1. Discuss the pathophysiology of coronary artery atherosclerosis. Include discussion of risk factors associated with the development of this disease. (10 points)
Coronary artery atherosclerosis is most commonly comprised of atherosclerotic fibrous fatty obstructions of the large epicardial vessels, which provide for blood flow and transport nutrients, oxygen, and elimination of metabolic waste products such as CO2, lactic acid, and hydrogen ions. Coronary artery atherosclerosis is a progressive disease related to and accumulating atheroma (fibrous fatty plaque), which damage the supporting vessels of the heart and eventually progress to cardiac complications such as angina pectoris, MI, heart failure, and extracardiac complications. …show more content…
Nitroglycerin acts directly on vascular smooth muscle to promote vasodilation. Nitroglycerin produces both arterial and venous dilation, which leads increase hemodynamic function, increase CO, and increased tissue perfusion. Venous dilation leads lead to a reduction in return blood flow to the heart and a decrease in preload, while arteriole dilation decreases SVR and afterload. Reduction in preload and afterload leads to reduction in cardiac workload, which decreases cardiac O2 demand. Further, a reduction in preload also helps to improve subendocardial blood flow compromised by coronary artery atherosclerosis. Coronary dilation will further enhance the oxygen supply/demand ratio and diminish the anginal pain. Systemic arterial dilation reduces afterload, which can enhance cardiac output while at the same time reducing ventricular wall stress and oxygen demand. Nitrogylycrin should be intitailly infuses at a rate 5mcg/min and then tritrated until and adequate response has been achieved (i.e. titrated every 5 minutes in 10-20 mcg/min increments with a max infusion rate of 400 mcg/min). During infusion, the HR (watch for tachycardia r/t hypotension) and BP (especially reflex tachycardia r/t hypotension-often pretreated with beta blocking agent) should be closely monitored. Monitor vitals and compare to baseline q15 & q30 after IV