10/16 - Pathology of the Heart Flashcards
normal heart weights what percent of body weight? g in females and males
0.4% 0.5%
250-320 g in females
300-360 g in males
what is increased heart weight or ventricular thickness
hypertrophy
what is enlarged heart chambers
dilation
what is increased heart weight or thickness or enlarged heart chambers
cardiomegaly
what is main function of heart
pumping of blood
how does pumping function of heart occur
- coordinated contraction (during systole)
- coordinated relaxation (during diastole) of cardiac myocytes of myocardium
how is contraction achieved
shortening of serial contractile elements (sarcomeres) within parallel myofibrils
what is the other function of heart instead of being primarily pump
endocrine function
what are released from heart in response to increased stretch? what does this result in?
release protein hormones
1. promotes vasodilation
2. stimulate renal salt and water elimination
what are the heart valves
4: tricuspid, pulmonary, mitral, and aortic
what maintain unidirectional flow in heart
heart valves
valve function depends on what
- mobility
- pliability
- structural integrity
of AV vavlves of cusps of semilunar valives
cardiac valves are lined by what
endothelium
what is part of the conductin system
- SA node pacemaker
- AV node
- AV bundle (bundle of His)
- right and left bundle branch divisions
what is at the junction of R atrial appendage and SVC
SA node
what is located at right atrium along interatrial septum
AV node
what connects the right atrium to the ventricular septum
AV bundle (bundle of His)
what stimulates respective ventricles via further arborization into Purkinje network
right and left bundle branch divisions
Cardiac myocytes rely almost exclusively on ___ for their energy needs
oxidative phosphorylation
how does blood supply maintain energy
- high density of mitchondria
- constant supply of oxygenated blood
is the myocardium extremely vulnerable to ischemia
yes
nutrients and oxygen are delivered t the heart via what
coronary arteries with ostia immediately distal to aortic valve
does the myocardium of mammals have very LOW or HIGH replicative potential after fetal and neonatal live
LOW
myocardium of mammals average ___% cardiomyocytes turnover per year in adult humans
less than 1%
so has very low capacity of regeneration
more forms of heart disease become more prevalent when
with each advancing decade
the size of ___ is reduced in later life in heart
left ventricular capacity (particularly in base to apex dimension)
reduced size of left ventricle is exacerbated by what
HT as basal ventricular septum protrudes into left ventricular outflow tract (so called sigmoid septum)
compared to younger myocardium, an elderly heart as waht
- Fewer myocytes
- Deposition of extracellular amyloid that stiffens the heart
what is a condition in which a heart cannot pump blood to adequately meet the metabolic demands of the peripheral tissues, or can do so only at elevated filling pressures
heart failure (CHF)
what is the common end stage of many forms of chronic heart diseases
CHF
are adaptive mechanisms capable of maintaining adequate cardiac capacity?
yes it can potentially maintain, but can ultimately be OVERWHELMED
what is increased filling volume that dilates the heart and increases contractivity and stroke volume
Frank-Starling mechanisms
what is the released of norepinephrine, activation of renin-angiotensin-aldoesterone? basically the kidneys are attemptin to help heart function
activation of neurohumoral system
how can the heart be overwhelmed
- Frank-Starling mech
- acivation of neurohumoral system
- myocardial adaptations
heart failure can result from what
- systolic dysufnction
- diastolic dysfunction
what is the deterioration of myocardial contractile dysfunction? examples?
systolic dysfunction
e.g., HT, valvular disease
what is the inability of heart chambers to expand? examples?
diastolic dysfunction
e.g., myocardial fibrosis, amyloid deposition, constrictive pericarditis
left sided heart failure = ___ failure
LUNG failure
what is left sided heart failure most often caused by
- Ishemic heart disease (IHD) (coronary a)
- Hypertension (other artieries have HT)
- Aortic and mitral valvular disease (heart)
- primary myocardial disease (heart)
clinical and morphologic effects of left sided CHF are consequence of what
- Passive congestion (blood-backing up) in the pulmonary circulation
- Stasis of blood in the left-sided chamber
- Inadequate perfusion of down stream tissue leading to organ dysfunction
what is the most commonly affeted organ in LHF
heavy wet lungs (pulmonary congestion)
what does pulmonary congestion lead to
- dyspnea
- orthopenea
- paoxysmal noctural dyspnea
clinical signs of LS-CHF
- dyspenea
- orthopnea
- pulmonary edema
- pleural effuction
- fatigue, tachycardia
what is breathlesness
dyspnea
what is dyspnea while lying down
orthopnea
what is buildup of fluid in lungs
pulmonary edema
what is buildup of fluid in tissues lining the lungs
pleural effusion
what most commonly causes RIGHT sided heart fialure
left sided heart failure
T/F: Any increase in pressure on the left side of the heart inevitably burdens the right side of the heart
TRUE
in right sided heart failure, are clinical features the same as left sided CHF?
YES
are isolated right sided CHF frequent? who does this occur in?
INFREQUENT!
Occurs in patients with one of
variety of disorders affecting the lungs;
hence often called cor pulmonale
what are clinical signs of RS-CHF
- Systemic venous congestion
- Soft tissue edema
- Distended neck veins
- Enlarged liver
- Increased deep vein thromboses/pulmonary emboli
what is the ISOLATED right side of the heat to fail due to lung pathology
Cord Pulmonale
causes of cor pulmonale? most common cause?
- Pulmonary hypertension (most common cause)
- Scleroderma (damages lungs)
- COPD
- Cystic fibrosis
- Severe bronchiectasis
- Obstructive sleep apnea
- Idiopathic
CHF tx
- focus on correcting underlying cause (valvular defect or inadequate cardiac perfusion)
- salt restriction
- pharmacological agents
pharmacological agents for CHF tx
- diuretics (reduce volume overload)
- positive inotropes (increase cardiac contractibility)
- ACE-inhibitors
even if you treat CHF does it remains a serious cause of morbidity and mortality
yes