The apex beat (lat. ''ictus cordis''), also called the apical impulse, is the

pulse In medicine, the pulse refers to the rhythmic pulsations (expansion and contraction) of an artery in response to the cardiac cycle (heartbeat). The pulse may be felt ( palpated) in any place that allows an artery to be compressed near the surfac ...

felt at the point of maximum impulse (PMI), which is the point on the

precordium In anatomy, the precordium or praecordium is the portion of the body over the heart and lower chest.sternum The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major bl ...

at which the

cardiac The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissu ...

impulse can be felt. The cardiac impulse is the vibration resulting from the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

rotating, moving forward, and striking against the chest wall during

systole Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers of the heart are refilling ...

. The PMI is not the

apex of the heart The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissu ...

but is on the precordium not far from it. Another theory for the occurrence of the PMI is the early systolic contraction of the longitudinal fibers of the left ventricle located on the endocardial surface of this chamber. This period of the cardiac cycle is called isovolumic contraction. Because the contraction starts near the base of the left ventricle and spreads toward the apex most of the longitudinal fibers of the left ventricle have shortened before the apex. The rapidly increasing pressure developed by the shortening of these fibers causes the aortic valve to open and the apex to move outward causing the PMI. Anatomical dissection of the musculature of the apex reveals that muscle fibers are no longer longitudinal oriented but form a spiral mass of muscular tissues which may also have an effect on the ability of the apex to contract longitudinally. After the longitudinal fibers contract, the ejection of blood out of the left ventricle is accomplished by the torsional (as one would wring out a face cloth) action of the circumferential muscle fibers of the left ventricle that are in the mid-portion of the ventricle and contract after the longitudinal fibers. During the longitudinal fiber contraction, the volume of the left ventricle has not changed keeping the apex in intimate contact with the chest wall allowing the ability to feel the apex move outward before the heart empties greater than 55% of its volume and the apex falling away from the chest wall.

Identification

The normal apex beat can be palpated in the

precordium In anatomy, the precordium or praecordium is the portion of the body over the heart and lower chest.dextrocardia, the apex beat may be felt on the right side.

Interpretation

Image:Apex_beat.png, Algorithm for classification of the apex beat characters

Lateral and/or inferior displacement of the apex beat usually indicates enlargement of the heart, called cardiomegaly. The apex beat may also be displaced by other conditions: * Pleural or pulmonary diseases * Deformities of the chest wall or the thoracic vertebrae Sometimes, the apex beat may not be palpable, either due to a thick chest wall, or conditions where the

stroke volume In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the ventricle (heart), ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an Echocardiography, echocardiogram and subtra ...

is reduced; such as during

ventricular tachycardia Ventricular tachycardia (V-tach or VT) is a cardiovascular disorder in which fast heart rate occurs in the ventricles of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple ...

or shock. The character of the apex beat may provide vital

diagnostic Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...

clues: * A forceful impulse indicates volume overload in the heart (as might occur in

aortic regurgitation Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...

) * An uncoordinated ( dyskinetic) apex beat involving a larger area than normal indicates ventricular dysfunction; such as an aneurysm following myocardial infarction * A pulse deficit between the PMI and periphery may occur in some

arrhythmias Arrhythmias, also known as cardiac arrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. Essentially, this is anything but normal sinus rhythm. A resting heart rate that is too fast – above 100 beats ...

, such as premature ventricular contraction or

atrial fibrillation Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...

. Sustained apex beat, namely prolonged upward cardiac force during

in a

physical exam In a physical examination, medical examination, clinical examination, or medical checkup, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions ...

, can be seen in some chronic conditions such as

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

and aortic stenosis, especially in elderly and females. An algorithm for the classification of some common apex beat characteristics is shown in the image

References

External links

Examination of Cardiac Apex Beat
{{DEFAULTSORT:Apex Beat Cardiology