Effect of pericardial pressure on human coronary circulation

A 52-year-old patient underwent percutaneous balloon pericardiotomy because of rapid fluid accumulation. During the procedure, we calculated the amoun t of blood flow to the nondiseased left anterior descending coronary artery while pericardial pressure was gradually increased by the infusion of warm ed normal saline solution. Coronary vasodilator reserve was assessed by int racoronary adenosine. With increasing pericardial pressure, there mas a con tinuous decline in coronary blood flow, due to an increase in coronary vasc ular resistance, and an unaffected hyperemic response throughout. The maxim al hyperemic flow was far less under increased pericardial pressure than at normal pressure, which implies an augmented susceptibility to myocardial i schemia.