Coronary perfusion pressure is the pressure gradient between the right atrial diastolic pressure and the aortic diastole pressure. Coronary perfusion pressure is extremely beneficial when administering CPR as it shows the flow of blood to the heart muscle. Coronary perfusion pressure correlates with the coronary blood flow and determines the outcome during a cardiac arrest. Coronary perfusion pressure therefore determines whether the CPR is adequately being performed and maintaining appropriate perfusion to the heart muscle. The CPP minimum is 15 mm Hg for spontaneous profusion of circulation. Coronary perfusion pressure can also indicate blockages, oxygen consumption of the heart muscle and heart failure.
Measure the diastole atrial pressure by using the doppler flowmetry technique. Diastole atrial pressure is the pressure inside the heart muscle when the arteries are relaxed. The lowest relaxed arterial pressure in the aorta just before the ventricle ejects blood into the aorta.
Measure the left ventricular diastolic pressure with the Doppler flowmetry method. Ventricular pressure is normally less than the pressure in the aorta, however ventricular pressure increases rapidly. Elevated left ventricular pressure is a risk factor during any cardiac procedure. The flow of blood to the left ventricle occurs normally during diastole and is determined by the coronary artery pressure or the diastolic pressure minus the left ventricular diastolic pressure, the diastolic interval and the coronary vasodilation.
Take the pulmonary artery occlusion pressure or PAOP which reflects the left ventricular end-diastolic pressure. The LVEDP is the amount of pre-loading of pressure on the ventricular coronary fibres before the systole pressure starts. This is extremely important in calculating the coronary performance because as the pre-loading increases, the contractile force increases in the heart muscle
Minus the aortic diastole pressure from the left ventricular diastolic pressure and it gives the cardiac perfusion pressure rate. CPP can therefore be calculated using this equation DAP - PAOP = CPP.
Things you need
- Reflected ultrasound, echocardiogram or doppler flowmeter
- "The Journal of the American Medical Association"; Coronary Perfusion Pressure in CPR; 1990
- "European Journal of Anaesthesiology"; Calculating Coronary Perfusion; May 2006; Volume 23, Issue 5
- "Oxford Journals"; Coronary Perfusion Related Changes in Myocardial Contractile Force and Systolic Ventricular Stiffness