Ischemic Heart Disease Flashcards
What is forward and backward heart failure?
Forward - inadequate cardiac output
Backward - congestion of venous circulation, normally accompanies forward
What is low output vs. high output failure?
Low - heart unable to pump all blood delivered to it from veins
High - heart pumps enough blood but for non cardiac reason delivery of nutrients and oxygen to tissue is not adequate
What are the three compensatory mechanisms employed during heart failure?
- Activation of neurohormonal systems - release of NE increases HR and contractility, activation of RAAS increases peripheral resistance and blood volume, atria secrete ANP in response to distension which produces vasodilation, natriuresis, and diuresis
- Frank starling mechanism - increased stretch of myocytes increases contractility by increasing number of myosin heads that can attach to actin in sarcomere
- Myocardial hypertrophy - pressure overload leads to concentric hypertrophy (increase in cell diameter), volume overload leads to eccentric hypertrophy (increase in cell length)
What are the four main causes of left sided heart failure?
Ischemic heart disease
Systemic hypertension
Mitral or aortic valve disease
Primary diseases of myocardium
What are the main causes of right sided heart failure?
Left sided heart failure
Diseases of pulmonary parenchyma or vasculature
What are the clinical findings in left sided heart failure?
Predominantly pulmonary symptoms
Dyspnea, cough, pulm venous congestion, leakage of fluid and RBCs into alveoli
What is the morphology of left sided heart failure?
Pulm congestion and edema
Hemosiderin in macrophages in alveoli = heart failure cells
Dependent upon underlying disease process
What are the clinical findings in right sided heart failure?
Peripheral edema, ascites, hepatosplenomegaly, pleural effusions, dependent pitting edema
What is the morphology of right sided heart failure?
Hepatosplenomegaly with nutmeg liver
Pleural effusions
Pedal edema
What are the two forms of hypertension?
Systemic - entire body except lungs
Pulmonary (cor pulmonale) - only increase in BP is in pulm vasculature
What are the criteria for pathologic diagnosis of hypertensive heart disease?
Left ventricular hypertrophy with no other identified cause and a history of or evidence of hypertension (hyaline arteriosclerosis)
What are the clinical findings in systemic hypertensive heart disease?
Left ventricular hypertrophy without dilation
Ischemic heart disease, progressive renal failure, cerebral vascular hemorrhage, heart failure
What are the criteria for pathologic diagnosis of cor pulmonale?
Right ventricular hypertrophy and dilation
What are the two forms of cor pulmonale?
Acute - follows thromboemboli that obstruct >50% of vasculature
Chronic - prolonged pressure overload on right ventricle
What are the causes of cor pulmonale?
Diseases of pulmonary parenchyma - COPD, CF, fibrosis, pneumoconiosis
Diseases of pulm vessels - recurrent thromboemboli, pulm arteritis
Disorders affecting chest movement - kyphoscoliosis, obesity
Disorders inducing pulm arterial constriction - metabolic acidosis, hypoxemia
What are the four clinical syndromes composing the general category of ischemic heart disease?
Angina pectoris (stable, unstable, prinzmetal)
Acute MI
Chronic ischemic heart disease
Sudden cardiac death
What is the most common underlying cause of ischemic heart disease?
Coronary artery atherosclerosis
Other than growth, what acute changes in a plaque can contribute to obstruction of vessel?
Vasospasm of vessel
Hemorrhage into plaque
Thrombosis
What three conditions are comprised by the term acute coronary syndrome?
Unstable angina
Acute MI
sudden cardiac death
What is an acute plaque change?
Rupture, fissuring, or ulceration of plaque will expose lipid core to the blood - very thrombogenic
Plaque of certain size can become neovascularized & hemorrhage
What are vulnerable plaques?
Thin fibrous cap (<6.5 micrometer) and thick core less stable and more likely to rupture
Besides cap and core, what are other factors affecting the stability of a plaque?
Collagen remodeling
Adrenergic stimulation - through development of hypertension or vasospasm
What are three factors affecting development of ischemic heart disease?
Inflammation
Thrombus - can organize (directly increasing size of plaque) or stimulate migration of smooth muscles in (indirect)
Vasoconstriction - stimulated by adrenergic agonists, thromboxane, and imbalance between vasoconstrictors and dilator
What is angina pectoris?
Chest pain due to non-sustained and reversible myocardial ischemia
3 types - stable, unstable, prinzmetal