Cardio Flashcards
Dense collagenous scar after myocardial infarction: type … collagen
Type I collagen (the most abundant type: provides strength and support for skin, tendons, bones, ligaments…)
Contractility is intrinsic to the myocardium and does not change with changes in myocardial …?
Fiber length
Force-velocity is different from contractility
Virus linked to myocarditis?
Coxsackievirus B
Ebstein anomaly is a congenital heart disease, where the tricuspid leaflets are too low. What maternal condition is it related to?
Lithium use
Thiazide diuretics lower blood pressure by inhibiting…?
Na / Cl cotransporters, decreasing their reabsorption. They activate the RAAS. Increased aldosterone result in hypokalemia , which can lead to muscle cramps, weakness and (when severe) cardiac arrhythmias
Preferred treatments for atrial fibrillation with rapid ventricular response?
Calcium channel blockers and beta blockers
Digoxin has a narrow therapeutic index. Symptoms of digoxin intoxication?
Blurred vision, abnormal color perception, cardiac arrhythmias, nausea, vomiting, dizziness, confusion…
Beta blockers: how do they work?
They decrease myocardial work and oxygen demand by slowing the ventricular rate and reducing contractility. They also lower peripheral resistence (afterload) by decreasing circulating levels of vasoconstricting hormones.
Class III antiarrhythmic drugs (amiodarone, dofetilide, sotalol): mechanism of action?
They predominantly block potassium channels and inhibit the outward potassium currents, thereby prolonging repolarization and total action potencial duration
Inferior wall myocardial infarction:
ST elevation in which leads?
Occlusion most commonly of which artery?
Leads II, III and aVF
Right coronary artery. This artery supplies blood to the SA node, the AV node and most of the bundle of His. Therefore, conduction impairment is common in pacients with inferior wall MI. Sinus bradycardia is the most common arrhythmia in these pacients.
Teste ergométrico não sugestivo de isquemia miocárdica looks like…?
Segmento ST sem desnivelamentos
Redução de amplitude de QRS
Padrão de repolarização precoce, que desaparece com o ex (segmento ST supradesnivelado na fase de controle)
Symptoms of stable angina do not become prominent until approximately …% of the cross-sectional area of the coronary artery lumen is occluded
70
Pathophysiology of ST elevation myocardial infarction?
Ruptured atherosclerotic plaque with overlying fully obstructive thrombus
Dilated cardiomyopathy: causes?
Idiopathic, genetic mutations (eg duchenne muscular dystrophy), infection, alcohol abuse, drugs, wet beriberi (little Vit B1)
