Cardiovascular: Diseases of the Veins

• Alterations of cardiovascular function can manifest as various diseases and conditions.

Diseases of the Veins

• Varicose veins are veins in which blood has pooled, leading to distended, tortuous, and palpable vessels due to trauma or gradual venous distention.
• Risk factors for varicose veins include age, female gender, family history, obesity, pregnancy, deep vein thrombosis, and prior leg injury.
• Chronic venous insufficiency involves inadequate venous return over time, often due to varicose veins or valvular incompetence, potentially leading to venous stasis ulcers.
• Signs of chronic venous insufficiency include edema and skin discoloration as well as venous stasis ulcers.
• Thrombus formation in veins can obstruct venous flow, increasing venous pressure, with the thrombus attached to the vessel wall, and a thromboembolus detaching and traveling.
• Factors promoting thrombosis in veins include venous stasis, venous endothelial damage, and hypercoagulable states (Triad of Virchow), influenced by conditions like cancer, orthopedic surgery/trauma, heart failure, and immobility.
• Venous thrombi are more common than arterial thrombi.
• Factor V Leiden mutation is an important risk factor for thrombus formation.

Diseases of the Arteries

• Diseases of the arteries include hypertension and hypotension, aneurysm, thrombus formation and embolism, peripheral vascular disease, peripheral artery disease, atherosclerosis, coronary artery disease, and myocardial ischemia.

Hypertension

• Hypertension involves the consistent elevation of systemic arterial blood pressure, with sustained systolic pressure of 130 mm Hg or greater, or a diastolic pressure of 80 mm Hg or greater.
• Primary hypertension, also known as essential or idiopathic hypertension, is influenced by genetic and environmental factors, affecting 92% to 95% of individuals with hypertension.
• Risk factors for primary hypertension include family history, diet (high sodium, low potassium, calcium, magnesium), tobacco and alcohol consumption, obesity, and glucose intolerance.
• Secondary hypertension is caused by a systemic disease process that elevates peripheral vascular resistance or cardiac output, such as renal vascular or parenchymal disease, adrenocortical tumors, adrenomedullary tumors, and certain drugs.
• Major complications of severe hypertension include chronic damage to blood vessels and tissues, leading to target organ damage in the heart, kidney, brain, and eyes, as well as myocardial hypertrophy.
• Complicated hypertension can lead to myocardial hypertrophy, angina pectoris, coronary artery disease, heart failure, myocardial infarction, and sudden death.
• Hypertensive crisis involves rapidly progressive hypertension with systolic pressure above 180 mm Hg and/or diastolic pressure usually above 120 mm Hg, which is life-threatening.
• Untreated hypertensive crisis can result in papilledema, cardiac failure, CVA, retinopathy, and uremia.

Hypotension

• Orthostatic hypotension involves a decrease in both systolic and diastolic blood pressure upon standing, due to a lack of normal blood pressure compensation in response to gravitational changes.
• Diagnostically, orthostatic hypotension is defined as a decrease in systolic blood pressure of at least 20 mm Hg or a decrease in diastolic blood pressure of at least 10 mm Hg within 3 minutes of moving to a standing position.

Aneurysm

• An aneurysm is a local dilation or outpouching of a vessel wall or cardiac chamber.
• True aneurysms involve the weakening of all three layers of the vessel wall, while false aneurysms are extravascular hematomas communicating with the intravascular space.
• The aorta is most susceptible to aneurysms, especially the abdominal aorta, with causes including atherosclerosis and hypertension, potentially leading to aortic dissection or rupture.
• Aortic aneurysms are often asymptomatic until rupture, which causes severe pain and hypotension; thoracic aortic aneurysms can cause dysphagia and dyspnea.
• Cerebral aneurysms, often occurring in the circle of Willis, can cause symptoms of increased intracranial pressure and stroke.
• Heart aneurysms can result in dysrhythmias, heart failure, and embolism.

Thrombus Formation

• Thrombus formation involves a blood clot that remains attached to the vessel wall, influenced by factors such as intimal injury/inflammation, obstruction of flow, and pooling (stasis).
• A thromboembolus is a thrombus that dislodges and travels in the bloodstream.
• Arterial thrombi are linked to intravascular conditions promoting coagulation or blood stasis.
• Valvular thrombi are commonly associated with pericardial inflammation.

Embolism

• Embolism involves the obstruction of vessels by an embolus, which is a bolus of matter circulating in the bloodstream.
• Emboli can consist of dislodged thrombi, air bubbles, amniotic fluid, aggregate of fat, bacteria, cancer cells, or foreign substances.
• Embolism can cause ischemia or infarction to tissues distal to the obstruction, resulting in organ dysfunction and pain.
• Occlusion of the coronary artery causes myocardial infarction, and occlusion of the cerebral artery causes MI.

Peripheral Vascular Disease

• Thromboangiitis obliterans (Buerger disease) is an autoimmune disease of peripheral arteries strongly associated with smoking.
• Thromboangiitis obliterans is characterized by the formation of thrombi filled with inflammatory and immune cells, leading to permanent occlusion of small- and medium-sized arteries in feet and hands.
• Thromboangiitis obliterans causes pain and tenderness in the affected area, often leading to gangrenous lesions and amputations.
• Raynaud phenomenon is characterized by episodic vasospasm in arteries and arterioles of the fingers.
• Primary Raynaud phenomenon is a vasospastic disorder of unknown origin.
• Secondary Raynaud phenomenon is associated with systemic vascular diseases, pulmonary hypertension, hypothyroidism, secondary disorders or conditions like collagen vascular disease, and long-term exposure to cold environments.
• Raynaud phenomenon involves changes in skin color and sensation caused by ischemia

Atherosclerosis

• Atherosclerosis is a form of arteriosclerosis involving thickening and hardening of the arterial walls caused by the accumulation of lipid-laden macrophages, leading to plaque development.
• Risk factors for atherosclerosis encompass diabetes, smoking, hyperlipidemia/dyslipidemia, hypertension, and autoimmunity.
• Atherosclerosis initiates from endothelial injury, progressing through inflammation, cellular proliferation, macrophage migration and adherence, and LDL oxidation (foam cell formation).
• Atherosclerosis can lead to fatty streaks, fibrous plaques, and complicated plaques, resulting in inadequate perfusion, ischemia, and necrosis.

Peripheral Arterial Disease

• Peripheral arterial disease involves atherosclerotic disease of arteries that perfuse limbs, characterized by intermittent claudication.

Coronary Artery Disease

• Coronary artery disease involves vascular disorders that narrow or occlude the coronary arteries, leading to myocardial ischemia.
• Atherosclerosis is the most common cause of coronary artery disease and the primary cause of heart disease.
• Nonmodifiable risk factors for coronary artery disease include increased age, family history, and male gender or female gender postmenopause.
• Modifiable risk factors include dyslipidemia, hypertension, cigarette smoking, diabetes mellitus and insulin resistance, obesity/sedentary lifestyle, and atherogenic diet.
• Nontraditional risk factors for coronary artery disease include markers of inflammation and thrombosis, high-density C-reactive protein, troponin I, adipokines, chronic kidney disease, air pollution, ionizing radiation and microbiome.
• Transient myocardial ischemia involves temporary deprivation of the coronary blood supply, resulting in stable angina, Prinzmetal angina, silent ischemia and mental stress-induced ischemia.
• Acute coronary syndromes include unstable angina (reversible myocardial ischemia) and myocardial infarction.
• Myocardial infarction involves extended obstruction of the myocardial blood supply causing death of myocytes, classified as STEMI or non-STEMI or subendocardial or transmural infarction.
• Structural changes in myocardial infarction include myocardial stunning, hibernating myocardium, and myocardial remodeling.
• Manifestations of myocardial infarction include sudden severe chest pain, nausea, vomiting, diaphoresis, and dyspnea.
• Complications of myocardial infarction include sudden cardiac arrest due to ischemia, left ventricular dysfunction, and electrical instability.

Disorders of the Pericardium

• Disorders of the pericardium include acute pericarditis, pericardial effusion, and tamponade.and constrictive pericarditis.

Disorders of the Myocardium

• Disorders of the myocardium, cardiomyopathies, include dilated cardiomyopathy, hypertrophic cardiomyopathy, hypertensive (valvular) hypertrophic cardiomyopathy, and restrictive cardiomyopathy.

Disorders of the Endocardium

• Valvular dysfunctions are a disorder of the endocardium with mitral valve prolapse syndrome, acute rheumatic fever and rheumatic heart disease, and infective endocarditis all considered disorders of the endocardium.
• Valvular stenosis includes aortic stenosis and mitral stenosis while Valvular regurgitations include aortic regurgitation, mitral regurgitation, and tricuspid regurgitation.
• Valvular stenosis is obstruction and narrowing whereas regurgitation indicated incompetency or backflow.
• Mitral valve prolapse involves one or both cusps of the mitral valve billowing upward into the left atrium during systole, which can lead to mitral regurgitation if blood leaks into the atrium and Patients may be asymptomatic or have vague symptoms.

Rheumatic Fever

• Rheumatic fever is a systemic, inflammatory disease caused by a delayed immune response to pharyngeal infection by group A beta-hemolytic streptococci.
• Rheumatic fever presents as a febrile illness with inflammation of the joints, skin, nervous system, and heart, and if left untreated, may cause rheumatic heart disease.
• Common manifestations of rheumatic fever include fever, lymphadenopathy, arthralgia, nausea/vomiting, abdominal pain, and tachycardia while major clinical manifestations include carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules.

Infective Endocarditis

• Infective endocarditis is inflammation of the endocardium caused by agents like bacteria, viruses, fungi, rickettsiae, and parasites.
• Pathogenesis of infective endocarditis involves damaged (prepared) endocardium, blood-borne microorganism adherence, and proliferation of the microorganism (vegetations).
• Classic findings include fever, new or changed cardiac murmur, and petechial lesions of the skin, conjunctiva, and oral mucosa while characteristic physical findings include Osler nodes and Janeway lesions.
• Patients also experiecne weight loss, back pain, night sweats, and heart failure.

Heart Failure

• Heart failure occurs when the heart is unable to generate adequate cardiac output or results from it's inability meet the metabolic demands of the body, to provide adequate perfusion of tissues, leading to increased diastolic filling pressure of the left ventricle and increased pulmonary capillary pressures.

Heart Failure: Definitions

• This involves the inability of the heart to pump blood at a sufficient rate to meet the metabolic demands which can lead to a complex clinical syndrome characterized by abnormalities in cardiac function and neurohormonal regulation, which are accompanied by effort intolerance, fluid retention and a reduced longevity brought on from structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood.

Left Heart Failure

• Systolic heart failure where ejection fraction is less than 40% because of the of heart to generate adequate cardiac output to perfuse tissues which disrupts contractility, preload, and afterload decreasing cardiac output, which progressively worsens.
• Manifestations of systolic heart failure: Dyspnea, orthopnea, cough-of-frothy-sputum, fatigue, decreased urine output, and edema, as well as pulmonary edema, hypotension/hypertension, and S3 gallop.
• Diastolic heart failure. Results in pulmonary congestion despite normal stroke volume and cardiac output, from hypertension-induced myocardial hypertrophy and myocardial ischemia-induced ventricular remodeling which also decreases the compliance of left ventricle as well as abnormal diastolic relaxation, which manifests as dyspnea on exertion, fatigue.
• Common result pulmonary edema over time and S4 gallop.

Pathophysiology of Heart Failure

• Four basic mechanisms: increased blood volume (excessive preload), increased resistance to blood flow (excessive afterload), decreased contractility, and decreased filling.

Right Heart Failure

• An inability of right ventricle to provide adequate blood flow at a normal venous pressure.
• Right Heart Failure can result from an increase in left ventricular filling pressure that is reflected back into the pulmonary circulation.
• Right heart failure is most commonly caused by a diffuse hypoxic pulmonary disease.

High-Output Failure

• High-output failure is the inability of the heart to supply the body with adequate nutrients despite adequate blood volume and normal or elevated myocardial contractility caused by anemia, hyperthyroidism, septicemia, beriberi.

Shock

• Shock the failure of the cardiovascular system to perfuse the tissues adequately, leading to impaired cellular metabolism: manifested by impaired oxygen use, and impaired glucose use.
• Manifestations based on shock type often include feeling weak, cold, nauseated, dizzy, confused, afraid, thirsty, short of breath as well as hypotension, tachycardia, increased respiratory rate.

Types of Shock

• Cardiogenic: heart failure
• Hypovolemic: insufficient intravascular fluid volume
• Neurogenic: neural alterations of vascular smooth muscle tone
• Anaphylactic: immunologic processes
• Septic: infection

Multiple Organ Dysfunction Syndrome

• Progressive dysfunction of two or more organ systems resulting from uncontrolled inflammatory response to illness or injury.
• Causes: Most common: sepsis and septic shock, caused by severe trauma, burns, major surgery, blood transfusion, renal or liver failure, or pancreatitis.
• Manifestations: Fever, tachycardia, dyspnea, altered mental status, hyperdynamic/hypermetabolic stages, and ARDS and individual organ manifestation of renal, GI, Cardiac, or Nervous systems being seen.