Transesophageal echocardiographically guided atrial transseptal catheterization in patients with normal-sized atria: incidence of complications.

The incidence of cardiac complications from atrial transseptal catheterization has never been quantified in patients with normal-sized atria. Series defining the complication rate are derived from diseased hearts with structural changes that may alter the complication rate of the procedure. The generation of a standardized incidence of perforation in a population of structurally normal atria has important implications. A total of 46 atrial transseptal catheterizations guided by transesophageal echocardiography (TEE) for radiofrequency ablation of left-sided accessory pathways was performed in 42 patients during a 3-year period (1990-1993). Clinical and echocardiographic data were analyzed, with special attention given to TEE reports pre- and post-transseptal catheterization. Only one complication occurred in the 46 procedures (2.2%): a perforation of the left atrium that led to pericardial effusion and cardiac tamponade. In a small series of patients with normal sized atria, we have demonstrated that TEE-guided transseptal catheterization in a procedure with a low complication rate.

Fee-for-service versus capitation-based reimbursement: how the payment method affects utilization of echocardiographic services by referring physicians.

Historically, health insurance carriers (HIC) have reimbursed physicians on a fee-for-service basis for echocardiographic studies. With the emergence of managed care, the HIC now may have the option of paying on a capitation basis. To determine whether the method of reimbursement had any bearing on the types of patients referred for echocardiographic services, we conducted a two-phase (retrospective) study. In Phase One, we assessed two groups of ambulatory patients with regard to patient characteristics, medical reason for referral, and echocardiographic results. Group A (4,066 patients) had insurance plans that stipulated reimbursement for echocardiographic services as part of capitation for cardiology services. Group B (3,061 patients) had plans that reimbursed for echocardiographic services on a fee-for-service basis. In Phase Two, we assessed a total of 5,947 patients (3,833 from Group A and 2,114 from Group B) over a period of 40 months to determine the frequency of referral for a second echocardiogram within 2 years of a normal one and the repeat normalcy rate. The results showed that the capitation reimbursement group included younger, predominantly female patients who were referred more often for a more benign reason and who more frequently were diagnosed echocardiographically with less severe disease, higher rates of normalcy, and repeat normalcy. These findings suggest that in our geographic area the capitation method of reimbursement permitted more liberal utilization of echocardiographic services. In this era of cost awareness, the study suggests the need for better screening of patients referred for echocardiographic services.

Ablation of left free-wall accessory pathways using radiofrequency energy at the atrial insertion site: transseptal versus transaortic approach.

INTRODUCTION: Transcatheter ablation of the left free-wall atrioventricular accessory pathways (AP) by delivery of radiofrequency current at the ventricular insertion site has been shown to be effective. The efficacy of such a technique targeting the atrial insertion site of the AP was evaluated. METHODS AND RESULTS: One hundred consecutive patients with left free-wall APs and symptomatic supraventricular tachyarrhythmias were included. APs were manifest in 55 patients and concealed in 45. There were 55 men and 45 women with a mean age of 35 years. A total of 107 left free-wall APs were identified in these patients. In these 100 patients, successful ablation was accomplished in all by using a transseptal (45 patients) or transaortic (54 patients) technique. In one patient, ablation was accomplished from within the coronary sinus. Seven patients required a repeat ablative procedure, which was performed successfully. During 107 ablative procedures, six were associated with nonfatal complications including pericardial effusion (hemopericardium) in two patients, mild mitral regurgitation in two patients, swelling of the left arm in one patient, and staphylococcal bacteremia in one patient. Eighty-two (82%) patients underwent a repeat electrophysiologic study 6 to 8 weeks after successful ablation and were found to have no functioning AP or inducible supraventricular tachycardia. During a mean follow-up of 20 +/- 8 months, none of the 100 patients had a recurrence of tachyarrhythmias. CONCLUSION: These data indicate that the atrial insertion site of the AP can be successfully ablated in the majority of patients with left free-wall APs by using either a transseptal or transaortic approach. Furthermore, both techniques are associated with minimal morbidity and no mortality.

Transesophageal echocardiography with a single-plane probe. Long-axis views of the heart from the apical (transgastric) approach.

The literature suggests that during transesophageal echocardiography (TEE), a short-axis view can be obtained in the gastric position using a single-plane probe. Recently, we have found that a long-axis apical display of the heart can be achieved by placing the tip of the probe in the fundus of the stomach. In a 3-month period, we attempted to obtain this view in 54 consecutive patients. Twelve of the patients had TEE done under general anesthesia, while the other 42 patients had the procedure performed under sedation with midazolam at hospital bedside or as an outpatient. The long-axis transgastric view was obtained in 51 of the 54 patients (94%). The image quality was graded subjectively as good in 39 (72%) and fair in the other 12 patients (22%). This view helped to establish the diagnosis in eight patients (15%) and to increase the level of confidence about the accuracy of the diagnosis in 23 (43%) other patients. Four patients' findings are described. We conclude that the new long-axis transgastric view is easy to obtain, does not add much time to the usual TEE study, does not add to the low complication rate of TEE, and may help to interrogate the distal structures of the heart.

Variations in the cell-free translating apparatus of cultured animal cells as a function of time during cell growth.

Vero M3 cells, a line derived from the kidney of an African Green Monkey, display certain alterations in their protein synthetic apparatus as a function of time during a growth cycle. (Growth cycle here refers to exponential growth of unsynchronized cells in culture and their subsequent passage into the stationary phase.) The capacity of cytoplasmic extracts of these cells to promote endogeneous mRNA-mediated polypeptide synthesis or poly U-mediated polyphenylalanine synthesis declines from the second day after the initiation of the growth cycle. The ribosome sedimentation profile indicates that after the second day of growth a decrease also occurs in the total amount of ribosomes per cell, and that a shift occurs from predominantly polyribosome structures to predominantly subunits and monoribosomes structures. The activity of the translation factor, elongation factor 1, also progressively decreases after the second day of growth. Furthermore, when crude factor preparations from cells in the second day of growth (Exponential phase) and from cells in the fifth day of growth (Stationary phase) are compared for leucyl-tRNA synthetase and prolyl-tRNA synthetase activities, it is found that the extracts from fifth-day cells have significantly less activity. The activity of another enzyme, acid phosphatase, remains relatively unaffected as a function of time during the cell growth cycle. When HeLa S3 plating cells are grown under the same conditions, they do not display the same responses.