Can Doppler systemic venous flow indices predict central venous pressure in children?

Tricuspid valve, superior vena cava (SVC), and hepatic vein Doppler patterns may be abnormal in right heart anomalies and have been used to predict high central venous pressure (CVP) in adults. The purpose of this study was to evaluate the relationship of these systemic venous flow indices to CVP in children. Children undergoing cardiac catheterization were studied prospectively using simultaneous recordings of mean CVP with pulsed-Doppler tracings of SVC, hepatic vein, and tricuspid valve flow. Systemic venous Doppler measurements included peak velocities and velocity time integrals for ventricular systole (S), ventricular diastole (D), and ventricular systole (B), and atrial systole (A). Tricuspid inflow Doppler E and A waves were recorded also. Patients with significant tricuspid stenosis or regurgitation, systemic venous obstruction, and nonsinus rhythm were excluded. The 42 patients ranged in age from 0.2 to 21.0 years and in weight from 3.0 to 68.0 kg. Mean CVPs ranged from 1 to 17 mmHg. Catheterization indications included hemodynamic evaluation (25 patients), transplant biopsy, (11 patients), and interventional procedures (6 patients). No SVC or tricuspid valve Doppler measurement correlated with CVP. Hepatic vein peak D, peak B, and peak A significantly correlated with CVP (r = 0.34 - 0.55; P < 0.05, linear regression). For all correlations, the r values were low with significant overlap among patients. Thus, in children, only hepatic vein peak velocities correlate with CVP. Because of the low r values and significant overlap among patients, the currently used Doppler indices have a low sensitivity for predicting CVP in this age group.

How much guidewire is too much? Direct measurement of the distance from subclavian and internal jugular vein access sites to the superior vena cava-atrial junction during central venous catheter placement

OBJECTIVE

The introduction of excessive lengths of guidewire during placement of central venous catheters from the internal jugular vein (IJV) or the subclavian vein (SCV) can result in rare but significant complications. To identify a "safe" guidewire insertion length, the authors performed direct intravascular measurement of the distance from these venous access sites to the superior vena cava-atrial junction (CAJ), and evaluated these distances relative to the patients' height, weight, sex, and chest radiographs.

DESIGN

Prospective, nonrandomized observation.

SETTING

The Interventional Radiology Department of a tertiary care referral hospital.

PATIENTS

100 adults (45 women, 55 men) evaluated during fluoroscopically directed central venous catheter placement.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The distance from the IJV or SCV access site was directly measured using fluoroscopy and an intravascular guidewire. 40 right IJVs, 31 right SCVs, 16 left SCVs, and 13 left IJVs were studied. Comparative measurements from the postprocedure radiograph were made in 20 of these cases. All measurements were correlated with patient sex, height, and weight. The mean distance from all access sites to the superior vena cava-atrial junction was 18.0 cm. The right IJV distance was the shortest, averaging 16 cm. The left SCV distance was the longest, averaging 21.2 cm. Right SCV and left IJV distances were 18.4 and 19.1 cm, respectively, but this difference was not statistically significant. Weight and radiographic measurements did not correlate with the measured vascular distance, although there was a trend toward longer distances in taller patients and males.

CONCLUSIONS

Patient height, weight, and measurements from previous chest radiographs are less reliable in predicting a safe wire length than is the access site selected. In most cases, 18 cm should be considered the upper limit of guidewire introduced during central catheter placement in adults. The guidewires supplied in catheter kits should have lengths correlated to those of the catheters, and should have distance markings printed upon them.

Aberrant left brachiocephalic vein: CT imaging findings and embryologic correlation

Computed tomography was utilized to evaluate aberrant left brachiocephalic vein (ALBCV), an infrequently discussed congenital vascular anomaly among Chinese people. Associated vascular variation and possible embryonic correlation are discussed. Since 1990, a total of 14 cases of ALBCV have been reported in patients receiving CT scan of chest, and was mainly an incidental diagnosis. One case was confirmed angiographically and two others were confirmed by magnetic resonance imaging. Emphasis was placed on the entry of the azygos vein into the superior vena cava (SVC), the length of the SVC, and the presence of other cardiovascular abnormalities. Of the 14 cases of ALBCV, the level of azygos vein entry was higher than the origin of the SVC in 7 cases: 4 were approximately the same level and 3 were lower. The average length of the SVC was approximately 5. 6 cm shorter than that of the general population, which is approximately 7.0 cm. Three cases had associated vascular anomaly. Most cases of ALBCV had azygos vein drainage level higher than or equal to the origin of the SVC. Right-sided aorta is one of the causes giving rise to the ALBCV during embryonic development. The CT scan remains a definitive diagnostic modality for ALBCV.

Failure of left-sided implantable cardioverter defibrillator implantation due to absence of left brachiocephalic vein

Implantation of an implantable cardioverter defibrillator by the transvenous approach was impossible from the left side in a patient with on absence of the left brachiocephalic vein; the left subclavian vein was connected by a large left superior intercostal vein to the accessory hemiazygos vein that joined the azygos vein; then the blood flowed into the superior vena cava. Implantation was successfully attempted using the right-sided venous access.

[Atresia of the right atrial orifice of the coronary sinus with persistent left superior vena cava: a case report]

A 39-year-old woman presented with atresia of the right atrial orifice of the coronary sinus with a persistent left superior vena cava detected at cardiac catheterization. She was admitted with frequent episodes of angina at rest and on exertion. Coronary angiography, including spasm provocation test, yielded normal results. However, left coronary arteriography demonstrated a dilated coronary sinus and a persistent left superior vena cava draining into the innominate vein. The contrast medium leaked slightly into the right atrial cavity through the obstructed orifice of the coronary sinus. Atresia of the coronary sinus orifice is a rare malformation usually found at autopsy. Only 3 cases have been reported in Japan. This is the first adult Japanese case detected when the patient was still alive.

Surgical treatment of an endovascular metastatic melanoma of the superior vena cava

A 42-year-old woman, who had undergone excision of a melanoma of her right forearm 3 years before (Breslow's index 4.4 mm), was admitted to hospital for the evaluation of an superior vena cava syndrome. The thoracic CT scan and the phlebography showed obstruction of the superior vena cava by an endovascular tumor. Abdominal, pelvis and cranial CT scans did not reveal any other metastatic localization. Surgery with extracorporeal circulation was performed. The mass was resected and histopathologic examination confirmed the endovascular metastatic melanoma. There was no heart metastasis. The patient was then given a polychemotherapy. She was still alive after 18 months of follow-up after the initial metastasis. To our knowledge, no similar case has previously been reported and surgical treatment, as for isolated heart metastatic melanoma, may be considered for vascular metastasis, as in our case.

Weekly prophylactic urokinase instillation in tunneled central venous access devices

PURPOSE

To determine the safety and efficacy of weekly prophylactic urokinase therapy in tunneled central venous access devices (VADs).

MATERIALS AND METHODS

A prospective, randomized study was performed in 105 patients who underwent tunneled VAD placement between March 1997 and April 1998. The patients were randomized to receive either twice-daily heparin flushes (14 heparin flushes per week; group A, n = 52) or twice-daily heparin flushes with once-weekly urokinase (UK) instillation (13 heparin flushes, one UK flush per week; group B, n = 53). Patients were followed up by examination and/or interview at 1, 3, and 6 months for signs and symptoms of delayed catheter-related complications.

RESULTS

The total number of indwelling catheter-days was similar between groups (5,450 in group A, 5,276 in group B). The total number of infectious complications and fibrin sheaths formed was greater for group A (n = 11; 21.1%) than group B (n = 3; 5.7%) (P = .02). There were no side effects noted from the prophylactic UK administrations.

CONCLUSION

Prophylactic UK is advantageous in preventing delayed catheter-related complications.

Transvenous parasympathetic cardiac nerve stimulation: an approach for stable sinus rate control

INTRODUCTION

Epicardial electrical stimulation of parasympathetic nerves innervating the sinus node has been shown to decrease sinus rate. We investigated whether intravascular parasympathetic cardiac nerve stimulation (IPS) can be achieved over a relatively long-term period to slow the supraventricular rate.

METHODS AND RESULTS

Fifteen dogs were investigated. IPS was performed with rectangular stimuli (0.05-msec duration, 20 Hz) using a catheter with an expandable electrode basket. The catheter was positioned in the superior vena cava (SVC; n = 9) or right pulmonary artery (RPA; n = 6). The basket then was expanded to hold the catheter in place. Nonfluoroscopic identification of effective IPS sites was achieved within 5 minutes in the SVC. Increasing IPS voltage resulted in a graded response of supraventricular rate slowing. A 50% prolongation of the baseline atrial cycle length was achieved with 28 V in the SVC (1,056 +/- 355 msec vs 489 +/- 154 msec; P < 0.001) and 25 V in the RPA (1,181 +/- 306 msec vs 518 +/- 138 msec; P < 0.01). The rate slowing started immediately after IPS onset, terminated abruptly after IPS cessation, and could be maintained over 10 hours. A rate slowing effect also was observed when the sinus rate was increased by isoproterenol (SVC: 304 +/- 8 msec/RPA: 341 +/- 9 msec with isoproterenol vs SVC: 635 +/- 12 msec with isoproterenol + IPS at 39 V/ RPA: 584 +/- 16 msec with isoproterenol + IPS at 38 V; n = 6).

CONCLUSION

IPS results in a significant supraventricular rate slowing that is stable over a relatively long period and may be applied to slow undesirable sinus tachycardia in acute ischemic syndromes or to counteract undesirable chronotropic effects of catecholamines during treatment of cardiogenic or septic shock and acute congestive heart failure.

Effects of age and physiologic variables on right ventricular filling dynamics in normal subjects

The reference values for right ventricular (RV) filling of normal persons and the effects of physiologic variables in a large series have not been described. The objective of this study was to characterize superior vena cava, hepatic vein, and RV inflow Doppler measurements in a large normal reference group to reflect the aging process, gender, heart rate, and effects of respiration. We prospectively performed pulsed-wave Doppler echocardiography of the superior vena cava, hepatic vein, and RV inflow during inspiration, expiration, and apnea in 115 healthy volunteers (62 women and 53 men) ranging in age from 21 to 84 years (mean +/- SEM 48 +/- 17). For analysis, the study subjects were classified by age into 2 groups: those < 50 years of age (group 1; n = 60) and those > or = 50 years of age (group 2; n = 55). Multiregression models were used to assess the influence of age, gender, and heart rate on Doppler variables. There were important differences in superior vena cava and RV inflow between the 2 groups. Group 2 had a greater superior vena cava peak atrial flow velocity (16 +/- 3 vs 13 +/- 3 cm/s), flow integrals (1.5 +/- 0.4 vs 1.1 +/- 0.3 cm), and reverse flow as a percentage of forward flow (17 +/- 6% vs 14 +/- 6%) than group 1. In group 2, peak RV inflow early filling velocity (41 +/- 8 vs 51 +/- 7 cm/s) and ratio of early filling-to-atrial filling (1.3 +/- 0.4 vs 2 +/- 0.5) were lower than that of group 1. Likewise, peak atrial filling velocity was higher (33 +/- 8 vs 27 +/- 8 cm/s) and deceleration time was longer (198 +/- 23 vs 188 +/- 22 ms) in group 2. The superior vena cava and hepatic vein peak forward flow velocities were significantly higher during inspiration than during expiration and apnea. Similarly, RV inflow velocities were significantly higher during inspiration than in expiration and apnea. Multiregression analysis showed that age, gender, and heart rate had important effects on Doppler variables. Thus, this study demonstrates the effects of aging and normal physiologic variable flow velocities in the superior vena cava, hepatic veins, and RV inflow in a large series of normal subjects.

Persistent left superior vena cava and partial anomalous pulmonary venous connection: incidental diagnosis by transesophageal echocardiography during coronary artery bypass surgery

Transesophageal echocardiography plays an important role in the intraoperative treatment of the heart surgery patient. Its utility in the description of both known and unexpected cardiac pathology is well established. We describe a patient with a previously undiagnosed partial anomalous pulmonary venous connection along with a persistent left superior vena cava scheduled for routine coronary artery bypass graft surgery (CABG).

Intracardiac echocardiography via the transvenous approach with use of 8F 10-MHz ultrasound catheters

OBJECTIVE

To study the safety and feasibility of intracardiac imaging using a novel 8F 10-MHz non-over-the-wire ultrasound catheter system.

SUBJECTS AND METHOD

Intracardiac imaging using a transfemoral venous approach was performed in 33 adults, 14 men and 19 women, aged 25 to 66 years (mean, 46 years). Six were normal subjects, 12 had congenital heart diseases (5 atrial septal defects, 3 ventricular septal defects, 1 tetralogy of Fallot, 2 patent ductus arteriosus, and 1 Ebstein anomaly), 14 had valvular heart diseases (12 mitral stenoses and 2 calcific aortic stenoses), and 1 had acute pulmonary embolism.

RESULTS

Ultrasound images were obtained, without any complications, from the right side of the heart in all subjects. The atria and ventricles could be recognized by anatomic relationships to the cardiac chambers and the valves by their characteristic motion during each cardiac cycle. The vessels were verified by their connections to the cardiac chamber and by contrast echocardiography if indicated.

CONCLUSION

Intracardiac imaging using the 8F 10-MHz non-over-the-wire ultrasound catheter system via a transfemoral venous approach is feasible and safe. Intracardiac echocardiography is potentially useful for assessing a variety of cardiac anomalies and in guiding and monitoring certain intervention procedures.

[Carcinomatous pericarditis monitored by pulsed Doppler echocardiography of superior vena cava: hemodynamics from pericardial effusion to pericardial solid invasion]

We utilized pulsed Doppler echocardiography to monitor changes in a patient with carcinomatous pericarditis, from pericardial effusion with cardiac tamponade to pericardial solid invasion. Characteristic changes in superior vena cava (SVC) pulsed Doppler flow patterns were observed after invasion of the pericardium. SVC pulsed Doppler flow patterns are a useful aid in differentiating between solid invasions and recurrent pericardial effusion with pericardial thickening: this diagnostic capability is not readily available with computed tomography.

Experience with a low profile bipolar, active fixation pacing lead in pediatric patients

Continued miniaturization of permanent pacing systems has promoted use of this technology in younger and smaller pediatric patients. Intermedics ThinLine 438-10 active fixation pacing leads (4.5 Fr lead body) were implanted in 26 patients (17 males/9 females; 9.9 +/- 6.9 years). Twenty of 26 patients received dual chamber systems, 6 of 26 patients single lead systems. Each patient has been followed 3 months. Pacemaker analysis at implant and 6 months later evaluated pulse width thresholds at 2.5 V (atrial 0.07 +/- 0.02 vs 0.13 +/- 0.02 ms [P = 0.01]; ventricular 0.08 +/- 0.04 ms vs 0.20 +/- 0.04 ms [P = 0.01]); sensing thresholds (atrial 4.1 +/- 0.41 mV vs 4.0 +/- 4.2 mV [P = NS]; ventricular 9.7 +/- 0.72 vs 9.3 +/- 0.94 mV [P = NS]); and impedance (atrial 345 +/- 12 vs 370 +/- 120 O [P = 0.04]; ventricular 412 +/- 17 vs 458 +/- 190 O [P < 0.01]). One volt lead failed with exit block at approximately 6 weeks. The youngest (9 months to 5 years) and smallest (6.5-18.0 kg) ten patients have each shown by venography to have at least mild venous stenosis at the lead(s) insertion site; five patients demonstrated collateral formation around asymptomatic obstruction, with no thrombus formation. The Intermedics 438-10 ThinLine pacing lead has demonstrated good and stable early postimplant electrical parameters. Angiographic evaluation in our smaller patients has shown evidence for asymptomatic venous obstruction.

[Reopening of a persistent left superior vena cava in the early postoperative period following bidirectional cavopulmonary anastomosis--treatment by coil embolization]

Diagnosis of systemic venous drainage is mandatory for patients with congenital heart disease planned for cavopulmonary anastomosis or any Fontan-type palliation. Preexisting venous channels as the persistent left superior vena cava are common in cardiac anomalies and may lead to postoperative deterioration and cyanosis. We describe a 6 month old boy with a complex imbalanced atrioventricular septal defect who developed cyanosis in the very early postoperative period, following bidirectional cavopulmonary anastomosis. It was caused by ineffective lung perfusion due to a reopened persistent left superior vena cava with drainage to the coronary sinus.He underwent coil embolization of the persistent left superior vena cava with retrievable coils and cyanosis improved. Coil embolization is an effective alternative to secondary surgery, especially for hemodynamically compromised patients in the postoperative period.

Extracardiac total cavopulmonary connection via an atrial and pericardial tunnel

We performed extracardiac total cavopulmonary connection using only native tissue in two patients with complex heart disease. The extracardiac lateral tunnel was constructed from pedicled autologous pericardium and atrial wall During follow-up both patients remained in the New York Heart Association functional class I and demonstrated normal sinus rhythm. These modifications not only avoid the risk of potential postoperative complications due to artificial materials, but also allow growth of the conduit.

Right ventricular thrombosis early after bidirectional Glenn shunt

Thrombosis in the right ventricle occurred early after bidirectional superior cavopulmonary shunt in 2 patients with pulmonary atresia with intact ventricular septum and major right ventricular coronary artery communication, and perioperative brain infarction occurred in 1 patient. Clinicians should be aware of the hazards of this potentially lethal complication, and transfusion of platelets and fresh plasma should be minimized. Although the hemodynamic state is good, echocardiography should be performed frequently and strict anticoagulation should be started as early as possible.

'You didn't see them, but now you do!': use of balloon occlusion angiography in the identification of systemic venous anomalies before and after cavopulmonary procedures

We describe the importance of angiographic identification of collateral venous channels by balloon occlusion venography after bidirectional cavopulmonary connections. Use of the balloon occlusion technique is essential for identification of these vessels, as they can easily be missed by standard venous angiography, with possible clinical consequences for postoperative management.

Right ventricular diastolic function after repair of tetralogy of Fallot: its relationship to the insertion of a 'transannular' patch

Examined was the effect of surgical technique, particularly the insertion of a transannular patch, on right ventricular diastolic function, and the relationship of forward flow in the pulmonary arteries during late diastole to right ventricular diastolic function in patients with tetralogy of Fallot. Transtricuspid, superior caval venous and pulmonary arterial Doppler spectrals were obtained and compared between 44 patients who had been repaired with a transannular patch; 14 patients who had been repaired with muscular resection and/or pulmonary valvotomy; six who had been repaired with an infundubular patch; and 32 normal children. The velocities of forward flow during late diastole in the pulmonary arteries of normal children ranged from 19.8 to 29.4 cm s(-1) (mean 24.9 +/- 2.8 cm s(-1)) throughout the respiratory cycle. Restrictive right ventricular physiology, defined on the basis of increased forward flow in the pulmonary arteries during late diastole (> 30 cm s(-1)) was present in 25 (57%) of 44 patients with tetralogy of Fallot repaired using a transannular patch. Right ventricular volume was 50.1 +/- 23.7 cm3 in patients with a restrictive right ventricle and 64.9 +/- 21.4 cm3 in patients in whom the ventricle was non-restrictive (p < 0.03). QRS duration was 140 +/- 18 and 156 +/- 24 ms in patients with restrictive and non-restrictive right ventricular physiology respectively (p < 0.003). Restrictive physiology was not encountered in patients with tetralogy in whom the pulmonary valve had been preserved. It is concluded that right ventricular restriction is present in many patients with tetralogy of Fallot at mid-term follow-up subsequent to repair using a 'transannular' patch. Restriction is associated with smaller right ventricular size and less prolongation of the QRS complex.

Absence of the superior vena cava: difficulties for pacemaker implantation

Endocardial pacemaker electrode implantation can be difficult in patients with anomalous superior vena cava (SVC). Venography and CAT scan showed that the patient lacked SVC venous drainage and that systemic veins drained into the inferior vena cava through the azygos vein. A temporary stimulation electrode was placed by puncture of the femoral vein, permanent stimulation by venotomy of the epigastric vein, with the electrode inserted through the external iliac vein.

Bubble contrast echocardiography in detecting pulmonary arteriovenous shunting in children with univentricular heart after cavopulmonary anastomosis

OBJECTIVES

We sought to compare bubble contrast echocardiography and pulmonary angiography in detecting pulmonary arteriovenous malformation (PAVM) in children with cavopulmonary anastomosis (CPA), and to examine anatomic and physiologic variables associated with the development of PAVM.

BACKGROUND

Development of PAVM in patients with CPA may cause profound cyanosis. Pulmonary arteriovenous malformation has been traditionally diagnosed by pulmonary angiography with reported incidence of 20% to 25% in patients with CPA.

METHODS

Fourteen patients (age 1.1 to 12.6 years) with any forms of CPA and normal pulmonary venous drainage formed the study population. All patients underwent cardiac catheterization and pulmonary angiography. Bubble contrast echocardiographic studies were performed with injection of 10 ml of agitated saline solution into branch pulmonary arteries. Transthoracic echocardiograms using an apical view were performed to assess the appearance of bubble contrast in the systemic ventricles. We compared the results of pulmonary angiograms and contrast echocardiograms, and findings of contrast echocardiograms between lungs with hepatic venous blood flow and lungs without hepatic venous blood.

RESULTS

Ten of the 14 patients (71%) had positive contrast echocardiographic studies, compared with three (21%) detected by pulmonary angiograms (p = 0.01). No difference was found in pulmonary artery pressure, transpulmonary gradient or presence of heterotaxy syndrome between patients with positive contrast echocardiographic studies and patients with negative studies. However, patients with positive contrast echocardiograms tended to have lower oxygen saturation (81%) and higher hemoglobin (16.4 g/dl) compared with patients with negative studies (88% and 14.7 g/dl, p = 0.10 and p = 0.18 respectively). Patients with Glenn shunt or unidirectional Fontan had higher incidence of PAVM (10/11) compared with patients with classic or lateral tunnel Fontan (0/3, p = 0.01). All 12 lungs with no perfusion of hepatic venous blood had positive contrast echocardiographic studies. Lungs with no hepatic venous blood flow were more likely to develop PAVM compared with lungs with hepatic venous blood flow (12/12 and 3/16 respectively, p < 0.01).

CONCLUSIONS

Bubble contrast echocardiography is more sensitive in detecting PAVM compared with pulmonary angiography. The prevalence of PAVM in patients with CPA may be much higher than what had been reported previously. Lungs with no hepatic venous blood flow are more likely to develop PAVM than lungs with hepatic venous blood flow.

Trousseau's syndrome with brachiocephalic vein thrombosis in a patient with uterine carcinosarcoma. A case report

The authors treated a patient with the previously unreported occurrence of brachiocephalic vein and superior vena cava thrombosis in association with a distantly located cancer. A 71-year-old woman presented with swelling over the right side of the neck and abdominal distension. Physical examination revealed a huge mass, and computed tomography demonstrated thrombosis of the brachiocephalic vein and superior vena cava accompanied by jugular vein dilatation. No coagulation disorder was demonstrable. After anticoagulation and thrombolysis, hysterectomy was performed; microscopic examination of the specimen revealed uterine carcinosarcoma. Even though local tumor obstruction is a much more common cause of neck vein thrombosis, a distant occult cancer can present as this form of Trousseau's syndrome. In patients with otherwise unexplained neck vein thrombosis, examination not only of the head and neck but also of the abdomen and pelvis should be pursued.

Isolated connection of the right superior caval vein to the left atrium: non-invasive neonatal diagnosis

Isolated anomalous drainage of the right superior caval vein to the left atrium is a very rare cause of cyanosis in the newborn. Herein, the cross-sectional echocardiography and colour Doppler findings of this malformation are described.