Normal Heart
Epidemiology:
Common sites:
Gross features:
- females: 250-300g avg
- males: 300-350g avg
- RV thickness:
0.3-0.5cm
- LV thickness: 1.3-1.5cm
- Electrical
avenues:
- sinoatrial node is located near the junction
of the right atrial appendage with the
superior vena cava
- atrioventricular node is located in the right atrium
along the atrial septum
- the bundle of
His courses from the right atrium to the summit of the ventricular
septum
- it divides into
right and left bundle branches
- blood supply:
- Left anterior
descending artery:
- apex
- anterior wall
of left ventricle
- anterior 2/3rds
of ventricular septum
- Left circumflex
artery:
- Lateral wall of
left ventricle
- Right coronary artery:
- Right ventricle
- Postero-basal wall of left ventricle
- Posterior third
of the right ventricle
- Note that in 20%
of individuals, the left circumflex artery gives rise to the posterior
descending branch and therby perfuses the posterior third of the septum and the
posterior wall of the left ventricle
- Chronic ischemia
causes small collaterals to enlarge over time and the blood flow
dynamics are altered
- Changes with
aging:
- Increased epicardial fat
- Reduction in
size of left ventricular cavity
- Rightward shift
and tortuosity of a dilated ascending aorta
- Leftward bending
of basal ventricular septum, bulging into left ventricular outflow tract
(sigmoid septum)
- Calcification of
the mitral annulus and aortic valve (aortic stenosis)
- Fibrous
thickening of valves
- Lambl excrescenses
(small filiform processes) on the closure
lines of aortic and mitral valves
- Deposition of amyloid in myocardium in some
- Accumulation of lipofuscin deposits within myocytes
- Basophilic
degeneration – an accumulation of gray-blue byproduct of glycogen metabolism
within myocytes
Histologic features:
- Valves:
- Dense collagenous layer at outflow surface (fibrosa)
- Central core of
loose connective tissue (spongiosa)
- Elastin-rich layer at inflow surface (ventricularis)
Immunophenotype:
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Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
References: