Heart Sounds and Cardiac Output

These flashcards cover the key concepts related to heart sounds, heart function, cardiac output, and heart failure as discussed in the lecture.

What are the two primary heart sounds called?

S1 (lub) and S2 (dub)

What causes the first heart sound (S1)?

The closing of the atrioventricular valves during ventricular contraction.

What causes the second heart sound (S2)?

The closing of the semilunar valves during ventricular diastole.

What is the significance of S3 heart sound?

It may indicate blood flow into the atria or be heard in younger individuals, athletes, or pregnant women.

What could S4 heart sound indicate?

Contraction of the atria against a stiff ventricle, possibly indicating left ventricular failure.

How are heart murmurs typically graded?

On a scale of 1 to 6, with 1 being the least severe and 6 being the most severe.

What is a common cause of heart murmurs?

Turbulent blood flow, often due to incompetent valves.

What does stroke volume represent?

The amount of blood pumped from each ventricle with one contraction.

How is cardiac output calculated?

By multiplying heart rate by stroke volume.

What is the normal resting cardiac output in adults?

About 5.25 liters per minute.

What factors can influence heart rate?

Intrinsic factors, endocrine system, nervous system, and environmental factors.

What is preload in relation to cardiac function?

The amount of stretch of the ventricular walls at the end of diastole.

What does afterload refer to?

The pressure the ventricles must generate to exceed the pressure in the aorta.

What is the role of norepinephrine in heart function?

It increases the heart rate and force of contraction by stimulating beta-1 adrenergic receptors.

What role does acetylcholine play in heart function?

It decreases heart rate by hyperpolarizing pacemaker cells.

What is congestive heart failure (CHF)?

A condition where the heart cannot pump enough blood to meet the metabolic needs of the body.

What are common symptoms of heart failure?

Shortness of breath, fatigue, swelling in legs/ankles, rapid heartbeats.

What complication arises from left-sided heart failure?

Pulmonary congestion, leading to fluid buildup in the lungs.

What complication arises from right-sided heart failure?

Peripheral congestion, leading to swelling in the systemic circuit.

What treatments are commonly used for heart failure?

Diuretics, beta blockers, ACE inhibitors, and lifestyle changes.

What can persistent hypertension lead to regarding heart function?

It forces the heart to work harder, leading to heart muscle wear and potential failure.

How does atherosclerosis affect heart function?

It narrows arteries due to plaque buildup, increasing pressure and workload on the heart.

What happens to cardiac muscle after a heart attack?

It is replaced with scar tissue, which does not contract effectively.

Why do heart murmurs require careful diagnosis?

They can be caused by various underlying conditions and their treatment varies accordingly.

What does the term 'Kentucky gallop' refer to?

The rhythmic sound of S1, S2, and S3 heart sounds resembling the sound of a galloping horse.

What impact can exercise have on cardiac output?

It can significantly increase heart rate and stroke volume, thereby increasing cardiac output.