This educational image consists of a clinical photograph (a) and a schematic diagram (b) illustrating a dual left anterior descending (LAD) coronary artery variant. The photograph displays a dissected human heart specimen in the anterior view, highlighting the course of the coronary vasculature. Labeled structures include the Anterior Interventricular Sulcus (AIS) and two distinct 'Long LAD' branches descending parallel to each other. The schematic representation details the origin of these vessels from the Left Coronary Artery (LCA), alongside the Right Coronary Artery (RCA) and Circumflex Artery (CX). A critical anatomical feature demonstrated is the 'intramural course' of the right-sided LAD branch, where a portion of the vessel is embedded within the myocardium (myocardial bridge) before resurfacing. This variant is clinically significant for cardiothoracic surgery and interventional cardiology, as it represents a deviation from standard coronary anatomy (specifically resembling Pellegrini Type XIII) that can impact diagnostic interpretation and surgical planning for revascularization.

This diagnostic coronary angiogram consists of two panels demonstrating the anatomy of the coronary arterial tree. The left panel shows a hypoplastic right coronary artery (RCA), characterized by its small caliber and limited distal distribution. The right panel displays the left coronary system, including the left anterior descending (LAD) and circumflex (CX) arteries. The images reveal a left-dominant coronary circulation pattern, where the circumflex artery provides the primary blood supply to the posterior aspect of the heart. A notable finding is the marked tortuosity of the epicardial vessels, a feature often associated with chronic hypertension and arterial remodeling. Despite the tortuous course, there is no evidence of hemodynamically significant obstructive stenoses in the epicardial segments of the LAD, CX, or RCA. This study illustrates non-obstructive coronary artery disease in a patient with left-dominant anatomy and vessel tortuosity.

Summary : This figure presents multiple cardiac CT images illustrating the anatomy and course of the coronary arteries, with specific attention to the left anterior descending artery (LAD), right coronary artery (RCA), and their relationship to the interventricular septum (IVS) during different phases of the cardiac cycle. photo: # Cardiac Anatomy Overview : • Panel A shows a 3D reconstructed cardiac CT image highlighting the RCA, LAD, and a diagonal branch (Dg). • The LAD is traced along the anterior surface of the heart, with a white arrow indicating its course. • The RCA is visible on the right side of the heart. • A white arrowhead marks a specific anatomical point on the LAD. # Coronary Artery Course : • Panel B displays a curved multiplanar reconstruction of the LAD, with a white arrowhead indicating a notable segment. • The LAD is seen running along the anterior interventricular groove. # Interventricular Septum (IVS) Relationship : • Panel C shows a cross-sectional CT image of the heart, with the IVS labeled. • The white arrowhead points to the LAD as it courses over the IVS. # Cardiac Cycle Phases : • Panels D and E compare the LAD's appearance during diastole and systole. • Both panels show the LAD (white arrows) in similar anatomical positions, but the surrounding cardiac structures differ due to the phase of the cardiac cycle. # Technical Details : • Images are grayscale except for the 3D reconstruction in panel A, which uses color to differentiate anatomical structures. • No scale bars or magnification details are provided. • Labels include RCA (right coronary artery), LAD (left anterior descending artery), Dg (diagonal branch), and IVS (interventricular septum). # Spatial Relationships : • The LAD is consistently shown on the anterior surface of the heart, running parallel to the IVS. • The RCA is positioned on the right side of the heart. • The anatomical course of the LAD is compared across different imaging planes and cardiac phases. # Analysis : • The figure demonstrates the anatomical course of the LAD and its relationship to the IVS, as well as the consistency of its position during diastole and systole. • The use of multiple imaging planes and 3D reconstruction provides a comprehensive view of coronary artery anatomy. • No obvious anomalies or pathologies are visible in the presented images.

This diagnostic image is a 12-lead electrocardiogram (ECG) demonstrating a combination of conduction abnormalities and ST-segment deviations. The ECG shows a widened QRS complex with an rSR' pattern in the right precordial leads (V1-V3), characteristic of a Right Bundle Branch Block (RBBB). Concomitant left axis deviation is present, indicative of a Left Anterior Fascicular Block (LAFB), together forming a bifascicular block pattern. Notably, there is mild, diffuse ST-segment elevation (STE) visible in the lateral leads (I, aVL, V4-V6) and inferior leads (II, aVF). In the clinical context of non-ischemic dilated cardiomyopathy with negative cardiac biomarkers, these ST-segment changes represent a chronic, non-ischemic ST-elevation (NISTE) pattern rather than acute myocardial infarction. The ST segments appear relatively stable and are associated with secondary repolarization changes from the intraventricular conduction delay. This tracing serves as an educational example of how baseline conduction defects and cardiomyopathy can simulate or mask ischemic patterns, emphasizing the importance of clinical correlation and comparison with prior ECGs in diagnosis.

This diagnostic image is a 12-lead electrocardiogram (ECG) demonstrating a sinus rhythm with features characteristic of left ventricular hypertrophy (LVH) and left axis deviation. The limb leads show a predominantly positive QRS complex in Lead I and a predominantly negative QRS complex in Lead aVF, consistent with left axis deviation. In the precordial leads (V1-V6), there is evidence of voltage criteria for LVH, specifically high-amplitude R-waves in the lateral leads (V5 and V6) and deep S-waves in the right precordial leads (V1 and V2). The ST segments and T waves are generally unremarkable across most leads, though there is a slight ST depression and T-wave inversion in the lateral leads, which can be associated with an LVH strain pattern. This tracing serves as an educational example of cardiac remodeling secondary to chronic hypertension or renal disease in a preoperative clinical context.

A standard 12-lead electrocardiogram (ECG) displayed on a pink grid background, illustrating bifascicular block findings. The tracing reveals sinus tachycardia with a marked left axis deviation, characterized by a predominantly positive QRS complex in lead I (black arrow) and a negative QRS deflection in lead aVF (green arrow). The precordial leads show classic morphology for a right bundle branch block (RBBB), specifically highlighting an rsR' pattern in lead V2 (blue arrow). Combined, the left axis deviation (suggestive of left anterior fascicular block) and the RBBB findings constitute a bifascicular block. The image provides clinical teaching value for identifying intraventricular conduction delays and cardiac axis abnormalities in an acute clinical setting.