The American journal of cardiology
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In this study, we sought to determine the use of transesophageal echocardiography (TEE) as the primary imaging technique to assist in the placement of endovascular catheters during minimally invasive, port-access cardiac surgery. The recent development of endovascular catheters that are placed via the femoral artery and vein has enabled patients to be placed on cardiopulmonary bypass without the need for direct visualization of the heart or great vessels via sternotomy. This has allowed cardiac surgery to be performed through smaller thoracotomy incisions. ⋯ TEE was able to adequately visualize the cardiac structures and assist in the placement of the endovascular catheters in all patients. Fluoroscopy was only helpful as an aid to TEE for placement of the coronary sinus catheter. TEE is an excellent imaging modality for the proper placement of these new endovascular catheters, obviating the need for fluoroscopy, except to be on standby and for placement of the coronary sinus catheter.
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It has been shown that beta-adrenergic blocking agents may reduce the rate of aortic root dilation and the development of aortic complications in patients with the Marfan syndrome. This may be due to beta-blocker-induced changes in aortic stiffness, of which distensibility and pulse wave velocity are in vivo measurable derivatives. We studied changes in distensibility at 4 levels of the aorta and pulse wave velocity along the entire aorta after 2 weeks of beta-blocker therapy in 6 Marfan syndrome patients and in 6 healthy volunteers, using magnetic resonance imaging (MRI) combined with brachial artery blood pressure measurements. ⋯ At baseline, the Marfan syndrome patients exhibited decreased distensibility at the level of the ascending aorta (2 +/- 1 vs 6 +/- 2 10(-3)mm Hg(-1), p <0.01) and increased pulse wave velocity (6.2 +/- 0.4 vs 3.9 +/- 0.4 ms(-1), p <0.01) compared with control subjects. Only the Marfan syndrome patients had a significant increase in aortic distensibility at multiple levels and a significant decrease in pulse wave velocity after beta-blocker therapy (ascending aorta distensibility: 2 +/- 1 vs 4 +/- 1 10(-3)mm Hg(-1), p <0.05; abdominal aorta distensibility: 5 +/- 2 vs 8 +/- 3 10(-3)mm Hg(-1), p <0.05; pulse wave velocity: 6.2 +/- 0.4 vs 5.0 +/- 1.0 ms(-1), p <0.05). Thus, aortic stiffness in Marfan syndrome, together with mean blood pressure, is reduced by beta-blocker therapy, and MRI is well suited to detect these changes by measuring distensibility and pulse wave velocity.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Differences between local investigator and core laboratory interpretation of the admission electrocardiogram in patients with unstable angina pectoris or non-Q-wave myocardial infarction (a Thrombin Inhibition in Myocardial Ischemia [TRIM] substudy).
The present study compares the on-site interpretation of an admission electrocardiogram (ECG) with core laboratory results in a large, multicenter trial of 516 patients diagnosed with unstable angina pectoris or non-Q-wave myocardial infarction. The local investigators evaluated the admission ECG regarding ST-T changes before the ECGs were sent to the core laboratory for blinded interpretation. The strength of agreement between the observations was described by kappa statistics. ⋯ Independent variables, including peak creatine kinase-MB and 30-day outcome, were more closely related to core laboratory results than the local investigator's interpretation of the admission ECG. Thus, in the present study, considerable differences were demonstrated between the on-site interpretation of the admission ECG and the blinded evaluation performed in the core laboratory regarding relatively simple electrocardiographic variables. The results suggest that more widespread use of independent evaluation of clinical data should be incorporated in future clinical trials.