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.

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.

Thromboembolus from a ligated left atrial appendage.

The left atrial appendage of patients with mitral valve disease is commonly a source of thromboembolus and is often ligated during mitral valve surgery to diminish this risk. However, ligation is often incomplete. We describe a patient with a stroke whose only source of embolus was an incompletely ligated left atrial appendage. Attempts to exclude the left atrial appendage from the arterial circulation by suture ligation may not decrease the risk of thromboemboli and instead may increase such risk.

Electrical modulation of cardiac contractility: clinical aspects in congestive heart failure.

Heart failure is a highly prevalent disease in western society. Drug therapies aimed at increasing myocardial contractility have been associated with decreased survival. Several short and mid term clinical studies have suggested adjuvant or alternative therapies to congestive heart failure using modified pacing techniques that were aimed to increase contractility (e.g. Paired pacing) or restore synchrony of contraction (biventricular pacing). While delivery of paired pacing was abandoned during the early 70's, biventricular pacing has recently emerged as an adjuvant treatment to limited group of congestive heart failure patients with aberrant left ventricular conduction. In this brief review, we describe our initial safety and efficacy experience in patients with heart failure using a novel non-stimulatory electrical approach to the delivery of positive inotropic therapy to the failing myocardium. The study suggests that unlike modified pacing techniques, delivery of the signal to the left ventricle during the refractory period resulted in a rapid increase in myocardial contractility and improved hemodynamic performance. The near instantaneous contractility improvement achieved by this type of stimulus was shown to be safe and effective independently of the primary cause of heart failure or the function of the conduction system. Unlike pharmacologic treatments, which have a relatively constant effect, use of electrical stimuli may prove useful as a new therapeutic modality in the treatment of heart failure with which contractility can be improved when and as needed.