A variant of type IV dual left anterior descending coronary artery
Prashanth Panduranga1, Rajkumar Gangappa Nadakinamani2 1 Department of Cardiology, National Heart Center, Royal Hospital, Muscat, Sultanate of Oman 2 Department of Cardiology, Badr Al Samaa Polyclinic, Muscat, Sultanate of Oman
Date of Submission
28-May-2018
Date of Acceptance
08-May-2019
Date of Web Publication
13-Dec-2019
Correspondence Address: Dr. Prashanth Panduranga Department of Cardiology, National Heart Center, Royal Hospital, Post Box 1331, Muscat-111 Sultanate of Oman
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/ACCJ.ACCJ_3_18
Abstract
In type IV dual left anterior descending (LAD) coronary artery, one short LAD artery originates from the left main coronary artery and the second long LAD takes origin from the right coronary sinus or right coronary artery (RCA) with an independent distal anterior interventricular sulcus course. Here, we describe a patient with a variant of Type IV dual LAD wherein the first LAD originated from the left main coronary artery but was long (instead of a usual short one) and the second LAD did not have an independent distal anterior interventricular sulcus course. It originated from proximal RCA coursing with a retro-aortic loop and continuing at mid-segment of the first LAD without independent course.
Keywords: Coronary anomaly, dual left anterior descending, left anterior descending artery
How to cite this article: Panduranga P, Nadakinamani RG. A variant of type IV dual left anterior descending coronary artery. Ann Clin Cardiol 2019;1:39-40
How to cite this URL: Panduranga P, Nadakinamani RG. A variant of type IV dual left anterior descending coronary artery. Ann Clin Cardiol [serial online] 2019 [cited 2023 Mar 26];1:39-40. Available from: http://www.onlineacc.org/text.asp?2019/1/1/39/272999
Introduction
Dual left anterior descending (LAD) artery had been reported to occur with an incidence of 1%.[1] According to Spindola-Franco Classification,[1] in Types I–III, both short and long LADs originate from a common LAD trunk, and in Type IV, one short LAD artery originates from the left main coronary artery and the second long LAD takes origin from the right coronary sinus or right coronary artery (RCA). Short LAD lies in the proximal anterior interventricular sulcus, giving rise to septal perforators and diagonals, and does not reach the apex. The second LAD from the right side lies in the distal anterior interventricular sulcus and can follow either anterior (Type IV), septal, or interarterial course to the interventricular groove, which is further named as Type V and VI, respectively, by few authors.[2],[3] Here, we describe a patient with a rare variant of Type IV dual LAD.
Case Report
A 41-year-old male, nondiabetic, nonhypertensive, nonsmoker, was referred from a private clinic with exertional angina class II for few months, and exercise test was reported positive for ischemia. His echocardiogram was reported normal with no regional wall motion abnormalities and good left ventricular systolic function. Coronary angiogram revealed normal left main arising from left sinus branching into LAD and left circumflex artery. There was ostial LAD minor disease with mid and distal LAD normal. This LAD artery arising from the left sinus was long with normal anterior interventricular sulcus course reaching the apex. It gave a diagonal branch proximally. Left circumflex artery had proximal significant lesion [Figure 1]a. A tortuous first obtuse marginal was seen curving around the proximal LAD. Interestingly, there was retrograde filling of a vessel from mid-LAD [[Figure 1]a, arrowhead]. RCA was arising from the right sinus and was dominant and normal [[Figure 1]b. However, there was coronary anomaly in the form of dual LAD origin. A second LAD was arising from the proximal RCA [[Figure 1]b and Video 1]. This LAD was also long with a retro-aortic loop, and two septal branches were seen arising from this anomalously arising LAD [[Figure 1]b and [Figure 2]a, arrowhead]. In addition, this LAD stopped at mid-course of the first LAD and was seen continuing as the mid-segment of first LAD [Figure 2]b, arrowhead and Video 2]. There were no flow-obstructing lesions in either of the LAD. The coronary anomaly and the left circumflex lesion were explained to the patient, and he preferred optimal medical therapy.
Figure 1: (a) Coronary angiogram showing normal left main arising from left sinus, ostial left anterior descending minor disease. Left circumflex artery had proximal significant lesion. A tortuous first obtuse marginal was seen curving around proximal left anterior descending. Note retrograde filling of a vessel from mid left anterior descending (arrowhead). (b) Right coronary artery arising from right sinus, dominant and normal. A second left anterior descending was arising from the proximal right coronary artery giving rise to two septal branches (arrowhead)
Figure 2: (a) Second left anterior descending was long with an anterior loop and two septal branches were seen arising from this anomalously arising left anterior descending (arrowhead). (b) This left anterior descending stopped at mid-course of the first left anterior descending and was seen continuing at mid-segment of first left anterior descending (arrowhead)
The LAD after originating from the left main normally courses in the anterior interventricular sulcus toward the cardiac apex and gives off diagonal branches to the anterolateral wall of the left ventricle and septal perforators to the interventricular septum. In dual LAD, there are two LADs (a short and a long branch) which course and supply different parts of the anterior interventricular sulcus. Spindola-Franco et al. described four variants of dual LAD.[1] In Types I–III dual LAD, both the short and long LADs originate from a common LAD trunk. In dual LAD I and II, the long LAD descends on the left ventricular side (Type I) or the right ventricular side (Type II), of the anterior interventricular sulcus, and then re-enters the distal part of interventricular sulcus. In Type III, the long LAD courses intramyocardially proximally and appears on the epicardial surface in the distal part of the sulcus. In Type IV dual LAD coronary artery, one short LAD artery originates from the left main coronary artery and the second long LAD takes origin from the right coronary sinus or RCA and can follow either anterior, septal, or interarterial course with an independent distal anterior interventricular sulcus course.[2],[3],[4]
In this patient with Type IV dual LAD, there were two important rarities. One was the presence of long first LAD (instead of a usual short one). The second was that the second LAD did not have an independent distal anterior interventricular sulcus course as seen in other types of Type IV dual LAD. It originated from proximal RCA coursing with a retro-aortic loop and continuing at mid-segment of the first LAD. To the best of our knowledge, this variant of Type IV anomaly has not been reported previously. Cardiac coronary computerized tomography scan can confirm the angiographic findings and delineate the anomalous course but was not available. If significant atherosclerosis occurs in such patients, it can have percutaneous interventional or surgical implications if not recognized precisely as noted by Sajja et al.[5]
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Spindola-Franco H, Grose R, Solomon N. Dual left anterior descending coronary artery: Angiographic description of important variants and surgical implications. Am Heart J 1983;105:445-55.
Subban V, Murdoch D, Pincus M. Dual left anterior descending coronary artery with origin of short left anterior descending coronary artery from left main shaft: A rare coronary anomaly. J Invasive Cardiol 2014;26:E59-60.
Lee Y, Lim YH, Shin J, Kim KS. A case report of type VI dual left anterior descending coronary artery anomaly presenting with non-ST-segment elevation myocardial infarction. BMC Cardiovasc Disord 2012;12:101.
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