Percutaneous transluminal coronary angioplasty (PTCA) has had complications related to dilating catheters and guide wires such as coronary artery dissection, spasm, rupture, and perforation. This report describes four patients who developed cardiac tamponade following PTCA, presumably from right ventricular (RV) perforation. All four received large doses of heparin during PTCA and three received antiplatelet therapy. In three cases, cardiac tamponade occurred several hours after PTCA. All patients did well following operative intervention and no patient required repair of a cardiac perforation. We postulate that impaired hemostasis in the presence of an otherwise inconsequential RV perforation causes tamponade. Three alternatives to provide standby pacing are proposed.

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The decline of the activated partial thromboplastin time (APTT) following discontinuation of heparin infusion was measured in six intra-aortic balloon pump (IABP) patients. The heparin infusion requirement was determined for eight other IABP patients during stable therapeutic anticoagulation. Following discontinuation of infusion, APTT declined with a relatively constant half-life (t 1/2 of 2.4 +/- 0.08 hr, suggesting elimination by first-order kinetics. In comparison, the t 1/2 following single bolus doses has been shown to be markedly dose dependent, increasing from 30 min at low doses to 2 hr at very high doses. The heparin requirement for IABP patients was found to be 16 +/- 2.5 U/kg/hr, similar to that reported for other clinical situations. The t 1/2 of the APTT following discontinuation of heparin infusion can be used to time invasive procedures that would best be done with normal hemostasis.

We compared visual estimate and digital caliper measurement of coronary stenoses, utilizing both a 50% and 70% diameter reduction as a definition of significance and both experienced angiographers and cardiology fellows as readers. Ten angiograms were interpreted twice, using the different methods, by four readers, two months apart. The angiograms were divided into 12 vessel segments. Stenoses were judged more severe by visual estimate in 11 segments. Seven of twelve segments had significant differences between readers using the visual estimate, but no significant differences were obtained using caliper measurements. Variability was highest for fellows using the visual method. Interobserver agreement was highest using the digital caliper and the 70% criteria. Intraobserver agreement was most dependent on the amount of time taken in film interpretation. The digital caliper appears to be preferable in interpreting angiograms, particularly for cardiology fellows.

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A method for inserting two catheters into a subclavian vein, using a single puncture, is described. Ten patients are reported in whom pulmonary arterial and temporary pacing catheters were inserted by this method. Similar techniques are discussed.

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