Coronary care types

The coronary care type is not uniformly defined. There are two different definitions in the literature (since both are common, both definitions are presented here):

• Definition 1: The classification is made according to coronarographic aspects. This also corresponds to Schlesinger's suggestions. The most common type of care is called "normal / balanced care". (Kaltenbach 1980)
• Definition 2: The second definition states that the type of supply is determined by the dominant coronary vessel. This is defined as the vessel which supplies the following cardiac parts via the ramus interventricularis posterior (RIVP):
  • the inferior parts of the septum
  • the diaphragmatic wall of the left ventricle (Stierle 2017)

The data on the frequency of the individual types of care differ greatly in this respect (Kaltenbach 1980)

There are three types of supply:

1. balanced / balanced or also normal supply type

2. left supply type

3. type of legal care (Herold 2019)

Anatomy

For the sake of clarity, only the vessels that are important for the assignment of the individual types of supply are mentioned below. The coronary vascular system consists of two arteries: a right (RCA) and a left (LCA) coronary artery.

Left coronary artery: It consists of a short main trunk divided into an anterior interventricular ramus (RIVA) and a circumflex ramus (RCX). In the further course of the RCX the R. interventricularis posterior (RIVP) emerges from the RCX (Alkadhi 2009).

Right coronary artery: The right coronary artery (RCA) consists of a longer main trunk which is divided at the crux cordis into a ramus interventricularis posterior (RIVP) and a ramus posterolateralis dexter (RPLD) (Blade 2015).

Ring and loop system: The ring and loop system serves as a model to describe the arterial supply of the heart, since the arterial supply depends on the individual anatomy of the coronary arteries. The right coronary artery and the ramus circumflexus form a ring at the base of the heart - in the respective sulcus - between atrium and ventricle, on which a loop is placed at right angles. This loop is formed by the ramus interventricularis anterior and the ramus interventricularis posterior. The point at which the posterior longitudinal sulcus, the interatrial sulcus and the dexter atrioventricular sulcus cross is called the crux cordis. The right coronary artery and the ramus circumflexus show the greatest variability at the vascular ring, as do the ramus interventricularis anterior and the ramus interventricularis posterior of the vascular loop.

The classification of the different types of supply depends on which areas of the myocardium are supplied by the right coronary artery or the left coronary artery (Cracow 2005).

• Balanced type: In the balanced type, the proximal left coronary artery and the proximal right coronary artery have a similar caliber. Both supply the posterior wall of the heart in approximately equal parts (Schünke 2009). The left coronary artery supplies the posterior wall of the left ventricle through the ramus circumflexus and the rr. posterolateralis (roscomb 1984) (Kaltenbach 1980). The ramus interventricularis originates from the right coronary artery and supplies the diaphragmatic (inferior) posterior wall of the left ventricle (Kaltenbach 1980 / Roskamm 1984) via the ramus interventricularis posterior and the ramus posterolateralis.
• Left restoration type: In the left restoration type, the proximal ramus circumflexus has a large diameter (Stierle 2014). The entire left ventricle and the posterior septum (Stierle 2014) are supplied via the LCA. The ramus circumflexus delivers the ramus interventricularis posterior (roscomb 1984). The right coronary artery is only weakly developed. It does not reach the crux cordis and does not participate in the supply of the left ventricle. It supplies only the right atrium and the right ventricle (Lapp 2014).
• Right-sided / extreme right-sided: In the right-sided type, the arterial supply to the left ventricle is mainly through the right coronary artery. The ramus interventricularis posterior also branches off from the right coronary artery and supplies the interventricular septum with its inferior parts. One or more branches of the posterior interventricular ramus extend to the diaphragmatic wall of the left ventricle and supply it (Lapp 2014). The ramus circumflexus of the left coronary artery is only weakly developed. Although the RCX of the left coronary artery delivers some rami marginalis, these do not reach the crux cordis. (Kaltenbach 1980).
• Extreme right ventricularsupply type: If the entire posterior wall of the left ventricle is supplied by the right coronary artery, this is called an "extreme right ventricular supply type". In this case the ramus circumflexus is only present as a small branch (Lapp 2014).

According to definition II: The definition II is based exclusively on the point of origin of the RIVP and thus determines the type of supply.

• Right-sided supply type: Here the RIVP originates from the right coronary artery.
• Left supply type: In this case, the RIVP originates from the left coronary artery (Alkadhi 2009)
• Balanced restoration type: In this case the RVIP originates from the right coronary artery and all posterolateral branches originate from the ramus circumflexus (Lapp 2014).

Since the two different definitions mentioned above exist, the frequency of the individual types of care varies greatly.

1. balanced / balanced or even normal supply type

• Definition I:

The normal type of care represents the largest patient group with 60 % to 80 % (Herold 2019).

• Definition II: According to this definition, about 12 % of patients are included (Stierle 2017).

2. type of legal care / extreme legal care

• Definition I: The right-hand-supply type occurs in 10 % to 20 % of cases.

• Definition II: Here, the legal care type occupies the largest group with about 75% (Stierle 2017).

Extreme type of care: an extreme type of care is found in about 5% of cases (Krakow 2005)

3. left supply type

• Definition I: It occurs at about 10 % to 20 %.

• Definition II: According to this, it makes up about 12 % (Stierle 2017).

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