HEART I Flashcards
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
__________ is the most common situation, the cardiac muscle contracts weakly and the chambers cannot empty properly-so called systolic dysfunction
failure of the pump
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
lesions that prevent the valve opening (calcific aortic valve stenosis) or cause increased ventricular chamber pressures (systemic hypertension, or aortic coarctation) can overwork the myocardium, which has to pump against obstruction
obstruction to flow
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
valve pathology that allows backward flow of blood results in increased volume workload and may overwhelm the pumping capacity of the affected chambers
regurgitant flow
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
defects (congenital or acquired) that divert blood inappropriately from one chamber to another or from one vessel to another, lead to pressure and volume overloads
shunted flow
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
uncoordinated cardiac impulses or blocked conduction pathways can cause arrhythmias that slow contractions or prevent effective pumping altogether
disorders of cardiac conduction
OVERVIEW OF CARDIAC PATHOPHYSIOLOGY
loss of circulatory continuity (e.g. gunshot wound through the thoracic aorta may lead to massive blood loss, hypotensive shock, and death)
rupture of the heart of major vessel
HEART FAILURE
____________: increased filling volumes dilate the heart, thereby increasing actin-myosin cross-bridge formation, and enhancing contractility and stroke volume
frank-sterling mechanism
HEART FAILURE
___________: these augment heart function and/or regulate filling volumes and pressures
_________ by adrenergic nerves of the autonomic nervous system, elevating heart rate
_________ promoting water and salt retention and increasing vascular tone
_________ counterbalancing the RAAS through diuresis and vascular smooth muscle relaxation
activation of neurohumoral systems
- release of norepinephrine
- activation of the RAAS
- release of atrial natriuretic peptide
HEART FAILURE
_________: in many pathologic states, heart failure is preceded by cardiac hypertrophy, a compensatory response to increased mechanical work
myocardial adaptations
HEART FAILURE
CARDIAC HYPERTROPHY
sustained increased in ______________ of either ventricle due to pressure overload, volume overload, or trophic signals causes myocytes to increase in size (cellular hypertrophy)
mechanical work
HEART FAILURE
CARDIAC HYPERTROPHY
the pattern of hypertrophy reflects the nature of the stimulus:
in _____________ new sarcomeres are predominantly assembled in parallel to the long axes of cells, expanding the cross-sectional area of myocytes in ventricles and causing a concentric increase in wall thickness
in contrast, __________ is characterized by new sarcomeres being assembled in series within existing sarcomeres leading to ventricular dilation
pressure-overload hypertrophy
volume-overload hypertrophy
LEFT SIDED HEART FAILURE: TWO FEATURES
_______ is defined by insufficient ejection fraction (pump failure), and can be caused by any or the many disorders that damage or derange the contractile function of the left ventricle
_______ the left ventricle is abnormally stiff and cannot relax during diastole
systolic failure
diastolic failure
LEFT SIDED HEART FAILURE:
the ________ are telltale signs of previous episodes of pulmonary failure
heart failure cells
hemosiderin laden macrophages
RIGHT SIDED HEART FAILURE
________– is most commonly caused by left-sided heart failure
right sided heart failure
RIGHT SIDED HEART FAILURE MORPHOLOGY
____________. congestion of the hepatic and portal vessels may produce pathologic changes in the liver, the spleen and the GI tract
liver and portal systems
CHD
________ or “holes in the heart” including atrial septal defects or ventricular septal defects
________ either at the level of valves or the entire cardiac chamber as in hypoplastic left heart syndrome
________ including inappropriate routing of the great vessels from the ventricles or anomalous coronary arteries
septal defects
stenotic lesions
outflow tract anomalies
CLASSIFICATION OF ATRIAL SEPTAL DEFECT
__________- 90% result from deficient septum secundum formation near the center of the atrial septum
_________ - 5% occur adjacent to the av valves and are often associated with AV valve abnormalities
_________ - 5% located near the entrance of the SVC and can be associated with anomalous pulmonary venous return to the right atrium
secundum ASD
primum anomalies
sinus venosus defects
CONGENITAL HEART DISEASE
of the 30 or so genes present on this chromosome segment, deletion of the ________ transcription factor gene is probably the culprit lesion
TBX1 gene
CLASSIFICATION OF VSD VENTRAL SEPTAL DEFECT
about 90% occur in the region of the membranous intraventricular septum (______________), and the majority are 2-3 cm in diameter.
The remaining 10% occur below the pulmonary valve (____________)
membranous VSD
infundibular VSD
CHD (LEFT TO RIGHT SHUNTS)
__________ are abnormal, fixed openings in the atrial septum caused by incomplete tissue formation that allows communication of blood between left and right atria
Atrial septal defect
CHD
Ventricular septal defect Morphology
VSDs are classified according to their location and magnitude. About 90% occur in the region of the intraventricular septum (____________)
Majority are 2-3 cm in diameter. The remaining 10% occur below the pulmonary valve (__________)
membranous VSD
infundibular VSD
CHD RIGHT TO LEFT SHUNTS
4 CARDINAL FEATURES OF TETRALOGY OF FALLOT
(V, O, A, R)
ventricular septal defect
obstruction of the right ventricular outflow tract
aorta that overrides the VSD
right ventricular hypertrophy
OBSTRUCTIVE LESIONS
___________- of the aorta ranks high in frequency among the common structural anomalies
coarctation of the aorta
