Sudden cardiac death
(SCD)
·
Defined as unexpected death from cardiac causes early
after or without the onset of symptoms. In the vast majority of cases in adults
SCD is a complication and often the first clinical manifestation of IHD.
Infrequently, it is a consequence of myocarditis, mitral valve prolapse, or
hypertrophic cardiomyopathy.
·
The ultimate mechanism of death is almost always a
lethal arrhythmia, presumably triggered by previous conduction system scarring,
acute ischemic injury, or electrical instability due to electrolyte imbalance.
·
Morphology. Marked coronary atherosclerosis with
critical (greater than 75%) stenosis involving more than one of the three major
vessels is present in 80 to 90 % of victims; only 10 to 20% of cases are of
nonatherosclerotic origin.
Chronic Ischemic
Heart Disease (CIHD)
·
The designation of CIHD is used for the heart of
patients often but not exclusively elderly, who individuously develop
congestive heart failure (CHF), sometimes fatal, as a consequence of ischemic
myocardial damage.
·
Most cases of CIHD constitute simply postinfarctional
cardiac decompensation or slowly ischemic myocyte degeneration.
·
Cardiosclerosis
can be local postinfarctional and diffuse atherosclerotic.
·
Macroscopically: on section white
foci of sclerosis or brown coloration of the heart, hypertrophy of left
ventricle or, in contrary, some reduction in heart size, moderate to severe
multivessel stenosing coronary atherosclerosis and sometimes total occlusions
resulting from organized thrombi.
·
Microscopically: diffuse or local perivascular and interstitial fibrosis. In
some cases the hypertrophy of adjacent myocytes occurs, in others cases
myocytic atrophy with perinuclear deposition of lipofuscin appears.
·
Due to postinfarctional cardiosclerosis the chronic heart’s aneurysm may develops.
·
The pericardial surface of the heart in CIHD may have
adhesions as the result of healing of pericarditis also associated with post
myocardial infarctions.
·
Cardiosclerosis leads to chronic cardiac
insufficiency, which is characterized by congestion: edema, cyanosis,
petechias; indurations of organs (lungs, kidneys, spleen) and development of
the “nutmeg” liver.
·
Patients may die due to cardiacdecompensation or
thromboembolism.
