Predictors of conversion to sinus rhythm using ibutilide for atrial fibrillation or flutter.

To determine what factors can predict conversion to sinus rhythm, we retrospectively studied 201 consecutive patients who received ibutilide for treatment of atrial fibrillation or flutter. On multivariate analysis, the following factors were significantly associated with conversion: recent onset of arrhythmia, an underlying atrial flutter rhythm, lack of a history of congestive heart failure, and lack of concomitant digoxin therapy.

Echocardiographic diagnosis of left ventricular outflow tract obstruction caused by an acquired subaortic membrane after mitral valve replacement.

Although an acquired subaortic membrane has been reported as a cause of left ventricular outflow tract (LVOT) obstruction in various clinical settings, it previously has not been reported after mitral valve surgery. We describe 3 cases of acquired LVOT obstruction that resulted from development of a subaortic membrane after mitral valve replacement. This report emphasizes the role of an acquired subaortic membrane in LVOT obstruction after mitral valve replacement, the use of echocardiography in diagnosing this condition, and the importance of early intervention.

Endoluminal exclusion of an iliac artery aneurysm by Wallstent endoprosthesis and PTFE vascular graft.

Aneurysms isolated in the iliac artery and measuring more than 3 cm in diameter are associated with an increased rate of rupture and a high mortality rate. The current therapy recommended for such aneurysms is surgical exclusion. Percutaneous exclusion of isolated iliac aneurysms with covered or uncovered stents, however, reduces the morbidity and mortality rates associated with surgery by obviating the need for general anesthesia, avoiding significant blood loss, and reducing in-hospital recuperation time. We report the case of a patient who had an isolated atherosclerotic iliac artery aneurysm that was successfully excluded percutaneously by use of an endovascular prosthesis (WALLSTENT Endoprosthesis) made by Schneider (USA), Inc; Minneapolis, Minn, in conjunction with the Thin-Walled GORE-TEX (polytetrafluoroethylene) Vascular Graft (W.L. Gore & Associates, Inc.; Flagstaff, Ariz). Although various stent devices have been used recently in conjunction with a polytetrafluoroethylene graft to exclude peripheral arterial aneurysms, the self-expandable WALLSTENT has not been used with polytetrafluoroethylene in this fashion and for this purpose until recently. We present herein the technical aspects of endoluminal exclusion of the isolated iliac artery aneurysm with this composite stent-graft.

Results of a national survey on anticoagulation for PTCA.

In order to assess the current practice patterns in the United States for anticoagulation during PTCA, a survey was sent to the ACC membership. A total of 377 surveys from physicians performing PTCA were tabulated; 5 (1.3%) respondents performed < 20 PTCAs/year, 128 (34.0%) performed 20-75 PTCAs/year, 141 (37.4%) performed 75-150 PTCAs/year, 98 (26.0%) performed > 150 PTCAs/year and 5 (1.3%) did not report their volume. Seventy-eight (20.7%) were at university hospitals 153 (40.6%) were at other teaching hospitals, 142 (37.7%) were at non-teaching hospitals and 4 (1.1%) did not report their institutional affiliation. A total of 76.8% of respondents routinely started with a 10,000 U bolus of heparin, while only 3.2% of respondents used only a weight-adjusted heparin bolus. Fifty-nine percent of respondents routinely used intra-procedure heparin infusions, usually 1000 U/hr. Anticoagulation monitoring was used by 92.6% of respondents during PTCA, almost always activated clotting times (ACTs). Of the 335 physicians who used ACTs to guide heparin therapy during PTCA, 59.1% used the Hemochron device, 16.7% used the HemoTec device, and 24.2% did not know which machine they used. Lower volume operators and operators at non-teaching hospitals were more likely not to know the type of ACT machine used. Post-procedure heparin infusions (usually titrated to an aPTT > 2 x control) were used by 70.3% of respondents. Lower volume operators were more likely to use post-procedure heparin infusions. Thus, heparin therapy for PTCA continues to be largely empiric, although the vast majority of cardiologists surveyed use ACT-guided heparin therapy for the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive imaging of the cardiovascular system with electron beam computed tomography and magnetic resonance imaging.

Two new noninvasive imaging modalities have emerged in recent years that provide images of the heart and great vessels with high temporal and spatial resolution: electron beam (or ultrafast) computed tomography and magnetic resonance imaging. Because both modalities acquire images in three dimensions, they can provide unique diagnostic information above and beyond that of more traditional noninvasive modalities such as two-dimensional echocardiography and radionuclide techniques. This review discusses the technical evolution and clinical application of these two imaging techniques, with particular emphasis on progress made over the past year. Specific areas addressed for each include technical aspects and clinical applications from both the imaging and physiology perspective.