ross procedure: evaluation of the stenotic valve area by proximal isovelocity surface area (PISA).

The proximal isovelocity surface area (PISA) technique has been used to evaluate valvular regurgitant flow, regurgitant orifice area, and stenotic valve area. This report shows the usefulness of this Doppler technique in quantifying the stenotic valve area of a pulmonic valve homograft prosthesis after the Ross procedure. The patient was a 35-year-old man who had a Ross procedure 3 years earlier for aortic stenosis, which included replacement of the pulmonic valve with a cryopreserved homograft pulmonic valve. With an aliasing velocity set at 40 cm/s and a PISA radius of 1.1 cm, the pulmonic valve area was calculated as follows: Pulmonic valve peak flow rate = 2 x3.14 x1.12 x40 = 304 mL/s; Pulmonic valve area = Peak flow rate / Peak velocity = 284/350 = 0.87 cm2.

Infiltrative nonamyloidotic monoclonal immunoglobulin light chain cardiomyopathy: an underappreciated manifestation of plasma cell dyscrasias.

BACKGROUND: Infiltrative cardiomyopathies are characterized by diastolic dysfunction. In monoclonal plasma cell dyscrasias, organ compromise may be produced by tissue deposition of monoclonal immunoglobulins or their constituent peptides independently of the effects of unbridled plasma cell proliferation. The deposits may be fibrillar, as in light chain amyloid (AL) or nonfibrillar, as in light chain deposition disease (LCDD). AL disease of the heart is a restrictive cardiomyopathy. We hypothesized that, despite differences in physical properties, nonamyloidotic light chain deposition in the myocardium could produce similar clinical and physiological abnormalities. METHODS: Cardiac tissue from five patients with LCDD and cardiac dysfunction was examined by immunohistochemical and electron microscopic techniques. Hospital charts, electrocardiograms, echocardiograms and cardiac catheterization results were reviewed. In two cases, the original echocardiograms were reanalyzed. RESULTS: The five patients with nonamyloidotic light chain deposits in the myocardium had either mechanical or electrocardiographic abnormalities. In four with adequate clinical documentation, the diastolic dysfunction and conduction abnormalities were similar or identical to that described in cardiac AL disease. CONCLUSIONS: Although nonamyloidotic immunoglobulin light chain deposits in the myocardium differ in distribution and ultrastructural organization from the fibrillar deposits of AL disease, an analogous pattern of diastolic dysfunction and conduction disturbances results. The diagnosis should be considered in patients with a plasmacytic dyscrasia and restrictive cardiomyopathy in whom Congo red staining of endomyocardial biopsy tissue is negative. The diagnosis can be established by using the appropriate immunohistochemical and ultrastructural tissue examinations.

Diagnosis of a giant coronary aneurysm with multiple imaging modalities.

Echocardiography demonstrated an 8-cm mass adjacent to the right side of the heart in a 79-year-old man with a history of hypertension and a repaired abdominal aortic aneurysm. The results of Doppler echocardiography and magnetic resonance imaging suggested the diagnosis of an unusually large coronary artery aneurysm, and this was confirmed with coronary angiography. At surgery, the 8- to 10-cm coronary aneurysm was resected, and the patient made an uneventful recovery.

Surgical left atrial appendage ligation is frequently incomplete: a transesophageal echocardiograhic study.

OBJECTIVES: This study sought to determine the incidence of incomplete ligation of the left atrial appendage (LAA) during mitral valve surgery. BACKGROUND: Ligation of the LAA to prevent future thromboembolic events is commonly performed during mitral surgery. However, success in completely excluding the appendage from the circulation has never been systematically assessed. METHODS: Using transesophageal Doppler echocardiography, we studied 50 patients who underwent mitral valve surgery and ligation of the LAA. Thirty patients were studied immediately postoperative, and 20 patients were studied 6 days to 13 years after surgery. Incomplete ligation was detected by demonstrating a color jet traversing the separation between the left atrial body and appendage. RESULTS: Transesophageal echocardiography detected incomplete LAA ligation in 18 of 50 (36%) patients. The incidence of incomplete ligation was not significantly different between patients studied immediately postoperative and patients studied at various times after surgery. Type of mitral surgery (repair vs. replacement), operative approach (sternotomy vs. port access), left atrial size or degree of mitral regurgitation did not significantly correlate with the incidence of incomplete appendage ligation. However, the power to detect a significant difference in left atrial size was only 64%. Spontaneous echo contrast or thrombus was identified within appendages in 9 of 18 (50%) patients with incomplete ligation, while 4 of these 18 (22%) patients had thromboembolic events. CONCLUSIONS: Surgical LAA ligation is frequently incomplete. The similar incidence of incomplete ligation detected immediately postoperative and at various times thereafter suggest that this results from an intraoperative phenomenon rather than from gradual dehiscence of sutures over years. The incidence of incomplete left atrial ligation was unrelated to type of surgery, surgical approach, left atrial size or degree of mitral regurgitation. Residual communication between the incompletely ligated appendage and the left atrial body may produce a milieu of stagnant blood flow within the appendage and be a potential mechanism for embolic events.

Aortic valve replacement in patients with aortic stenosis and severe left ventricular dysfunction.

BACKGROUND: The outcome of aortic valve replacement for severe aortic stenosis is worse in patients with impaired left ventricular function. Such dysfunction in aortic stenosis may be reversible if caused by afterload mismatch, but not if it is caused by superimposed myocardial infarction. METHODS: From our echocardiography database, 55 patients with severe aortic stenosis (valve area < or =0.75 cm2) and ejection fractions of 30% or lower who subsequently underwent aortic valve replacement were included. The operative mortality and clinical follow-up were detailed. RESULTS: There were 10 perioperative deaths (operative mortality, 18%). Twenty (36%) of the 55 patients had a prior myocardial infarction. In the 35 patients without prior myocardial infarction, there was only 1 death (3%). In contrast, 9 of 20 patients with prior myocardial infarction died (mortality rate, 45%; P< or =.001). The factors significantly associated with perioperative death on univariate analysis (functional class, mean aortic gradient, and prior myocardial infarction) were entered into a model for stepwise logistic regression. This multivariate analysis showed that only prior myocardial infarction was independently associated with perioperative death (odds ratio, 14.9; 95% confidence interval, 2.4-92.1; P = .004). CONCLUSIONS: The risk of aortic valve replacement in patients with severe aortic stenosis and severely reduced left ventricular systolic function is extremely high if the patients have had a prior myocardial infarction. This information should be factored into the risk-benefit analysis that is done preoperatively for these patients, and it may preclude operation for some.

Atheromas of the thoracic aorta: clinical and therapeutic update.

Atherosclerotic lesions of the thoracic aorta have recently been recognized as an important cause of stroke and peripheral embolization, which may result in severe neurologic damage as well as multiorgan failure and death. Their prevalence is approximately 27% in patients with previous embolic events. Transesophageal echocardiography is the modality of choice for the diagnosis of these atheromas, although computed tomography, magnetic resonance imaging and intraoperative epiaortic ultrasound are complementary. Two clinical syndromes account for the embolic phenomena, atheroemboli and, more commonly, thromboemboli. In addition to such superimposed thrombi, plaque thickness (especially > or =4 mm) also correlates with embolic risk. This risk is high, with 12% of patients having a recurrent stroke within approximately one year, and up to 33% of patients having a stroke or peripheral embolus. In addition, aortic atheromas (as seen with intraoperative transesophageal echocardiography and intraoperative epiaortic ultrasound) are an important cause of stroke during heart surgery requiring cardiopulmonary bypass. Such strokes occur during approximately 12% of cardiac operations employing cardiopulmonary bypass when aortic arch atheromas are seen with transesophageal echocardiography (six times the general intraoperative stroke rate). Although anticoagulant strategies have been reported with encouraging results in nonrandomized studies, prospective, randomized data must be developed before an effective and safe treatment strategy can be determined. This review details the current state of knowledge in this area, including the clinical and pathologic evidence that thoracic aortic atherosclerosis is an important embolic source, data which guide current therapy and future directions for clinical investigation.