Cardio

Question 1

Features of Acute Myocarditis

Answer 1

Inflammation of the myocardium leads to global enlargement of heart and dilation of all chambers. Major cause of sudden caused of death in adults <40 years old.

Presentation is very variable, can include dyspnea, chest pain, fever, arrhythmias (persistent tachy out of proportion to fever is very characteristic)

Causes:
viral (adenovirus, coxsackie B, parvo, HIV, HHV-6), lymphocytic infiltrate with focal necrosis highly indicative of viral myocarditis

parasitic (T. cruzi, T. gondii)

look in book theres more stuff!!! pg 323

complications: sudden death, arrhythmias, heart block, dilated cardiomyopathy, HF, mural thrombus with systemic emboli

Question 2

How does age affect:
Aorta 
Actual thickness of heart
Conduction
Baroreceptor/adrenergic responses

Answer 2

Stiffens aorta: Elastin is replaced w/ collagen (reduced compliance)
which leads to inc. Pulse pressure (high systolic HTN)

Thickness: causes concentric LVH.
Dec. Cardiac output.

Conduction: cells degenerate – dec. resting/maximal heart rate

Baroreceptor response: Decreases.
Causes orthostasis and circulating catecholamines and a dec. heart rate/contractility response.

Question 3

Explain Paroxysmal Supraventricular Tachycardia

and treatment

Answer 3

This is most often due to a reentrant tract between the atrium and ventricle, most commonly the AV node. Commonly presents as sudden onset heart palpitations, diaphoresis, and light-headedness.

tx: slowing down the AV node by adenosine and vagal maneuvers, electrical cardioversion if hemodynamically unstable, definitive treatment is catheter ablation of the reentry tract

Question 4

Inc. in Stroke volume is seen with..

Answer 4

Inc. Contractility (anxiety, exercise)
Inc. Preload (Early pregnancy)
Dec. Afterload