Question

Mr. K. is a 57-year-old man who consulted his physician after noticing marked leg pains while playing golf. He had previously noticed increasing fatigue and discomfort in his legs associated with moderate exercise. When sitting for extended periods with legs dangling, his legs became red, and sometimes his feet felt numb. His history indicates he smokes cigarettes and is chronically overweight. His blood cholesterol and other lipid levels are abnormal, and his physician suspects peripheral atherosclerosis as the cause of his discomfort.

1. Discuss the development of atherosclerosis, including the predisposing factors in this case and the pathophysiological changes. (See Atherosclerosis.)
2. Discuss the complications that might develop in this patient. (See Atherosclerosis—Pathophysiology, Signs and Symptoms.)
3. Discuss the treatments for all aspects of the patient’s condition, including slowing the progress of the atherosclerosis, maintaining circulation in the leg, and treating complications. (See Atherosclerosis—Treatment.)

Mr. K reports that the sharp pain started about 2 days ago and it has gotten so bad that he cannot lie down. He rates the pain as an 8 on a scale of 1 to 10, and it radiates to his neck and back. It is much worse when he takes a deep breath, but leaning forward seems to help him. Family history is significant for heart disease and hypertension

4. What labs would be helpful in confirming or ruling out a myocardial infarction, and what are the advantages of each?
5. If Mr. H has acute coronary syndrome, what ECG changes are expected?

Answer 1

There are few theories on how atherosclerosis occurs. Some of the risk factors for developing atherosclerosis are hypertension, diabetes mellitus, family history, obesity, nicotine smoking, elderly male, increased cholesterol and lipid levels in blood.

These conditions cause endothelial injuries by mechanical and chemical processes. The Low density lipoproteins enter tunica intima ( inner  layer of blood vessels), gets oxidised and active endothelial cells to produce adhesion molecules for leukocytes. The leukocytes adhere to intima layer and monocytes enter into tunica intima, engulf oxidised LDLs. They form foam cells which promote migration of smooth-muscle cells into the tunica intima from tunica media and also promote their proliferation. This in turn causes increase in collagen and hardening of the blood vessels. Foam cells  when they die release the LDLs causing the plaque to increase in size which can get ruptured and cause thrombosis.

The patients can develop complications like embolism, aneurysm formation, narrowing of arteries causing gangrene, ulceration and ischemia like myocardial ischemia and cerebral ischemia.

The signs and symptoms include thrills and bruit over the narrowed arteries, pain and feeble or absent pulse in the affected limbs. The arteries are thickened and can be felt. There can be features of ischemia like chest pain, altered kidney function, transient ischemic attacks and eye signs.

The treatment includes reduction or removal of risk factors. The patient is advised to avoid smoking cigarettes, control weight and to do regular exercise. The patient is asked to control the diet to keep the diabetes, hypertension, hyperlipidemia and hypercholestrolemia in check. Anti platelet drugs can be given. Surgical and interventional techniques like Percutaneous transluminal Angioplasty, thrombectomy, endarterectomy, vein grafts, by pass surgeries and few other are available. If gangrene sets in, the limb is to be amputated. The complications include surgical and anaesthetic complications like allergies, hemorrhages, secondary infections, damage to adjacent structures etc.

The diagnosis for MI can be made using electrocardiogram, echocardiogram, biochemical markers,coronary angiography, radionuclide imaging and other investigations like full blood count, complete blood picture, serum electrolytes, lipid profile, renal function tests etc. Electrocardiography is used to study cardiac rhythm, diagnosis of MI, to know effects of drugs on heart, chamber size etc. Echocardiography can be used to find out ventricular function, valves function, structure of heat and it’s anomalies. Radionuclide imagine helps in finding areas of infraction and perfusion of heart. Coronary angiography helps to find the site of block.

The ECG changes that can occur in acute coronary syndrome are ST segment elevation. In MI there will be an ST segment elevation of more than 2mm in chest leads. This changes is seen in leads corresponding to the infracted region of myocardium.

This is a brief discussion on the topic. Hope this helps you out. Feel free to give your feedback and if you want further elaborate explanation on this topic. Thank you and have a great day.