occur after surgical operations or major trauma,
when clot fragments break away from HEALING
wounds. Doctors use ANTICOAGULATION THERAPYto
control microinfarction.
See also ASPIRIN THERAPY; HEART ATTACK; ISCHEMIC
HEART DISEASE; KIDNEY; MYOCARDIAL INFARCTION;
STROKE; TRANSIENT ISCHEMIC ATTACK(TIA).
minimally invasive cardiac surgery Surgical
methods that combine ENDOSCOPY and CARDIAC
CATHETERIZATIONto repair damaged HEARTvalves or
clear obstructive ATHEROSCLEROTIC PLAQUE. Some
methods involve making several small incisions in
the chest and between the ribs to gain access to
the heart. Others involve inserting microscopic
tools, via cardiac catheterization, into the heart.
There remain questions as to whether minimally
invasive cardiac surgery is of greater or lesser risk
than OPEN HEART SURGERY.
Though significantly less traumatic, minimally
invasive cardiac surgery restricts the surgeon’s
ability to see the condition of the heart. Minimally
invasive cardiac surgery done “off-pump” (with-
out CARDIOPULMONARY BYPASS), further challenges
the surgeon’s ability to operate on a moving tar-
get. Countering these concerns are the reduced
trauma to the chest because the STERNUM(breast-
bone) can remain intact, as well as avoiding the
risks of cardiopulmonary bypass. Recovery is
much more rapid and significantly less painful
than with traditional open heart surgery. How-
ever, the surgeon cannot reach the back of the
heart using minimally invasive procedures, limit-
ing the value of these methods for treating CORO-
NARY ARTERY DISEASE (CAD) that involves the
posterior CORONARY ARTERIES.
See also MINIMALLY INVASIVE SURGERY; POSTOPERA-
TIVE PROCEDURES; PREOPERATIVE PROCEDURES; SURGERY
BENEFIT AND RISK ASSESSMENT.myocardial infarction Death of HEARTtissue. The
most common cause of myocardial infarction is
occlusion of the CORONARY ARTERIESsuch as occurs
as a consequence ofCORONARY ARTERY DISEASE(CAD)
or less frequently of coronary ARTERY spasm.
Myocardial infarction is the clinical term doctors
use for HEART ATTACK. The MYOCARDIUMhas very
high oxygen needs, as oxygen is the only energy
source for myocardial cells (unlike most other cells
in the body, except the BRAIN, that also use GLU-
COSEfor energy). Myocardial tissue does not have
significant ability to regenerate.
Myocardial tissue that dies not only can no
longer contract to aid in the heart’s function but86 The Cardiovascular System
Type of Medication Common Products Actions/Effects Cardiovascular Conditions
sodium channel disopyramide, flecainide, slow electrical conduction severe ventricular tachycardia
blocker mexiletine, moricizine, in the heart; regulate
procainamide, heart rate
propafenone, quinidine,
tocainide
thrombolytic anistreplase, streptokinase, dissolve blood clots deep vein thrombosis; ischemic stroke;
(intravenous hospital tissue plasminogen MYOCARDIAL INFARCTION
administration only) activator (tPA), urokinase
vasoconstrictor epinephrine constrict blood vessels; HYPOTENSION
raise blood pressure
vasodilator hydralazine, isosorbide dilate blood vessels; angina pectoris;CORONARY ARTERY DISEASE;
dinitrate, isosorbide decrease the heart’s hypertension
mononitrate, workload; lower blood
mecamylamine, pressure
minoxidil, nitroglycerin