The Cardiovascular System Flashcards
What is Atherosclerosis?
A type of Arteriosclerosis or hardening of the arteries. The term Atherosclerosis, comes from the greek word Atheros meaning paste or porridge and Sclerosis meaning hardness, denotes the formation of fibrofatty lesions in the intimal lining of the large and medium-sized arteries such as the Aorta, the Coronary Arteries and the Large Vessels that supply the Brain. There has been a Gradual decline in Deaths from Atherosclerosis, over the last few decades, Coronary Artery Disease remains a leading cause of death in the West.
What Happens during Atherosclerosis?
Inflammation is a key factor in the Development of Atherosclerosis. As LDL Cholesterol accumulates in the Arterial wall, it undergoes chemical changes and signals to endothelial cells to latch onto White Blood Cells circulating in the Blood. These Immune Cells penetrate Intima and Trigger an Inflammatory response, devouring LDLs, to become fat-laden ‘Foam Cells’ and form a Fatty Streak, the Earliest stage of Atherosclerotic plaque. The Plaque continues to grow and Forms a Fibrous Cap. Substances released by Foam cells can eventually Destabilise the cap, allowing it to Rupture, causing a blood clot which can block Blood Flow and Trigger a Heart Attack.
What are the Major Complications of Atherosclerosis and Stats?
Including Ischaemic Heart Disease, Stroke and Peripheral Vascular Disease account for approximately 30% of Deaths in the UK.
Begins as an Insidious Process and typically clinical signs of the Disease do not develop for 20-40 Years or Longer.
Fibrous plaques commonly begin to appear in the third decade.
Artery Wall thickens as a result of Invasion and Accumulation of WBCs (Foam cells, Macrophages laden with Fat) and Proliferation of Smooth Muscle Cells in the Tunical Intima, Creating a Fibro-Fatty Plaque. Atherosclerosis is a Syndorme affecting Blood Vessels due to a Chronic Inflammatory response of WBCs in the Artery Wall, Promoted by LDLs. Arteries harden as Multiple Plaques form within the Arteries.
What is the Aetiology and Risk Factors for Atherosclerosis - Hypertension?
Hypertension - Major Risk factor that increases risk twofold. The Most common cause of Health Problems in Adults, the leading risk factor for Cardiovascular disease. Effects Approximately 1 Billion people worldwide. More Common in young men then women. Middle Aged men have higher BP than Women, until Women reach menopause. More Common in Black African Races, in people from lower Socioeconomic classes and in older Age Groups. Primary (essential) Hypertension, term applied to 95% of Cases, where no Cause is Identified. Secondary Hypertension results from an Identifiable Condition such as Kidney or Endocrine Disease.
What is meant by Hyperlipidaemia?
An Excess of Lipids in the Blood. Triglycerides, Phospholipids and Cholesterol. Hypercholesterolaemia is implicated in the development of Atherosclerosis. Low Density Lipoprotein (LDL), sometimes called the bad Cholesterol, is the Main Carrier of Cholesterol. The Uptake of LDL by Macrophages in the Arterial Wall can result in the Formation of Foam Cells and the Development of Atherosclerosis.
High Density Lipoprotein (HDL) is Synthesised in the Liver and is Often referred to as the Good Cholesterol. Participated in Carrying Cholesterol from the Peripheral tissues (including Atheromatous Plaques) to the Liver from where it is probably Excreted. Studies have shown that Regular Exercise, moderate alcohol consumption and use of statins increase HDL levels, smoking and metabolic syndrome associated with Decreased Levels of HDL.
What does Cigarette Smoking Cause?
Closely Linked with CVD and Sudden Death. Causes Endothelial Damage. Prolonged Smoking doubles the Damage to the Endothelium. Stopping reduces risk of endothelial damage significantly.
What can Type 2 Diabetes Mellitus Cause?
Increases Risk of Disease by Greater than Twofold.
Combined with Hypertension, risk increases by Eightfold.
How does Visceral Fat Affect you?
Stored within the Abdominal Cavity and therefore stored around a number of important Internal Organs such as the Liver, Pancreas and Intestines. Storing Large amounts of Visceral Fat is associated with an Increased Risk of Heath Problems including Type 2 Diabetes and CVD. ‘Beer Belly’ or ‘Apple Shape’ have the Highest Risk.
What are Clinical Manifestations?
Atherosclerotic Plaques produces their Effects through:
- Narrowing of the Vessel and Production of Ischaemia.
- Sudden Vessel obstruction due to Plaques as they Haemorrhage or Rupture.
- Thrombosis and Formation of Emboli resulting from damage to the Endothelium.
- Aneurysm formation due to Weakening of the Vessel Wall.
In Larger Vessels such as the Aorta, important complications are Thrombus Formation and Weakening of the Vessel Wall.
In Medium-Sized Vessels such as the Coronary and Cerebral Arteries, Ischaemia and Infraction due to vessel occlusion are more Common.
Although Atherosclerosis can affect any organ or tissue, the Arteries supplying the Heart, Brain, Kidneys, Lower extremities and Small Intestines are most Frequently involved.
What is a Myocardial Infarction?
Acute STEMI, Heart Attack, is characterised by the Ischaemic Death of Myocardial Tissue associated with Atherosclerosis Disease of the Coronary Arteries. The Area of Infraction is Determined by the Coronary Artery that is Affected and by its disruption of Blood Flow. Approx’ 30-40% of Infracts affect the Right Coronary Artery, 40-50% affect the Left Anterior Descending Artery and the Remaining 15-20% affects the Left Circumflex Artery.
What Occurs in a Myocardial Infarction?
Abrupt onset with Pain as the Significant Symptom. Typically Severe and Crushing, often Described as constricting Suffocating or ‘Like Something sitting on my Chest’. Usually Substernal, Radiating to the Left Arm, Neck or Jaw, although it may be experienced in other areas of the Chest as well. Unlike Pain of Angina, Pain is more Prolonged and is not relieved by rest or Nitroglycerin, often requiring use of Narcotics. Women often experience atypical Chest Discomfort and the Elderly may complain of Shortness of Breath Rather than Pain.
What are the Symptoms of Myocardial Infarction?
Gastrointestinal Complaints are Common. Nausea and Vomiting may occur.
Epigastric Distress may be mistaken for Indigestion.
Fatigue and Weakness, often of limbs
Tachycardia, Anxiety, Restlessness and Feelings of impending doom.
May be a Productive Cough with Frothy Sputum
Skin - Pale, Cool and Moist
Hypotension and Shock.
Sudden Death from STEMI is Death that occurs within 1 Hour of Symptoms.
Usually attributable to fatal arrhythmias, which may occur without evidence of Infarction. Early monitoring and Hospitalisation improves chances of Averting Sudden Death.
What is a STEMI?
ST Elevation Myocardial Infarction.
Most Serious type of Myocardial Infarction.
There is a long interruption to the Coronary Blood Supply. Caused by a total blockage of the Coronary Artery, which can cause Extensive damage to a Large area of the Myocardium.
Mainly Affects the Heart’s Lower Chambers.
Between 2.5% and 10% of patients with a STEMI, Die within 30 days.
What is Angina Pectoris?
Myocardial Ischaemia occurs when the ability of the Coronary Arteries to supply blood is inadequate to meet the Metabolic needs of the Heart.
The Chest Pain that occurs is precipitated by situations that increase the work demands of the Heart, such as physical exertion, emotional stress and exposure to cold.
Pain is described as a constricting, squeezing, or suffocating sensation. Usually steady, increasing in intensity at onset and end of attack.
Commonly located in precordial or substernal area of chest.
Pain is Similar to Myocardial Infarction, may radiate, may also be confused with indigestion.
Typically provoked by exertion or emotional stress and relieved within minutes by rest or nitroglycerins.
Delay of 10+ Minutes before relief, or pain that occurs at rest, or increasing in intensity, suggest more than Angina.
What is an Aortic Aneurysm?
An Aneurysm is an Abnormal, localised dilation of a blood vessel. They can occur in Arteries and Veins, but they are most common in the Aorta.
Once initiated the Aneurysm grows larger as the tension in the Vessel Increases. If untreated, the Aneurysm may rupture because of Rising Tension.
Unruptured Aneurysm may cause damage by exerting pressure on adjacent structures and impending blood flow.
They may involve any part of the Aorta - The ascending Aorta, Aortic Arch, Descending Aorta, Thoracoabdominal Aorta or the Abdominal Aorta. There may be multiple Aneurysms.
Often caused by Atherosclerosis, many patients have hypertension, occur more frequently in men over 50, who smoke.
