A patient has blocked coronary arteries, which causes ischemia and angina. Why m

Question

A patient has blocked coronary arteries, which causes ischemia and angina. Why might a blockage in the coronary arteries cause ischemia and angina? What situations would increase these symptoms for the patient and why? One prescription for this patient could include calcium channel blockers. Why would this be useful? Include the pacemaker cells and the myocardial cells in your answer. Additionally, they could take a nitroglycerin tablet sublingually for chest pain. Nitroglycerin acts directly on smooth muscle, producing relaxation and vessel dilation. How would this relieve chest pain?

Explanation / Answer

4 a

Ischemia is a state in which the blood flow is limited or reduced in a part of the body. Angina pectoris occurs due to myocardial ischemia because of imbalance between myocardial blood supply and oxygen demand characterized by chest pain and discomfort. Due to blockage in coronary artery it gets narrowed leads to decrease blood flow and thus oxygen to the heart muscles. The situation in which symptoms gets increased are family history of heart disease (genetic reason), high cholesterol, obesity, sedentary lifestyle, diabetes, kidney disease, hypertension (they all linked with high fatty diets which leads to lipid deposition over arteries followed by artery narrowing and decreased oxygen supply to heart).

4 b

Calcium channel blockers blocks L-Type Voltage-dependent calcium channels which is responsible for excitation-contraction of cardiac muscle and for regulating aldosterone secretion in endocrine cells of the adrenal cortex. They are also involved in the conduction of the pacemaker signals with pacemaker cells. The Blockage of L-Type Voltage-dependent calcium channels by Calcium channel blockers leads to following

They reduce contraction of the arteries and increases arterial diameter (vasodilation).

Acts on cardiac muscles cells (myocardium), to reduce the force of contraction of the heart.

Slows down the conduction of electrical activity within the heart, they slow down the heart beat.

Reduce aldosterone production, which leads to lower blood pressure.

4 c

Chest pain in angina generally characterized when the heart muscles doesn’t getting enough blood supply (thus the oxygen) due to artey narrowing. Nitroglycerin, is a vasodilator drug that dilates blood vessels(open up) to improve blood flow. It also relaxes the smooth muscles of vessels and prevent esophageal spasm and in this manner it relieves chest pain.

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