The responses of left ventricular end-systolic pressure-diameter relationship to acute pressure overload induced by aortic constriction

The aim was to investigate the responses of the left ventricular (LV) end-systolic pressure-diameter relationship (ESPDR) to acute pressure overload. ESPDRs were made by 2-min ascending and descending aortic constrictions before and after administration of propranolol and atropine sulphate (both 0.2 mg kg^-1 i.v.) in eight open-chest dogs with the pericardium preserved. LV anterior-posterior diameter was measured with ultrasonic crystals. In the ascending aortic constriction, end-diastolic pressure (EDP) and end-diastolic diameter (EDD) were unchanged and ESPDR shifted to the left. In the descending aortic constriction, EDP and EDD increased from 6.8±0.7 to 8.8±0.9mmHg (P < 0.01) and from 32.7±1.4 to 34.5+1.6 mm (P < 0.05) and ESPDR shifted to the right. After administration of propranolol and atropine sulphate, cases having smaller changes in EDD during 2 min constriction (0.3+0.3 mm in all cases of ascending, 0.3 + 0.2 mm in four cases of descending aorta) showed a leftward shift of ESPDR. The remaining four cases of descending aortic constriction with larger changes in EDD (1.8 + 0.8 mm, P < 0.05) showed a rightward shift of ESPDR. An inverse curvilinear correlation was found between percentage changes in EDD and in the slopes. These results suggest that the responses in ESPDR to acute pressure overload were determined by not only changes in the contractile state but also the interplay between adaptation to acute pressure overload (the Anrep effect) and preload.     

Effect of Spiral Flow on the Transport of Oxygen in the Aorta: A Numerical Study

To test the hypothesis that the spiral flow pattern in the human aorta may play a beneficial role in the transport of oxygen, hence sparing the ascending aorta from atherosclerosis, a comparative study on the distribution of oxygen flux to the arterial wall was carried out numerically for three aorta models. The first one (Model 1) was constructed based on MRI images of a human aorta acquired in vivo. The second (Model 2) was made the same as Model 1 but without the three branches. The third (Model 3) was similar to Model 2 only with the aortic torsion removed. The results showed that without the torsion, the flow fashion in Model 3 was very different from the swirling flows in Models 1 and 2 and exhibited the typical characteristics of Dean flow with two symmetrical helical structures. In Models 1 and 2, the average Sherwood number (Sh) in the ascending aorta with the presence of a strong spiral flow was not only higher than that in the inner wall of the descending aorta where the spiral flow faded out, but also generally higher than that in Model 3. The comparison between Models 2 and 3 demonstrated that the averaged Sh from ascending aorta to aortic arch was relatively higher for Model 2. In conclusion, the spiral or swirling flow may have certain physiological significance in the aorta and play a positive role in the transport of oxygen by enhancing oxygen flux to the arterial wall.     

Association between the rotation and three‐dimensional tortuosity of the proximal ascending aorta

Age‐related morphological changes of the aorta, including dilatation and elongation, have been reported. However, rotation has not been fully investigated. We focused on the rotation of the ascending aorta and investigated its relationship with tortuosity. One hundred and two consecutive patients who underwent computed tomography coronary angiography were studied. The angle at which the en face view of the volume‐rendered image of the right coronary aortic sinus (RCS) was obtained without foreshortening was defined as the rotation index. It was defined as zero if the RCS was squarely visible in the frontal view, positive if it rotated clockwise toward the left anterior oblique (LAO) direction, and negative if it rotated counter‐clockwise toward the right anterior oblique (RAO) direction. The tortuosity was evaluated by measuring the biplane tilt angles formed between the ascending aorta and the horizontal line. The mean rotation index, posterior tilt angle viewed from the RAO direction (α_RAO), and anterior tilt angle viewed from the LAO direction (α_LAO) were 4.8 ± 16.3, 60.7 ± 7.0°, and 63.6 ± 9.0°, respectively. Although no correlation was observed between the rotation index and the α_LAO (β = ?0.0761, P = 0.1651), there was a significant negative correlation between the rotation index and α_RAO (β = ?0.1810, P < 0.0001). In multivariate regression analysis, the rotation index was an independent predictor of the α_RAO (β = ?0.1274, P = 0.0008). Clockwise rotation of the proximal ascending aorta exacerbates the tortuosity by tilting the aorta toward the posterior direction. Clin. Anat. 27:1200–1211, 2014. © 2014 Wiley Periodicals, Inc.     

<Emphasis Type="Italic">In Vivo</Emphasis> Strain Analysis of Dilated Ascending Thoracic Aorta by ECG-Gated CT Angiographic Imaging

Accurate assessment of aortic extensibility is a requisite first step for elucidating the pathophysiology of an ascending thoracic aortic aneurysm (ATAA). This study aimed to develop a framework for the in vivo evaluation of the full-field distribution of the aortic wall strain by imaging analysis of electrocardiographic- (ECG) gated thoracic data of 34 patients with ATAA. Seven healthy controls (i.e., non-aneurysmal aorta) from patients who underwent ECG-gated CT angiography for coronary artery diseases were included for comparison. To evaluate the systolic function, ECG-gated computed tomography (CT) angiography was used to generate patient-specific geometric meshes of the ascending aorta, and then to estimate both the displacement and strain fields using a mathematical algorithm. Results evidenced stiff behavior for the aneurysmal aorta compared with that of the healthy ascending aorta of the controls, with patients over 55 years of age displaying significantly lower extensibility. Moreover, the patient risk as quantified by the ratio of in vivo strain to the ruptured one increased significantly with increased systolic blood pressure, older age, and higher pressure-strain modulus. Statistical analysis also indicated that an increased pressure-strain modulus is a risk factor for ATAAs with bicuspid aortic valve, suggesting a different mechanism of failure in these patients. The approach here proposed for the in vivo evaluation of the aortic wall strain is simple and fast, with promising applicability in routine clinical imaging, and could be used to develop a rupture potential criterion on the basis of the aortic aneurysm extensibility.     

Development of an animal experimental model for a bileaflet mechanical heart valve prosthesis

The objective of this study was to develop a pre-clinical large animal model for the in vivo hemodynamic testing of prosthetic valves in the aortic position without the need for cardiopulmonary bypass. Ten male pigs were used. A composite valved conduit was constructed in the operating room by implanting a prosthetic valve between two separate pieces of vascular conduits, which bypassed the ascending aorta to the descending aorta. Prior to applying a side-biting clamp to the ascending aorta for proximal grafting to the aortic anastomosis, an aorta to femoral artery shunt was placed just proximally to this clamp. The heart rate, cardiac output, Vmax, transvalvular pressure gradient, effective orifice area and incremental dobutamine stress response were assessed. A dose-dependent increase with dobutamine was seen in terms of cardiac output, Vmax, and the peak transvalvular pressure gradient both in the native and in the prosthetic valve. However, the increment was much steeper in the prosthetic valve. No significant differences in cardiac output were noted between the native and the prosthetic valves. The described pre-clinical porcine model was found suitable for site-specific in-vivo hemodynamic assessment of aortic valvular prosthesis without cardiopulmonary bypass.     

Comparison of arterial waves derived by classical wave separation and wave intensity analysis in a model of aortic coarctation

Coarctation of the aorta may develop during fetal life and impair quality of life in the adult because upper body hypertension and aneurysm formation in the descending aorta may develop. We used our computational model of the young adult arterial circulation, incorporated aorta coarctation over a range from 0 to 80% and evaluated the effects in terms of forward pressure (P ⁺ ) and backward pressure (P ⁻ ). Predictions at several sites proximal and distal to the coarctation using an impedance-based waveform separation method (WSA) and the time-domain technique of wave intensity analysis (WIA) yielded comparable outcomes. A large reflected backward compression wave was seen proximal to the coarctation. Both techniques, WSA and WIA, gave the same results in terms of P ⁺ and P ⁻ . A descending index (DI) was formulated as the difference between peak systolic pressure and valve closure pressure, divided by the pulse pressure. DI increased with stenosis severity for mild to moderate aortic coarctations that did not yet cause evident hypertension. This index may allow for early diagnosis by noninvasive estimation of coarctation severity.     

Adaptations of aortic and pulmonary artery flow parameters measured by phase-contrast magnetic resonance angiography during supine aerobic exercise

Purpose

Increased oxygen uptake and utilisation during exercise depend on adequate adaptations of systemic and pulmonary vasculature. Recent advances in magnetic resonance imaging techniques allow for direct quantification of aortic and pulmonary blood flow using phase-contrast magnetic resonance angiography (PCMRA). This pilot study tested quantification of aortic and pulmonary haemodynamic adaptations to moderate aerobic supine leg exercise using PCMRA.

Methods

Nine adult healthy volunteers underwent pulse gated free breathing PCMRA while performing heart rate targeted aerobic lower limb exercise. Flow was assessed in mid ascending and mid descending thoracic aorta (AO) and main pulmonary artery (MPA) during exercise at 180 % of individual resting heart rate. Flow sequence analysis was performed by experienced operators using commercial offline software (Argus, Siemens Medical Systems).

Results

Exercise related increase in HR (rest: 69 ± 10 b min^?1, exercise: 120 ± 13 b min^?1) resulted in cardiac output increase (from 6.5 ± 1.4 to 12.5 ± 1.8 L min^?1). At exercise, ascending aorta systolic peak velocity increased from 89 ± 14 to 122 ± 34 cm s^?1 (p = 0.016), descending thoracic aorta systolic peak velocity increased from 104 ± 14 to 144 ± 33 cm s^?1 (p = 0.004), MPA systolic peak velocity from 86 ± 18 to 140 ± 48 cm s^?1 (p = 0.007), ascending aorta systolic peak flow rate from 415 ± 83 to 550 ± 135 mL s^?1 (p = 0.002), descending thoracic aorta systolic peak flow rate from 264 ± 70 to 351 ± 82 mL s^?1 (p = 0.004) and MPA systolic peak flow rate from 410 ± 80 to 577 ± 180 mL s^?1 (p = 0.006).

Conclusion

Quantitative blood flow and velocity analysis during exercise using PCMRA is feasible and detected a steep exercise flow and velocity increase in the aorta and MPA. Exercise PCMRA can serve as a research and clinical tool to help quantify exercise blood flow adaptations in health and disease and investigate patho-physiological mechanisms in cardio-pulmonary disease.     

Non-invasive monitoring of central blood pressure by electrical impedance tomography: first experimental evidence

There is a strong clinical demand for devices allowing continuous non-invasive monitoring of central blood pressure (BP). In the state of the art a new family of techniques providing BP surrogates based on the measurement of the so-called pulse wave velocity (PWV) has been proposed, eliminating the need for inflation cuffs. PWV is defined as the velocity at which pressure pulses propagate along the arterial wall. However, no technique to assess PWV within central arteries in a fully unsupervised manner has been proposed so far. In this pilot study, we provide first experimental evidence that electrical impedance tomography (EIT) is capable of measuring pressure pulses directly within the descending aorta. To obtain a wide range of BP values, we administrated noradrenalin and nitroglycerine to an anesthetized pig under mechanical ventilation. An arterial line was inserted into the ascending aorta for measuring reference BP. EIT images were generated from 32 impedance electrodes placed around the chest at the level of the axilla. Regions of Interest (ROI) such as the descending aorta and the lungs were automatically identified by a novel time-based processing algorithm as the respective EIT pixels representing these structures. The correct positions of these ROIs were confirmed by bolus injections of highly conductive concentrated saline into the right heart and into the ascending aorta. Aortic pulse transit time (PTT) values were determined as the delay between the opening of the aortic valve (obtained from arterial line) and the arrival of pressure pulses at the aortic ROI within the EIT plane. For 11 experimental conditions, with mean BP ranging from 73 to 141 mmHg, strongly significant correlation (r = −0.97, P < 0.00001) between central BP and aortic PTT was observed, suggesting that EIT-derived aortic PTT is a potential non-invasive surrogate of central BP.     

Role of Re-entry Tears on the Dynamics of Type B Dissection Flap

Mortality during follow-up after acute Type B aortic dissection is substantial with aortic expansion observed in over 59% of the patients. Lumen pressure differential is considered a prime contributing factor for aortic dilation after propagation. The objective of the study was to evaluate the relationship between changes in vessel geometry with and without lumen pressure differential post propagation in an ex vivo porcine model with comparison with patient clinical data. A pulse duplicator system was utilized to propagate the dissection within descending thoracic porcine aortic vessels for set proximal (%circumference of the entry tear: 40%, axial length: 2 cm) and re-entry (50% of distal vessel circumference) tear geometry. Measurements of lumen pressure differential were made along with quantification of vessel geometry (n = 16). The magnitude of mean lumen pressure difference measured after propagation was low (~ 5 mmHg) with higher pressures measured in false lumen and as anticipated the pressure difference approached zero after the creation of distal re-entry tear. False lumen Dissection Ratio (FDR) defined as arc length of dissected wall divided by arc length of dissection flap, had mean value of 1.59 ± 0.01 at pressure of 120/80 mmHg post propagation with increasing values with increase in pulse pressure that was not rescued with the creation of distal re-entry tear (p < 0.01). An average FDR of 1.87 ± 0.27 was measured in patients with acute Type B dissection. Higher FDR value (FDR = 1 implies zero dissection) in the presence of distal re-entry tear demonstrates an acute change in vessel morphology in response to the dissection independent of local pressure changes challenges the re-apposition of the aortic wall.     

Finite element modeling of the thoracic aorta: including aortic root motion to evaluate the risk of aortic dissection

Objective: We propose that the aortic root motion plays an important role in aortic dissection.

Methods and results: A finite element model of the aortic root, arch and branches of the arch was built to assess the influence of aortic root displacement and pressure on the aortic wall stress. The largest stress increase due to aortic root displacement was found at approximately 2 cm above the top of the aortic valve. There, the longitudinal stress increased by 50% to 0.32 MPa when 8.9 mm axial displacement was applied in addition to 120 mmHg luminal pressure. A similar result was observed when the pressure load was increased to 180 mmHg without axial displacement.

Conclusions: Both aortic root displacement and hypertension significantly increase the longitudinal stress in the ascending aorta, which could play a decisive role in the development of various aortic pathologies, including aortic dissection.     

Continuous measurement of aortic radius changein vivo with an intra-aortic ultrasonic catheter

The radii of the inner and outer walls of the aorta and the intravascular blood pressure were recorded simultaneously in the descending thoracic aorta of intact, living dogs using 7·5 MHz ultrasound. Blood pressure and the A-mode signals containing wall echoes were also recorded on videotape which was later replayed for processing. Thein vivo data were compared with data obtained on the same vessels post mortem. The change in radius due to a pressure change from 80 to 125 mmHg was calculated from thein vivo andin vitro data. After normalising the radius changes with respect to the radius at 80 mm Hg, the ratio of thein vivo andin vitro values ranged from 0·66 to 1·36 with a mean of 0·94. The changes in radius were comparable with previously reported values obtained using various techniques.     

Outcomes of midterm circulatory support by left ventricular assist device implantation with descending aortic anastomosis

For some patients undergoing left ventricular assist device (LVAD) implantation, the perfusion tube is anastomosed to the descending aorta instead of the currently more prevalently used ascending aorta. Purpose of this study was to assess retrospectively the outcomes of LVAD patients with descending aortic anastomosis. Between March 2007 and March 2010, six patients underwent LVAD implantation with descending aortic anastomosis with Toyobo or Jarvik 2000 LVAD at our institute. Their average circulatory support time was 434 (range 82–751) days. Both types of LVAD afforded adequate circulatory support, and inotrope treatment and mechanical ventilation were discontinued relatively early. Echocardiograms of the three patients with Jarvik 2000 LVAD revealed antegrade flow in the ascending aorta during the intermittent low-speed period. Among them, one patient developed infarction in the right brain hemisphere because of thromboembolism, whereas another patient developed pneumonia in the left lung followed by a lethal systemic infection. One patient on Toyobo LVAD support reached heart transplantation without morbidity. Another patient implanted with Toyobo LVAD, whose left ventricular function was too poor to generate forward flow through aortic valve, developed thrombus in the ascending aorta. No embolic events were observed in the organs below the diaphragm. In conclusion, descending aortic anastomosis of the perfusion tube can be used for LVAD implantation for some patients, but considerable risks of morbidities, including thromboembolic events and/or infection, should be recognized.     

Myocardial ferritin content is closely related to the degree of ischaemia

Aims: The mechanical properties of arteries play a major role in the regulation of blood pressure and cardiac performance. The effect of sympathetic stimulation on the mechanical properties of the proximal brachial artery was analysed in 18 healthy volunteers, nine young (25 ± 2 years) and nine elderly (69 ± 2 years). Methods: A non‐invasive ultrasonic echo‐tracking system for measurement of systolic/diastolic variation of the proximal brachial artery diameter in combination with intra‐arterial pressure measurements was used to determine wall mechanics. The pressure–diameter (P–D) relationship, distensibility coefficient (DC), compliance coefficient (CC) and stiffness(β) were obtained at rest and during sympathetic stimulation induced by lower body negative pressure (LBNP). Results: The peripheral vascular resistance increased by 100 and 72%, respectively in the young and elderly during LBNP (P < 0.001). Simultaneously, the mechanical properties of the proximal brachial artery remained unaltered, as estimated from both P–D relationship and stiffness in young (β‐index rest: 5.2 ± 0.9, LBNP: 5.5 ± 1.3, NS) as well as elderly (β‐index rest: 13.6 ± 4.6, LBNP: 16.1 ± 4.7, NS). Conclusions: LBNP‐induced sympathetic activation does not change proximal brachial artery mechanics, in contrast to earlier reports on the muscular distal brachial artery. This may imply that the transition between elastic and muscular artery behaviour is within the length of the brachial artery, where the site of transition from elastic to muscular wall structure needs to be specified in future studies.     

Post-Vagotomy Mechanical Characteristics and Structure of the Thoracic Aortic Wall

This study assessed the long-term effect of vagotomy on the structure and passive mechanical characteristics of the thoracic aorta under a wide range of stresses in vitro. Eight healthy Landrace pigs underwent bilateral vagotomy distal to the origin of the recurrent laryngeal nerve, and 10 pigs were sham-operated. Three months post-surgery, the aorta was excised and specimens from the ascending aorta, arch, and descending thoracic aorta were subjected to histomorphometrical evaluation and uniaxial tensile-testing until failure. Elastic modulus-stress data were plotted and submitted to regression analysis. Structural remodeling after vagotomy was characterized as vascular growth in the ascending aorta and arch, and as thinning in the descending thoracic aorta. In the aortic segments of vagotomized animals, the area density of elastin and collagen was increased, but smooth muscle density was decreased. Similar differences in regression parameters and failure strength between groups were found in all aortic segments, indicating that the vessel wall was stiffer and stronger in vagotomized animals. In the clinical setting, disease states or drugs blocking the regulatory role of the vagi nerves on the aortic wall may have undesirable consequences on the mechanical performance of the thoracic aorta, and therefore on hemodynamic homeostasis.     

The association between wedging of the aorta and cardiac structural anatomy as revealed using multidetector‐row computed tomography

The aortic root is wedged within the cardiac base. The precise extent of aortic wedging, however, and its influence on the surrounding cardiac structures, has not been systematically investigated. We analysed 100 consecutive patients, who underwent coronary arterial computed tomographic angiography. We assessed the extent of aortic wedging by measuring the vertical distance between the non‐adjacent aortic sinus and the inferior epicardium. A shorter distance indicates deeper aortic wedging. We assessed the tilt angle and diameter of the ascending aorta, the relative heights of the left atrial roof and the oval fossa, the shape of the proximal right coronary artery, the angle of the aorta relative to the left ventricular axis, and the lung volume. The mean extent of wedging was 42.7 ± 9.8 mm. Multivariate analysis revealed that ageing, male gender, increased body mass index, patients without cardiomyopathy, the extent of tilting and dilation of the ascending aorta, and lung volume were all independent predictors for deeper aortic wedging (R² = 0.7400, P < 0.0001). The extent of wedging was additionally correlated with a relatively high left atrial roof (R² = 0.1394, P < 0.0001) and oval fossa (R² = 0.1713, P < 0.0001), the shepherd's crook shape of the proximal right coronary artery (R² = 0.2376, P < 0.0001), and the narrowness of the angulation of the root relative to the left ventricular axis (R² = 0.2544, P < 0.0001). In conclusion, ageing, male gender, obesity, background cardiac disease, aortic tilting and dilation, and lung volume are all correlated with the extent of wedging of the aortic root within the cardiac base.     

超声心动图在诊断主动脉弓离断中的应用价值

目的 探讨主动脉弓离断的超声心动图特征,以提高对该疾病的认识及诊断能力。方法 回顾性分析我院16例经手术、心血管造影及双源CT证实的主动脉弓离断的超声特征。结果 超声心动图正确诊断11例（68.75%）均为A型;误诊5例（31.25%）,其中3例IAA-A型,2例IAA-B型;主动脉弓离断超声心动图特征为:主动脉弓与降主动脉之间的连续性中断,升主动脉发育不良,肺动脉明显扩张,明显增宽肺动脉通过未闭动脉导管与降主动脉连接。结论 超声心动图是诊断主动脉弓离断的首选方法,在超声检查中发现肺动脉明显扩张,升主动脉发育不良,并且肺动脉高压与心内畸形不匹配者,应警惕主动脉弓离断可能,仔细探查主动脉弓,若主动脉及分支显示不清,联合MRI、CT检查可提高诊断率。     

Influence of varying conduit resistance on native heart function with nonpulsatile left heart bypass

Nonpulsatile left heart bypass (NPLHB) represents a new era in cardiac support. We examined the impact of circuit resistance on ventricular loading with NPLHB. Pressure head-flow (H-Q) curves of NPLHB were measured with four grades of circuit resistance in a mock circulation. Lower resistance result, in a shallower H-Q relationship. Based on this results, NPLHB (ventricular apex to descending aorta) with ratios of 75% and 100% was evaluated for its hemodynamic effect in seven anesthetized sheep. Two grades of circuit resistance were generated with each bypass flow. A shallower H-Q relationship was noted at the lower circuit resistance when increased bypass flow fluctuations occurred during a single cardiac cycle (75%:0.9 ±0.4 to 12.2±2.8,P<0.0001; and 100%: 0.6±0.1 to 2.3 ±1.2l/min,P=0.011, with higher and lower resistance, respectively). Improved left ventricular peak pressure also resulted (75%:112±9 to 104±8,P=0.0002; and 100%: 59±26 to 13±5 mmHg,P=0.0045). In conclusion, NPLHB with lower circuit resistance improves the bypass flow response to change in pressure head during the cardiac cycle. This results in increased systolic bypass flow and improved systolic pressure unloading. Therefore, circuit resistance needs to be taken into account when designing NPLHB systems and when assessing their pump effect.     

Extraordinary branching pattern of the aortic arch

A CT‐scan of a 75‐year‐old patient showed an aneurysm of the descending aorta with a maximum diameter of 4.8 cm involving the left subclavian artery. Due to the fact that the patient had several comorbidities including a severe chronic obstructive pulmonary disease he was treated only conservatively. However, there were several interesting findings on the CT‐scan: the branching pattern of the aortic arch revealed a left carotid artery arising as first side branch of the distal part of the ascending aorta. This vessel crosses the midline right in front of the trachea. Apart from that the patient did not have a brachiocephalic trunk: the right carotid artery arose as the first branch from the aortic arch and crossed the right subclavian artery anteriorly. Furthermore, the left subclavian seemed to arise from the descending aorta and not from the aortic arch. Clin. Anat. 26:1006–1007, 2013. © 2013 Wiley Periodicals, Inc.     

On the classification of dissecting aortic aneurysms

Aortic dissections are most commonly categorized into types A and B depending on the involvement of ascending or descending aorta based on the Stanford system and into types I, II and III using DeBakey classification. The latest classification was proposed by the European Society of Cardiology in 2001. The authors present their own classification of distal aortic dissecting aneurysms that takes into account antegrade and retrograde dissection of the aorta, besides localization of proximal fenestration. Surgical strategies for the treatment of different variants of aortic dissecting aneurysms are considered.     

Asymmetric Cell–Matrix and Biomechanical Abnormalities in Elastin Insufficiency Induced Aortopathy

Aortopathy is characterized by vascular smooth muscle cell (VSMC) abnormalities and elastic fiber fragmentation. Elastin insufficient (Eln ^+/? ) mice demonstrate latent aortopathy similar to human disease. We hypothesized that aortopathy manifests primarily in the aorto-pulmonary septal (APS) side of the thoracic aorta due to asymmetric cardiac neural crest (CNC) distribution. Anatomic (aortic root vs. ascending aorta) and molecular (APS vs. non-APS) regions of proximal aorta tissue were examined in adult and aged wild type (WT) and mutant (Eln ^+/? ) mice. CNC, VSMCs, elastic fiber architecture, proteoglycan expression, morphometrics and biomechanical properties were examined using histology, 3D reconstruction, micropipette aspiration and in vivo magnetic resonance imaging (MRI). In the APS side of Eln ^+/? aorta, Sonic Hedgehog (SHH) is decreased while SM22 is increased. Elastic fiber architecture abnormalities are present in the Eln ^+/? aortic root and APS ascending aorta, and biglycan is increased in the aortic root while aggrecan is increased in the APS aorta. The Eln ^+/? ascending aorta is stiffer than the aortic root, the APS side is thicker and stiffer than the non-APS side, and significant differences in the individual aortic root sinuses are observed. Asymmetric structure–function abnormalities implicate regional CNC dysregulation in the development and progression of aortopathy.