Arterial Sinus Research Articles

Evolving Concepts of Myocardial Energy Metabolism: More Than Just Fats and Carbohydrates.

Although mitochondrial fatty acid and carbohydrate oxidation are the major source of ATP production in the heart, it is becoming increasingly clear that oxidation of other energy substrates, such as ketones and branched chain amino acids (BCAAs), can also contribute to energy production. Of importance is that alterations in cardiac ketone and branched chain amino acids metabolism may also impact the severity of heart failure through alterations in cellular signaling, despite these fuels providing a lower contribution to overall energy production. Dating back to the first studies investigating glucose uptake in the isolated rabbit heart by Locke and Rosenheim in 1907 to the first studies in humans in the late 1940s by Richard Bing and colleagues assessing cardiac substrate extraction via measurement of arterial coronary sinus differences, cardiac energy metabolism has been a topic of interest for cardiologists and scientists alike. The importance of energy metabolism in the heart has become widely appreciated, as has the dynamic nature of the heart’s ability to metabolize a wide range of energy substrates to meet its energy requirements. Fatty acids are recognized as a key source of energy for the heart, as well as carbohydrates, such as glucose and lactate (Figure).1 In 1961, Shipp et al2 were the first to demonstrate that increasing fatty acid availability to the heart results in a marked inhibition of glucose oxidation, though credit for the reciprocal relationship between fatty acids and glucose metabolism (glucose/fatty acid cycle) is attributed to the work of Randle et al.3 Confirmation of Randle’s glucose/fatty acid cycle in the rodent heart has since been demonstrated in the human heart.1 Figure. Interaction of energy substrates for oxidative energy production and branched chain amino acid (BCAA)/ketone body regulation of cellular signaling in the heart .The figure depicts how energy substrates compete …

Pulsatile tinnitus associated with dehiscent internal carotid artery: An irremediable condition?

Dehiscent internal carotid artery (ICA) in the middle ear is a rare condition, with conservative treatment primarily recommended. We report the case of a 63-year-old patient referred to the Ear, Nose, and Throat (ENT) ward for unbearable pulsatile tinnitus. Otoscopy revealed a normal right tympanic membrane, with pulsatile tinnitus but without hearing impairment. Based on imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI) of the temporal bone, as well as Doppler ultrasound of the internal carotid artery and sigmoid sinus, the diagnosis of ICA canal dehiscence into the tympanic cavity was established, thus excluding the diagnosis of aberrant ICA.Following the patient's own request, we undertook surgical correction, with the technique used described in the report. Immediately postoperatively, the pulsatile tinnitus had disappeared, with no surgical complications noted. At the 9-month follow-up, otoscopy revealed a healthy right tympanic membrane and the patient reported no remaining symptoms.

Point-by-point parent artery/sinus obliteration using detachable, pushable, 0.035-inch coils.

Parent artery occlusion for intractable aneurysms or sinus packing for dural arteriovenous fistulas (DAVFs) is sometimes difficult and requires many expensive coils to accomplish complete occlusion. To help solve these problems, we reviewed our experience using 0.035-inch coil (0.035 coil; Boston Scientific, San Leandro, CA, USA), which has been used in cardiovascular and abdominal lesions. These 0.035 coils were preferably used in addition to the detachable and fibered coils for patients with intractable aneurysms, traumatic vessel blowout, and DAVF. Our strategy was as follows: (1) detachable coils were deployed first for the ideal anchoring of the coils; (2) small fibered coils were additionally deployed to stabilize the coil mass; (3) 0.035 coils were deployed to complete the occlusion. From January 2012 to December 2013, seven consecutive patients were treated by endovascular embolization with 0.035 coils. Reasons for intervention were parent artery occlusion for carotid blowout (n = 1), internal carotid artery aneurysm (n = 2), traumatic vertebral artery injury (n = 2), vertebral AVF (n = 1), and transverse sinus-sigmoid sinus DAVF (n = 1). In our cases, a mean of 20.1 ± 8.5 coils per vessel were placed, and mean total coil length was 258.4 ± 91.5 cm per vessel. All procedures were safely performed and complete occlusions achieved. From our initial experience and treatment results, we believe endovascular parent artery occlusion or sinus packing with 0.035 coils to be useful in terms of reducing the number and expense of coils and also accomplishing immediate occlusion.

Changes in intracranial venous blood flow and pulsatility in Alzheimer’s disease: A 4D flow MRI study

Cerebral blood flow, arterial pulsation, and vasomotion may be important indicators of cerebrovascular health in aging and diseases of aging such as Alzheimer’s disease. Noninvasive markers that assess these characteristics may be helpful in the study of co-occurrence of these diseases and potential additive and interacting effects. In this study, 4D flow MRI was used to measure intra-cranial flow features with cardiac-gated phase contrast MRI in cranial arteries and veins. Mean blood flow and pulsatility index as well as the transit time of the peak flow from the middle cerebral artery to the superior sagittal sinus were measured in a total of 104 subjects comprising of four groups: (a) subjects with Alzheimer’s disease, (b) age-matched controls, (c) subjects with mild cognitive impairment, and (d) a group of late middle-aged with parental history of sporadic Alzheimer’s disease. The Alzheimer’s disease group exhibited: a significant decrease in mean blood flow in the superior sagittal sinus, transverse sinus, middle cerebral artery, and internal carotid arteries; a significant decrease of the peak and end diastolic blood flow in the middle cerebral artery and superior sagittal sinus; a faster transmission of peak flow from the middle cerebral artery to the superior sagittal sinus and increased pulsatility index along the carotid siphon.

August 2016 at a glance: the new ESC guidelines, and pathophysiology, epidemiology and prognosis of heart failure.

This issue has our new ESC guidelines for the diagnosis and treatment of heart failure (HF).1 Compared with the previous 2012 guidelines, major changes regard the introduction of the new category of patients with mid-range left ventricular ejection fraction (EF), a new algorithm for the diagnosis of HF, the inclusion of new exams for patients' evaluation, recommendations to prevent or delay the development of overt HF, including antidiabetic treatment with empaglifozin, a new algorithm for HF treatment, with the replacement of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers with an angiotensin receptor neprilysin inhibitor in the patients still symptomatic with a low EF, updated indications to cardiac resynchronization therapy, new evidence regarding treatment of comorbidities and more detailed indications for mechanical circulatory support.1 Treatment of HF with preserved EF (HFpEF) and treatment of acute HF are updated and summarized with new algorithms but, unfortunately, no major change is present, as no new drugs have reached evidence for treatment in these conditions.2, 3 A last paragraph with our gaps in evidence and a table with the messages about what to do or not to do in HF nicely summarize both future developments and current evidence.1 The use of cardiac implantable electronic devices to monitor and predict episodes of decompensation in HF patients is reviewed by Hawkins et al.4 Interestingly, a new strategy, moving from crisis detection to health maintenance, aimed at maintaining the “ideal state” and treating any deviation from homeostasis is proposed.4 A new rat model of HF, based on subtotal nephrectomy with development of stable chronic kidney disease and HFpEF, is described by Primessnig et al.5 Abnormalities in diastolic function were attended by a progressive upregulation of Na+/Ca2+ exchanger protein expression with a concomitant reduced Ca2+ extrusion capacity, with an increased activity in the reverse mode, e.g. Ca2+ import. Consistently, the administration of a Na+/Ca2+ inhibitor improved diastolic function acutely and cardiac function and remodelling in the long-term with new perspectives for HFpEF treatment.5 Marques et al. have measured microRNAs in arterial and coronary sinus venous samples in healthy volunteers and HF patients.6 Upregulation or downregulation of different microRNAs and cardiac release of micro-RNAs was found in the failing hearts, compared with controls, confirming the potential role of microRNAs as biomarkers and/or targets of treatment.6-10 Christ et al. have examined trends in HF hospitalizations in Germany.11 From 2000 to 2013, the absolute number of HF hospitalizations and of HF-related in-hospital days has continued to increase and this increase has been more pronounced in the older subjects. HF has remained the leading cause of hospitalizations and of in-hospital deaths in Germany. These data contrast with other recent studies from different countries showing a stable or decreasing proportion of HF hospitalizations.12, 13 Aging of the population, changes in the diagnostic procedures, outpatient care, and in the coding and reimbursement systems may all have influenced these results. Similar to previous data in patients with HF and reduced EF,14 QRS duration and morphology, namely left bundle branch block, are shown to have an independent prognostic value also in the patients with HFpEF enrolled in the I-PRESERVE clinical trial.15 The prognostic significance of the electrocardiographic abnormalities is shown also in the patients hospitalized for acute HF by another study.16 An article regarding patients hospitalized for acute HF shows the strong and independent relation between an increased length of hospital stay and post-discharge mortality at 90 days. Length of hospitalization was not predicted by baseline variables related to HF severity but was strongly associated with the occurrence of in-hospital worsening HF.17 The independent prognostic role of functional mitral regurgitation in patients with acute HF and either reduced or preserved EF, and in patients undergoing cardiac resynchronization therapy, respectively, is shown in two other studies.18, 19

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors Using Image-Based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study

Transsphenoidal surgery (TSS) is the most common approach for the treatment of pituitary tumors. However, misdirection, vascular damage, intraoperative cerebrospinal fluid leakage, and optic nerve injuries are all well-known complications, and the risk of adverse events is more likely in less-experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation coupled with neuronavigation in localizing neurovascular structures during TSS. Twenty-five patients with a pituitary tumor underwent preoperative 3-T magnetic resonance imaging (MRI), and MRI images loaded into the navigation platform were used for segmentation and preoperative planning. After patient registration and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe or Doppler probe on or as close as possible to the target. Preoperative segmentation of the internal carotid artery and cavernous sinus matched with the intraoperative endoscopic and micro-Doppler findings in all cases. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. Image guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of cases. The mean accuracy of the measurements was 1.20 ± 0.21 mm. Image-based preoperative vascular andneural element segmentation, especially with 3-dimensional reconstruction, is highly informative preoperatively and potentially could assist less-experienced neurosurgeons in preventing vascular and neural injury during TSS. In addition, the accuracy found in this study is comparable to previously reported neuronavigation measurements. This preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.

An unusual case of ST elevation myocardial infarction in a teenager with a coronary artery fistula.

Coronary artery fistula (CAF) is an abnormal connection between a coronary artery and any of the 4 chambers of the heart or any of the great vessels (superior vena cava, pulmonary artery, pulmonary veins, or coronary sinus). This abnormality is most often congenital1 and, although representing the most common coronary arterial malformation, is a rare cardiac anomaly. The incidence is of 0.002% of the general population and of 0.4% of all cardiac malformations.2

The transcardiac gradient of cardio-microRNAs in the failing heart.

Differential microRNA expression in peripheral blood has been observed in patients with heart failure, suggesting their value as potential biomarkers and likely contributors to disease mechanisms. In the present study, we aimed to evaluate the transcardiac gradient of 84 cardio-microRNAs in healthy and failing hearts to determine which microRNAs are released or absorbed by the myocardium in heart failure. Eight healthy volunteers and nine patients with congestive heart failure were included. Arterial and coronary sinus blood samples were collected, and microRNAs were extracted. The expression of microRNAs was analysed using real-time PCR by the miScript miRNA PCR Array Human Cardiovascular Disease. In coronary sinus samples, the microRNAs miR-16-5p, miR-27a-3p, miR-27b-3p, miR-29b-3p, miR-29c-3p, miR-30e-5p, miR-92a-3p, miR-125b-5p, miR-140-5p, miR-195-5p, miR-424-5p, and miR-451a were significantly down-regulated, and let-7a-5p, let-7c-5p, let-7e-5p, miR-23b-3p, miR-107, miR-155-5p, miR-181a-5p, miR-181b-5p and miR-320a were up-regulated in heart failure. Left ventricular filling pressure was negatively correlated with miR-195, miR-16, miR-29b-3p, miR-29c-3p, miR-451a, and miR-92a-3p. The failing heart released let-7b-5p, let-7c-5p, let-7e-5p, miR-122-5p, and miR-21-5p, and absorbed miR-16-5p, miR-17-5p, miR-27a-3p, miR-30a-5p, miR-30d-5p, miR-30e-5p, miR-130a-3p, miR-140-5p, miR-199a-5p, and miR-451a. In silico analyses suggest that the transcardiac gradient of microRNAs in heart failure may target pathways related to heart disease. We determined the transcardiac gradient of cardio-microRNAs in failing hearts, which supports the use of these microRNAs as potential biomarkers. The microRNAs described here may have a role in the pathophysiology of heart failure as they might be involved in pathways related to disease progression, including fibrosis.

Location of the extraosseous and intraosseous arterial anastomosis of the maxillary sinus in edentulous specimens.

The aim of this anatomical study was to measure the distance from the intraosseous and extraosseous arterial anastomoses of the maxillary sinus to the alveolar ridge in edentulous specimens dissected from human cadavers. Forty edentulous maxillary specimens were dissected, anatomically prepared, and injected for a better visualization of the maxillary sinus artery. This study showed that the mean distance from the alveolar ridge to the extraosseous anastomosis was 16mm for the second maxillary molar, 12mm for the first maxillary molar, and 13mm for the second maxillary premolar. For the intraosseous anastomosis to the alveolar ridge, the mean distance was 17mm for the second maxillary molar, 13mm for the first maxillary molar, and 14mm for the second maxillary premolar. Under the conditions of this study, we found that the mean distance from the alveolar crest to the extraosseous anastomosis and intraosseous anastomosis was shortest for the first maxillary molar and second maxillary premolar and greatest for the second maxillary molar. These findings provide data whose relevance for clinical dentistry is that they can be applied to minimize the risk of damage to the arterial network of the maxillary sinus during surgical procedures in this region.

Cerebral Sinus Thrombosis: A Rare but Fatal Complication of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic autoimmune disease. Extra intestinal manifestation of IBD has been reported to be 25 to 35%. There is a well-known risk of thrombosis in patients with IBD. It rarely involves cerebral vasculature in the form of arterial stroke or venous sinus thrombosis. This case is about 35 yrs old male who was a known case of ulcerative colitis for the last 10 years. He presented with history of severe thunderclap headache for the last few hours along with vomiting. He also had three episodes of seizure, generalized tonic clonic in nature. The examination does not show any focal asymmetry except mild drowsiness. His CT brain showed Focal cortical and subcortical area in the left posterior parietal region displaying multiple foci of hyper density with perifocal edema. CT venogram showed an intraluminal filling defect in the superior sagittal sinus suggestive of venous sinus thrombosis. Conclusion: Cerebral venous sinus thrombosis are considered as one of the rare but fatal complication of inflammatory bowel disease. It must be considered in all those with inflammatory bowel disease wherein absence of any other vascular risk factor patient presents with acute severe headache and focal or diffuse neurological symptoms including seizure

Traumatic Penetrating Injury to Left Temporal Lobe, Cavernous Sinus, and Internal Carotid Artery: Case Report

Traumatic Penetrating Injury to Left Temporal Lobe, Cavernous Sinus, and Internal Carotid Artery: Case Report

Direct Carotid-Cavernous Sinus Fistula Following Closed Head Injury

A case of direct carotid-cavernous sinus fistula (CCF) after closed head injury is presented. A 22-year-old male presented to the emergency department of Shohada Tajrish Hospital with the chief complaint of blurred vision and pulsatile retro-orbital headache. The patient had closed head injury due to car accident 2 month ago with lower limb fracture. After a 2-week symptom-free period, he developed scalp and right facial tingling, along with pulsatile retro-orbital headache and vision problems. His vital signs were within normal limits, but on primary evaluation the patient orbital and carotid bruits could be recognized. Computed tomography (CT) scan and magnetic resonance imaging (MRI) suggested the carotid-cavernous sinus fistula, which was confirmed by brain angiographic imaging findings. Carotid-cavernous sinus fistula is an uncommon condition that is usually caused by head trauma but can advance spontaneously in about one fourth of patients with CCF. The connection between the carotid artery and cavernous sinus leads to increased pressure in the cavernous sinus and compression of its contents, and finally advances the clinical symptoms and signs seen. Diagnosis is based on clinical evaluation and neuroimaging techniques. The target of management is to decrease the pressure within the cavernous sinus, which results in gradual recovery of symptoms.

Methodology study for the anatomic structure of aortic root using three-dimensional transesophageal echocardiography

Objective To establish a quantitative analysis method for the anatomic structure of aortic root by real-time three-dimensional transesophageal echocardiography, and to explore the reliability and repeatability of this method. Methods Ninety five adult patients underwent RT-3DTEE were included in this study.Full-volume 3D images of aortic root were acquired and analyzed offline with QLab-3DQ (iE33, Philips). The three mutually perpendicular plane were determined. Results 1) Aortic root: At the end of diastole, the diameter and area of coronary artery sinus bottoms level was 1.84 cm and 3.45 cm2; the diameter and area of top commissural level was 2.97 cm and 7.77 cm2; the diameter and area of sino-tubular junction level was 2.72 cm and 5.44 cm2. 2) Aortic sinus: right coronary sinus was widest, left coronary sinus was the most stenosis(P 0.50). The measurement of each parameter, which analysis among different angles showed that 0° region were more accurate than others. Conclusions 3D quantitative analysis to aortic root can be established by full-volume RT-3DTEE images and has better reliability and repeatability. Key words: Echocardiography, transesophageal; Echocardiography, real-time three-dimensional; Aortic root; Methodology; Quantitative analysis

COMPUTATIONAL MODEL OF PLATELET FLOW IN CAROTID ARTERY BIFURCATION

Atherosclerotic plaque tends to occur and develop in carotid artery sinus, where stenoses and other lesions can cause cerebral disturbances. The hemodynamics and the platelet profiles in the carotid artery are simultaneously simulated in the present study to reveal the mechanism of the atherosclerotic plaque formation. Firstly, an unsteady PISO solver on unstructured tetrahedral grids is developed to simulate the hemodynamics of carotid artery bifurcation. And small platelets are treated as spherical solid particle described by Newtonian motion equation in the simulation, including inertial force, drag force, shear lift force, virtual mass force and pressure gradient force. Secondly, the visualization experiment for the platelet flow in the straight micro-channel is setup to validate the numerical model. Using the present method, the platelet flow in a carotid artery bifurcation is analyzed. The results show that the outer vascular wall near the bifurcation is more vulnerable in carotid artery sinus, which is mainly due to the lower wall shear stress (WSS) and platelets backflow in the region.

Abstract 12942: Modified Glucose-Insulin-Potassium Regimen Provides Cardiac and Renal Protection With Improved Tissue Perfusion and Metabolism in Patients Undergoing Cardiopulmonary Bypass Surgery

Background: Laboratory studies demonstrate glucose-insulin-potassium (GIK) as a potent cardioprotective intervention but clinical trials have yielded mixed results, presumably due to varying formulas and treatment timing of GIK. This study evaluated the effects of modified GIK given perioperatively in patients undergoing cardiopulmonary bypass (CPB) surgery. Methods and Results: In this prospective, randomized, double-blinded trial with 930 patients, 750 mL GIK (200 g/L glucose, 66.7 U/L insulin and 80 mmol/L KCl) or placebo treatment was administered intravenously at 1 mL/kg/h 10 min before anesthesia. The primary outcome was the incidence of major adverse cardiac events (MACE). No significant difference in mortality was observed between the two groups. GIK therapy reduced the incidence of MACE (OR, 0.57; 95% CI, 0.43-0.75; P<0.001), enhanced cardiac function recovery with better glucose controlled without increasing perioperative blood glucose compared with placebo group. These benefits were associated with increased glucose uptake (9.5±4.6% vs. 5.6±2.6% in Placebo, P=0.005) and less lactate excretion (8.4 ± 9.2% vs. 33.4 ± 22.6% in Placebo, P<0.001) evidenced by the difference between arterial and coronary sinus, more glycogen store analyzed by transmission electron micrograph, and increased phosphorylation of IRS-1 and Akt in the hearts of GIK-treated patients. Importantly, GIK therapy significantly reduced blood lactate at 1 h, 6 h and 12 h after operation compared with placebo group (all P<0.001), indicating a enhanced tissue perfusion during CPB. Accordingly, patients treated with GIK had decreased markers of renal and hepatic injury, lower incidences of acute kidney injury and extended intensive care. Conclusions: Modified GIK regimen administrated perioperatively reduced the incidence of MACE and preserved cardiac and renal function in patients undergoing CPB surgery. These benefits were associated with activation of insulin signaling, improved myocardial metabolism and enhanced systemic tissue perfusion afforded by GIK. Clinical Trial Registration_URL: www.clinicaltrials.gov . Unique identifier: NCT01516138.

Abstract 17410: Catheter-based Radiofrequency Renal Denervation Decreases Renal Norepinephrine Spillover and Improves Cardiac Contractile Function in a Porcine Model of Ischemic Heart Failure

Background: Catheter-based radiofrequency (RF) renal denervation (RD) has been shown to decrease renal norepinephrine (NE) spillover in animal models and humans with hypertension. Nevertheless, the effect of RD on renal NE spillover in systolic heart failure (HF) is unknown. Methods: Ischemic HF model was created in 16 porcine by inducing myocardial infarction (MI) via coronary embolization of the left circumflex artery followed by rapid ventricular pacing for 4 weeks (MI+HF). Of these, 8 porcine underwent bilateral RD using the EnligHTN System (St. Jude Medical) and the remaining 8 served as control. All animals were given daily oral metoprolol ZOK (50 mg) plus ramipril (2.5 mg). Serum NE levels at different sites and index of cardiac contractility (dP/dt max /IP) were measured at baseline, immediately after MI (post-MI), at MI+HF and at 10 weeks follow-up. Renal arteries were then prepared for histological analysis. Results: RD significantly increased the dP/dt max /IP as compared with the control group (P<0.05, Figure 1a). RD also decreased the arterial and coronary sinus NE (P<0.05), and renal NE spillover (-54%, P=0.06) at 10 weeks as compared with MI+HF (Figures 1b & 1c). Histological examination showed significant reduction of renal sympathetic efferent nerves (tyrosine hydroxylase+) at proximal, middle and distal portions of the renal artery after RD as compared with the control group (-65%, P<0.05, Figure 1d). Conclusions: In a porcine model of ischemic HF, bilateral RD using catheter-based RF effectively destroys renal nerves to decrease renal NE spillover, and improves LV contractile function compared with medical therapy alone.

Anomalous Origins of Coronary Arteries From the Pulmonary Artery: A Comprehensive Review of Literature and Surgical Options.

Anomalous origins of coronary arteries from the pulmonary artery are rare malformations in which the coronary arteries originate from pulmonary artery sinuses or branches. The consequences are variable although, in most cases, these anomalies lead to severe coronary hypoperfusion and ventricular dysfunction. Surgical correction is indicated once the diagnosis is established due to high early mortality associated with the disease. In nearly all cases, the anomalous artery can be excised from its pulmonary origin, mobilized, and reimplanted directly into the ascending aorta using different surgical techniques. In rare circumstances, technical modifications must be used to restore a normal dual coronary perfusion. The emphasis of this article is to provide a collective review of surgical options published in the literature.

Age-related changes in pial arterial structure and blood flow in mice

Age-related cerebral blood flow decreases are thought to deteriorate cognition and cause senescence, although the related mechanism is unclear. To investigate the relationships between aging and changes in cerebral blood flow and vasculature, we obtained fluorescence images of young (2-month-old) and old (12-month-old) mice using indocyanine green (ICG). First, we found that the blood flow in old mice's brains is lower than that in young mice and that old mice had more curved pial arteries and fewer pial artery junctions than young mice. Second, using Western blotting, we determined that the ratio of collagen to elastin (related to cerebral vascular wall distensibility) increased with age. Finally, we found that the peak ICG intensity and blood flow index decreased, whereas the mean transit time increased, with age in the middle cerebral artery and superior sagittal sinus. Age-related changes in pial arterial structure and composition, concurrent with the observed changes in the blood flow parameters, suggest that age-related changes in the cerebral vasculature structure and distensibility may induce altered brain blood flow.

Characterisation and Comparison of Acute Haemodynamic, Cardiac Biochemical and Hormonal Response to Different Ventricular Pacing Sites in the Normal Heart

Acute cardiac response to right ventricular pacing is unknown. We aimed to assess the acute haemodynamic, biochemical and hormonal response to asynchronous right ventricular pacing and investigate whether there is a difference between an apical and outflow tract site. In 21 patients with normal cardiac function, haemodynamics, brain natriuretic peptide and high sensitive troponin T were measured in response to 10minutes of pacing at each site in a randomised crossover fashion and compared. Pacing both sites there were significant increases in pulmonary capillary wedge pressures (p<0.001) and QRS width (p< 0.01). In comparison to baseline, apical pacing demonstrated significant (p<0.05) increases in arterial peptide and troponin levels and venous peptide levels. Outflow tract pacing compared to baseline demonstrated significant (p<0.05) increases in arterial peptide and venous, arterial and coronary sinus troponin. There were no significant differences in responses between sites. Asynchronous right ventricular pacing demonstrated significant increases in filling pressures, cardiac hormonal and biochemical response above baseline with very short durations of pacing (10minutes). There was no difference in response between sites. These findings imply that even very short periods of right ventricular based pacing are potentially deleterious.

Proposal of Venous Drainage-Based Classification System for Carotid Cavernous Fistulae With Validity Assessment in a Multicenter Cohort.

Carotid cavernous fistulae (CCFs) are most commonly classified based on arterial supply. Symptomatology and treatment approach, however, are largely influenced by venous drainage. To propose an updated classification system using venous drainage. CCFs with posterior/inferior drainage only, posterior/inferior and anterior drainage, anterior drainage only, and retrograde drainage into cortical veins with/without other drainage channels were designated as types 1, 2, 3, and 4, respectively. CCFs involving a direct connection between the internal carotid artery and cavernous sinus were designated as type 5. This system was retrospectively applied to 29 CCF patients. Our proposed classification was significantly associated with symptomatology (P < .001). Type 2 was significantly associated with coexisting ocular/orbital and cavernous symptoms only (P < .001), type 3 with ocular/orbital symptoms only (P < .01), and type 4 demonstrated cortical symptoms with/without ocular/orbital and cavernous symptoms (P < .01), respectively. There was a significant association of our classification system with the endovascular treatment approach (P < .001). Types 1 and 2 were significantly associated with endovascular treatment through the inferior petrosal sinus (P < .01). Type 3 was significantly associated with endovascular treatment through the ophthalmic vein (P < .01) and type 5 with transarterial approach (P < .01), respectively. Types 2 (27.6%) and 3 (34.5%) were most prevalent in this series, whereas type 1 was rare (6.9%), suggesting that some degree of thrombosis is present, with implications for spontaneous resolution. Type 2 CCFs demonstrated a trend toward partial resolution after endovascular treatment (P = .07). Our proposed classification system is easily applicable in clinical practice and demonstrates correlation with symptomatology, treatment approach, and outcome.