Atlas of Human Anatomy in Cross Section: Appendix: Topography of the Thorax and Abdomen

Heart and Heart Valves

Ronald A. Bergman, Ph.D., Adel K. Afifi, M.D., Jean J. Jew, M.D., and Paul C. Reimann, B.S.
Peer Review Status: Externally Peer Reviewed

Base, Highest Point

The highest point of the base of the heart varies in level from the lower third of the fourth to the upper third of the eighth thoracic vertebrae, with the average position being at a level between the middle and lower thirds of the sixth thoracic vertebra, as reported by Eycleshymer and Schoemaker. Merkel and Morris put the highest point of the base of the heart at the level of the fifth thoracic vertebra; Giacomini and Cunningham put it at the level of the fourth thoracic spine.

Apex, Lowest Point

The lowest point of the apex of the heart varies, according to Eycleshymer and Schoemaker, from the eighth thoracic disk to the eleventh thoracic disk with the average position being at the level of the lower third of the tenth thoracic vertebra. Merkel reported the average level of the apex to be the ninth thoracic vertebra. Sibson (cited but not referenced in Eycleshymer and Schoemaker) and Cunningham put the apex at the level of the eighth thoracic spine.

With reference to the anterior thoracic wall, Eycleshymer and Schoemaker found the apex of the heart at the level of the fifth intercostal space in the mamillary line. According to Joessel, Schultze, and others, the apex lies at the level of the fifth intercostal space midway between the parasternal and mamillary lines. Merkel states that the heart is so movable that it is unreasonable to give definite topographic data. Merkel and Eycleshymer and Schoemaker quote Ebstein (cited but not referenced in Eycleshymer and Schoemaker) as follows: "the heart in men whose heights range from 130 to 170 cm extends from 2 to 2.5 cm to the right of the sternum. In men whose heights range from 170 to 190 cm the heart extends 2.5 to 3 cm to the right of the sternum." No data for women were given, but there is no reason to believe that the data should be any different. Merkel states that a "normal" heart does not extend to the left beyond the mamillary line but is usually medial to this line. Distally, a "normal" heart extends to the xiphosternal junction, seldom if ever overlapping the upper end of the xiphoid process.

Tricuspid Valve

The tricuspid valve varies in level, according to Eycleshymer and Schoemaker, from the upper third of the seventh to the middle third of the tenth thoracic vertebrae. They report the average position as being at the level of the upper third of the ninth thoracic vertebra.

With reference to the anterior thoracic wall, the tricuspid valve is slightly to the right of the median line, opposite the sternal end of the fourth intercostal space. Braune reports that the center of the valve lies opposite the middle of the right half of the sternum at the level of the sternal end of the fourth costal cartilage. Merkel draws a line "slightly curved" to the right, from a point in the lower margin of the third costal cartilage (1.5 to 1.8 cm to the left of the sternum) to the sternal end of the sixth costal cartilage on the right. The superior portion of this line, i.e., to the lower portion of the third intercostal space, corresponds to the mitral valve, whereas the inferior portion of the line corresponds to the tricuspid valve. Langer and Toldt also adopt this line and place the middle of the tricuspid valve opposite the sternal end of the fifth cartilage. They illustrate the valve extending from the middle of the fourth to the middle of the sixth costosternal )unction. Spalteholtz reports that it lies behind the right half of the sternum at the level of the sternal end of the fourth intercostal space. Quain finds it lying behind the sternum slightly to the left of the fourth intercostal space and the fifth costal cartilage. Cunningham says it lies obliquely behind the right half of the sternum at the level of the fourth and fifth cartilages and the intervening space. Piersol finds it at the sternal end of the fifth costal cartilage. According to Debierre, the tricuspid valve lies opposite a line that begins at the sternal end of the fourth left costal cartilage, extends obliquely downward and to the right, crosses the midsternal line opposite the fourth intercostal space, and ends at the chondrosternal articulation of the fifth costal cartilage. Its extent ranges from 4 to 4.2 cm.

Pulmonary Valve

Eycleshymer and Schoemaker found the pulmonary valve to vary in position from the fourth thoracic disk to the lower third of the eighth thoracic vertebra. The average position is at the level of the sixth thoracic disk. With reference to the anterior thoracic wall, these same authors found the pulmonary valve lying in the second intercostal space, with its center about 1 cm from the sternum. According to Luschka, the pulmonary valve lies in the second intercostal space; its center is near the left border of the sternum. Henke and Engle place it lower at the level of the third left costal cartilage. Braune says it lies opposite the upper border of the third left costal cartilage 0. 5 cm from the sternum. Merkel has it opposite the upper portion of the third costal cartilage, with the center of the valve at the chondrosternal )unction. Langer and Toldt and Corning find it opposite the third left chondrosternal junction. Quain reported it immediately to the left of the sternum and opposite the third costal cartilage; Cunningham, opposite the upper border of the third left chondrosternal junction; Morris, opposite the third left chondrosternal); and Piersol, behind the sternal end of the third left costal cartilage. Debierre states the pulmonary orifice lies opposite a nearly transverse line that passes along the lower part of the second intercostal space and the upper margin of the third costal cartilage. The medial end of the line reaches, or extends slightly upon, the sternal margin. Its extent ranges from 2.2 to 2.5 cm.

Mitral Valve

The position of the mitral valve varies, according to Eycleshymer and Schoemaker, from the middle of the sixth to the upper third of the tenth thoracic vertebrae, with the average position being at the level of the middle of the eighth thoracic vertebra. With reference to the anterior thoracic wall, the center of the mitral valve in Eycleshymer and Schoemaker's subject was found opposite the upper portion of the sternal end of the fourth left costal cartilage. Joessel, Spalteholtz, and Piersol report that it lies behind the sternal end of the left third intercostal space. Braune found its center opposite a point in the middle of the third left intercostal space 1 cm from the sternum. Merkel and Langer and Toldt place it as stated above under the description for the tricuspid valve. Quain reported that it lies slightly to the left of the auriculoventricular groove and opposite the fourth costal cartilage and the adjacent part of the sternum. Cunningham finds it behind the left half of the sternum at the level of the fourth rib. According to Debierre, it lies opposite a line that begins at the inferior border of the middle portion of the third costal cartilage, passes obliquely downward and to the right across the third intercostal space and the articulation of the fourth costal cartilage, and ends at or in the margin of the sternum opposite the fourth intercostal space. Its extent ranges from 3.8 to 4 cm.

Aortic Valve

The aortic valve varies in location from the fifth thoracic disk to the upper third of the ninth thoracic vertebra. The average position, according to Eycleshymer and Schoemaker, is at the level of the middle third of the seventh thoracic vertebra. With reference to the anterior thoracic wall, the aortic valve lies directly behind the sternum, opposite the lower portion of the second interspace and the third costal cartilage.

The aortic valve, according to Luschka, lies opposite a line that cuts obliquely the sternal extremity of the third intercostal space, in such a position that its right half is behind the sternum and its left half is behind the intercostal space. Braune reports that the center of the aortic valve lies opposite the middle of the left half of the sternum at the level of the third costal cartilage. Merkel states that it begins behind the sternal extremity of the third right costal cartilage, from which point it extends to the left and downward until the mesial plane is reached. Langer and Toldt and Corning place it opposite the sternal end of the third intercostal space nearer the midplane than the pulmonary valve. Quain says it is behind the left half of the sternum at the level of the third costal cartilage and Cunningham, behind the left half of the sternum at the level of the lower border of the third left costal cartilage. Piersol locates it behind the left half of the sternum and a little below and to the right of the pulmonary valve, the two overlapping about one-fourth their diameters. Debierre indicates that the aortic valve lies opposite a line that begins at the middle of the third left costal cartilage near its sternal end, passes slightly downward and to the right, and ends in the midsternal line at the level of the inferior border of the third costal cartilage or the third intercostal space. Its extent ranges from 2.2 to 2.5 cm.

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