Intracardiac Catheterization Research Articles

Artificial intelligence machine learning based evaluation of elevated left ventricular end-diastolic pressure: a Cleveland Clinic cohort study.

Left ventricular end-diastolic pressure (LVEDP) is a key indicator of cardiac health. The gold-standard method of measuring LVEDP is invasive intra-cardiac catheterization. Echocardiography is used for non-invasive estimation of left ventricular (LV) filling pressures; however, correlation with invasive LVEDP is variable. We sought to use machine learning (ML) algorithms to predict elevated LVEDP (>20 mmHg) using clinical, echocardiographic, and biomarker parameters. We identified a cohort of 460 consecutive patients from the Cleveland Clinic, without atrial fibrillation or significant mitral valve disease who underwent transthoracic echocardiography within 24 hours of elective heart catheterization between January 2008 and October 2010. We included patients' clinical (e.g., heart rate), echocardiographic (e.g., E/e'), and biomarker [e.g., N-terminal brain natriuretic peptide (NT-proBNP)] profiles. We fit logistic regression (LR), random forest (RF), gradient boosting (GB), support vector machine (SVM), and K-nearest neighbors (KNN) algorithms in a 20-iteration train-validate-test workflow and measured performance using average area under the receiver operating characteristic curve (AUROC). We also predicted elevated tau (>45 ms), the gold-standard parameter for LV diastolic dysfunction, and performed multi-class classification of the patients' cardiac conditions. For each outcome, LR weights were used to identify clinically relevant variables. ML algorithms predicted elevated LVEDP (>20 mmHg) with good performance [AUROC =0.761, 95% confidence interval (CI): 0.725-0.796]. ML models showed excellent performance predicting elevated tau (>45 ms) (AUROC =0.832, 95% CI: 0.700-0.964) and classifying cardiac conditions (AUROC =0.757-0.975). We identified several clinical variables [e.g., diastolic blood pressure, body mass index (BMI), heart rate, left atrial volume, mitral valve deceleration time, and NT-proBNP] relevant for LVEDP prediction. Our study shows ML approaches can robustly predict elevated LVEDP and tau. ML may assist in the clinical interpretation of echocardiographic data.

Intracardiac electrophysiology to characterize susceptibility to ventricular arrhythmias in murine models.

Introduction: Sudden cardiac death (SCD) and ventricular fibrillation are rare but severe complications of many cardiovascular diseases and represent a major health issue worldwide. Although the primary causes are often acute or chronic coronary diseases, genetic conditions, such as inherited channelopathies or non-ischemic cardiomyopathies are leading causes of SCD among the young. However, relevant experimental models to study the underlying mechanisms of arrhythmias and develop new therapies are still needed. The number of genetically engineered mouse models with cardiac phenotype is growing, making electrophysiological studies in mice essential tools to study arrhythmogenicity and arrhythmia mechanisms and to test novel treatments. Recently, intracardiac catheterization via the jugular vein was described to induce and record ventricular arrhythmias in living anesthetized mice. Several strategies have been reported, developed in healthy wild-type animals and based on aggressive right ventricular stimulation. Methods: Here, we report a protocol based on programmed electrical stimulation (PES) performed in clinical practice in patients with cardiac rhythm disorders, adapted to two transgenic mice models of arrhythmia - Brugada syndrome and cardiolaminopathy. Results: We show that this progressive protocol, based on a limited number of right ventricular extrastimuli, enables to reveal different rhythmic phenotypes between control and diseased mice. In this study, we provide detailed information on PES in mice, including catheter positioning, stimulation protocols, intracardiac and surface ECG interpretation and we reveal a higher susceptibility of two mouse lines to experience triggered ventricular arrhythmias, when compared to control mice. Discussion: Overall, this technique allows to characterize arrhythmias and provides results in phenotyping 2 arrhythmogenic-disease murine models.

Abstract 12374: Machine Learning-Based Evaluation of Elevated Left Ventricular End-Diastolic Pressure

Background: Left ventricular end-diastolic pressure (LVEDP) is clinically relevant due to its association with diastolic dysfunction and other outcomes. The gold-standard method of measuring LVEDP is invasive intra-cardiac catheterization. Echocardiography is routinely used for non-invasive estimation of left ventricular (LV) filling pressures; however, correlation with invasive LVEDP is variable. Goal: We sought to use machine learning (ML) algorithms to predict elevated LVEDP (> 20 mmHg) using clinical, echocardiographic, and biochemical parameters. Methods: We used a cohort of 460 consecutive patients without atrial fibrillation or significant mitral valve disease who underwent transthoracic echocardiography within 24 hours of elective heart catheterization. We included patients’ clinical (e.g. age), echocardiographic (e.g. left ventricular ejection fraction), and biochemical (e.g. N-terminal brain natriuretic peptide) data. We fit logistic regression, random forest, gradient boosting, and support vector machine algorithms in a 20-iteration train-validate-test workflow and measured performance using average area under the receiver operating characteristic curve (AUROC). We also performed multi-class classification of the patients’ cardiac conditions and predicted elevated tau (> 45), the gold-standard parameter for LV diastolic dysfunction. For each outcome, logistic regression weights were used to identify clinically relevant variables. Results: ML algorithms predicted LVEDP > 20 mmHg with good performance (AUROC = 0.779). ML models showed excellent performance predicting elevated tau (AUROC = 0.830) and classifying a variety of cardiac conditions (AUROC = 0.837 - 0.973). We identified several clinical variables (e.g. BMI, heart rate) relevant to LVEDP prediction. Conclusion: Our study shows ML approaches can robustly predict elevated LVEDP and tau. ML may assist in the clinical interpretation of echocardiographic data.

Low-Dose Empagliflozin Improves Systolic Heart Function after Myocardial Infarction in Rats: Regulation of MMP9, NHE1, and SERCA2a.

The effects of the selective sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin in low dose on cardiac function were investigated in normoglycemic rats. Cardiac parameters were measured by intracardiac catheterization 30 min after intravenous application of empagliflozin to healthy animals. Empagliflozin increased the ventricular systolic pressure, mean pressure, and the max dP/dt (p < 0.05). Similarly, treatment with empagliflozin (1 mg/kg, p.o.) for one week increased the cardiac output, stroke volume, and fractional shortening (p < 0.05). Myocardial infarction (MI) was induced by ligation of the left coronary artery. On day 7 post MI, empagliflozin (1 mg/kg, p.o.) improved the systolic heart function as shown by the global longitudinal strain (−21.0 ± 1.1% vs. −16.6 ± 0.7% in vehicle; p < 0.05). In peri-infarct tissues, empagliflozin decreased the protein expression of matrix metalloproteinase 9 (MMP9) and favorably regulated the cardiac transporters sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) and sodium hydrogen exchanger 1 (NHE1). In H9c2 cardiac cells, empagliflozin decreased the MMP2,9 activity and prevented apoptosis. Empagliflozin did not alter the arterial stiffness, blood pressure, markers of fibrosis, and necroptosis. Altogether, short-term treatment with low-dose empagliflozin increased the cardiac contractility in normoglycemic rats and improved the systolic heart function in the early phase after MI. These effects are attributed to a down-regulation of MMP9 and NHE1, and an up-regulation of SERCA2a. This study is of clinical importance because it suggests that a low-dose treatment option with empagliflozin may improve cardiovascular outcomes post-MI. Down-regulation of MMPs could be relevant to many remodeling processes including cancer disease.

Pulmonary arterial banding in mice may be a suitable model for studies on ventricular mechanics in pediatric pulmonary arterial hypertension

BackgroundThe role of interventricular mechanics in pediatric pulmonary arterial hypertension (PAH) and its relation to right ventricular (RV) dysfunction has been largely overlooked. Here, we characterize the impact of maintained pressure overload in the RV–pulmonary artery (PA) axis on myocardial strain and left ventricular (LV) mechanics in pediatric PAH patients in comparison to a preclinical PA-banding (PAB) mouse model. We hypothesize that the PAB mouse model mimics important aspects of interventricular mechanics of pediatric PAH and may be beneficial as a surrogate model for some longitudinal and interventional studies not possible in children.MethodsBalanced steady-state free precession (bSSFP) cardiovascular magnetic resonance (CMR) images of 18 PAH and 17 healthy (control) pediatric subjects were retrospectively analyzed using CMR feature-tracking (FT) software to compute measurements of myocardial strain. Furthermore, myocardial tagged-CMR images were also analyzed for each subject using harmonic phase flow analysis to derive LV torsion rate. Within 48 h of CMR, PAH patients underwent right heart catheterization (RHC) for measurement of PA/RV pressures, and to compute RV end-systolic elastance (RV_Ees, a measure of load-independent contractility). Surgical PAB was performed on mice to induce RV pressure overload and myocardial remodeling. bSSFP-CMR, tagged CMR, and intra-cardiac catheterization were performed on 12 PAB and 9 control mice (Sham) 7 weeks after surgery with identical post-processing as in the aforementioned patient studies. RV_Ees was assessed via the single beat method.ResultsLV torsion rate was significantly reduced under hypertensive conditions in both PAB mice (p = 0.004) and pediatric PAH patients (p < 0.001). This decrease in LV torsion rate correlated significantly with a decrease in RV_Ees in PAB (r = 0.91, p = 0.05) and PAH subjects (r = 0.51, p = 0.04). In order to compare combined metrics of LV torsion rate and strain parameters principal component analysis (PCA) was used. PCA revealed grouping of PAH patients with PAB mice and control subjects with Sham mice. Similar to LV torsion rate, LV global peak circumferential, radial, and longitudinal strain were significantly (p < 0.05) reduced under hypertensive conditions in both PAB mice and children with PAH.ConclusionsThe PAB mouse model resembles PAH-associated myocardial mechanics and may provide a potential model to study mechanisms of RV/LV interdependency.

Abstract 15634: High-fat Diet Consumption Accelerates Cardiometabolic Impairment via Deteriorating Mitochondrial Function in Non-obese Spontaneously Type 2 Diabetic Rats

Introduction: Type 2 Diabetes Mellitus (T2DM) is a complex disease which is related to genetic, environmental, and lifestyle factors. In genetically-induced T2DM rats, normal diet could induce spontaneous diabetes, and induce left ventricular (LV) dysfunction over time. However, the effect of high-fat diet (HFD) in these genetically-induced T2DM rats on the cardiometabolic changes, including LV function and cardiac mitochondrial function has rarely been investigated. Hypothesis: High-fat diet (HFD) consumption accelerates the development of T2DM and LV dysfunction by inducing mitochondrial dysfunction in genetically-induced non-obese T2DM-Spontaneously Diabetic Torii (SDT) rats. Methods: Male SDT rats (n=18/group) were divided into 2 groups to receive either normal diet (ND, 19.77% fat) or HFD (57.60% fat) for 4, 8 or 12 weeks. At each time course, cardiac function determined by echocardiography and the pressure-volume loop determined by invasive intracardiac catheterization were assessed. The heart was removed to study cardiac mitochondrial function at each time-course. Results: The body weight, food intake, and visceral fat were not different between ND and HFD rats at any times. Increased blood glucose was seen earlier at week 4 in HFD rats, but later at week 12 in ND rats. The development of LV contractile dysfunction and decreased stroke volume was observed earlier at week 8 in HFD rats, compared to ND rats and HFD rats at the baseline. Increased cardiac mitochondrial ROS production and decreased mitochondrial membrane potential (i.e. mitochondrial depolarization) was observed earlier at week 8 in HFD rats, compared to ND rats (Fig). Conclusions: High-fat diet accelerates cardiometabolic impairments via impaired cardiac mitochondrial function in genetically-induced non-obese T2DM rats.

Nitric Oxide Synthase 2 Induction Promotes Right Ventricular Fibrosis.

The ability of the right ventricle to compensate pressure overload determines survival in pulmonary arterial hypertension (PAH). Nitric oxide (NO) reduces the right ventricular afterload through pulmonary vasodilation, but excessive NO amounts cause oxidative stress. Oxidative stress drives remodeling of pulmonary arteries and the right ventricle. In the present study, we hypothesized that nitric oxide synthase 2 (NOS2) induction leads to excessive NO amounts that contribute to oxidative stress and impair right ventricular adaptation to PAH. We used a surgical pulmonary artery banding (PAB) mouse model in which right ventricular dysfunction and remodeling occur independently of changes in the pulmonary vasculature. Three weeks after PAB, NOS2 expression was increased twofold in the hypertrophied right ventricle on transcript and protein levels together with increased NO production. Histomorphology localized NOS2 in interstitial and perivascular cardiac fibroblasts after PAB, which was confirmed by cell isolation experiments. In the hypertrophied right ventricle, NOS2 induction was accompanied by an increased formation of reactive oxidants blocked by ex vivo NOS inhibition. We show that reactive oxidant formation in the hypertrophied right ventricle is in part NOS2 dependent (in NOS2-deficient mice [NOS2-/-]). Lack of NOS2 induction prevented superoxide scavenging and decreased reactive oxidant formation. Functional measures of cardiac function by noninvasive echocardiography together with intracardiac catheterization revealed no differences in heart function between both genotypes after PAB. However, reduced NO and reactive oxidant formation in the hypertrophied right ventricle of NOS2-/- mice was linked to reduced collagen accumulation through reduced collagen deposition from the cardiac fibroblast. Together, our data demonstrate a profibrotic role for NOS2 induction in the hypertrophied right ventricle.

MR Safe Robotic Manipulator for MRI-Guided Intracardiac Catheterization

This paper introduces a robotic manipulator to realize robot-assisted intracardiac catheterization in magnetic resonance imaging (MRI) environment. MRI can offer high-resolution images to visualize soft tissue features such as scars or edema. We hypothesize that robotic catheterization, combined with the enhanced monitoring of lesions creation using MRI intraoperatively, will significantly improve the procedural safety, accuracy, and effectiveness. This is designed particularly for cardiac electrophysiological (EP) intervention, which is an effective treatment of arrhythmia. We present the first MR Safe robot for intracardiac EP intervention. The robot actuation features small hysteresis, effective force transmission, and quick response, which has been experimentally verified for its capability to precisely telemanipulate a standard clinically used EP catheter. We also present timely techniques for real-time positional tracking in MRI and intraoperative image registration, which can be integrated with the presented manipulator to improve the performance of teleoperated robotic catheterization.

A New and Safe Mode of Ventilation for Interventional Pulmonary Medicine: The Ease of Nasal Superimposed High Frequency Jet Ventilation.

We use pulmonary interventional procedures for the diagnosis of pulmonary diseases either for benign or malignant lesions. Flexible bronchoscopy with or without radial endobronchial ultrasound, convex-probe endobronchial ultrasound and electromagnetic navigation are procedures performed in centers with experience in diagnostic pulmonary medicine. The method of sedation and ventilation is very important in order to avoid or handle with success complications. Proper respiration during pulmonary (or other interventional) procedures is a key factor. Apart from the proper sedation method we have to choose the proper ventilation method which decides respiratory movement. Superimposed high-frequency jet ventilation (SHFJV) is supposed to be safe and effective in clinical practice. Although this perception is commonly accepted, there is no study proving its safety on the basic of reliable data. We analyzed the data of 100 patients in different interventional settings (bronchoscopy with or without navigational approach, left atrial appendage closure (LAAC) or intracardiac catheterization) using nasal SHFJV. Mainly analyzed were capillary ABG-Data at the beginning and end of the intervention under sedation. The aim was to analyze if a risk scenario for the patient by using the nasal SHFJV can be derived by measuring the changes of pCO2, pO2, cBase Excess, cHCO3 and PH. Due to our data we conclude that this method of ventilation can be easily and safely used in interventional medicine for patients with all kind of comorbidities such as; chronic respiratory disease, lung cancer, interstitial lung disease, structural heart disease and heart failure.

Interactive training system for interventional electrocardiology procedures.

Recent progress in cardiac catheterization and devices has allowed the development of new therapies for severe cardiac diseases like arrhythmias and heart failure. The skills required for such interventions are very challenging to learn, and are typically acquired over several years. Virtual reality simulators may reduce this burden by allowing trainees to practice such procedures without risk to patients. In this paper, we propose the first training system dedicated to cardiac electrophysiology, including pacing and ablation procedures. Our framework involves the simulation of a catheter navigation that reproduces issues intrinsic to intra-cardiac catheterization, and a graphics processing unit (GPU)-based electrophysiological model. A multithreading approach is proposed to compute both physical simulations (navigation and electrophysiology) asynchronously. With this method, we reach computational performances that account for user interactions in real-time. Based on a scenario of cardiac arrhythmia, we demonstrate the ability of the user-guided simulator to navigate inside vessels and cardiac cavities with a catheter and to reproduce an ablation procedure involving: extra-cellular potential measurements, endocardial surface reconstruction, electrophysiology mapping, radio-frequency (RF) ablation, as well as electrical stimulation. A clinical evaluation assessing the different aspects of the simulation is presented. This works is a step towards computerized medical learning curriculum.

In Acute Myocardial Infarction Liver Parameters Are Associated With Stenosis Diameter.

Detection of high-risk subjects in acute myocardial infarction (AMI) by noninvasive means would reduce the need for intracardiac catheterization and associated complications. Liver enzymes are associated with cardiovascular disease risk. A potential predictive value for liver serum markers for the severity of stenosis in AMI was analyzed.Patients with AMI undergoing percutaneous coronary intervention (PCI; n = 437) were retrospectively evaluated. Minimal lumen diameter (MLD) and percent stenosis diameter (SD) were determined from quantitative coronary angiography. Patients were classified according to the severity of stenosis (SD ≥ 50%, n = 357; SD < 50%, n = 80). Routine heart and liver parameters were associated with SD using random forests (RF). A prediction model (M10) was developed based on parameter importance analysis in RF.Age, alkaline phosphatase (AP), aspartate aminotransferase (AST), and MLD differed significantly between SD ≥ 50 and SD < 50. Age, AST, alanine aminotransferase (ALT), and troponin correlated significantly with SD, whereas MLD correlated inversely with SD. M10 (age, BMI, AP, AST, ALT, gamma-glutamyltransferase, creatinine, troponin) reached an AUC of 69.7% (CI 63.8-75.5%, P < 0.0001).Routine liver parameters are associated with SD in AMI. A small set of noninvasively determined parameters can identify SD in AMI, and might avoid unnecessary coronary angiography in patients with low risk. The model can be accessed via http://stenosis.heiderlab.de.

Estenosis pulmonar pura

La ayuda invalorable de los nuevos procedimientos de investigación cardiológica nos ha permitido realizar un mejor estudio de las diferentes anomalías cardíacas. Entre ellos juega un papel importante el cateterismo intracardíaco, el que nos permite determinar datos tales como la gasometría y las curvas de presiones; la cineangiocardiografía puede detectar pequeñas anomalías que escapan incluso al cateterismo intracardíaco y el gran auge que tiene en nuestros días la cirugía cardíaca por medio de la circulación extracorpórea. Así, tenemos que, revisando los estudios realizados en décadas pasadas sobre todo en lo que se refiere a cardiopatías congénitas y entre ellas la Estenosis Pulmonar Pura encontramos conceptos y porcentajes que han variado. Desde Morgagni en 1791, que describió el primer caso de estenosis pulmonar valvular, pasando por Abbot (9 casos), Brock y Campbell (18 casos) Abrahams y Wood (26 casos) Kírklín y col. (100 casos) y otros, llegamos a 1961 en que Sherf realiza un estudio en forma exhaustiva de esta anomalía con la ayuda de la angiocardiografía. Por lo anterior se puede apreciar que la estenosis pulmonar aislada no es de excepcional rareza (63) como se pensó en un principio. Conforme se ha ido perfeccionando los métodos de diagnóstico auxiliares se ha podido demostrar que más bien es frecuente; ocupando el tercer o cuarto lugar entre las cardiopatías congénitas. El propósito del presente trabajo es relatar el estudio de 22 casos de Estenosis Pulmonar Pura, que fueron vistos, en el Servicio de Cardiología del Hospital Militar Central entre los años 1960-1964.

Study of the effectiveness of musical stimulation during intracardiac catheterization

Intracardiac catheterization is a routine physical examination. Due to psychological strains, several psychosocial interventions, including music therapy, have been proposed. The aim of the present study was to examine whether the preventive or adjuvant use of music therapy results in a reduction in both subjective and objective anxiety and thus leads to a reduction in sedative medication. METHODS OF ASSESSMENT: N=83 patients (48 male, 35 female, 66+/-11 yrs) waiting for scheduled cardiac catheterization were randomly allocated to one of three groups: control group (standard care), exposure group (music stimulation during the procedure), or coaching group (additional music therapeutic coaching). Target variables were subjective anxiety and physiological parameters. Music intervention did effectively reduce subjective anxiety (STAI-S reduction pre-post: exposure 11 pt, coaching: 4 pt, control: 6 pt; p=0.033). Physiological values and medication did not differ between groups. The use of music stimulation during the catheterization has a relaxing and calming effect on patients. It seems to be especially beneficial in a subgroup of patients with higher-than-average psychological strains.

The Effects of Bongardia Chrysogonum (L) Spach Extract on the Serum Parameters and Liver, Kidney, and Spleen Tissues in Rats

ABSTRACTThe tubers of Bongardia chrysogonum, which are used in the folk medicine in the form of 2–3% decoction in the province of Gaziantep, are supposed to treat urinary track, prosthate disorders, and hemorrhoid. The objective of this study was to assess the effect of these tubers on some serum parameters and spleen, liver, and kidney tissues in rats. One, two, and three percent decoctions of the B. chrysogonum were prepared, and instilled into the stomach of the rats, 0.2 ml/day, for 60 days via an orogastric tube. The serum glucose, creatinine, urea, uric acid, total cholesterol, triglycerides, total protein, albumin, globulin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatine kinase (CK), lactate dehydrogenase (LDH), sodium (Na), potassium (K), calcium (Ca), chloride (Cl), phosphorus (P), and magnesium (Mg) levels were measured in the blood obtained via intracardiac catheterization on 15th, 30th, 45th, and 60th days, respectively. Overall health status of rats was assessed by histopathologic examinations and by the nitric oxide level of spleen, liver, and kidney tissues. It was found that there was a decrease in the serum levels of glucose, urea, total cholesterol, triglycerides, total protein, AST, ALT, ALP, Na, K, Cl, P, and Mg (p<0.05) while the levels of creatinine, uric acid, CK, and LDH remained unchanged (p>0.05). The serum albumin, globulin, and Ca levels risen to the normal levels in the long term (>30days) following a significant decrease in the short term (<30 days). Macroscopic and microscopic examinations revealed that spleen, liver, and kidney of the animals were normal, and the nitric oxide level of only liver tissues was significantly higher. In conclusion, the decoction extract obtained from B. chrysogonum tubers lowers the carbohydrate and lipid metabolism. The extract has no significant effect on the aminoacid and protein metabolism. The decrease in serum glucose, triglycerides, and cholesterol level may be attributed to reduced intestinal uptake of these metabolites. Triterpenoid saponins exist in the extract may reduce the metabolite absorption via altering membrane property of villi in the intestine. Daily instillation of the extract for 60 days did not have an adverse effect on the tissues examined and higher level of liver nitric oxide was attributed to increased blood flow in the livers.

Cardiac troponin T and myocardial injury during routine cardiac catheterisation in children

Background: This study aims to investigate whether intracardiac catheterization produces myocardial damage on pediatric heart. Methods: Five blood samples were collected (basal, immediate post procedure, at 4, 12 and 24 h after the procedure) for troponin T and creatine kinase MB (CKMB) from 48 consecutive patients (age: 5.34±6.03 years). The effect of age, duration of procedure, pulmonary hypertension, cyanosis, and medication taken for congestive heart failure on the levels of troponin T and CKMB were sought. Results: The increase in CKMB (basal CKMB: 3.93±3.70 ng/ml; peak CKMB: 8.68±10.89 ng/ml; P<0.0001) and troponin levels (basal troponin: 0.002±0.003 ng/ml; peak troponin: 0.11±0.23 ng/ml; P<0.0001) over time was significant in the study group. Additionally younger patients (≤1 year), patients with pulmonary hypertension (mean pulmonary artery pressure >25 mmHg), longer procedure time (>30 min), and patients taking anti-congestive heart failure therapy had significantly higher levels of CKMB and troponin ( P>0.05). Conclusion: All patients undergoing cardiac catheterization are under risk of myocardial injury, and younger patients with pulmonary hypertension and especially with compensated cardiac failure have increased risk of myocardial damage, and need to be handled carefully.

ARTERIOVENOUS FISTULA WITH HEMATURIA IN AN ABDOMINAL AORTIC ANEURYSM-A CASE REPORT-

This paper describes a case of arteriovenous fistula which is relatively rare in ruptured abdominal aortic aneurysm (AAA). A 67-year-old man visited a nearly hospital because of abrupt hematouria and referred to the hospital under a diagnosis of AAA. On admission intracardiac catheterization revealed accerelated cardiac output O2-step up at the left common iliac vein. Aortography showed an arterioveneous fistula in the left iliac vein. In the operation, under the left sided retroperitoneal approach, the fistula was closed via inside of the left common iliac aneurysm using several mattress sutures. during the procedure, back-flow of the blood through the fistula was readily controlled by Fogarty Balloon Catheter indwelt in the left common iliac vain. The aneurysm was then replaced conventionally by a bifurcated vascular prosthesis. The postoperative course was uneventful and he is free from any symptoms. For better prognosis of this disease, early diagnosis and early treatment are mandatory.

Assessment of prosthetic mitral valve pressure gradients by means of ultrasound Doppler technique and on-line spectral analysis.

The blood speed through prosthetic mitral valves was determined using ultrasound Doppler techniques combined with on-line spectral analysis. Spectral analysis was particularly suitable for maximum velocity estimation due to its superior ability in discriminating between Doppler signals and white background noise. From a simplified Bernoulli equation the corresponding transprosthetic pressure drop was calculated and estimates were compared against pressure gradients obtained by conventional intracardiac catheterization. A close relationship between the ultrasonic- and the manometric transprosthetic pressure gradients was found, but the ultrasonic method tended to systematically underestimate the pressure gradients slightly.

Vascular intracardiac catheterization technique for multiphasic evaluation of rat heart in vivo

Extensive in vivo classification of the latent or acute cardiotoxic manifestations associated with exposure to chemicals has been limited in the past to larger laboratory animals. To facilitate the conduct of similar studies in smaller experimental animals, a cardiologic model with the rat is introduced that permits determination of in vivo cardiac contractility (e.g., left intraventricular pressure, dP dt ) and excitability (e.g., atrioventricular node conductivity, His-Purkinje system conduction time) with subsequent biochemical analysis of the same heart. To evaluate the influence of possible surgically induced artifacts on the metabolic parameters measured, three surgical protocols were compared: invasive intracardiac catheterization, sham surgery, and nonsurgical control. Male Sprague-Dawley rats were weighed and anesthetized with sodium pentobarbital. Venous blood hematocrit and serum osmolalities were determined in rats subjected to sham and intracardiac catheterization procedures. Surface limb-lead ECG recordings were obtained from rats in these two groups throughout the surgical and catheter manipulation procedures. In rats subjected to the intracardiac catheterization procedure, an electrode was inserted into the right jugular vein and advanced into the right atrium for recording the His bundle electrogram. An ultraminiature solid-state cathetertip pressure transducer was inserted into the right carotid artery and advanced into the left ventricle for recording left ventricular contractility characteristics. Upon completion of the electrode and catheter manipulations, myocardial contractility and excitability indices were assessed for time-dependent changes during a 20-min stabilization period. Subsequently, heart perchloric acid extracts were prepared from hearts frozen in liquid N 2, and metabolite (e.g., ATP, ADP, AMP, IMP, phosphocreatine, inorganic phosphate) concentrations were analyzed. Cardiac contractility and excitability characteristics, including peak left intraventricular and isovolumic pressures, peak dP dt , time to peak dP dt , heart conduction intervals, and heart rate, stabilized within 10 min after surgery. Thereafter, no surgically induced physiologic or metabolic changes were detected relative to either sham-treated or nonsurgical controls. These findings demonstrate the feasibility and integrity of this method and suggest its potential utility for investigating the in vivo cardiotoxicity of various chemical agents using the rat as the animal model.

Clinical diagnosis of persistent left superior vena cava by observation of jugular pulses

In seven patients with persistent left superior vena cava (LSVC) diagnosed at surgery or by intracardiac catheterization, the difference in amplitude between the left and the right jugular pulses was investigated. In sex cases the left jugular pulse had greater amplitude and in the seventh case the opposite was true, but this patient had “mirror-image” dextrocardia with situs inversus and therefore it was considered a positive sign. The greater amplitude of the jugular pulse in the same side of the anomalous superior vena cava (usually the left), appears to be a useful sign to suspect the diagnosis of this malformation.

Hydrothorax From Subclavian Vein Catheterization

To the Editor:— Widespread use of the subclavian vein for the collection of blood samples, intravenous infusions, monitoring central venous pressure, and intracardiac catheterization began with the description by Wilson et al in 1962.1The subclavian route continues to gain popularity.2-4Complications are rarely attributed to this method, but hemothorax, tension pneumothorax, subcutaneous emphysema, brachial plexus injury, septicemia, subclavicular hematoma, cutaneous bleeding, pneumothorax, subclavian artery injury, infection, thoracic duct injury, air embolism, catheter embolization, subclavian thrombophlebitis, and arteriovenous fistula are possible. Additionally, iatrogenic hydrothorax is another potential complication that deserves comment. Report of a Case.— A 55-year-old woman underwent cholecystectomy on Nov 29, 1968, for cholecystitis secondary to cholelithiasis. Postoperatively, because of a problem in maintaining an intravenous route, a percutaneous infraclavicular subclavian vein catheterization was performed on the second postoperative day (a free return of blood was demonstrated). After receiving 1,500 cc of lactated Ringer's solution, she developed