Term
| how does HTN affect the heart? |
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Definition
| HTN puts an increased work demand on the heart resulting in pressure overload and ventricular hypertrophy |
|
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Term
| which ventricle does systemic HTN affect? |
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Definition
| the L ventricle (most common kind). LV hypertrophy is thickness past 2 cm, and can result from consistent systemic HTN |
|
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Term
| which ventricle does portal/pulmonary HTN affect? |
|
Definition
the R ventricle - resulting in cor pulmonale (failure of the right side of the heart brought on by
long-term high blood pressure in the pulmonary arteries and right
ventricle of the heart) |
|
|
Term
| what are secondary effects of HTN? |
|
Definition
| increased risk of ischemia, CAD |
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Term
| how does HTN affect the L ventricle? |
|
Definition
| myocardial dysfunction, cardiac dilation, CHF, and sudden death. these are due to increased resistance, cyclic hypertrophy to attempt to overcome this and resulting progressive loss of filling capacity |
|
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Term
| are HTNsive hearts at risk for sudden death? |
|
Definition
| yes, they are proarrhythmogenic |
|
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Term
| what is needed to make HTNsive heart dx? |
|
Definition
| clinical findings, hx of HTN, and supporting pathology - such as LVH w/out other cardiovascular pathology or other organs with HTNsive changes |
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|
Term
| what are general and microscopic gross characteristics of L sided HTNsive heart disease? |
|
Definition
| L ventricular wall thickness > 2 cm. the ventricular wall becomes stiff, impairing diastolic filling, the L atrium is also enlarged, there is an increase in transverse diameter of myocytes and interstitial fibrosis may occur in advanced stages |
|
|
Term
| what is R-sided HTNsive heart disease? |
|
Definition
| R-sided HTNsive heart disease or cor pulmonale is often due to pressure overload of the R ventricle. R ventricular hypertrophy, dilation, and possible failure due to pulmonary HTN - most cases arise from pulmonary disorders such as emphysema or primary pulmonary HTN |
|
|
Term
| can R sided HTNsive heart disease (cor pulmonale) be acute or chronic? |
|
Definition
|
|
Term
| what is acute cor pulmonale ususally due to? |
|
Definition
| acute cor pulmonale is often associated with massive pulm embolisms - can cause instantaneous death. |
|
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Term
| what is chronic cor pulmonale is often due to? how does it appear morphologically? |
|
Definition
| chronic cor pulmonale is often due to prolonged pressure overload associated with chronic lung disease (such as COPD, often occupationally related - and is often marked by interstitial fibrosis formation occluding the vasculature in the lungs). morphologically, the R ventricle is often dilated w/hypertrophy causing thickness measuring up to 1 cm. there may be resultant compression of the L ventricular chamber along with regurgitation and fibrous thickening of the tricuspid valve |
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|
Term
| can someone have L and R HTNsive heart disease? |
|
Definition
| yes, for example a smoker may have R ventricular HTNsive disease due to lung damage - but L ventricular HTNsive disease due to systemic HTN due to nicotine |
|
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Term
| what are common infectious organisms that can cause myocarditis? |
|
Definition
| coxsachieviruses a & b, chaga's disease (trypanosoma cruzi), bacteria such as neisseria/borrelia, and fungi (candida albicans). ECHO virus, influenza, HIV, CMV, trichnosis (helminths) |
|
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Term
| what are non-infectious reasons for myocarditis? |
|
Definition
| sarcoid (lymph node and lung involvement primarily, noncaseating granulomas - not necrotic), SLE (affects endo-, epi-, and myocardium), drug induction, radiation induction, and giant cell myocarditis |
|
|
Term
| can lyme disease cause a heart block? |
|
Definition
|
|
Term
| what are immune-mediate reactions that can cause myocarditis? |
|
Definition
| postviral, poststreptococcal (rheumatic fever), SLE, drug hypersensitivity, and transplant rejection |
|
|
Term
| what are 2 common causes of myocarditis with unknown etiology? |
|
Definition
| sarcoidosis and giant cell myocarditis |
|
|
Term
| what are the gross findings of myocarditis? |
|
Definition
| the heart is often dilated and has soft focal hemorrhage. if the myocarditis has viral involvement, there may be **mononuclear cell infiltrate/necrosis, if bacterial, **neutrophil infiltrate. there is often myocyte degeneration/necrosis. and w/giant cell myocarditis - giant cells. sometimes the causative organisms themselves may be visible |
|
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Term
| what is seen with giant cell myocarditis? who is affected by it? |
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Definition
| abundant giant cells, as well as eosinophils/plasma cells/macrophages/lymphocytes and extensive necrosis are seen with giant cell myocarditis. it affects the young and middle aged, who when affected often have a poor prognosis w/a rapid and lethal clinical course. the etiology is not well understood. |
|
|
Term
| who is more likely to be affected by hypersensitivity myocarditis? |
|
Definition
|
|
Term
| what characterizes hearts affected byhypersensitivity myocarditis? |
|
Definition
| interstitial cell infiltrates, perivascular lymphocytes, macrophages, a large number of *eosinophils. drugs such as methyldopa can cause this |
|
|
Term
| are pt w/cardiac sarcoidosis syptomatic? |
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Definition
|
|
Term
| what can happen if pts with cardiac sarcoidosis have these lesions in the cardiac conduction system? |
|
Definition
|
|
Term
| what is seen histologically in pts with cardiac sarcoidosis? |
|
Definition
| noncaseating *granulomas w/giant cells, *no eosinophils and no myocyte necrosis |
|
|
Term
| is myocarditis symptomatic? how dangerous is it? |
|
Definition
| often it is not symptomatic. in most cases myocarditis is self-limiting - but they can cause lethal arrhythmias or develop dilated cardiomyopathy to the point where a transplant is necessary |
|
|
Term
| what are some other less common causes of myocardial disease? |
|
Definition
| cardiotoxic drugs, catecholamines, amyloidosis, iron overload, and hyperthyroidism/hypothyroidism |
|
|
Term
| what have many chemotherapeutic/immunotherapeutic drugs been linked to? |
|
Definition
| cardiac complications, often resulting in dilated cardiomyopathy. |
|
|
Term
| what drugs have been linked to myocardial injury and sometimes sudden death? |
|
Definition
| lithium, phenothiazides, chloroquine, and cocaine |
|
|
Term
| what are the general changes seen in hearts affected negatively by cardiac drugs? can these be reversed on removal of the drug? |
|
Definition
| myofiber swelling, cytoplasmic vacuolization fatty change - which may result in complete resolution of cardiac function if the drug is removed |
|
|
Term
| how can catecholamines (adrenaline) affect the heart and cause myopathy? |
|
Definition
| intense autonomic stimulation or exogenous administration of large doses of vasopressor agents can result in myocardial damage consisting of myocardial necrosis w/*contraction bands and often w/*sparse mononuclear filtrate. this may be seen w/cocaine use, pheochromocytoma, or sudden emotional/physical stress. |
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|
Term
| other than increased HR, how can catecholamines affect the heart? |
|
Definition
| a Ca+ overload may be produced to the myocytes or vasoconstriction to the coronary arteries (common w/cocaine) |
|
|
Term
| what is amyloidosis in terms myopathy? |
|
Definition
| amyloidosis is beta-pleated deposition of a insoluble extracellular fibrillar protein fragments in sheets. it may be restricted to the heart, or it can be associated with systemic amyloidosis |
|
|
Term
| what is a disease that produces an excessive amount of amyloid? |
|
Definition
| multiple myeloma - a plasma cell disorder which increases the amount of plasma cells |
|
|
Term
| what is senile amyloidosis? |
|
Definition
| a kind of amyloidosis usually restricted to the heart and seen in the elderly population. it results from deposition of transthyretin (responsible for transporting thyroxine and retinal binding protein). it has a better prognosis than systemic amyloidosis |
|
|
Term
| what kind of CMP is cardiac amyloidosis usually associated with? |
|
Definition
|
|
Term
| how does cardiac amyloidosis present? |
|
Definition
| the heart may be normal to firm to rubbery. the atria may be dilated (not ventricles) or of normal size and small nodules may be present on the atrial endocardial surface. |
|
|
Term
| where is amyloid found in the heart? |
|
Definition
| in the interstitium, conduction tissue, valves, endocardium, pericardium, and small intramural coronary arteries (not just the myocytes) |
|
|
Term
| how can amyloid be stained for? |
|
Definition
| amyloid stains positive green with congo red dye |
|
|
Term
| what does amyloid produce around cardiac myocytes and capillaries? |
|
Definition
| rings, which in some cases can compress the lumen of the vessels, resulting in ischemia |
|
|
Term
| how can iron overload affect the heart? what causes iron overload? |
|
Definition
| in high enough amounts (due to hemochromatosis or multiple blood transfusions), iron can deposit in the ventricles and myocardium, causing it to dilate and may produce systolic dysfunction by acting on the metal dependent enzyme systems by inducing O2 free radical injury |
|
|
Term
| how does a heart affected by iron overload appear? |
|
Definition
| rusty brown due to cardiac myocyte accumulation of hemosiderin esp in the perinuclear region. this is accompanied by cellular degeneration and fibrosis. w/an elecron microscope, abundant perinuclear iron containing lysosomes are present |
|
|
Term
| what are the different disorders of the ion channels affecting the heart? |
|
Definition
| long QT syndromes, brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and short QT syndrome |
|
|
Term
| what is long QT syndrome? |
|
Definition
| this can be hereditary (dominant gene - 1 in 5000) or can be acquired after taking certain medications (anti-psychotic, antiarhythmic, allergy). |
|
|
Term
| what is one of the more common genetic causes of sudden death? |
|
Definition
| long QT syndrome - 10% present with sudden death as first and last symptom. people often experience symptoms during rigorous physical activity |
|
|
Term
| who is more likely to experience long QT symptoms, men or women? |
|
Definition
|
|
Term
| can an EKG dx a prolonged QT? however, what % of gene positive people are at a normal or borderline prolonged QT interval w/ just an EKG? |
|
Definition
| yes, 30% in routine screenings |
|
|
Term
| what causes long QTs? are they detectable in autotopsy? |
|
Definition
| prolonged ventricular repolarization and a tendency toward torsades de pointes and ventricular fibrillation. they are undetectable in autotopsy, ut blood and tissue samples can be tested for mutated genes |
|
|
Term
| what is brugada syndrome? who does it mostly affect? |
|
Definition
| an inherited ion channelopathy that causes unexplained sudden death. it is seen in middle-aged males of south east asia and most arrhythmic events occur in the early 40s |
|
|
Term
| can brugada syndrome be screened for? |
|
Definition
|
|
Term
| what is the defect causing brugada syndrome? is it detectable on autopsy? |
|
Definition
| a defect in the alpha subunit of the cardiac Na+ channel gene (SCN5A). it is not detectable on autopsy |
|
|
Term
| what is catecholaminergic polymorphic ventricular tachycardia? |
|
Definition
| a syndrome associated with sudden unexplained death w/exercise seen in several finish and italian families. it is characterized by syncopal spells in childhood/adolescence often triggered by exercise or stress |
|
|
Term
| what is the mortality rate of pts with catecholaminergic polymorphic ventricular tachycardia? |
|
Definition
|
|
Term
| is catecholaminergic polymorphic ventricular tachycardia detectable with an EKG? |
|
Definition
| no, a stress test would probably have to be performed |
|
|
Term
| what is the defect causing catecholaminergic polymorphic ventricular tachycardia? |
|
Definition
| a defective Ca++ channel that leads to abnormal conduction predisposing the heart to ventricular tachycardia and sudden death |
|
|
Term
| what is short QT syndrome? |
|
Definition
| a syndrome associated with sudden cardiac death and premature atrial fibriallation. it has been linked with mutations in the KCNH2 and KCNQ1 genes. early onset atrial fibrillation may be seen in adolescence. |
|
|
Term
| what is the mortality rate for pts with catecholaminergic polymorphic ventricular tachycardia? is it detectable in resting EKGs or autopsy? what is the specific defect? |
|
Definition
| 30-50% by age 30. resting EKGs and autopsys are unremarkable. the syndrome is due to defective Ca++ channels leading to abnormal conduction, predisposing the heart to ventricular tachycardia and sudden death |
|
|
Term
|
Definition
| this results from a sudden blunt impact to the precordial area, resulting in abnormal cardiac activity - leading to cardiac arrest or sudden death. there is usually no evidence of anatomical or structural cardiac injuries and the impact is of low energy/low speed |
|
|
Term
| what causes commotio cordis? |
|
Definition
| ventricular fibrillation. most pts die immediately, while others have a bried period of survival before terminal cardiac arrest. the impact of the precordial area conincides with a vulnerable period of ventricular repolarization |
|
|
Term
| is there usually soft tissue injury associated with commotio cordis? who is it seen most commonly in? |
|
Definition
| there is no significant cardiac injury associatedwith commotio cordis, just minor soft tissue injury. commotio cordis is seen most commonly in children and adolescents playing baseball or karate. it is also see in car accidents. there is an absence of preexistent cardiac abnormalities, rib or sternal fractures |
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