See also CARDIOVASCULAR DISEASE PREVENTION;
COAGULATION; CORONARY ARTERY DISEASE(CAD); DEEP
VEIN THROMBOSIS(DVT); MEDICATIONS TO TREAT CARDIO-
VASCULAR DISEASE; MUSCLE.
intra-aortic balloon pump (IABP) counterpulsa-
tion A method to relieve strain on the HEART
when there is significant damage to the heart such
as after a major HEART ATTACK, in end-stage HEART
FAILUREwhile awaiting HEART TRANSPLANTATION, or in
cardiovascular SHOCK. Such circumstances result in
the heart being unable to pump enough BLOODto
meet the body’s needs. IABP counterpulsation
helps pull blood through the AORTA, assisting the
left ventricle’s pumping efforts.
The cardiologist inserts the IABP on the tip of a
catheter during a CARDIAC CATHETERIZATION, thread-
ing it through a small incision in a major peripheral
ARTERYnear the surface of the SKIN, such as the
femoral artery in the groin or the brachial artery in
the upper arm. The IABP rests in the root of the
aorta, its inflated balloon cuff holding it firmly in
place. An inner ringlike balloon forms the inside
channel of the IABP, inflating and deflating in syn-
chronization with the CARDIAC CYCLE. The channel
narrows as the IABP inflates during diastole (filling
of the ventricles) and widens as the AIBP deflates
during systole (contraction of the ventricles). The
effect is to pull blood into the aorta at the same time
the left ventricle pumps blood out, easing the
amount of pressure necessary to move the blood. A
computer closely monitors the heart’s electrical
patterns to precisely time the inflation and defla-
tion of the IABP’s inner balloon.
See also ENHANCED EXTERNAL COUNTERPULSATION
(EECP).
ischemic heart disease (IHD) The consequential
condition that results when CORONARY ARTERY DIS-
EASE(CAD) and other conditions that affect the
heart’s blood supply deprive the HEARTof oxygen
over an extended period of time. Ischemia is the
medical term for a temporary interruption of
BLOODflow; in ischemic heart disease (IHD), the
interruptions are temporary but recurrent. Cardiac
ischemia occurs when the CORONARY ARTERIESare
unable to provide the heart with enough blood to
meet its oxygen needs. Coronary artery spasm,
which often occurs with moderate to advanced
CAD, also can generate ischemic episodes.
Ischemia often results in a specific kind of dis-
comfort or PAIN, ANGINA PECTORIS. However, many
people who have IHD have what doctors call
silent ischemia that causes no symptoms until
HEART ATTACK, and sometimes not even then. Silent
heart attack can further contribute to the IHD
when parts of the heart MUSCLEare no longer
functional. IHD may alternately improve and
worsen according to the person’s activity level, as
the heart’s oxygen needs increase with activity.
The diagnostic path seeks to identify the under-
lying condition of the symptoms, which is usually
CAD though sometimes ARRHYTHMIAdisorders are
to blame. Treatment targets the causative condi-
tion, and may include ANGIOPLASTYor CORONARY
ARTERY BYPASS GRAFT(CABG) as well as medications
to regulate the heart’s rate and workload.
Ischemic heart disease generally improves with
these measures.
See alsoATHEROSCLEROSIS; CARDIOVASCULAR DIS-
EASE PREVENTION; LIVING WITH CARDIOVASCULAR DIS-
EASE; TRANSMYOCARDIAL LASER REVASCULARIZATION
(TMLR).70 The Cardiovascular System