Quiz 35: Pharmacotherapy of Angina Pectoris and Myocardial Infarction
The patient named Bill heard that he can become tolerant to the drug nitroglycerine which is being prescribed to him. By tolerant we mean that the long term use of the drug makes the receptors of the drug in our body familiar to that drug. This ultimately decreases its effect with the usual dose; means the drug is not able to produce its complete effect. So, to have the required level of effect, the dose has to be increased. The dose cannot be increased to an unlimited extent as it may pose danger to the health of the patient. Thus, the only way to deal or avoid the tolerance of the drug is that the drug should be withdrawn (not given) for a week or two and then again restarted with the same dose and schedule.
The cardiac workload means the amount of blood that heart receives and pump after purification with the help of lungs. CAD (Coronary Artery Disease) is the heart condition when one or more coronary arteries of the patient get narrow due to atherosclerosis (the deposition of plaque formed of cholesterol around the walls of the artery). If the patient with CAD would be injected with normal saline then the blood volume increases that ultimately increases the pressure of blood inside the blood vessels. The plaque of fat already provides less area for blood and more volume will push the arteries causing the stress on the walls. This stress causes angina in CAD patients. Thus, the infusion of normal saline increases the cardiac workload. The CAD patient may experience chest pain due to angina. This occurs because the increase pressure of blood will not be able to provide sufficient oxygen to the coronary arteries.
Michael and his family want to know about his heart's conditions. The description that would be given to them is as follows: The arteries of the heart (coronary arteries) have got stiff and narrow due to age and deposition of fat. This narrowing and stiffening of the arteries is providing less oxygen to the heart muscles. This is causing the pain in the chest due to insufficient oxygen. This ultimately causes dizziness, cold sweats and nausea to Michael.