Transesophageal echocardiographic description of the mechanisms of aortic regurgitation in acute type A aortic dissection: implications for aortic valve repair.

OBJECTIVES: The purpose of this study was to use transesophageal echocardiography (TEE) to define the mechanisms of aortic regurgitation (AR) in acute type A aortic dissection so as to assist the surgeon in identifying patients with mechanisms of AR suitable for valve preservation. BACKGROUND: Significant AR frequently complicates acute type A aortic dissection necessitating either aortic valve repair or replacement at the time of aortic surgery. Although direct surgical inspection can identify intrinsically normal leaflets suitable for repair, it is preferable for the surgeon to correlate aortic valve function with the anatomy prior to thoracotomy. METHODS: We studied 50 consecutive patients with acute type A aortic dissection in whom preoperative TEE findings were considered by the surgeons in planning aortic valve surgery. Six patients did not undergo surgery (noncandidacy or refusal) and one patient had had a prior aortic valve replacement and therefore was excluded from the analysis. RESULTS: Twenty-seven patients had no or minimal AR and 22 had moderate or severe AR. In all, there were 16 with intrinsically normal leaflets who had AR due to one or more correctable aortic valve lesion: incomplete leaflet closure due to leaflet tethering in a dilated aortic root in 7; leaflet prolapse due to disrupted leaflet attachments in 8; and dissection flap prolapse through the aortic valve orifice in 5. Of these 16 patients, 15 had successful aortic valve repair whereas just 1 underwent aortic valve replacement after a complicated intraoperative course (unrelated to the aortic valve). Nine patients underwent aortic valve replacement for nonrepairable abnormalities, including Marfan's syndrome in four, bicuspid aortic valve in four, and aortitis in one. In patients undergoing aortic valve repair, follow-up transthoracic echocardiography at a median of three months revealed no or minimal residual AR, and clinical follow-up at a median of 23 months showed that none required aortic valve replacement. CONCLUSIONS: When significant AR complicates acute type A aortic dissection, TEE can define the severity and mechanisms of AR and can assist the surgeon in identifying patients in whom valve repair is likely to be successful.

Penetrating atherosclerotic aortic ulcers.

Penetrating atherosclerotic aortic ulceration is a unique disease with distinct management and prognostic implications. It is an important clinical entity that must be distinguished from classic aortic dissection and rapid expansion or contained rupture of a thoracic aortic aneurysm. Although symptoms of penetrating aortic ulceration may mimic dissection, the characteristic signs of dissection are absent. New imaging modalities have made it possible to establish the diagnosis of penetrating aortic ulceration with a high degree of accuracy and to tailor management according to the presence of complications. Physicians should be aware of the possibility of atherosclerotic aortic ulceration, particularly in elderly patients with systemic atherosclerosis and hypertension who have sudden onset of chest or back pain.

Directional coronary atherectomy in women compared with men.

The influence of gender on the procedural outcome of directional coronary atherectomy (DCA) is controversial. This study of 373 consecutive patients (418 lesions) undergoing DCA demonstrates that the procedural success rate of DCA is significantly lower in women compared with men (72.7 vs. 82.9%, p = 0.011). Women have significantly smaller coronary arteries than men (2.5 mm vs. 2.7 mm, p = 0.028) and were older than men (66 vs. 61 years, p = 0.0001). Multivariate analysis identifies small coronary vessel size rather than female gender per se as an independent predictor of poor procedural outcome. Procedural success rates in women with coronary vessel size > or = 2.5 mm is significantly higher (92.2%) than in women with coronary vessel size < 2.5 mm (73.1%), and parallels that in men with vessel size > or = 2.5 mm (89.3%). Inability to engage the ostium of the coronary artery adequately with the guiding catheter and to cross the lesion with the atherectomy device is significantly more common in women compared with men. Major ischemic complication rates are similar in women and men (8.5 vs. 8.7%). Groin complications are significantly more common in women compared with men (13.5 vs. 2.9%). We conclude that procedural success rates in women may be improved by careful patient selection, with particular attention to small vessel size. DCA is best performed in vessels > 2.5 mm in diameter.

Long-term follow-up of mitral paraprosthetic regurgitation by transesophageal echocardiography.

Paravalvular regurgitation (PVR) is an uncommon complication of mitral valve replacement (MVR). Although severe PVR is almost always repaired immediately when recognized during surgery, there are little data available on the management of patients with mild and moderate PVR. This study includes eight patients with mild (n = 6) and moderate (n = 2) PVR identified by transesophageal echocardiography at the time of MVR who were treated conservatively. Clinical and echocardiographic follow-up was obtained at a mean of 16.3 months. Two of six patients with mild PVR at the time of MVR and two of two patients with moderate PVR at the time of MVR deteriorated clinically and echocardiographically over time. We suggest that moderate PVR should be corrected at the time of valve-replacement surgery, if this can be performed without high operative risk. Mild PVR should probably also be repaired, if this can be performed at low risk, because some will progress. Patients left with mild PVR after surgery, or patients in whom PVR is recognized only after surgery, should be followed up carefully with serial clinical and echocardiographic examinations.

Directional coronary atherectomy can be successfully performed in the elderly.

The influence of age on the clinical and angiographic outcome of directional coronary atherectomy is evaluated. Results demonstrate that DCA can be performed successfully in the vast majority (78.7-90%) of patients in all age groups. However, there is a non-statistical trend toward decreased success rates in the elderly (P > .05). Major ischemic complications and groin complications tend to be more common in the elderly (P > .05). Blood transfusions are required significantly more often in the elderly (P < .05). Directional coronary atherectomy is a useful method of coronary artery revascularization in all age groups, including the elderly.

Tissue plasminogen activator (t-PA).

Tissue plasminogen activator (t-PA) developed from recombinant DNA technology is a highly effective thrombolytic agent. Its main clinical application is in the treatment of acute myocardial infarction (MI), with most beneficial results occurring in patients treated early after the onset of symptoms. When t-PA was compared with other thrombolytic agents, such as streptokinase (SK) and anisolyted plasminogen streptokinase (APSAC), the data obtained from the mega trials (GISSI 2 and ISIS 3) revealed no significant difference in mortality. However, in the recent GUSTO trial involving 41,000 patients, t-PA-treated patients had a significantly lower mortality rate compared to SK-treated patients. Aggressive adjunctive therapy, including intravenous heparin in combination with aspirin, may have accounted for this difference.

Discrete subaortic valvular stenosis: the clinical utility and limitations of transesophageal echocardiography.

Transesophageal echocardiography (TEE) is a useful technique in the diagnosis and intraoperative assessment of discrete subaortic stenosis (DSS). It allows clear visualization of the subaortic membrane, which may be missed by transthoracic echocardiography, differentiates DSS from other causes of left ventricular outflow tract obstruction, and accurately detects the presence of associated aortic regurgitation and bacterial endocarditis. Limitations in its use include inadequate visualization of the left ventricular outflow tract by TEE in the presence of a prosthetic mitral valve or mitral annular calcification, and improper alignment of the Doppler cursor across the outflow tract.

Significant mitral regurgitation is protective against left atrial spontaneous echo contrast and thrombus as assessed by transesophageal echocardiography.

This retrospective study examines whether a relationship exists between the severity of mitral regurgitation (MR) and the presence of left atrial spontaneous echo contrast and/or thrombus (SEC/THR) as assessed by transesophageal echocardiography in 427 consecutive patients. Clinical data were evaluated in 316 of these patients. Nine percent of patients with MR < or = 2+ versus < 1% of those with MR > or = 3+ had SEC/THR (p < 0.03). Atrial fibrillation, left ventricular dysfunction, mitral stenosis, and mitral valve prosthesis were demonstrated to be independent positive predictors of left atrial SEC/THR, whereas MR > or = 3+ was an independent negative predictor of SEC/THR. SEC/THR was less common in patients with MR > or = 3+ than in patients with MR < or = 2+ for any given number of independent positive predictors of SEC/THR. This relationship did not hold true in patients with a mechanical mitral prosthetic valve. Clinical data revealed a trend towards a lower prevalence of stroke or transient ischemic attacks in patients with MR > or = 3+. Stroke and transient ischemic attacks were significantly more common in patients with SEC/THR (p < 0.001). We suggest that significant MR may be protective against the formation of left atrial SEC/THR.

Pitfalls in the echo-Doppler diagnosis of hypertrophic cardiomyopathy.

While Doppler echocardiography has become the gold standard for the diagnosis of hypertrophic cardiomyopathy, there are many pitfalls in its use. Some of these pitfalls are technical in nature resulting from inadequate image quality, incorrect transducer angulation, and improper equipment settings. Other pitfalls relate to the diversity and heterogeneity in defining hypertrophic cardiomyopathy and to the host of disorders that may mimic it by echocardiography. The pattern and extent of ventricular hypertrophy, systolic anterior motion of the mitral valve, and Doppler determination of left ventricular outflow tract obstruction, diastolic dysfunction, and mitral regurgitation are discussed, as are wall-motion abnormalities and myocardial echo reflectivity. While these echocardiographic features of hypertrophic cardiomyopathy are nonspecific when seen in isolation, their combined presence in the appropriate clinical setting makes the diagnosis likely.

Transesophageal echocardiographic evaluation of a transthoracic echocardiographic pitfall: a diaphragmatic hernia mimicking a left atrial mass.

Diaphragmatic hernia may mimic a left atrial mass when imaged by transthoracic echocardiography. In this case study we emphasize the value of transesophageal echocardiography in clarifying the cause of this apparent atrial mass.