Inferior Vena Cava Contrast Research Articles

Inferior vena cava contrast reflux grade is associated with a reduced cardiac index in acute pulmonary embolism

Background and AimsPatients with intermediate-risk pulmonary embolism (PE) commonly present with a significantly reduced cardiac index (CI). However, the identification of this more severe profile requires invasive hemodynamic monitoring. Whether inferior vena cava (IVC) contrast reflux, as a marker of worse right ventricular function, can predict invasive hemodynamics has not been explored. MethodsThis was a single-center retrospective study over a 3-year period of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization. CT pulmonary angiograms were reviewed, and contrast reflux was graded as no/minimal reflux (limited to the IVC) or substantial (opacification including hepatic veins) based on an established scale. ResultsSubstantial contrast reflux was present in 29 of 85 patients (34 %) and associated with a lower CI (1.8 ± 0.4 L/min/m2 v. 2.6 ± 1.0 L/min/m2, p < 0.001), higher pulmonary artery systolic pressure (53.2 ± 19.5 mmHg v. 44.0 ± 12.1 mmHg, p = 0.025), and worse right ventricular systolic function. An IVC contrast reflux grade > 3 was a significant predictor for a CI ≤2.2 L/min/m2 (OR: 22.5, 95 % CI: 4.8, 104.4, p < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for substantial contrast reflux for a CI ≤2.2 L/min/m2 were 62.6 %, 93.1 %, 94.6 %, and 56.2 %, respectively. These findings remained significant in a multivariable model and were similar when isolating for intermediate-risk patients (n = 72, 85 %). ConclusionsThe degree of contrast reflux is highly specific for a reduced cardiac index in PE even when isolating for intermediate-risk patients. Real-time prediction of a hemodynamic profile may have added value in the risk-stratification of PE.

Evaluation of Predictive Value of CT Pulmonary Angiography for Right Ventricular Failure in Patients with Pulmonary Embolism

Purpose: Right ventricle failure is a well-known complication following pulmonary thromboembolism. Although Computed Tomography Pulmonary Angiography (CTPA) findings are supposed to be a surrogate for patients’ outcome, investigations based on this issue is not still elucidated. Thus, in the current study, we assessed patients’ CTPA findings and compared the result with echocardiographic findings. Materials and Methods: A total of 36 patients with proven pulmonary thromboembolism were enrolled and a comparison was made between indices in CTPA (interventricular septal deviation to the right side, inferior vena cava contrast reflux, and right ventricle diameter to left ventricle diameter ratio) and echocardiographic findings for detecting right ventricular failure. Also, the reliability of the aforementioned indices was sought for predicting mortality. Results: No significant correlation was found between CTPA indices and echocardiographic findings. The highest sensitivity and positive predictive value in CT pulmonary angiography for detecting right ventricle dysfunction were revealed to be for Right Ventricle Diameter (RVD) / Left Ventricle Diameter (LVD) &gt; 1 (63.64%), abnormal septal deviation (75.00%), respectively. Conclusion: Our results revealed that CTPA indices can reliably predict the upcoming mortality risk. On the other hand, these indices were not well-correlated with echocardiographic findings.

Huge Aortic Aneurysm? Massive Fistula!

A 73 year old man presented to the emergency room with lumbar pain, dyspnoea, and oliguria. An abdominal tender pulsatile mass with a thrill and bilateral lower limb oedema were noted. Abdominal X ray revealed a giant calcified spherical mass (A; arrows). Computed tomography angiography showed a 14 cm infrarenal abdominal aortic aneurysm associated with inferior vena cava contrast filling during the arterial phase (B; arrow). Blood work revealed a serum creatinine of 5.2 mg/dL (basal 0.6 mg/dL) and N terminal pro B type natriuretic peptide of 25 000 pg/dL.

Prognostic Value of Reflux of Contrast into the Inferior Vena Cava and Hepatic Veins on CT Pulmonary Angiography in Patients of Pulmonary Embolism

A pulmonary embolism (PE) that obstructs pulmonary arterial blood flow is a medical emergency. Its early detection and appropriate management can be lifesaving. CT pulmonary angiography (CTPA) is currently in use as a standard tool for diagnosis of PE. This study was performed to determine the prognostic accuracy of contrast reflux into the inferior vena cava (IVC) and hepatic veins on CTPA in patients suffering from acute PE. Materials and Methods The study was composed of 285 patients between 15 to 85 years of age that had filling defects in pulmonary arteries on CTPA that were consistent with those of a pulmonary embolism. The extent of contrast reflux into the IVC and hepatic veins was determined on the basis of a Groves scale. The patients were followed for a period of 30 days. Results Of 285 total patients, 200 (70.17%) survived the post PE period of 30 days and were labeled as survivors. The other 85 (29.83%) patients did not survive the 30-day duration and were called non-survivors. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of IVC contrast reflux grading were 65.8%, 90%, 73.68%, 86.12 % and 82.8 % respectively. Conclusion We conclude that IVC contrast reflux grading assessed on helical CT is a beneficial tool for predicting prognosis in cases of acute PE.

Correlating computed tomography pulmonary angiography signs of right ventricular strain in pulmonary embolisms to clinical outcomes.

INTRODUCTION:Right ventricular strain (RVS) in pulmonary embolism (PE) can be used to stratify risk and direct intervention. The clinical significance of computed tomography pulmonary angiogram (CTPA)-derived radiologic signs of RVS, however, remains incompletely characterized. We retrospectively analyzed a cohort of persons with acute PE to determine which, if any, findings of RVS on CTPA correlate with clinical outcomes.METHODS:All patients with PE diagnosed on CTPA from March 2013 through February 2015 at Lyndon B. Johnson Hospital were identified. Their records were retrospectively reviewed to identify length of stay, intensive care unit (ICU) placement, hemodynamic failure, use of thrombolytics, vasopressor requirement, mechanical ventilation, and attributable mortality. Three radiologists, blinded to clinical outcomes, separately reviewed the cohort's CTPAs to identify signs of RVS – pulmonary trunk size, internal size of the right and left ventricles, paradoxical interventricular septal bowing, inferior vena cava (IVC) contrast reflux, and hepatic vein contrast reflux.RESULTS:In our cohort of 102 persons, 12 demonstrated hemodynamic failure, 13 required ICU placement, 3 received thrombolysis, and 5 had death attributable to PE. The greatest interobserver agreement among radiologists existed for the presence of increased pulmonary trunk size (0.76 kappa by %agreement) and hepatic vein contrast reflux (0.92 kappa by %agreement). A multiple regression analysis found that when 100% radiologist agreement existed, presence of paradoxical intravenous septal bowing predicted thrombolytic usage (P = 0.02), and the presence of IVC reflux predicted attributable mortality (P = 0.03).CONCLUSION:Only IVC contrast reflux was associated with increased mortality, and no other sign of RVS on CTPA correlated with clinical outcomes. This suggests that most signs of RVS on CTPA do not reliably predict PE severity. Therefore, RVS seen by CTPA should be used cautiously in weighing the decision to initiate thrombolytics.

Prediction of short term outcome of pulmonary embolism: Parameters at 16 multi-detector CT pulmonary angiography

PurposeTo evaluate the accuracy of computed tomography pulmonary angiography (CTPA) parameters, for predicting short-term mortality in patients with acute pulmonary embolism (PE). Materials and methodsThirty-two patients with proven PE had CT pulmonary angiography were included in the study. The clot burden using the Qanadli score (QS), and the right ventricular dysfunction (RVD) parameters were assessed on CT by calculating right ventricular/left ventricular (RV/LV) diameter ratios, interventricular septum abnormality, inferior vena cava contrast reflux, azygous vein and superior vena cava measures. Contrast density in pulmonary artery and descending aorta was evaluated for all patients. Patients were followed up for 30days and then classified as survivors or non survivors. ResultsThirty-two patients were included in the study, 23 (71.8%) of them were classified as survivors, and the other nine (28.1%) patients died within the first month (non survivors). There was a positive, but weak correlation between the Qanadli score and the short term mortality (P value=0.05). There was a statistically significant relationship between the RV/LV ratio and PE-related mortality, with a P value<0.001. Also, there was a good correlation between degree of IVC reflux and PE outcome (P<0.001). The PA/AO diameter ratio, SVC diameter and azygous vein diameter showed no statistically significant difference between survivors and non survivors. ConclusionsCTPA findings that may predict short term mortality are the high grades of inferior vena cava reflux, RV/LV diameter ratio more than 1.2, and clot burden >18 according to the Qanadli score and to a lesser degree the interventricular septum abnormality.

CT Signs of Right Ventricular Dysfunction: Prognostic Role in Acute Pulmonary Embolism

The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements, to predict adverse outcomes in patients with acute pulmonary embolism (PE). Three-dimensional ventricular volume measurements based on chest CT have become feasible for routine clinical application; however, their prognostic role in patients with acute PE has not been assessed. We evaluated 260 patients with acute PE for the following CT signs of RV dysfunction obtained on routine chest CT: abnormal position of the interventricular septum, inferior vena cava contrast reflux, right ventricle diameter (RVD) to left ventricle diameter (LVD) ratio on axial sections and 4-chamber (4-CH) views, and 3-dimensional right ventricle volume (RVV) to left ventricle volume (LVV) ratio. Comorbidities and fatal and nonfatal adverse outcomes according to the MAPPET-3 (Management Strategies and Prognosis in Pulmonary Embolism Trial-3) criteria within 30 days were recorded. Fifty-seven patients (21.9%) had adverse outcomes, including 20 patients (7.7%) who died within 30 days. An RVD(axial)/LVD(axial) ratio >1.0 was not predictive for adverse outcomes. On multivariate analysis (adjusting for comorbidities), abnormal position of the interventricular septum (hazard ratio [HR]: 2.07; p = 0.007), inferior vena cava contrast reflux (HR: 2.57; p = 0.001), RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 2.51; p = 0.009), and RVV/LVV ratio >1.2 (HR: 4.04; p < 0.001) were predictive of adverse outcomes, whereas RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 3.68; p = 0.039) and RVV/LVV ratio >1.2 (HR: 6.49; p = 0.005) were predictive of 30-day death. Three-dimensional ventricular volume measurement on chest CT is a predictor of early death in patients with acute PE, independent of clinical risk factors and comorbidities. Abnormal position of the interventricular septum, inferior vena cava contrast reflux, and RVD(4-CH)/LVD(4-CH) ratio are predictive of adverse outcomes, whereas RVD(axial)/LVD(axial) ratio >1.0 is not.

Does kyphoplasty reduce potential for extra-vertebral and intravascular polymethylmethacrylate leakage when compared with vertebroplasty?

Frank M. Phillips, MD, Thomas A. McNally, MD, Chicago, IL, USA; Isador H. Lieberman, MD, Cleveland, OH, USA; Eeric Truumees, MD, Troy, MI, USAIntroduction: Vertebroplasty involves injection of polymethylmethacrylate (PMMA) under high pressure into a fractured vertebral body in an attempt to restore stability and reduce pain. During vertebroplasty, local PMMA leakage is common, with postvertebroplasty computed tomography (CT) scans showing extravertebral cement in up to 65% of levels treated [1]. Clinically significant cases of epidural or foraminal PMMA leakage have been reported. In addition, during vertebroplasty, PMMA may enter the vasculature, and pulmonary embolism of PMMA has been reported. Kyphoplasty involves the inflation of a balloon tamp in a fractured vertebral body in an attempt to restore vertebral body height, while creating a cavity to be filled with PMMA. Proponents of this technique claim that the cavity created allows for low-pressure placement of thicker PMMA into the fractured vertebra thus reducing the risk of extravertebral PMMA leakage. This study tested the hypothesis that with kyphoplasty there is less potential for PMMA leakage and systemic exposure than with vertebroplasty.Methods: During 11 consecutive kyphoplasty procedures for osteopenic vertebral compression fractures, intravertebral contrast studies were performed. Seven thoracic and 4 lumbar-level fractures were studied. The mean patient age was 75 years, and the mean duration of fracture pain was 3.2 months. During the procedure, 5 cc of Omnipaque 180 were injected after positioning an 11-gauge trochar within the vertebral body (mimicking injection during vertebroplasty). Dynamic continuous fluoroscopic images (Siemans OEC) were obtained during contrast injection. The dye was then flushed with sterile saline. We then proceeded with the kyphoplasty procedure, and after bilateral balloon tamp inflation and tamp removal, contrast was injected into the cavity created (mimicking PMMA injection during kyphoplasty). Extravertebral leakage of contrast was scored based on extent of fill of the inferior vena cava (IVC), epidural vessels and direct extension of contrast beyond the walls of the vertebral body (0 to 6 total points). During kyphoplasty procedures, the authors had observed compaction of bone around the void created by the balloon tamp that might play a role in decreasing leakage of PMMA. In order to assess this, two human cadavers were treated with kyphoplasty procedures at multiple levels of the thoracolumbar spine. Spinal CT scans were performed, and the treated levels were evaluated for change in bony architecture within the vertebral body after balloon inflation and void creation with kyphoplasty.Results: With contrast injection at the vertebroplasty stage, immediate extravertebral/vascular spread of contrast was noted. With kyphoplasty, the injected contrast tended to fill the intravertebral cavity with occasional extravertebral spillage. The mean extravertebral contrast scores were 3.9 and 0.6 (p<.001) for vertebroplasty and kyphoplasty, respectively. In all 11 vertebroplasty studies, fill of the IVC was seen and was graded as “marked” in 9 of 11 studies. With kyphoplasty, IVC contrast was seen in 4 of 11 studies and was graded as “mild” in all 4. Epidural vessel fill was present in all 11 vertebroplasty studies and in 3 kyphoplasty studies. Direct extension of contrast through the vertebral walls was seen in 4 vertebroplasty and no kyphoplasty studies. CT scanning of the cadaver vertebra after kyphoplasty revealed a dense rim of compacted cancellous bone surrounding the cavity created by balloon inflation.Discussion: In this study, significantly less vascular fill and local leakage of contrast was seen after kyphoplasty when compared with vertebroplasty. The compacted rim of bone noted around the kyphoplasty cavity may act as a dam, reducing leakage of contrast. Of particular concern was the significant fill of the IVC and epidural vessels with contrast during vertebroplasty. Although extravertebral leakage of contrast may not correlate precisely with PMMA leakage, we believe that this study proposes a reasonable model for evaluating the relative safety of these procedures. In fact, PMMA monomer is soluble and may indeed have similar vascular fill to the contrast used in this study. We believe that the findings in this study have implications for PMMA extravasation and systemic monomer exposure for the two procedures.

Calcified thrombus in the right atrium: A rare complication of long-term parenteral nutrition in a child

A 5-year-old boy with short-bowel syndrome who receives home parenteral nutrition developed a calcified thrombus that involved the inferior vena cava (IVC) and the right atrium. Symptoms included 3 to 4 months of intermittent fever and 2 months of vague chest pain. Blood could not be aspirated from the IVC catheter and an IVC contrast study demonstrated the calcified thrombus. The intracardiac portion of the mass was removed surgically, but the IVC mass could not be completely excised. The boy developed a pericardial effusion 6 weeks after surgery. He was treated for this and 6 months after the initial surgery the patient was asymptomatic.

Total inferior vena cava thrombosis following coronary artery bypass surgery

A 44-yr-old male presented with abdominal and back pain following coronary bypass surgery (CABG). Total inferior vena cava (IVC) thrombosis was then documented by computed tomography as well as IVC contrast cineangiography. Furthermore, the patient developed multiple pulmonary emboli. This presentation with severe abdominal and back pain with lack of early peripheral edema without apparent hepatic or renal dysfunction and with extreme elevation of erythrocyte sedimentation rate seems rather unusual. To our knowledge, such massive IVC thrombosis has not been reported following CABG. Thrombolytic and anticoagulant therapy was utilized with good recovery.

Quantification of coronary artery bypass flow reserve in dogs using cine-computed tomography.

Routine coronary angiographic assessment of bypass graft patency does not allow quantification of bypass graft flow reserve. This study was designed to evaluate the use of cine-computed tomography (cine-CT) to determine relative bypass graft flow velocities and flow reserve. Saphenous vein grafts from the left innominate to the midleft circumflex coronary artery were placed in 5 dogs. The proximal portion of the left circumflex was then ligated. A 20-mHz Doppler probe to assess graft flow velocity, a cuff-type vascular occluder to provide variable graft occlusion, and an infusion line for selective drug administration were placed at the midgraft position. Electrocardiographically triggered scans were performed at levels of the aortic root and cardiac base following bolus inferior vena cava contrast administration. Continuous recordings of Doppler velocity and aortic pressure and intermittent measurements of cardiac output were obtained throughout the studies. Selective increases and decreases in coronary artery bypass graft flow velocity from control were performed using combinations of intragraft adenosine and/or variable graft occlusion. Simultaneous contrast clearance curves were generated from a region of interest in the ascending aorta and in the coronary artery bypass graft. Subsequent determinations of a parameter, delta PT (the time difference between peak opacification in the aorta and the bypass graft), were found to highly correlate with individual values of relative coronary bypass graft flow velocity (r = 0.74-0.97, n = 54). This study suggests that cine-computed tomography can be used to noninvasively quantify relative bypass graft flow velocities in individual dogs and eventually in patients.

Echocardiographic assessment of tricuspid regurgitation during ventricular demand pacing

Twenty patients from our pacemaker clinic population were assessed clinically and by saline contrast echocardiography (subxiphoid view) to determine the prevalence of tricuspid regurgitation (TR) and, if TR was present, its mechanism. The patients had no known TR before lead placement, a single transvenous right ventricular pacing lead present more than 6 months (mean 52, range 7 to 138), ventricular demand pacing alternating with sinus rhythm and rate programmability. Each patient was studied in sinus rhythm and during ventricular pacing. Using the criterion of inferior vena cava (IVC) contrast reflux during ventricular systole to diagnose TR, no patient had evidence of TR in sinus rhythm, consistent with clinical examination. During ventricular demand pacing, jugular venous pulse cannon A waves developed in 10 patients, and 18 patients (including these 10) had IVC contrast reflux during ventricular systole. Analysis of the timing of IVC reflux revealed its close temporal relation to the timing of atrial systole rather than a fixed timing during ventricular systole. This reflux occurred with loss of normal atrioventricular (AV) synchrony and the underlying mechanism in all cases was shown to be right atrial contraction against a closed tricuspid valve. Two patients who did not have such a pattern with pacing maintained normal AV synchrony. These observations indicate that: TR is an uncommon accompaniment of ventricular demand pacing; the jugular venous pulse and IVC echocardiographic contrast patterns during ventricular demand pacing simulate TR when AV asynchrony [corrected] occurs; and the IVC contrast pattern of pacing induced AV asynchrony [corrected] is best termed the cannon A wave synchronous pattern.

Spontaneous echographic contrast in the inferior vena cava

The inferior vena cava was examined for spontaneous contrast by two-dimensional echocardiography in 106 consecutive patients. Images of the inferior vena cava in six patients were inadequate and were excluded from further analysis. The study population included 100 patients, 41 men and 59 women. Twenty-three patients had an intravenous line or heparin lock in place at the time of the echocardiographic examination. Ten patients had definite contrast in the inferior vena cava, seven had equivocal contrast, and 83 had no contrast. The three groups did not differ significantly with respect to sex distribution, age, associated diagnoses, or inferior vena cava dimension. We concluded that spontaneous inferior vena cava contrast is commonly seen in adults, both normal subjects and patients with various types of heart disease. There was no specific category of heart disease that predominated in patients with spontaneous inferior vena cava contrast. Although it may be associated with impairment to filling of the right side of the heart and may resolve when normal right heart hemodynamics are restored, spontaneous inferior vena cava contrast is usually a finding with little clinical import. Several possible etiologic factors include microbubbles and aggregates of formed blood elements. Spontaneous inferior vena cava contrast is seen more frequently with a higher frequency imaging system.

Assessment of right heart hemodynamics by contrast echocardiography

We studied inferior vena cava contrast echocardiography after upper extremity injection in 70 subjects; 59 were patients and 11 were controls. Inferior vena cava contrast was seen in 35 patients and in 1 control. “A-wave synchronous pattern” of contrast apperance was observed in 13 patients and 1 normal subject. The pattern did not depend upon the height of right atrial a-wave pressure or the right ventricular (RV) end-diastolic pressure, but was related to the respiratory cycle. A “random pattern” of contrast appearance was seen in 3 patients with cardiac arrhythmia and normal right heart hemodynamics. One patient with ventricular premature beats showed both “a-wave synchronous” and “random” patterns. A “v-wave synchronous pattern” was found in 20 patients, of which 17 had tricuspid regurgitation. Persistence of inferior vena cava contrast correlated with the height of right atrial v-wave ( r = 0.87, p < 0.001) and the severity of tricuspid regurgitation estimated from RV cineangiography. The differences of RV systolic pressure and echocardiographic right ventricular dimension between the study patients with and without tricuspid regurgitation did not reach statistical significance. We conclude: (1) the echocardiographic RV dimension and the degree of RV hypertension are not predictors for the presence of tricuspid regurgitation and its severity; (2) inferior vena cava contrast echocardiography may be used to estimate the severity of tricuspid regurgitation.

Spontaneous contrast in the inferior vena cava in a patient with constrictive pericarditis

A 66 year old black man was examined because of fatigue and progressive right heart failure. A striking finding on his echocardiogram was intense and slow-moving contrast in the inferior vena cava. Cardiac catheterization revealed constrictive pericarditis, and pericardiectomy was performed. Postoperatively, spontaneous contrast was no longer present. This case helps explain the origin of spontaneous inferior vena cava contrast.

Diagnosing tricuspid regurgitation by direct imaging of the regurgitant flow in the right atrium using contrast echocardiography

To determine whether tricuspid regurgitation (TR) can be diagnosed by direct imaging of regurgitant flow in the right atrium (RA) using contrast echocardiography, echocardiography was performed in 35 patients using peripheral intravenous injections of 5% dextrose solution. Fifteen patients had TR judged by v-wave synchronous contrast appearance on the inferior vena cava echogram (a previously validated method for diagnosing TR), 5 of whom had clinically obvious TR. Twenty patients had no TR on inferior vena cava contrast echocardiography, 9 of whom were normal volunteers. On subsequent blind review, 13 of the 15 patients with TR were correctly identified on the basis of the regurgitant contrast flow just posterior to the tricuspid valve in the RA. Of the 20 without TR, 19 were correctly identified and there was 1 false-positive result. Using different criteria for the diagnosis (insisting on imaging of flow across the tricuspid valve in systole), another blinded observer correctly diagnosed only 8 of the 15 patients as having TR, but had no false-positive results. To avoid false-positive results, it is important to realize that there are 2 regions where retrograde flow can normally be seen in the RA: (1) briefly at the onset of systole coincident with tricuspid valve closure, and (2) in the posterior RA, as distinct from the anterior RA area just behind the tricuspid valve where TR is diagnosed in this study. It is concluded that direct imaging of regurgitant flow in the RA just posterior to the tricuspid valve is an accurate method for diagnosing or excluding TR and is ideally complementary to inferior vena cava contrast echocardiography in making this diagnosis.

Detection of atrial septal defect with left-to-right shunt by inferior vena cava contrast echocardiography.

Contrast echocardiography was used before cardiac catheterisation in 37 patients with atrial septal defect and a left-to-right shunt and in 18 patients with a raised right atrial and ventricular pressure to assess the contrast echo effect in the inferior vena cava. Using two dimensional contrast apical echocardiography we found a negative contrast echo effect within the right atrium in many but not all patients with atrial defect. Contrast echoes entering the inferior vena cava during presystole or early to mid-diastole were detected in patients with heart disease causing raised right atrial and ventricular pressures and also in all patients with atrial septal defect. No contrast echo effect in the inferior vena cava was detected in 10 normal subjects. The sensitivity of this contrast pattern in the inferior vena cava in diagnosing atrial septal defect was 100%. When other conditions causing raised right atrial pressure were excluded, the specificity and predictive accuracy were 100% for both. The presystolic contrast echo effect in the inferior vena cava, semiquantitatively graded, correlated with the size of the shunt determined by oximetry. In 20 patients re-examined after the surgical correction of the atrial septal defect, no presystolic contrast echo effect was detected in the inferior vena cava. Contrast echocardiography of the inferior vena cava is a valuable and reliable method for diagnosing atrial septal defect with left-to-right shunt.

Inferior vena cava echocardiography.

The inferior vena cava can be imaged during echocardiography from the subcostal transducer position as an echo-free space at a depth ranging from 6 to 15 cm from the abdominal wall. The normal inferior vena cava M-mode echocardiogram has a "a" and "v" pulsation pattern similar to that seen in the jugular venous tracing and exhibits prominent cyclic respiratory changes. Since right atrial activity can be seen as a pulsation on the M-mode inferior vena cava tracing, specific patterns can be observed during cardiac arrhythmias. In right heart failure the inferior vena cava is usually distended, with diminished respiratory collapse. In tricuspid regurgitation, contrast injected into an arm appears in the inferior vena cava during the "v" wave. "A-wave synchronous" inferior vena cava contrast or a contrast appearance unrelated to the cardiac cycle, frequently with deep inspiration, does not suggest tricuspid regurgitation.

Inferior Vena Cava Obstruction

Inferior vena cava (IVC) obstruction, manifested as bilateral, asymmetric, asymptomatic, pitting leg edema and scrotal swelling, developed in two patients with advanced prostatic cancer. Radiological confirmation was obtained in both patients. Inferior vena cava obstruction was the initial manifestation of disease progression and occurred in patients who were ambulatory without evidence of congestive heart failure or concurrent estrogen therapy. Early IVC contrast study is indicated in similar patients in whom asymptomatic bilateral leg edema of obscure origin develops.