Summary : This figure illustrates the left atrial (LA) pressure-volume relationship during the cardiac cycle, showing both time-course traces and a pressure-volume loop, with key phases of atrial function annotated and correlated with the ECG. line plot and loop diagram: # Panel A: LA Pressure and Volume Traces • Top trace: LA Pressure (y-axis, arbitrary units) over time. • Middle trace: LA Volume (y-axis, arbitrary units) over time. • Bottom trace: ECG waveform for temporal reference. • X-axis: Cardiac cycle phases, with systole and diastole labeled; diastole further subdivided into E, D, and A phases. • Five phases are color-coded and numbered: – (1) Atrial filling (red) – (2) Passive emptying (green) – (3) Diastasis (black) – (4) Active emptying (blue) – (5) Atrial relaxation (gray) • Vertical dashed lines demarcate transitions between phases. # Panel B: LA Pressure-Volume Loop • X-axis: LA Volume (arbitrary units). • Y-axis: LA Pressure (arbitrary units). • The loop is traced in a counterclockwise direction, with arrows indicating the sequence. • The same five phases (1–5) are color-coded as in Panel A. • The loop is divided into two segments: A-Loop (phases 1, 3, 4, 5) and V-Loop (phase 2). # Design Encodings : • Distinct colors for each phase (red, green, black, blue, gray). • Arrows on the loop indicate the direction of the cardiac cycle. • ECG trace provides timing reference for the pressure and volume changes. # Analysis : • The LA pressure and volume traces show cyclical changes corresponding to atrial filling, emptying, and relaxation. • The pressure-volume loop visually summarizes the dynamic relationship between LA pressure and volume, with distinct segments for passive and active phases. • The figure highlights the temporal coordination between atrial events and the ECG, emphasizing the mechanical and electrical coupling in the cardiac cycle.

Summary : This figure shows a pressure–volume loop for the left ventricle, illustrating how ventricular volume and pressure change during the cardiac cycle, with key phases and valve events annotated. The isovolumetric relaxation and contraction periods are highlighted, and systolic/diastolic blood pressures are marked. pressure–volume loop diagram: # Title & Axes : • No explicit title on the figure, but the legend describes it as a "Pressure–volume loop demonstrating changes in ventricular volume during filling and ejection with corresponding changes in intracavity pressure." • X-axis: "Left ventricular volume (mL)" with tick marks at 0, 20, 40, 60, 80, 100, 120, 140, 160. • Y-axis: "Left ventricular pressure (mmHg)" with tick marks at 0, 20, 40, 60, 80, 100, 120, 140. • Additional axis labels: "Left ventricular end-diastolic pressure" (blue, left), "End-diastolic volume" (blue, bottom right), "Stroke volume" (black, bottom center). # Phases & Events : • Isovolumetric relaxation: vertical line at low volume, pressure drops, labeled. • Diastolic filling: horizontal line at low pressure, volume increases, labeled. • Isovolumetric contraction: vertical line at high volume, pressure rises, labeled. • Ventricular ejection: curved line, volume decreases as pressure peaks and falls, labeled. • Valve events: – Mitral valve opens (bottom left corner, low pressure/volume). – Mitral valve closes (bottom right corner, high volume/low pressure). – Aortic valve opens (top right corner, high volume/high pressure). – Aortic valve closes (top left corner, low volume/high pressure). # Blood Pressure Markers : • Systolic BP: horizontal dashed blue line at ~120 mmHg. • Diastolic BP: horizontal dashed blue line at ~80 mmHg. # Design Encodings : • Black solid lines for the loop. • Blue dashed lines for blood pressure markers. • Blue text for end-diastolic volume/pressure. • Labeled arrows for direction of phases and valve events. # Analysis : • The loop traces the cardiac cycle, starting at low pressure/volume (end-systolic), filling during diastole, rising sharply during isovolumetric contraction, ejecting blood during ventricular ejection, and dropping pressure during isovolumetric relaxation. • Systolic and diastolic blood pressures are marked, showing the pressure range during ejection. • The width of the loop (horizontal distance) represents stroke volume. • The figure clearly distinguishes the four main phases and the timing of valve openings/closings, providing a comprehensive view of ventricular mechanics during a heartbeat.

This composite educational graphic details the pathophysiology of myocardial perfusion and coronary hemodynamics. Panel A features a pathophysiology diagram illustrating the extravascular forces and intraluminal pressures affecting the myocardial layers during the cardiac cycle. It compares diastole and systole, highlighting the differences in intramural pressure (PINTRAMURAL), left ventricular lumen pressure (PLUMEN), and pericardial space pressure (PPERICARDIUM). The diagram shows the subendocardial plexus and epicardial artery, emphasizing greater subendocardial compression and reduced vascular volume during systole. Panel B presents a cardiac perfusion quantification map from a patient with aortic stenosis (AS). The map is organized in a grid: rows represent basal, mid, and apical short-axis slices of the left ventricle; columns demonstrate stress perfusion, rest perfusion, and myocardial perfusion reserve (MPR). The color-coded mapping shows regional perfusion distribution, with the MPR column specifically highlighting global limitations in perfusion reserve. This visual is designed for medical education focusing on cardiovascular hemodynamics, coronary microcirculation, and the physiological impact of valvular heart disease on myocardial blood flow.

This diagnostic trace image displays eight simultaneous monophasic action potential (MAP) recordings, labeled MAP1 through MAP8, used in cardiac electrophysiology research. The primary focus is the determination of effective refractory periods (ERP) at a basic cycle length of 500 ms. The traces exhibit characteristic cardiac action potential morphology with rapid depolarization and subsequent repolarization phases. Throughout the 2-second time interval (indicated by the scale bar), regular pacing stimuli are followed by short-coupled extrastimuli (S2/S3) to test ventricular vulnerability and refractory periods. Variations in amplitude and morphology are visible across the different MAP traces, with a voltage scale of 7.5 mV provided for reference. Notable features include the presence of premature beats and varying repolarization kinetics (APD90/APD50) across different anatomical recording sites. This recording is representative of programmed electrical stimulation protocols used to assess spatial dispersion of repolarization and the propensity for arrhythmias such as ventricular tachycardia or torsade de pointes.

This Comparison Chart illustrates cardiac optical mapping data obtained from two different camera systems: the iDS (left column) and MiCAM (right column). Panels A and B display still frames of a Langendorff-perfused mouse heart, stained with a voltage-sensitive dye (Di-4-ANEPPS). Three color-coded pixels (blue, orange, and green) are marked on the ventricular surface of each heart image, indicating specific regions of interest. Panels C through H present the corresponding action potential (AP) waveforms recorded from these marked locations. The x-axis represents time in milliseconds (0–200 ms) and the y-axis shows normalized signal amplitude. The AP waveforms demonstrate characteristic cardiac electrophysiological phases, including rapid depolarization and subsequent repolarization. Visually, the iDS system images (A) appear brighter with a clearer anatomical outline but show higher high-frequency noise in the raw AP traces (C, E, G). In contrast, the state-of-the-art MiCAM system (B) produces traces with a higher signal-to-noise ratio (D, F, H), resulting in smoother AP curves. This comparison is used in cardiovascular research to validate the efficacy of lower-cost imaging systems for measuring cardiac activation sequences and action potential duration (APD).

Summary : This figure illustrates the relationship between the surface electrocardiogram (ECG) waveform and the myocardial action potential, highlighting the corresponding ion channels responsible for different phases of cardiac electrical activity. line diagram: # Panel A: Surface Electrocardiogram (ECG) Waveform : • Shows a typical ECG trace with labeled points: P, Q, R, S, T, and U. • The waveform represents the electrical activity of the heart during a cardiac cycle. • P wave: atrial depolarization. • QRS complex: ventricular depolarization. • T wave: ventricular repolarization. • U wave: sometimes seen, origin not fully understood. # Panel B: Myocardial Action Potential : • Plots membrane potential (mV) on the y-axis (ranging from -90 mV to above 0 mV) against time (msec) on the x-axis. • Shows the phases of the cardiac action potential: – Rapid upstroke (depolarization) due to I_Na (sodium current). – Early repolarization (I_to, transient outward potassium current). – Plateau phase (I_Ca-L, L-type calcium current). – Repolarization phase (I_Kr and I_Ks, rapid and slow delayed rectifier potassium currents). – Resting potential maintained by I_K1 (inward rectifier potassium current). # Ion Channels & Phases : • I_Na: Responsible for the initial rapid depolarization. • I_to: Contributes to early repolarization. • I_Ca-L: Maintains the plateau phase. • I_Kr and I_Ks: Mediate repolarization. • I_K1: Maintains the resting membrane potential. # Design Encodings : • Simple black line traces for both ECG and action potential. • Ion channel names are annotated above the relevant phases of the action potential. # Analysis : • The figure visually links the phases of the ECG waveform to the underlying myocardial action potential and the specific ion channels involved. • The QRS complex corresponds to the rapid depolarization (I_Na), while the T wave aligns with repolarization (I_Kr, I_Ks). • The plateau phase (I_Ca-L) is crucial for the duration of the QT interval, which is clinically significant for arrhythmia risk. • The diagram provides a clear educational overview of how surface ECG features relate to cellular electrophysiology.

Summary : This figure compares cardiac function under two conditions using two types of plots: (A) the Frank-Starling relationship between stroke volume and left ventricular filling, and (B) pressure-volume loops with end-systolic elastance (Ees) lines. line and schematic plot: # Panel A: Frank-Starling Curve : • Y-axis: Stroke Volume (no units shown). • X-axis: LVEDP or LVEDV (Left Ventricular End-Diastolic Pressure or Volume; no units shown). • Two curves are shown: – Curve 1: Higher, solid line, labeled "1". – Curve 2: Lower, dashed line, labeled "2". • Each curve has a point marked (solid dot) on it. # Panel B: Pressure-Volume Loop and End-Systolic Elastance : • Y-axis: Pressure (no units shown). • X-axis: Volume (no units shown). • Two pressure-volume loops: – Loop 1: Solid line, larger, leftward, labeled "1". – Loop 2: Dashed line, smaller, rightward, labeled "2". • Two Ees (end-systolic elastance) lines: – Ees 1: Steeper, solid line, labeled "1". – Ees 2: Less steep, dashed line, labeled "2". # Design Encodings : • Solid lines for condition 1, dashed lines for condition 2. • Dots mark specific points on the curves in panel A. • Pressure-volume loops are outlined, with loop 2 shown as a dashed outline. # Analysis : • Panel A shows that condition 1 (solid line) has a higher stroke volume for any given LVEDP/LVEDV compared to condition 2 (dashed line), indicating better cardiac function. • Panel B shows that condition 1 has a larger, leftward pressure-volume loop and a steeper Ees line, indicating greater contractility. Condition 2 has a smaller, rightward loop and a less steep Ees line, indicating reduced contractility. • The figure visually contrasts normal/enhanced versus impaired cardiac function using both stroke volume response and pressure-volume relationships.

This pathophysiology diagram illustrates the differences in regional oxygen saturation and blood flow distribution between a normal physiological state and circulatory shock. The diagram features anatomical icons of the brain, heart, and kidney, with arrows representing venous return and mixed venous output. In the 'Normal state,' the venous return from the brain is shown with a dark blue arrow (high extraction), while the return from the kidney is pale purple (low extraction), resulting in the relationship ScvO2 < SvO2. Conversely, in the 'Shock' state, the centralization of circulation is depicted: the kidney return becomes dark blue (indicating increased extraction or decreased perfusion), and the brain return becomes pale purple, leading to the inversion ScvO2 > SvO2. The comparison highlights how circulatory failure and compensatory vasoconstriction in visceral organs alter the balance between central venous oxygen saturation (ScvO2) and mixed venous oxygen saturation (SvO2), serving as a critical indicator for monitoring tissue perfusion and cardiac output adequacy in critical care settings.

This multi-panel figure illustrates the application of high-resolution micro-CT data in mathematical modeling of human cardiac anatomy and electrophysiology. Panel (a) presents a segmented 3D reconstruction of the cardiac conduction system, color-coded to show the sinus node (blue), paranodal area (turquoise), atrioventricular (AV) conduction axis (green), and the intricate right (red) and left (purple) Purkinje networks. Panel (b) overlays these segmented structures onto a semi-transparent 'ghosted' volume rendering of the whole heart, providing anatomical context within the right and left atria (RA, LA) and ventricles (RV, LV). Panel (c) provides a four-chamber cross-sectional view of cardiomyocyte orientation, using a color map to represent absolute helical angles (0° to 90°). This reveals complex transmural patterns and longitudinal alignment in the papillary muscles. Panel (d) shows a computer-generated isochrone map of cardiac depolarization (activation time in ms) seeded from the sinus node. This visualization integrates anatomically accurate geometry with electrophysiological measurements to demonstrate physiological conduction pathways across the myocardium.

Educational medical graphic illustrating abnormal ventricular conduction system (VCS) structure and electrophysiology in a mouse model of miR-1 overexpression. Panel A shows whole-mount P5 neonatal hearts with CCS-LacZ reporter activity; magnified views compare wild-type (WT) and transgenic (TG) atrioventricular bundles (AVB) and Purkinje fibers (PF), revealing significantly reduced PF branching in TG hearts. Panel B utilizes Irx3-LacZ staining to further demonstrate diminished PF density in the left bundle branch and right ventricle of TG mice. Panel C provides quantification, with a bar graph showing a statistically significant decrease in normalized PF density (p < 0.01). Panel D displays averaged lead aVF ECG tracings, highlighting a prolonged QRS duration in TG mice compared to WT. Panel E includes bar graphs of cardiac intervals (RR, PR, and QRS), confirming that while heart rate and AV node conduction are unchanged, VCS conduction is significantly slowed, as evidenced by increased QRS duration (p < 0.05). This composite figure demonstrates that premature miR-1 upregulation leads to Purkinje fiber hypoplasia and conduction dysfunction.

Summary : This figure presents six schematic diagrams of standard echocardiographic views used to visualize the heart chambers and valves, specifically focusing on the right ventricle (RV) and its relationship to other cardiac structures. illustration: # Views Presented : • Parasternal Long-Axis view: Shows RV, Ao (aorta), and LA (left atrium) in a longitudinal section. • Parasternal Long-Axis of the RV outflow view: Displays RVOT (right ventricular outflow tract), PA (pulmonary artery), and LV (left ventricle). • Parasternal Short-Axis of basal RV view (at MV level): Cross-sectional view at the mitral valve (MV) level, showing RV and MV. • Parasternal Short-Axis of mid RV view (at LV papillary muscle level): Cross-sectional view at the level of the LV papillary muscles, showing RV, LV, and papillary muscles (PM). • Modified Apical 4-chamber view: Displays RA (right atrium), RV, LA, and LV in a four-chamber perspective. • RA-focused apical 4-chamber view: Focuses on RA, RV, LA, and LV, emphasizing the right atrium. # Labels & Orientation : • Each diagram is labeled with anatomical structures (RV, LV, LA, RA, Ao, PA, MV, PM). • Orientation markers such as "Anterior," "Lateral," and "Septal" are provided for spatial reference. # Design Encodings : • Simple black-and-white line drawings. • Chamber walls and valves are outlined; no colour or shading. • Each view is titled below the corresponding diagram. # Analysis : • The figure systematically compares different echocardiographic views, highlighting how the right ventricle and associated structures appear in each orientation. • The progression from long-axis to short-axis and apical views demonstrates the versatility of echocardiography in assessing cardiac anatomy and function. • The inclusion of both standard and modified views allows for comprehensive visualization of the right heart.

This educational image presents a series of cardiac diagnostic images and anatomical diagrams detailing congenital heart defects. Panels A–F display episcopic confocal microscopy (ECM) cross-sections of experimental hearts. The four chambers—right atrium (RA), left atrium (LA), right ventricle (RV), and left ventricle (LV)—are labeled alongside the aorta (A) and pulmonary trunk (P). Panels A, C, D, and F show normal cardiac looping and septal anatomy, while panels B and E highlight perimembranous ventricular septal defects (VSDs) indicated by white arrowheads. Panel G consists of five comparative diagrams of the aortic arch and great vessels. The first diagram illustrates normal anatomy including the right and left carotid arteries (RCA/LCA) and subclavian arteries (RSA/LSA). Subsequent diagrams depict various great artery patterning defects: an interrupted aorta (arrows), hypoplastic collateral vessels (arrowheads), and anomalous origins of the right subclavian artery (RSA). These anomalies include the RSA arising from the pulmonary trunk (§), as a retrotracheal vascular sling from the descending aorta (‡), or as a vascular ring with dual attachments (*). This content demonstrates complex cardiovascular malformations associated with ciliary gene mutations.

This medical illustration consists of two diagrams depicting cardiac anatomy and pathology associated with myocardial infarction and surgical intervention. The left panel shows an anterior view of the heart with major structures labeled: Right Atrium (RA), Right Ventricle (RV), Left Atrium (LA), Left Ventricle (LV), Aorta (Ao), and Pulmonary Artery (PA). The coronary vasculature is highlighted, specifically the Right Coronary Artery (RCA) and Left Anterior Descending (LAD) artery. An 'incision line' is indicated on the apex of the left ventricle over a shaded area representing infarcted tissue. The right panel is a cross-sectional diagram focusing on the ventricular chambers. It illustrates a Ventricular Septal Defect (VSD), which is a communication between the left and right ventricles. Also labeled are the Aortic Valve (AV), an area of Myocardial Infarction (MI) in the ventricular wall, and adjacent Akinetic (AK) tissue. The illustration serves to demonstrate the anatomical location for a ventriculotomy used to repair post-infarction ventricular septal rupture.

**Imaging Modality:** Invasive Coronary Angiography (ICA); Fluoroscopy. **Anatomical Region:** Left Coronary Artery (LCA) system. **Observed Anatomy & Pathology:** This fluoroscopic image demonstrates the left coronary circulation in a projection showing the Left Main Coronary Artery (LMCA) bifurcating into the Left Anterior Descending (LAD) and the Left Circumflex (LCx) arteries. The LCx appears prominent and elongated, extending into the territory typically occupied by the Right Coronary Artery. **Characteristic Visual Features:** * **Coronary Dominance:** Visual evidence of left dominance, characterized by the LCx artery supplying the posterior descending artery (PDA) and the posterolateral branches. * **Vessel Morphology:** The LAD follows the anterior interventricular groove, giving off diagonal branches. The LCx travels within the atrioventricular groove, exhibiting a large distal extension toward the inferior wall of the heart. * **Contrast Opacification:** Homogeneous opacification of the arterial tree is visible, allowing for the assessment of luminal patency. **Key Diagnostic Features:** Identification of left coronary dominance is established by the LCx crossing the crux of the heart to provide the primary blood supply to the inferior diaphragmatic surface. This anatomical variant is a critical finding for percutaneous coronary intervention (PCI) planning and surgical revascularization.

**Imaging Modality:** Invasive coronary angiography (fluoroscopy). **Anatomical Region:** Coronary arterial circulation, specifically the right coronary artery (RCA) visualized in a Left Anterior Oblique (LAO) projection. **Observed Pathology/Anatomy:** This image demonstrates a "super-dominant" right coronary artery. The vessel exhibits significant caliber and extensive distribution, originating from the right coronary sinus. **Characteristic Visual Features:** * **Course:** The RCA traverses the right atrioventricular groove, extending past the crux of the heart. * **Territory:** The vessel provides not only the posterior descending artery (PDA) and posterior left ventricular (PLV) branches but also extends further to supply a large portion of the lateral and postero-lateral walls of the left ventricle. * **Vessel Morphology:** The RCA appears large-caliber and tortuous, showing no significant stenotic lesions in the visible segments. **Key Diagnostic Features:** The diagnostic hallmark is the unusual extension of the RCA beyond the crux, crossing the diaphragmatic surface to supply territories typically served by the left circumflex (LCx) artery. This anatomical variant represents an extreme form of right-sided coronary dominance.

This diagnostic image is a coronary angiogram (fluoroscopic x-ray) demonstrating a right-dominant coronary circulation. The primary focus is the Right Coronary Artery (RCA), which follows a characteristic 'C-shaped' trajectory within the right atrioventricular groove. The vessel exhibits typical anatomy, bifurcating at the crux of the heart into two significant terminal branches: the Posterior Descending Artery (PDA), which travels inferiorly to supply the posterior interventricular septum, and a prominent Posterolateral (PL) branch that travels toward the lateral wall, occupying the territory usually associated with the Left Circumflex Artery (LCX). The image displays the branching pattern and vessel morphology essential for assessing coronary artery disease. A subtle luminal irregularity or darkening is visible along the horizontal segment of the main vessel before the distal bifurcation, which may indicate atherosclerotic plaque or a focal stenosis. This visual serves as an educational example of coronary dominance and normal vs. variant coronary anatomy during cardiac catheterization.

Summary : This image shows a labeled cross-sectional view of the heart, highlighting the anatomical positions of the aortic valve (Ao), mitral valve (MV), and tricuspid valve (TV). photo: Scene Overview : • Main subject is a medical imaging scan (likely MRI or CT) of the heart in cross-section. • The image is grayscale, with three key cardiac structures labeled: Ao (aortic valve), MV (mitral valve), and TV (tricuspid valve). • The perspective is from above, looking down on the heart valves. Technical Details : • No scale bar or magnification is visible. • Labels are overlaid directly on the image: "Ao", "MV", "TV". • Imaging modality appears to be high-resolution, suitable for anatomical identification. Spatial Relationships : • Ao (aortic valve) is positioned centrally and slightly superior. • MV (mitral valve) is to the right of Ao. • TV (tricuspid valve) is to the left and slightly inferior to Ao. • The valves are shown in close proximity, consistent with their anatomical arrangement in the heart. Analysis : • The image provides a clear anatomical reference for the location of the aortic, mitral, and tricuspid valves in a cross-sectional heart scan. • Useful for educational or diagnostic purposes to identify valve positions and relationships.

This composite figure presents gross anatomical dissections and a histological section of the human heart, focusing on the anatomy of the aortic root and its spatial relationships. (a-b) Longitudinal sections demonstrate the aortic sinuses, mitral valve papillary muscles, and the muscular subpulmonary infundibulum of the right ventricular outflow tract (RVOT) abutting the coronary sinuses. (c) Atrial view showing the kidney-shaped mitral valve vestibule and its fibrous continuity with the left coronary and noncoronary aortic sinuses. (d) Opened aortic root photographed with transillumination, highlighting the left (L), right (R), and noncoronary (N) sinuses, interleaflet fibrous triangles, and the central fibrous body (brightest area). (e) Short-axis view from the atrial side illustrates the orientation of the aortic valve (Ao), mitral valve (MV), tricuspid valve (TV), and pulmonary sinuses (A, LP, RP). (f) Masson's trichrome stained cross-section confirms that all pulmonary valve leaflets have muscular infundibular support, whereas only two aortic valve leaflets possess muscular support. The collection serves to illustrate the fibrous and muscular components critical for understanding cardiac conduction pathways and valvular relationships.

A multi-panel educational graphic illustrating the anatomy, histology, and biomechanics of heart valves. Panels a-i through a-iii show clinical and schematic views of the four cardiac valves (Pulmonary, Aortic, Mitral, Tricuspid) and a decellularized porcine valve. Histological section (b) and diagram (c) identify the three-layered structure of the valve leaflet: the fibrosa (outer layer, rich in circumferentially oriented collagen), spongiosa (middle layer, containing glycosaminoglycans/GAGs for shock absorption), and ventricularis (inner layer, rich in radially oriented elastin). Panels (d) and (e) demonstrate the mechanical behavior of these layers during the cardiac cycle, showing how collagen and elastin fibers accommodate stress during systole and diastole. Panel (f) provides a gross photograph of a sheep aortic valve from the ventricular side, while (h) presents a histological stain (likely Movat's pentachrome) highlighting GAGs in blue within the spongiosa. Panel (i) shows the hinge area histology, emphasizing the complex fiber arrangement necessary for valvular durability and function.

This diagnostic image is a 3D-reconstructed computed tomography angiography (CTA) showing the human thoracic and abdominal aorta in a postoperative state. The aortic arch is prominently visualized with its primary branches, including the brachiocephalic trunk, left common carotid, and left subclavian arteries. The heart is positioned anteriorly to the descending aorta. A critical finding is the presence of a tortuous collateral vessel originating from the left lateral thoracic artery. This collateral pathway extends medially and inferiorly to provide retrograde blood supply to the artery of Adamkiewicz (AKA), serving as a vital compensatory mechanism following the occlusion of reconstructed intercostal arteries. The image highlights the vascular anatomy relevant to spinal cord perfusion and the clinical significance of preserving extra-anatomical collateral circulation during complex aortic surgeries to prevent neurological complications such as paraplegia. The reconstruction demonstrates the vessel's patency and winding morphology against the surrounding vascular structures.

A 3D volume-rendered Computed Tomography (CT) reconstruction of the aorta and surrounding thoracic structures. The image provides a detailed view of the entire aortic path, starting from the abdominal segment and ascending through the thoracic cavity to form the aortic arch. The three major supra-aortic branches—the brachiocephalic trunk, left common carotid artery, and left subclavian artery—are visible at the superior aspect of the arch. A prominent red arrow points to a focal outpouching or intimal irregularity located on the outer curvature of the distal aortic arch, characteristic of a penetrating aortic ulcer (PAU). The surrounding bony anatomy, including the ribs and vertebrae, is rendered with semi-transparency to provide anatomical context without obscuring the vascular pathology. This diagnostic image is intended for pre-procedural planning, demonstrating the specific morphology and localization of an atherosclerotic lesion within the aortic wall that carries a clinical risk of progression to dissection or rupture.

Summary : This illustration divides the thoracic aorta into anatomical zones, each labeled with a number from 0 to 11, to aid in clinical or surgical reference. diagram: # Zones of the Thoracic Aorta : • The aorta is segmented into 12 zones, numbered 0 through 11. • Zone 0: Proximal aortic arch. • Zones 1–3: Ascending aorta and arch, with zone 3 ending 2 cm distal to the left subclavian artery. • Zones 4–9: Descending thoracic aorta, with zone 4 starting after the arch and zone 9 ending before the bifurcation. • Zones 10–11: Abdominal aorta and iliac arteries. • The mid-point of the descending thoracic aorta is marked at approximately the T6 vertebral level. • Brachiocephalic, left common carotid, and left subclavian arteries branch from the arch near zones 0–3. # Annotations & Measurements : • "2 cm" is marked at the distal end of zone 3. • "Mid-point of descending thoracic aorta (approx. T6)" is labeled at zone 5. • Zones 10 and 11 correspond to the iliac arteries. # Layout : • The zones are arranged sequentially from the aortic root (top left) through the arch, descending thoracic aorta, and into the abdominal aorta and iliac arteries. • The diagram is a simplified line drawing, with each zone clearly demarcated by horizontal lines. # Analysis : • The figure provides a standardized anatomical reference for the thoracic and abdominal aorta, useful for describing the location of vascular pathology or interventions. • The segmentation highlights key anatomical landmarks, such as the arch branches and the aortic bifurcation. • The use of numbered zones facilitates precise communication in clinical and surgical contexts.

**Imaging Modality:** Cardiac Magnetic Resonance Imaging (MRI), axial plane. **Anatomical Region:** Mediastinum, specifically focusing on the heart and its surrounding serous membrane. **Observed Pathology:** The image demonstrates diffuse, significant thickening of the pericardium (indicated by the white arrow). The pericardial layers appear as a prominent, hypointense band surrounding the cardiac chambers. **Characteristic Visual Features:** - **Pericardial Thickness:** There is a measurable increase in the pericardial stripe thickness, exceeding the normal physiological limit (typically <2–3 mm). - **Morphology:** The thickening appears relatively uniform and circumferential along the anterior and lateral aspects of the heart. - **Signal Intensity:** The thickened tissue exhibits low signal intensity on this pulse sequence, consistent with fibrous or calcified tissue. **Clinical Significance:** These radiologic findings are highly suggestive of chronic pericarditis or constrictive pericarditis. The image provides a key diagnostic cue by highlighting the structural alteration of the pericardium which may lead to impaired diastolic filling. No significant pleural effusion or pulmonary parenchymal abnormalities are noted in this specific slice.

This composite educational graphic details the anatomy of the pericardium and its clinical presentation on imaging. The left side features a color-coded 'Anatomical scheme' illustrating the histological layers from external to internal: pericardial fat, fibrous pericardium, parietal pericardium, pericardial cavity, visceral pericardium (epicardium), epicardial fat, myocardium, endocardium, and cardiac chamber. A central panel correlates these anatomical spaces with specific pathologies of abnormal air collection: pneumomediastinum (superior to the parietal pericardium), pneumopericardium (within the pericardial cavity), and intravascular air (within the cardiac chamber). The right side shows a diagnostic axial chest CT image of a 47-year-old male with chronic kidney disease. Labeled features include pericardial fat (PF), parietal pericardium (white arrowheads), pericardial cavity (PC) containing a fluid collection, visceral pericardium (black arrowheads), epicardial fat (EF), myocardium (white asterisks), and cardiac chamber (CC). The image serves as a reference for distinguishing normal anatomical layers from pathological fluid or air accumulation in cardiovascular imaging.

This diagnostic multi-panel image presents contrast-enhanced computerized tomography (CT) and volume-rendered reconstructions of a patient with heterotaxy syndrome and left isomerism. The vascular anatomy demonstrates bilateral superior venae cavae (SVC) without a bridging vein; the left SVC is shown draining into a coronary sinus that empties into the right-sided left atrium (LA). A significant finding is an interrupted inferior vena cava (IVC) with azygos continuation, where the right-sided IVC continues superiorly via the azygos vein to the right-sided SVC. The common hepatic vein is also visualized draining independently. Intracardiac findings include a large atrial septal defect (ASD) in the superior portion of the septum and evidence of myocardial noncompaction in the left ventricle (LV). The pulmonary venous anatomy shows right and left pulmonary veins connecting to the posterior wall of the ipsilateral left atrium. These complex cardiovascular malformations are characteristic of isomerism of the left atrial appendages, illustrating critical diagnostic markers for surgical planning and systemic-to-pulmonary venous separation.

This composite figure illustrates diagnostic imaging and electroanatomical mapping related to pulmonary vein anatomy and surgical intervention. Panel A is an intracardiac angiogram showing the right inferior pulmonary vein (RIPV) opacified with contrast as it connects to the right atrium; metallic sternal wires from a prior cardiothoracic surgery are visible superiorly. Panels B, C, and D display 3D electroanatomical maps generated by the CARTO system, which use color coding to represent cardiac voltage or activation times. Purple typically indicates high voltage (healthy tissue), while red and warmer colors represent lower voltage or specific anatomical borders. Panel C depicts the isolation of normally connected pulmonary veins, including the right superior pulmonary vein (RSPV), with ablation points marked as red dots. Panel D shows an anomalous connection of the right inferior pulmonary vein (RIPV) and identifies the superior vena cava (SVC). This image set is designed for advanced medical education in cardiac electrophysiology and the management of anomalous pulmonary venous return.

This composite of four panels visualizes the cardiac conduction system (CCS) in murine models using fluorescent and enzymatic reporters. Panel A shows a Contactin2-eGFP reporter heart where the CCS is highlighted in bright green fluorescence against a pinkish-tan myocardial background. Key labeled landmarks include the sinus node at the superior right atrium, the atrioventricular (AV) node, the penetrating His bundle, the left and right bundle branches along the interventricular septum, and the distal Purkinje network branching into the ventricular walls. Panels B and C demonstrate LacZ-reporter expression (blue stain) in embryonic (E17.5) and adult hearts. Panel B highlights the broad distribution of the conduction system in the developing heart, while Panel C provides a higher-magnification view of Etv1-nuclear LacZ expression, delineating the fine, arborized network of the ventricular conduction system. Panel D shows a corresponding fluorescent view of the dense, subendocardial Purkinje fiber network in the left ventricle. These images serve as an educational anatomical reference for the components and physiological pathways of cardiac electrical impulse generation and propagation.

This composite educational material consists of a whole-heart specimen photograph (A), a magnified dissection view (B), and a labeled anatomical illustration (C), demonstrating the vascular supply to the atrioventricular (AV) conduction system from an inferior (diaphragmatic) perspective. The images highlight the AV node artery (red arrowheads) originating from the proximal posterolateral branch (PL) of the right coronary artery (RCA). Panel A shows the macro-anatomical relationship between the RCA, the posterior interventricular artery (PI), and the coronary sinus (CS). Panel B and C detail the inferior pyramidal space (blue dotted area) and the compact node (CN, green star). Key structures visualized include the central fibrous body (CFB), membranous septum (MS), tricuspid valve (TV), and the progression of the conduction axis from the inferior nodal extension (INE) through the penetrating bundle of His (PBH) and the branching bundle of His (BBH). This visual resource is designed for advanced medical education in cardiac anatomy and electrophysiology, specifically illustrating the dominant right coronary artery's contribution to the heart's electrical system.