Exam 3: The Heart Flashcards
(101 cards)
What is the first organ system to develop in utero?
cardiovascular system
What is the leading cause of death in the U.S.? Give some statistics.
Heart Disease
- 1 in every 4 deaths = ~ 1 death per minute
- 1/3 of all “premature” deaths (younger than 75)
How many people each year in the U.S. have CHF? How many are hospitalized? How many die from it?
5 million have CHF
1 million are hospitalized with CHF
300,000 die from CHF
What are the six categories for the pathophysiological mechanisms ass. with “heart disease”?
- Pump Failure (“contractile failure” or “systolic dysfunction”)
- Obstructed Flow
- Regurgitant Flow
- Shunted Flow
- Disordered Cardiac Conduction
- Rupture of the Heart Wall or Major Vessel
What is the most common mechanism of heart failure?
Pump failure (contractile failure or systolic dysfunction)–> they myocytes contract too weakly and chambers are unable to completely empty
What is the results of the Pump failure mechanism for heart disease?
reduced Stroke Vol. and reduced Cardiac Output
What may cause the Obstructed Flow mechanism for heart disease? Why is this bad?
- cardiac valve stenosis
- systemic HTN
heart must pump harder to overcome it, therefore works harder
What mechanism of cause is it when the cardiac valves do not seal properly? Why is this an issue?
Regurgitant Flow –> allows blood to travel against direction of flow and requires heart to pump same unit of blood, increasing workload on heart
What is the MC reason for Regurgitant Flow?
cardiac valvular disease
What heart failure mechanism is it when blood is inappropriately diverted from one region of the heart to another? What does this result in?
Shunted Flow–> results in overloading cardiac tissue by increasing pressure/blood volume w/in that region receiving the shunted blood
Disordered Cardiac Conduction mechanism for heart failure may causes what?
cardiac arrythmias–> which may cause heart palpitations, or produce lethal sudden cardiac death if arrhythmia is prolonged/sustained
What may cause the Rupture of the Heart Wall or Major Vessel mechanisms for heart failure?
severe elevations in cardiac pressure or external trauma —> result in a “loss of circulatory continuity” and heart quickly fails
When does Heart Failure (CHF) occur?
when cardiac dysfunction causes insufficient cardiac output and the heart fails to meet body’s metabolic requirementes
What form of heart failure initially involves sufficient cardiac output, but elevated filling pressures are required to achieve this level of CO?
compensated heart failure
What form of heart failure occurs when the heart failure occurs due to an increased tissue demand? How common is this?
High-output heart failure
small minority of heart failure cases and is secondary to conditions
What conditions may High-output heart failure be secondary to?
- Hyperthyroidism
- severe anemia
- large AV fistula
- Paget Disease (occasionally)
What three things may heart failure occur due to?
- Systolic dysfunction
- Diastolic dysfunction
- Valvular dysfunction
What cause of heart failure is due to the result of inadequate myocardial contraction? What is this form frequently a result of?
Systolic dysfunction
HTN or CAD (an ischemia heart disease)
What is the reduced cardiac output from systolic dysfunction sometimes referred to as?
“forward failure”
What cause of heart failure is due to the results of inadequate cardiac relaxation and inadequate filling of cardiac chambers?
Diastolic dysfunction
What are common causes of Diastolic dysfunction?
- myocardial fibrosis
- cardiac amyloidosis
- advanced concentric cardiac hypertrophy
- constrictive pericarditis
- secondary to pericardial tamponade
What cause of heart failure occurs following any valvular injury? What are causes of this?
Valvular Dysfunction Causes: - age-related calcific stensosi - infectious endocarditis - Libman-Sacks endocarditis from Lupus - Rheumatic Fever
What will “forward failure” due to systolic dysfunction result in?
an increase in “end-diastolic” volume and pressure and elevated venous blood volume and pressure—-> known as “backward failure”
Our cardiovascular system will attempt to adapt during early stages of heart failure from reduced myocardial contractility (systolic dysfunction). What are the 3 mechanisms of Compensated Heart Failure?
- Frank-Starling Mechanism
- Neurohumoral Activation
- Myocardial Structural Changes