Cardiovascular System: Key Concepts and Pathophysiology for Students

What is an abnormal cardiovascular assessment finding on an ECG regarding impulse generation?

Cardiac impulses generated in the AV node (normal impulses originate in the SA node).

Which blood vessel is responsible for the exchange of nutrients and gases between blood and tissues?

Capillaries

What is the direct end-effect of aldosterone in the RAAS pathway?

Aldosterone increases renal reabsorption of water and sodium (and promotes potassium excretion).

What are the primary direct end-effects of RAAS activation?

Increased blood pressure and sodium/water retention (via systemic vasoconstriction and fluid retention).

What are two primary functions of the systemic circulatory system?

1. Transports oxygen and nutrients throughout the body. 2. Removes metabolic waste products from tissues.

How is a cardiac ejection fraction of 65% interpreted?

Normal (normal resting ejection fraction is 55% to 70%).

What vascular effect occurs when Angiotensin I is converted to Angiotensin II by ACE?

Potent systemic vasoconstriction (increasing total peripheral vascular resistance and blood pressure).

Which hormone is released by cardiac chambers in response to increased blood volume and wall stretch?

Natriuretic peptide (e.g., ANP and BNP).

What is the definition of cardiac preload?

The pressure and stretch generated by the end-diastolic volume (EDV) in the ventricle just before contraction.

What hemodynamic change occurs in left ventricular preload during systolic heart failure?

Increased left ventricular preload (due to impaired contractility and elevated residual end-systolic volume).

Which classic symptom is associated with aortic valve stenosis due to increased myocardial workload and reduced coronary perfusion?

Angina (chest pain).

Why does mitral stenosis cause respiratory symptoms and require lung auscultation?

Stenotic mitral valve impedes blood flow from the left atrium into the left ventricle, causing pressure and blood to back up into the pulmonary veins and lungs.

Which blood laboratory marker directly correlates with the severity of heart failure and ventricular wall stretch?

B-type natriuretic peptide (BNP).

How does ejection fraction differ between systolic and diastolic heart failure?

Systolic heart failure has a reduced ejection fraction (≤40%), whereas diastolic heart failure has a preserved/normal ejection fraction (≥50%).

What is the primary therapeutic strategy when a patient has an elevated troponin level?

Reduce myocardial oxygen demand (e.g., by administering nitrates, beta-blockers, or calcium channel blockers).

What atypical clinical manifestations of myocardial ischemia are frequently seen in female patients?

Weakness, anxiety, sudden unexplained fatigue, and palpitations.

What HDL level is classified as low and serves as an independent risk factor for coronary artery disease (CAD)?

An HDL level below 40 mg/dL (e.g., 30 mg/dL).

What occurs to the mitral valve leaflets during ventricular contraction in Mitral Valve Prolapse (MVP)?

Leaflets billow or collapse backward into the left atrium during contraction (systole).

What are three major modifiable risk factors for coronary artery disease (CAD)?

Lack of physical activity, cigarette smoking, and an atherogenic diet.