Significant unfavorable geometrical changes in ascending aorta despite stable diameter at follow-up.

OBJECTIVE: The clinical importance of following up on the ascending aortic diameter lies in the fundamental presumption that wall pathology eventually manifests as a change in shape. However, the diameter describes the vessel locally, and the 55 mm criterion fails to prevent most dissections. We hypothesized that geometric changes across the ascending aorta are not necessarily imprinted on its diameter; i.e. the maximum diameter correlates weakly and insignificantly with elongation, surface stretching, engorgement, and tortuosity. METHODS: Two databases were interrogated for patients who had undergone at least 2 ECG-gated CT scans. The absence of motion artifacts permitted the generation of exact copies of the ascending aorta which then underwent three-dimensional analysis producing objective and accurate measurements of the centreline length, surface, volume, and tortuosity. The correlations of these global variables with the diameter were explored. RESULTS: Twenty-two patients, 13 male and 9 female, were included. The mean age at the first and last scan was 63.7 and 67.1 y, respectively. The mean diameter increase was approximately 1 mm/y. There were no dissections, while 7 patients underwent preemptive surgery. The yearly change rate of the global variables, normalized to height if applicable, showed statistically insignificant, weak, or negligible correlation with diameter increments at follow-up. Most characteristically, a patient's aorta maintained its diameter, while undergoing 1 mm/y elongation, 151 mm2/(y·m) stretching, 2366 mm3/(y·m) engorgement, and 0.02/y tortuosity. CONCLUSION: Maximum diameter provides a local description of the ascending aorta and cannot fully portray the pathological process across this vessel. Following up the diameter is not suggestive of length, surface, volume, and tortuosity changes.

Injecting a ventricular tachycardia into the heart-Α unique case report.

INTRODUCTION: A 52-year-old woman presented with a complex ventricular arrhythmia in an intraoperative context, during kyphoplasty for an osteoporotic fracture of a lumbar vertebra. The subject showed no indications of a previous cardiovascular condition. METHODS AND RESULTS: Causes of arrhythmias associated with the procedure were excluded. Due to her positive family history for dilated cardiomyopathy, upcoming thoughts were made for unmasking a previous asymptomatic cardiomyopathy. Nevertheless, an intracardiac cement embolism was diagnosed and, finally, the patient underwent an open-heart surgery with successful removal of the cardiac cement. Νo new arrhythmia recorded during follow up. CONCLUSION: To the best of our knowledge, this is the first reported case of ventricular arrhythmogenic presentation of a cardiac cement embolus after a KP procedure.

Extended law of laplace for measurement of the cloverleaf anatomy of the aortic root.

The cross-sectional shape of the aortic root is cloverleaf, not circular, raising controversy regarding how best to measure its radiographic "diameter" for aortic event prediction. We mathematically extended the law of Laplace to estimate aortic wall stress within this cloverleaf region, simultaneously identifying a new metric of aortic root dimension that can be applied to clinical measurement of the aortic root and sinuses of Valsalva on clinical computerized tomographic scans. Enforcing equilibrium between blood pressure and wall stress, finite element computations were performed to evaluate the mathematical derivation. The resulting Laplace diameter was compared with existing methods of aortic root measurement across four patient groups: non-syndromic aneurysm, bicuspid aortic valve, Marfan syndrome, and non-dilated root patients (total 106 patients, 62 M, 44 F). (1) Wall stress: Mean wall stress at the depth of the sinuses followed this equation: Wall stress = BP × Circumscribing circle diameter/(2 × Aortic wall thickness). Therefore, the diameter of the circle enclosing the root cloverleaf, that is, twice the distance between the center, where the sinus-to-commissure lines coincide, and the depth of the sinuses, may replace diameter in the Laplace relation for a cloverleaf cross-section (or any shaped cross-section with two or more planes of symmetry). This mathematically derived result was verified by computational finite element analyses. (2) Diameters: CT scan measurements showed a significant difference between this new metric, the Laplace diameter, and the sinus-to-commissure, mid-sinus-to-mid-sinus, and coronal measurements in all four groups (p-value < 0.05). The average Laplace diameter measurements differed significantly from the other measurements in all patient groups. Among the various possible measurements within the aortic root, the diameter of the circumscribing circle, enclosing the cloverleaf, represents the diameter most closely related to wall stress. This diameter is larger than the other measurements, indicating an underestimation of wall stress by prior measurements, and otherwise provides an unbiased, convenient, consistent, physics-based measurement for clinical use. "Diameter" applies to circles. Our mathematical derivation of an extension of the law of Laplace, from circular to cloverleaf cross-sectional geometries of the aortic root, has implications for measurement of aortic root "diameter." The suggested method is as follows: (1) the "center" of the aortic root is identified by drawing three sinus-to-commissure lines. The intersection of these three lines identifies the "center" of the cloverleaf. (2) The largest radius from this center point to any of the sinuses is identified as the "radius" of the aortic root. (3) This radius is doubled to give the "diameter" of the aortic root. We find that this diameter best corresponds to maximal wall stress in the aortic root. Please note that this diameter defines the smallest circle that completely encloses the cloverleaf shape, touching the depths of all three sinuses.

Prolonged complete atrioventricular block due to neostigmine and amiodarone interaction in an amyloidosis patient with left main dissection and postoperative intestinal pseudo-obstruction.

Cardiac amyloidosis has been strongly associated with postoperative intractable circulatory failure, and intestinal amyloidosis could lead to intestinal pseudo-obstruction. The latter can be treated with neostigmine, which is notorious for its brief bradyarrhythmic complications. The amyloidosis patient presented herein, suffered an iatrogenic left main dissection, failure of bailout stenting and finally underwent urgent surgery. Meticulous fluid and drug management was key to keeping this patient stable. Postoperative atrial fibrillation was treated with amiodarone. The postoperative course was complicated with intestinal pseudo-obstruction, which was ultimately resolved with neostigmine. This short-lived cholinesterase inhibitor interacted with amiodarone and caused a previously undocumented prolonged complete atrioventricular block that resolved 48 hours after both drugs' discontinuation. The neostigmine amiodarone interaction warrants clinical vigilance and is speculated to be due to their partially shared second messenger pathway involving cyclic adenosine monophosphate. Patients with cardiac amyloidosis could maintain hemodynamic stability perioperatively.

Debranching-first and proximal arch replacement for an innominate artery aneurysm: a case study.

The aneurysms of the innominate artery represent a rare form of aneurysmal disease. Management in an early elective basis is recommended due to the risk of stroke and rupture. Treatment options include open surgery, which is the gold standard, and endovascular repair. We describe the debranching-first technique and proximal arch replacement for a huge innominate artery aneurysm and discuss the surgical strategy for cannulation, perfusion and organ protection.

Thoracoabdominal Resection of Mucormycosis Lesions in a Leukemic Patient.

Mucormycosis is a rare fungal infection that poses a severe threat to immunocompromised patients. In the case presented herein, a 56-year-old leukemic patient, who was treated with amphotericin B and posaconazole, was scheduled for surgical resection of mucormycosis lesions that had spread to the thorax and abdomen. Surgery was aggressive and the resection involved the left lateral thoracoabdominal wall, 2 ribs, the left diaphragm, and the spleen. The patient tolerated the procedure well and the leukemia went into remission. Aggressive surgery can benefit immunocompromised patients with mucormycosis.

Pneumorachis associated with persistent tachycardia after blunt thoracic trauma.

Pneumorachis, or intraspinal air, can be a rare result of blunt thoracic trauma. We report the case of a 40-year-old man with multiple injuries and pneumorachis associated with persistent tachycardia. As factors that increase heart rate were gradually ruled out, intraspinal air was considered the potential culprit. Computed tomography revealed intraspinal air at the thoracic level, which possibly promoted cardiac arrhythmogenesis. Air may transiently compress the preganglionic cardiac sympathetic nerves and increase sympathetic output to the heart.

Subtle-discrete aortic dissection without bulging of the aortic wall. A rare but lethal lesion.

We report a subtle-discrete aortic dissection, without bulging of the aortic wall or aneurysm or valve pathology or periaortic effusion, which resulted in a lethal cardiac tamponade to a 35-year-old male.

Study of shape memory alloy fibers for the development of artificial myocardium.

INTRODUCTION: Circulatory support devices are employed to treat heart failure. Such a device could be made from shape memory alloy (SMA) fibers. These Ni-Ti fibers contract when electric current flows through them, thus resembling artificial muscles. An artificial myocardium device made from SMA fibers can directly compress the epicardial surface of a failing heart, thus contributing to the pumping action. Unlike modern mechanical circulatory support devices, there is no blood-contacting surface to provoke thromboembolism, hemorrhage, inflammatory response or hemolysis. METHODS: The experimental setup permitted a detailed study of a sample SMA fiber with great accuracy while the ambient temperature was controlled to resemble that of the human body. The current profile through the fiber was controlled (current shaping, CS) by a microcontroller and a portable computer. RESULTS: Parameters such as strain, contraction and relaxation velocities and the effect of ambient temperature were measured. The contraction and relaxation velocities were measured after applying various effective currents. It was found that the contraction velocity could be manipulated to reach that of the healthy myocardium through CS. On the other hand, the relaxation velocity was independent of the contraction velocity. CONCLUSIONS: A cardiac assist device can be made from SMA fibers. More studies need to be conducted in this direction.