Christos E. Nerantzis

Functional dominance of the right coronary artery: Incidence in the human heart

After injection of radiopaque medium, 200 human hearts were studied by direct observation and x‐ray analysis. The right coronary artery (RC) was dominant in 178 of these hearts as characterized by giving off the typical posterior interventricular artery (PIV), the posterior descending artery. Within this group, 19 specimens had right coronary arteries that gave off both a large posterior interventricular artery (LPIV) and a branch that continued beyond the crux termed a large extension of the right coronary (LERC). The subgroup of hearts supplied thusly was termed real right dominant (RRD). The RC in these hearts supplied the right ventricle and almost half of the left ventricle. These findings explain why proximal lesions of the RC in RRD hearts can be associated with extensive posterolateral ischemia and mitral dysfunction and should be of practical importance when considering angioplasty or by‐pass surgery. The diameters and lengths of the arteries of the RC in RRD hearts were measured and compared with the same parameters in typical right dominant hearts.

Variations in the origin and course of the posterior interventricular artery in relation to the crux cordis and the posterior interventricular vein: An anatomical study

Corrosion castings of 60 human hearts were used to demonstrate that the point of origin of the posterior interventricular artery (PIA), in relation to the crux cordis, is responsible for its subsequent course with respect to the posterior interventricular vein (PIV). In seven cases (12%), the PIA appeared as the continuation of the left circumflex, descending rightwards and on a deeper level of the PIV. In 53 cases (88%), the PIA arose from the right coronary artery (RCA) and 50 of these were selected to be classified into three groups, according to the PIAs origin and course. In group A (29 cases, 58%) and B (seven cases, 14%), the PIA emerged before the crux cordis and descended to the right or left of the PIV, respectively. In group C (14 cases, 28%), it originated at, or beyond, the crux cordis and descended along the left side of the PIV. Among the 50 cases, the PIA was found to be long in 34 (68%), large in 32 (64%), and long and large in 29 cases (58%). In 18 of the latter 29 cases (62%) or 36% of the 50 cases in total, the PIA arose as a continuation of the RCA (group A) and therefore these cases were easily accessible to interventional cardiologists and also to surgeons, since the PIA lay on the same or on a superficial level in relation to the PIV. This work describes and explains the variations of the PIA and concludes that at least 36% of these may be helpful in coronary artery angioplasty and bypass surgery. Anat. Rec. 252:413–417, 1998.

Histologic Findings of the Sinus Node and the Perinodal Area in Street Heroin Addicts, Victims of Sudden Unexpected Death

Abstract:  Sudden unexpected death is frequent in street heroin addicts. We conducted a histologic study of the sinus node (SN) to offer some evidence about the possible arrhythmogenic cause of death. Postmortem coronary angiography and microscopic examination of the SN and the perinodal area were performed in 50 heroin addicts (group 1) and in 50 nonaddicts (group 2), all men (16–40 years old). In heroin addicts, fatty and/or fibrous tissue replaced SN tissue in 21 cases (42%). Perinodal infiltration was found in 15 cases (30%). Fibromuscular dysplasia in branches of the sinus node artery (SNA) was found in eight cases (16%). Inflammation with focal and/or diffuse concentration of round cells was detected in the SN in 22 cases (44%). Old mural thrombi were also found in 13 cases (26%). The histologic changes in the SN and perinodal area offer an explanation about the possible mechanism of arrhythmia and sudden death in this population.

Variation in the blood supply of the sinus node

PurposeThe purpose of the study was to examine the anatomical variations in the blood supply to the sinus node.MethodsGross anatomical examination and angiographic evaluation were performed in 400 human hearts derived from victims of various accidents.ResultsThe sinus node artery was a branch of the right coronary artery in 245 cases, the left circumflex in 147 cases, and both coronary arteries in 8 cases. In one subject, two sinus node arteries were found to arise from the left circumflex artery, a finding never reported before.ConclusionsAnatomic and postmortem angiographic findings of a previously unreported case where the sinus node is perfused by two sinus node arteries originating from the left circumflex coronary artery are demonstrated. Knowledge of this anatomical variation is useful for anatomists and of clinical significance for the interventional cardiologists and mainly for the cardiac surgeons in planning the surgical procedures.

Sinus node artery originating from the posterior part of the right coronary artery.

PurposeThe purpose of the study was to examine the anatomical variations of the sinus node artery (SNA).MethodsGross anatomical examination, angiographic evaluation and if necessary dissection were performed in 200 human hearts derived from victims of various accidents.ResultsThe SNA was a branch of the right coronary artery in 118 [59%] cases, the left circumflex in 78 [39%] cases and both coronary arteries in 4 [2%] cases. In one subject, the SNA was found to arise from the distal part of the right coronary artery.ConclusionsIn our case, the sinus node was perfused by a SNA arising from the mid-posterior segment of the right coronary artery. Knowledge of this anatomical variation is useful for anatomists and of clinical significance for the interventional cardiologists and mainly for the cardiac surgeons in planning the surgical procedures.

A secret pathway of the sinus node artery.

Anatomic and postmortem angiographic findings of a previously unreported case of common origin of the left circumflex (LCX) and the sinus node (SN) arteries, from the left main (LM) coronary artery were demonstrated. Knowledge of this anatomical variation, although it does not give rise to symptoms, is essential for anatomist and mainly for the interventional cardiologists and cardiac surgeons for their procedures.

Original histologic findings in arteries of the right ventricle papillary muscles in human hearts

In this study we describe original histologic findings of the right ventricle papillary muscle (PM) arteries in people under 30 years old. We examined 666 samples taken from the tip, mid‐portion, and base of the PM in 56 males and 55 females, as well as samples from the rest of the right ventricle. The amount of smooth muscle cell (SMC) fibers in the tunica media (TM) led to their division into three groups: Group 1: 351 samples (53%); normal amount, normal lumen. The amount of SMCs increased from the tip (20%) to the base (48%). Group 2: 226 samples (34%); mild to moderately increased amount of SMCs, with narrowness, eccentric displacement, and uneven lumen shape. They decreased from the tip (42%) to the base (23%). Group 3: 89 samples (13%), with abundant SMCs that duplicated the arterial size, contrary to the other two groups. Their shape was round and their extremely narrow, centrally located lumen had a round or oval shape. These changes were restricted only to PM arteries and decreased from the tip (65%) to the mid‐portion (35%). This type of artery predominated compared to the other two groups, probably because of the narrow lumen. No inflammatory reaction or chronic ischemic changes were found in the PM and its arteries. The SMC changes in groups 2 and 3 were found in subjects older than 2 months. The above findings will provide anatomists, cardiologists, and physiologists with valuable knowledge. Anat Rec 266:146–151, 2002.

Histological Findings of the Atrioventricular Conductive System in Street Heroin Addicts, Victims of Sudden Unexpected Death

A study of the atrioventricular (AV) conducting tissue was considered necessary for the examination of probable histologic changes that could justify the arrhythmias observed in street‐heroin addicts. Postmortem coronary angiography and microscopic examination were performed in 50 heroin addicts (group A) and in 50 nonaddicts (group B), all male 16–40 years old. In group A, fatty and/or fibrous tissue replaced the AV node in 50% of cases while in group B in 14%. The main bundle was replaced by fatty and/or fibrous tissue in 44% in group A cases and 10% in group B. Intimal proliferation and fibromuscular dysplasia of the AV arteries in group A were correspondingly 26% and 14% and in group B 6% and 2%. Inflammation with focal and/or diffuse concentration of round cells of the AV node was detected in 54% in group A. These findings could explain a possible arrhythmia mechanism in this population.

Variant of the left coronary artery with an unusual origin and course: Anatomic and postmortem angiographic findings

This study demonstrates anatomic and postmortem angiographic findings characterizing the origin of the left coronary (LC) artery arising in common trunk with the right coronary (RC) artery from the right aortic sinus and its course via the ventricular septum (VS) to the left heart. This anomaly was a single finding observed among 388 angiographies and 60 corrosion castings. The course of the LC was divided in four segments. The first three form a curve that is upward concave. Large branches to the septomarginal trabecula (ST), VS, diagonals (DS), and the small anterior interventricular (anterior descending) artery originated from the outer part of this curve. In the anteroposterior x‐ray, the above curve resembles a deep‐bottom pot with a handle corresponding to the fourth segment. In the right anterior oblique, the first and second segments form a large erect angle. The third segment occupies the lower part of the absent proximal anterior interventricular artery, and the fourth crosses the outflow tract and the first segment in the middle. The course of these four segments of LC resembles the shape of the number 6. These findings are important for interpreting coronary angiographies in patients with this anomaly. Clin. Anat. 11:367–371, 1998.