Hemodynamic Disorders Flashcards
Hemodynamics:
the flow of blood
Systole:
the blood pumping phase of the cardiac cycle.
Diastole:
the chamber filling phase of the cardiac cycle
Preload:
the ventricular wall tension at the end of diastole (degree of myocyte stretch) determined by end-diastolic volume, reflected in end-diastolic pressure
Afterload:
the resistance the ventricle must overcome to pump its contents, determined by systolic blood pressure, reflected in ventricular systolic pressure
Myocardial contractility:
inotropic state determining the portion of the force of contraction independently of preload and afterload
Compliance:
the distendibility of the ventricle, determining the ease of filling it and, indirectly, the amount of filling and hence the amount of blood pumped
Heart failure:
inability of the heart to pump sufficient blood to meet the needs of the body
B-type natriuretic peptide:
a hormone secreted in heart failure in proportion to the severity
Mitral valve prolapse:
billowing of redundant mitral valve into the left atrium during systole thromboemboli from infective endocarditis
Rheumatic heart disease:
immune-mediated inflammation of the heart, especially valves, triggered by group A streptococcal infection
Libman-Sacks endocarditis:
autoimmune inflammation of the heart valves as part of systemic lupus erythematosus.
Marantic endocarditis:
non-bacterial thrombotic endocarditis, the deposition of blood clot on heart valves.
Vegetations:
colorful misnomer for blood clots on heart valves.
Osler nodes:
pea-sized tender nodules in fingers and toes from infected thromboemboli from infective endocarditis.
Janeway lesions:
hemorrhages on the palms or soles from infected thromboemboli from infective endocarditis.
Cor pulmonale:
heart disease caused by lung disease.
Arrhythmia:
disturbance in heart rhythm due to deranged cardiac electrical signaling.
PR interval:
time from start of P wave to end of QRS, normally 120-200 ms, indicative of conduction block around AV node if prolonged.
QT interval:
time from start of QRS to end of T wave, normally <440 ms, dangerous if prolonged due to risk of ventricular tachyarrhythmias.
Atrial fibrillation:
arrhythmia of chaotic atrial activation at a rapid rate causing an irregular heart rhythm due to variable conduction through the AV node.
Ventricular fibrillation:
immediately life-threatening arrhythmia of chaotic ventricular activation at a rapid rate with lack of cardiac pumping.
Channelopathy:
heart disease of arrhythmias due to defective cardiac myocyte ion channels, usually due to genetic mutations.
Torsades de pointes:
a polymorphic ventricular tachycardia with variation in QRS size and shape, creating an outline resembling a twisted ribbon on EKG
LV end-diastolic volume
150 ml
LV end-systolic volume
50 ml
Stroke volume
100 ml
Ejection fraction
67%
LV end-diastolic pressure
10 mm Hg
LV systolic pressure
130 mm Hg
RA pressure
3 mm Hg
RV systolic pressure
25 mm Hg
LA pressure
8 mm Hg
The greater the volume of blood delivered to the cardiac ventricles?
The more the cardiac myocytes (myofibers) are stretched and the greater the force of the next contraction.
Inotropic:
It means something like contractility-related.
The ventricular preload is measured by?
Both the ventricular end-diastolic pressure and end-diastolic volume are regarded as representing the preload.
Afterload is the resistance the ventricle?
Must overcome to pump out its contents during systole.
The force of ventricular contraction in systole is determined?
Preload, Afterload, Contractility, and Compliance
Compliance:
This is the stiffness of the ventricular wall.
What decreases ventricular compliance and what does it cause?
Fibrosis, amyloidosis or any other process causing interstitial infiltration by anything more rigid than normal decreases ventricular compliance. This restricts (impairs) cardiac pumping. This condition is referred to as restrictive cardiomyopathy.
Impaired cardiac filling?
Called diastolic dysfunction. Diastolic dysfunction does not typically reduce the ejection fraction.
Impaired cardiac pumping?
Called systolic dysfunction. Usually due to impaired contractility or greatly increased afterload, decreases the amount of blood ejected from the ventricle, the stroke volume, and the proportion of the end-diastolic volume ejected, the ejection fraction.
The five major categories of the factors determining the heart’s function as a pump, the cardiac output?
(1) preload, (2) afterload, (3) contractility, (4) compliance and (5) heart rhythm.
The most common cardiac hemodynamic disorder?
Cardiac failure is inability of the heart to pump sufficient blood to meet the needs of the body.
Cardiac failure epidemiology
More than half a million Americans are diagnosed with heart failure per year, and 5 million have it. Rises sharply in old age, from 0.8% of 50-59-year-old men and women to 6.6% of 80-89-year-old men and 7.9% of 80-89-year-old women.The prevalence in African-Americans is reported to be 25% higher than in whites.
Heart failure most common type?
Myocardial infarction, necrosis of part of the pump exceeding the ability of the surviving part to compensate. MI causes coronary artery disease, 17% due to smoking, 10% hypertension, 8% overweight, 3% diabetes mellitus and 2% valvular heart disease.
Chronic heart failure is most frequently caused by?
Old myocardial infarction(s), commonly multiple old myocardial infarctions. This is often called ischemic cardiomyopathy.
Coronary artery disease can also cause
Acute heart failure.
Myocardial infarction can develop heart failure how long?
In a few hours.
Uncontrolled severe hypertension can cause?
Heart failure by causing excessive afterload exceeding the ability of the heart to compensate rather than impaired contractility.
Stenosis of the aortic valve?
Can make it so hard to pump through a tiny opening that the excessive afterload exceeds the ability of the heart to compensate resulting in heart failure.
Heart failure due to aortic stenosis, severe hypertension or coronary artery disease typically causes the ejection fraction?
Lowers the ejection fraction.
Heart failure due to left ventricular hypertrophy, restrictive cardiomyopathy or pericardial disease is typically cause ejection fraction?
Preservation of the ejection fraction.
Congestive heart failure:
When the heart fails, blood backs up behind it waiting for take-off, resulting in congestion of the veins bringing blood back to the heart.
Most common cause Cardiomegaly?
Cardiomegaly due to heart failure is caused by dilation of the chambers much more often than thickening of the walls.
The most common symptom of heart failure is?
Dyspnea, the sensation of breathlessness, not getting enough air.
What increase in pulmonary venous pressure cause fluid to pass from the congested pulmonary veins into the interstitium.
When pulmonary venous pressure, which is normally 8 mm Hg, goes over 20 mm Hg, a transudate of fluid passes from the congested pulmonary veins into the interstitium.
Two most specific symptoms of heart failure?
Paroxysmal nocturnal dyspnea and orthopnea
Two most common symptoms of heart failure?
dyspnea and fatigue?
Signs of heart failure include?
Tachycardia, tachypnea, hypotension, pulmonary crackles, pulmonary wheezing, diaphoresis and gallops.
At what pulmonary venous pressure will transudate pass into the airspaces, and what can you hear when this happens?
25 mm Hg, transudate passes not only into the interstitium, but also into the airspaces. Crackles first heard at the lung bases.
Diaphoresis (sweating)?
Can be a sign of heart failure due to sympathetic nervous stimulation, a compensatory response.
A third heart sound (S3) early in diastole?
A dull, low-pitched sound attributed to rapid filling can be a sign of heart failure. Gallop
Dulled mental status due to inadequate cerebral perfusion and oliguria due to decreased renal perfusion?
Can also be signs of heart failure, but are not at all specific for heart failure.
The diagnosis of heart failure?
Often apparent from the history and physical examination.If not, chest x-ray findings of cardiomegaly (enlarged heart), pulmonary vascular congestion and interstitial or alveolar edema, Echocardiography, B-type natriuretic peptide (BNP) levels.
Biomarker of heart failure?.
Serum B-type natriuretic peptide, and the level correlates with the severity of the heart failure.
Hypertension causes?
Increased afterload; the left ventricle responds and compensates with concentric hypertrophy until it passes the limits of its ability to compensate.
The gallop associated with hypertensive heart?
An S4 gallop with the extra heart sound later in diastole than S3.
The atrial gallop of hypertensive heart disease sounds like?
Tennessee.
Hypovolemia is?
A hemodynamic disorder and one important to differentiate from cardiogenic hemodynamic disorders because the treatment is essentially the opposite.
The most common cause of hypovolemic shock?
Hemorrhage is the most common cause, but some cases are due to diarrhea or vomiting.
Acute heart failure has four profiles?
- Profile A Warm and Dry 2. Profile B Warm and Wet 3. Profile C Cold and Wet 4. L Cold and Dry.
Warm or cold in these profiles refers to?
The extremities. Warm extremities are either adequately perfused or abnormally perfused with peripheral vasodilation, the latter most commonly due to sepsis. Cold extremities are inadequately perfused and manifest peripheral vasoconstriction in response.
Wet or dry in these profiles refers to?
The patient as a whole. Wet patients have edema, jugular venous distension and pulmonary crackles indicative of volume overload and elevated left ventricular filling pressure. Dry patients lack these findings.
The warm and dry profile is most associated with?
Transient myocardial ischemia or heart failure from lung disease.
Warm and wet heart failure patients are?
Volume overloaded, but still managing to adequately perfuse their extremities.
Cold and wet patients are?
Fluid overloaded and no longer adequately perfusing their extremities.
Cold and dry profile is called?
“L” for “low” cardiac output; Can be mitral regurgitation and left ventricular dilatation, whose is suddenly active. Much more commonly, cold and dry patients with profile L have hypovolemia.
The cardiovascular control center?
In the medulla gets the message via the ninth and tenth cranial nerves.
Hypovolemia leading to shock elicits multiple cardiovascular compensatory responses.
Rapid breathing, increased sympathetic nervous activity and decreased parasympathetic nervous action, increases the heart rate, augments myocardial contractility and causes peripheral vasoconstriction. Increase RAAS.
Normal central venous pressure?
Essentially the same as right atrial pressure, 3 mm Hg.
In a fluid overloaded heart failure patient or a patient with right heart failure the central venous pressure will be?
Abnormally elevated.
In a hypovolemic patient, the central venous pressure?
Usually be low.
Hypovolemic shock treatment?
Fluids
Cardiogenic shock treatment?
Diuresis
Differentiating hypovolemic shock from cardiogenic shock is crucial because?
The treatments are opposite and mistaken diagnosis and treatment for one can be fatal for a patient who has the other.
The valve disease most commonly causing a hemodynamic disorder in the US?
Aortic stenosis.
Calcific aortic stenosis is?
The second most common valvular disease. (male/female ratio 3/1).
Calcific aortic stenosis there are three main causes?
(1) congenitally anomalous bicuspid valve (50% of cases), (2) “senile” degeneration, and (3) chronic rheumatic disease.
When the aortic valve opening is less than?
50% of normal size, significantly increased left ventricular pressure becomes necessary to push a normal stroke volume through it during systole.
Significantly increased left ventricular pressure?
This causes concentric left ventricular hypertrophy like hypertensive heart disease, with the same accompanying decrease in compliance.
Symptoms of calcific aortic stenosis
Angina pectoris (chest pain due to myocardial ischemia), syncope (loss of consciousness) and dyspnea (the sensation of being short of breath). Symptoms of aortic stenosis usually occur with exertion.
Signs of calcific aortic stenosis?
include a crescendo-decrescendo systolic (ejection) murmur, a weak delayed pulse and an atrial gallop.
Calcific aortic stenosis presents with angina, syncope or dyspnea and valve replacement after the development of symptoms?
Greatly improves survival.
Mitral regurgitation is?
The ejection of a portion of the left ventricular stroke volume backward into the left atrium due to insufficiency (incompetence) of the mitral valve.
The second most common valve disease causing a hemodynamic disorder in the US?
Mitral regurgitation
The most common cause of mitral regurgitation in the US?
Mitral regurgitation in the US is mitral valve prolapse, 67% (two-thirds) of cases. The second most common cause is ischemic heart disease,25% (one-quarter) of cases.
The pathophysiologic consequences of mitral regurgitation are?
(1) decreased forward stroke volume, (2) increased left atrial volume and pressure and (3) volume-related stress on the left ventricle because the added left atrial volume is returned to it along with the normal left atrial volume during diastole.
If mitral regurgitation is acute, left atrial pressure is?
Raised.
If mitral regurgitation is chronic, left atrial dilatation?
Allows it to hold the extra volume with less elevated pressure.
If rupture of a papillary muscle (due to myocardial infarction or infective endocarditis) causes sudden mitral regurgitation?
The resulting increased left atrial pressure, transmitted backward to the pulmonary circulation, may cause rapid pulmonary congestion and edema (“flash pulmonary edema”), a medical emergency.
The symptom of acute mitral regurgitation is?
Dyspnea.
The most common symptom of chronic mitral regurgitation is?
Fatigue (or “weakness”).
Severe chronic mitral regurgitation will cause heart failure manifested by?
Paroxysmal nocturnal dyspnea and orthopnea.
The sign of mitral regurgitation is?
An apical holosystolic (pansystolic) murmur, which sometimes has a harsh quality.
In severe acute mitral regurgitation, the murmur may be?
Decrescendo, reflecting the rapid equilibration between left atrial and ventricular pressures during systole.
Reduction of forward stroke volume from the normal of 100 ml to 75 ml or lower is associated with?
Clinical manifestations of heart failure.
25% reduction of forward stroke volume from the normal of 100 ml to 75 ml is associated with?
With clinical manifestations of heart failure.
Mitral valve prolapse is?
A billowing of redundant mitral valve into the left atrium during systole.
Mitral valve prolapse epidemiology?
It is the most common valvular disease (present in 2% of the population) with a slight female predominance (female/male ratio 3/2).
Mitral valve prolapse may occur with?
Connective tissue diseases such as Marfan syndrome.
Mitral valve prolapse gross pathology?
Features billowing, ballooning and floppy leaflet(s). Sometimes the chordae tendineae are elongated attenuated and vulnerable to rupture.
Mitral valve prolapse microscopic pathology?
Degeneration and attenuation of the outer zona fibrosa of the valve and expansion of the inner zona spongiosa with myxomatous tissue (resembling mucus microscopically).
Mitral valve prolapse symptoms?
Usually asymptomatic, but patients may experience chest pain or palpitations due to associated arrhythmias. It causes a midsystolic click and late systolic murmur.
Mitral valve prolapse diagnosis?
By physical examination, confirmed by echocardiography.