| dc.contributor.author | MacLeod, Robert Scott. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:40Z | |
| dc.date.available | 1990 | |
| dc.date.issued | 1990 | en_US |
| dc.identifier.other | AAINN64428 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55180 | |
| dc.description | Percutaneous transluminal coronary angioplasty (PTCA) is a palliative therapy for coronary artery disease in which a balloon-tipped catheter is inserted into a partially occluded coronary artery and inflated to pressures of 4-12 bar for durations of 10-300 s. The resulting block of antegrade blood flow provides an experimental model of ischemia which has been studied in this dissertation. The technique of body surface potential mapping (BSPM) was used to continuously record 117-lead ECGs from patients undergoing PTCA; isointegral maps recorded before inflation of the balloon were subtracted from those recorded during inflation to produce isointegral difference maps. Based on these difference maps, the inflations could be separated into groups which corresponded to the coronary artery which had been dilated. | en_US |
| dc.description | A mathematical solution to the inverse problem in electrocardiography was developed by which epicardial potential distributions could be calculated from body-surface distributions. This inverse solution was validated directly using simulated potentials from a single dipole source, and also indirectly by using the isointegral maps recorded during PTCA. From angiographic information of each patient's coronary circulation and the location of the PTCA balloon, it was possible to estimate the perfusion bed, and thus the ischemic region, for each inflation. While the angiographically determined location of the PTCA-induced ischemia agreed with a region predicted by the model, the inverse solution also yielded secondary regions predicted ischemia which could not be accounted for by clinical evidence. These results suggest that it is possible to construct a stable and useful inverse solution, which allows the recovery of the location of PTCA-induced ischemia in humans. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1990. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biophysics, Medical. | en_US |
| dc.title | Percutaneous transluminal coronary angioplasty as a model of cardiac ischemia: Clinical and modelling studies. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
