Narrowing of the superior vena cava-right atrium junction during radiofrequency catheter ablation for inappropriate sinus tachycardia: analysis with intracardiac echocardiography

OBJECTIVES

The study explored the potential for tissue swelling and venous occlusion during radiofrequency (RF) catheter ablation procedures using intracardiac echocardiography (ICE).

BACKGROUND

Transient superior vena cava occlusion has been reported following catheter ablation procedures for inappropriate sinus tachycardia (IST). Presumably, venous occlusion could occur owing to thrombus formation or tissue swelling with resultant narrowing of the superior vena cava-right atrial (SVC-RA) junction.

METHODS

Intracardiac echocardiography (9 MHz) was used to guide ablation catheter position and for continuous monitoring during RF application in 13 ablation procedures in 10 patients with IST. The SVC-RA junction was measured prior to and following ablation. Successful ablation was marked by abrupt reduction in the sinus rate and a change to a superiorly directed p-wave axis.

RESULTS

Eleven of 13 procedures were successful, requiring 29 +/- 20 RF lesions. Prior to the delivery of RF lesions, the SVC-RA junction measured 16.4 +/- 2.9 mm. With RF delivery, local and circumferential swelling was observed, causing progressive reduction in the diameter of the SVC-RA junction to 12.6 +/- 3.3 mm (24% reduction, p = 0.0001). A reduction in SVC-RA orifice diameter of > or = 30% compared to baseline was observed in five patients.

CONCLUSIONS

The delivery of multiple RF ablation lesions, often necessary for cure of IST, can cause considerable atrial swelling and resultant narrowing of the SVC-RA junction. Smaller venous structures, such as the coronary sinus and the pulmonary veins, would also be expected to be vulnerable to this complication. Thus, ICE imaging may be helpful in preventing excessive tissue swelling leading to venous occlusion during catheter ablation procedures.

Both atrial resection and superior vena cava replacement in sleeve pneumonectomy for advanced lung cancer

Extended sleeve pneumonectomy including removal of the superior vena cava, right atrium and parts of left atrium on cardiopulmonary bypass was successfully performed in a 40-year-old man. The tumour was histologically proven a T4 N1 stage with margins free from tumour. Adjuvant radiochemotherapy was administered postoperatively on an outpatient base. The patient did well for 7 months then he died from myocardial infarction due to metastatic infiltration of the right coronary artery. Other metastatic deposits were not found at autopsy. More data from extended pulmonary resections are required to demonstrate a benefit.

Left mediastinal central line malposition--a case report

Central venous line malpositioning in the left mediastinum is a rare event. A case of left superior intercostal vein central venous line placement is reported. Chest radiographs, especially lateral views and contrast studies, are useful for position evaluation. Catheter removal is prudent although the purpose of the catheter and the symptomatology can dictate further management of the malpositioned catheter.

[The persistence of the left vena cava superior and the absence of the right vena cava superior: the implications in the implantation of a definitive pacemaker]

Persistent left superior vena cava and associated absence of the right superior vena cava is exceedingly rare. The authors present a case, diagnosed when a DDD pacemaker system was being implanted, and point out its rarity, possibility of diagnosis by non invasive methods and technical implications in transvenous electrode implantation.

Placement of a pulmonary artery catheter via a previously unrecognized persistent left superior vena cava

This case report describes a patient with persistent left superior vena cava (LSVC) as discovered by difficult placement of a pulmonary artery catheter via the left subclavian vein. After positioning in wedge position, chest x-ray showed a catheter route suggestive of persistent LSVC. Since this abnormality may yield potential clinical complications, this possibility should be considered in every difficult central venous access.

Absence of the azygos vein associated with double superior vena cava--a case report

A rare case of absence of the azygos vein associated with double superior vena cava is presented. Imaging findings on plain chest film and on contrast-enhanced computed tomography are described, and the embryology of azygos and hemiazygos veins is reviewed.

Acute upper extremity deep venous thrombosis: safety and effectiveness of superior vena caval filters

PURPOSE

To evaluate the safety and effectiveness of percutaneous filter placement in the superior vena cava for prevention of pulmonary embolism (PE) due to acute upper extremity deep venous thrombosis (DVT) in patients with contraindications to or unsuccessful anticoagulation.

MATERIALS AND METHODS

Forty-one patients with acute upper extremity DVT and contraindications to or unsuccessful anticoagulation underwent percutaneous placement of a superior vena caval filter for prevention of PE. Four types of filters were used. Follow-up chest radiographs were used to detect filter migration, dislodgment, and fracture. Placements of central venous and Swan-Ganz catheters after filter insertion were recorded. Patients were followed up clinically for evidence of superior vena cava syndrome and PE. Kaplan-Meier survival rates were determined. Follow-up was 1 day to 221 weeks.

RESULTS

No complications such as filter migration, dislodgment, or fracture occurred (median follow-up, 12 weeks). No patients developed clinical evidence of PE due to upper extremity thrombosis or superior vena cava syndrome (median follow-up, 15 weeks). Catheters were placed subsequent to filter placement in 23 patients (56%) without complication.

CONCLUSION

Percutaneous filter placement in the superior vena cava is a safe and effective method for preventing symptomatic PE due to acute upper extremity DVT in patients in whom therapeutic anticoagulation has failed or is contraindicated.

[Color Doppler flow imaging study on the changes of collateral circulation between portal-superior vena cava and azygos vein before and after endoscopic ligation of the esophageal varix]

Color Doppler flow imaging (CDFI) was performed in 35 patients with portal hypertension and esophageal varix. Thirty subjects were served as control. After esophageal variceal ligation, CDFI observed that the portal-superior vena cava collateral veins were partialy blocked. The esophageal varices disappeared. The esophageal wall thinned. Diameter of left gastric vein enlarged and blood flow velocity decreased. Azygos diameter was reduced and blood flow velocity was decreased. Although diameter of portal vein was not changed, the blood flow velocity slightly increased. The results suggest that ligation treatment can have the tendency to increase blood flow of liver and stomach, which might aggravate gastric mucosal lesion.

Comparison of mitral inflow and superior vena cava Doppler velocities in chronic obstructive pulmonary disease and constrictive pericarditis

OBJECTIVE

This study was conducted to determine whether Doppler recording of superior vena cava flow velocities can differentiate chronic obstructive pulmonary disease from constrictive pericarditis in patients with a respiratory variation of > or = 25% in mitral inflow E velocity.

BACKGROUND

Although respiratory variation (> or = 25%) in mitral E velocity is the main diagnostic criterion for constrictive pericarditis by Doppler echocardiography, it can also be present in chronic obstructive pulmonary disease. Because the respiratory variation is due to increased change in intrathoracic pressure with respiration in chronic obstructive pulmonary disease, and to dissociation of intrathoracic-intracardiac pressure changes in constriction, it was hypothesized that the Doppler flow velocity pattern in the superior vena cava (affected by intrathoracic pressure) would be different in these two conditions.

METHODS

Pulsed-wave Doppler recording of mitral and superior vena cava flow velocities in 20 patients with chronic obstructive pulmonary disease who had > or = 25% respiratory variation in mitral E-wave velocity were compared with those of 20 patients who had surgically proved constrictive pericarditis.

RESULTS

Constrictive pericarditis and chronic obstructive pulmonary disease had similar respiratory variation in mitral E velocity (41% versus 46%). In the latter, the E/A ratio was lower (inspiration, 0.8+/-0.3 versus 1.5+/-0.7 [p < 0.0001]; expiration, 1.0+/-0.3 vs. 1.9+/-0.7 [p < 0.0001]) and deceleration time longer (inspiration, 198+/-53 ms versus 137+/-32 ms; expiration, 225+/-43 ms vs. 161+/-33 ms [p < 0.0001]). Inspiratory superior vena cava systolic forward flow velocity was significantly higher in chronic obstructive pulmonary disease (72.9+/-22.6 cm/s versus 36.2+/-9.3 cm/s, p < 0.0001), while expiratory systolic forward flow velocity was similar. Hence, there was a significantly greater respiratory variation in superior vena cava systolic forward flow velocity in chronic obstructive pulmonary disease without an overlap with constrictive pericarditis (39.5+/-18.8 cm/s vs. 4.2+/-3.4 cm/s, p < 0.0001).

CONCLUSIONS

Despite a similar respiratory variation in mitral E wave velocities, mitral inflow variables in chronic obstructive pulmonary disease are less restrictive compared with those in constrictive pericarditis. More importantly, patients with chronic obstructive pulmonary disease show a marked increase in inspiratory superior vena cava systolic forward flow velocity, which is not seen in patients with constrictive pericarditis.

[Usefulness of ultrasonography in the diagnosis of portal hypertension]

Portal hypertension syndrome is a common evolutive complication of several hepatic and extrahepatic diseases, being liver cirrhosis responsible for more than 80% of cases. When diagnosed it has prognostic value because of the high incidence of hemorrhagic, metabolic and infectious complications that these patients may develop. Clinical suspicion must be confirmed by objective complementary studies that provide information about the etiology and severity of the disease. In this review article we describe the contribution of ultrasonography in the evaluation of patients with portal hypertension as an objective diagnostic method and the usefulness of doppler ultrasound in the non-invasive hemodynamic assessment of the splanchnic and portal circulation.

Optimization of contrast delivery for pulmonary CT angiography

Pulmonary CT angiography is becoming an increasingly important tool for diagnosing Pulmonary Emboli. An important aspect in optimizing the quality of these studies is achieving maximum levels of enhancement of the pulmonary arteries. In this study we reviewed the current literature to see if there was any standardization of protocols to achieve this purpose, and found that there was no consensus. Using well described techniques for determining blood flow we were able to demonstrate the proper time delays to achieve the highest levels of enhancement. As contrast flows into the pulmonary arteries, the degree of enhancement rapidly reaches a plateau phase. This is then followed by a recirculation phase where enhancement starts to increase again. The proper time delays between scan time and start of contrast infusion should allow for enhancement to be within this recirculation phase. An experimental model was developed to demonstrate the principles.

Catheter-induced thrombus in the superior vena cava diagnosed by transesophageal echocardiography

BACKGROUND

To present the role of transesophageal echocardiography (TEE) in the diagnosis and management of catheter-related superior vena cava thrombosis.

CASE HISTORY

A 42-year-old woman with severe Crohn's disease presented with septic shock and pulmonary embolism three weeks after emergency laparotomy and ileocolic resection for small-bowel perforation with peritonitis. Cardiopulmonary evaluation with ECG, pulmonary artery catheter and TEE demonstrated no evidence of acute myocardial ischemia or ventricular dysfunction; hemodynamic indices were consistent with severe sepsis. TEE revealed a large sheathing thrombus surrounding a central venous catheter used for parenteral nutrition. A spiral CT scan of the chest confirmed multiple peripheral pulmonary emboli. Treatment consisted of systemic anticoagulation and antibiotics. To avoid further pulmonary embolism, the central venous catheter was not removed until six days later under TEE monitoring, which revealed that the thrombus was firmly adherent to the superior vena cava. The patient made an uneventful recovery and was discharged from hospital on long-term anticoagulant therapy.

CONCLUSION

In a case of catheter-induced superior vena cava thrombosis with septicemia and pulmonary embolism, bedside TEE was very helpful to make the correct diagnosis early, assess thrombus size during anticoagulation, and monitor cardiac performance and thrombus disposition during central venous catheter removal.

Transcatheter closure of an anomalous venous connection by a novel method

Left superior vena cavae draining to the left atrium have traditionally been treated with surgical ligation. Advances in cardiac catheterization have made transcatheter closure a viable alternative to surgery. We report on an innovative method using a Greenfield filter and Gianturco coils for closure of a persistent left superior vena cava.

Anomalous insertion of the superior or the inferior vena cava into the right atrium

Three cases with anomalous insertion of the superior or inferior vena cava into the right atrium are presented. One case was a 25-year-old healthy man with anomalous low insertion of the right superior vena cava into the right atrium. The remaining two cases were infants with complex cardiac anomalies showing anomalous high insertion of the inferior vena cava into the right atrium. The congenital anomalies of the connection between the superior and the inferior vena cava and the right atrium are rare. Angiographic and computed tomographic findings of these anomalies were reported.

Aortic valve stenosis causing a left-to-right shunt in persistent left superior vena cava communicating with the left atrium

This study demonstrated a rare anomaly of a persistent left superior vena cava draining into the left atrium in a patient with developing left-to-right shunt caused by bicuspid aortic stenosis. The venous system, including the coronary sinus, was otherwise normal. We believe that, in this anatomic situation, a marked increase in left ventricular impedance caused a moderate left-to-right shunt from the left atrium into the left innominate vein. At operation, the aortic valve was replaced with a mechanical prosthesis and the anomalous vein was ligated. The convalescence was uneventful.

[The significance of magnetic resonance venography in the pre-interventional clarification of a malignant superior venous obstruction]

PURPOSE

Comparison between peripheral digital subtraction venography (DSV) and magnetic resonance venography (MRV) in planning for stent placement in malignant superior central venous obstruction.

METHOD

19 patients with malignant central vein obstruction were examined by DSV (n = 19) and MRV (n = 19). For each patient 12 segment-vessel evaluation was performed to review for obstruction and then compared with the gold standard--selective catheter phlebography--performed at the time of stent insertion. Additionally, tumor extension and collateral venous outflow was noted.

RESULTS

Sensitivity, specificity, and accuracy amounted to 92%, 96%, and 95% for DSV and 98%, 100%, and 100%, respectively for MRV. The McNemar test revealed a significance between MR venography and DSV.

CONCLUSIONS

With regard to planning of stent placement, a more exact evaluation was possible with MR venography than with DSV. Thus, MR venography can replace DSV as the method of choice for clarifying malignant superior central vein obstructions prior to stent placement.

Discovery of left-sided superior vena cava during central venous catheterization

We describe a 3-yr-old patient in whom a central venous catheter (CVC) was inadvertently inserted into a persistent left superior vena cava (PLSVC). This congenital anomaly was diagnosed using transthoracic echocardiography. The aetiology and the implications for the anaesthetist are discussed.

Mediastinal venous anomalies: potential pitfalls in cancer diagnosis

Mediastinal venous anomalies encountered during CT assessments of cancer patients are often unsuspected and may be misinterpreted, particularly in the presence of intrathoracic disease. Errors in diagnosis result from a lack of intravenous contrast, concomitant mediastinal lymphadenopathy and primary intrathoracic tumour. The small calibre of vessels, previous mediastinal surgery and poor mediastinal planes are other confounding factors. An awareness of the anatomical features and optimal scanning technique are required to avoid misinterpretation.

A case of Behçet's disease with superior and inferior vena caval occlusion

Behçet's disease is a chronic multisystemic disorder involving many organs and characterized by recurrent oral and genital ulcers and relapsing iritis. A case of BD with large vein thrombosis involving superior and inferior vena cava is presented. Large vein thrombosis in BD is not commonly developed and most commonly observed in the inferior or superior vena cava. A review of the literature emphasizes the rarity of the combined superior and inferior vena caval occlusion. Existence of extensive large vein occlusion in BD is associated with limited therapy and poor prognosis.