The heart is located in the mediastinum within the pericardium. It has an apex pointed leftward and downward, a base oriented posteriorly, and three surfaces - sternocostal, diaphragmatic, and left. The heart has borders on the right, left, and inferiorly. The surfaces and borders divide the heart into areas for the atria and ventricles. Notable grooves on the heart include the coronary, interatrial, and interventricular grooves. Auscultation of the heart listens for heart sounds at the tricuspid, mitral, aortic, and pulmonic areas.

1. External features of heart

2. Position of heart

3. Features of heart
• Apex
• Base
• Surfaces (3)
– Sternocostal Surface
– Diaphragmatic Surface
– Left surface
• Borders (3)
• Right
• Left
• Inferior

4. Apex of the Heart
• Directed downwards,
forwards and to the left
• Formed by
– Left ventricle
• Lies at the level of
– Left 5th intercostal space 3.5
inch from midline
– About 9 cm from midline
– Inferomedial to left nipple
• Apex beat
– Sound of mitral valve closure

5. Base of the Heart (posterior surface)
 Bounded inferiorly by
 Posterior part of coronary
sulcus
 Lodges the coronary sinus
 Anastomosis between coronary
arteries
 Superior
 Transverse sinus
 Pulmonary trunk & aorta
Left
atrium

6. Base
(posterior surface)
• Formed by
– 2 atria
• Left atrium 2/3
• Right atrium 1/3
– 4 pulmonary veins open into it
 Directed backwards
 Lies opposite middle thoracic
vertebrae (5-8)
 Separated from them by
 Descending aorta
 Esophagus and oblique sinus
of pericardium

7. Anterior (Sternocostal) Surface
• Formed by
– Right atrium and right
ventricle
– Left ventricle

8. Anterior Surface
• Divided by
– coronary (atrio-ventricular)
groove into :
1. Atrial part, formed mainly by
right atrium.
2. Ventricular part , the right
2/3 is formed by right
ventricle, while the left l1/3
is formed by left ventricle.
 The coronary groove lodges
right coronary artery.

9. Anterior (Sternocostal) Surface
 The 2 ventricles are
separated by anterior
interventricular groove,
which lodges :
 Anterior interventricular
artery (branch of left
coronary).
 Great cardiac vein.

10. Anterior (Sternocostal) Surface
• Related to
– Body of Sternum
– Adjoining costal cartilage
• 3rd – 6th
• Area of superficial
cardiac dullness
– Due to cardiac notch of left
lung
• Portion of rt ventricle is not
covered

11. Major grooves of Anterior surface
• Coronary sulcus
– Between Atrium and ventricle
– Lodges
• Right part of coronary sulcus
– Right Coronary artery
• Left part of coronary sulcus
– Lt coronary artery
• Anterior interventricular
groove
– Between Right & left ventricles
– Lodges
• Anterior interventricular artery
• Great cardiac vein

12. Diaphragmatic Surface
 Formed by
 2-ventricles, mainly left
ventricle (left 2/3)
 Rests on diaphragm
 Directed inferiorly &
backward
 Separated from base of
heart
 By posterior part of
coronary sulcus.

13. Diaphragmatic Surface
 2-ventricles are separated by
 Posterior interventricular groove
 Which lodges:
 Posterior interventricular artery
 Middle cardiac vein

14. Borders of the Heart
• Right- SVC and RA
• Sulcus terminalis runs along
with it
• Left- LV and Lau
• Inferior- RV and LV

15. Right border
• Formed by
– Right atrium
• Extends
– From right side of SVC
– To IVC
• Features
– Sulcus terminalis
• Separates
– Sternocostal surface from
base

16. Right border - relations
• Medial to lateral
– Fibrous pericardium
– Rt. Phrenic nerve
– Rt pericardo phrenic vessels
– Rt. Mediastinal pleura
– Cardiac area of rt. lung

17. Inferior border
• From
– Inferior vena cava
• To
– Apex of heart
• By
– Right ventricle
– Left ventricle
• Separates
– Diaphragmatic surface
– Sternocostal surface
• Structure present
– Right marginal artery
– Notch – incisura apicis cordis

18. Left border
• From apex to left
auricle
• Separates
– Sternocostal surface
from left surface

19. Crux of heart
• Meeting point of
– Posterior
interventricular
– Atrioventricular
– Interatrial grooves

20. External features
• Sulci:
1. Coronary (atrioventicular)
sulci-
a) anterior b) posterior
2. Interatrial groove
o Visible posteriorly
3. Interventricular sulci/ groove
4. Crux is the posterior basal
surface at junction of
coronary and posterior
interventricular sulci and
internally atrial septum joins
the venticular septum

21. Auscultation
• Performed using a
stethoscope
• Help gather an
understanding of
– Cardiac rate and rhythm
– Condition of valves
– Congenital defects or an
underlying chronic condition

22. Heart Sounds
Where to listen on chest wall for heart sounds.

23. • Tricuspid area
– 4th - 5th intercostal space
– Left sternal edge
• Mitral area
– Left 5th intercostal space
– Mid-clavicular line
• Aortic area
– 2nd intercostal space
– Right sternal edge
– Aortic valve
• Pulmonic area
– 2nd intercostal space
– Left sternal edge
– Pulmonary valve