Automatic Computation for Pressure Controlled Intermittent Coronary Sinus Occlusion

Pressure controlled intermittent coronary sinus occlusion (PICSO) has been found to substantially salvage ischemic myocardium. By elevating venous pressure two mechanisms are involved namely the distention of venous vessels inducing mechanotransduction as well as a redistribution of venous flow towards ischemic areas. Mechanotransduction in endothelial cells inducing changes in the ischemic heart inducing myocardial salvage as well as myocardial recovery is blunted by possible consequences of myocardial perfusion deficits by limiting coronary inflow. To limit these severe side effects we have evaluated a new mathematical model to describe the Increase (Inflation) and decrease (deflation) in coronary Sinus pressure (CSP) following pressure controlled intermittent coronary sinus occlusion (PICSO) and release. The model is evaluated and compared on the basis of dogs, pigs and sheep. The model consists of two parts with three parameter double exponential function for each, and it was fitted by using the non-linear least squares algorithms. The new model was used in implementation of automatic computing module which is responsible to compute the following quantities for Inflation and Deflation: 1. Systolic and diastolic plateau. 2. Rise-Time of systolic and diastolic plateau. 3. The mean integral of the CSP (Area under the curve). 4. Number of heart beats impact in inflation and deflation periods. 5. Driving the slope of CSP Corresponding quantities for various coronary sinus balloon inflation and deflation cycles were computed with ranging from cycles being as short as 5sec/3sec (inflation/deflation ratio) to cycles as long as 12sec/8sec.