Internal Jugular Venous Pressure Research Articles

Jugular Venous Pressure and Kussmaul's Sign as Predictors of Outcome in Heart Failure.

Simplifying the estimation of internal jugular venous pressure (JVP) as visible or not visible above the right clavicle in the sitting position has attracted attention for risk assessment in patients with heart failure (HF). It remains unclear whether this simple assessment, combined with its inspiration response known as Kussmaul's sign, is useful in patients with HF who vary in features such as HF with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF).This study consisted of 246 patients who were admitted for the management of HF. JVP was assessed before discharge and considered high if visible at rest. The inspiration response was also examined. The primary outcome was a composite of all-cause death and hospitalization for worsening HF.One year after discharge, primary outcome events occurred in 91 patients (37%). The incidence of primary outcome was higher in patients with a high JVP at rest (odds ratio, 5.06; 95% confidence interval, 2.31-11.1; P = 0.0001) or with inspiration (odds ratio, 5.93; 95% confidence interval, 2.14-16.4; P < 0.01) than in patients without high JVP conditions. These findings were similarly observed among patients with HFrEF and HFpEF (odds ratios, 3.53 and 6.76; 95% confidence intervals, 1.68-8.68 and 2.19-15.5; P = 0.01 and < 0.01, respectively) and in subgroup analysis stratified by baseline characteristics of the patients.A high JVP at rest and with inspiration as assessed by this simple, practical method may be useful for risk assessment in patients with HF, independent of baseline characteristics.

Correlation between Ultrasound Measurements of Internal Jugular Venous Diameter and Central Venous Pressure Measurements as a Follow up Tool in Severe Sepsis

Correlation between Ultrasound Measurements of Internal Jugular Venous Diameter and Central Venous Pressure Measurements as a Follow up Tool in Severe Sepsis

Spectral characteristics of the internal jugular vein and central venous pressure pulses: a proof of concept study

In this proof-of-concept study the impact of central venous pressure (CVP) on internal jugular veins cross-sectional area (CSA) and blood flow time-average velocity (TAV) was evaluated in eight subjects, with the aim of understanding the drivers of the jugular venous pulse. CVP was measured using a central venous catheter while CSA variation and TAV along a cardiac cycle were acquired using ultrasound. Analysis of CVP, CSA and TAV time-series signals revealed TAV and CSA to lag behind CVP by on average 0.129 s and 0.138 s, with an inverse correlation between CSA and TAV (r= –0.316). The respective autocorrelation signals were strongly correlated (mean r=0.729-0.764), with mean CSA periodicity being 1.062 Hz. Fourier analysis revealed the frequency spectrums of CVP, TAV and CSA signals to be dominated by frequencies at approximately 1 and 2 Hz, with those &gt;1 Hz greatly attenuated in the CSA signal. Because the autocorrelograms and periodograms of the respective signals were aligned and dominated by the same underlying frequencies, this suggested that they are more easily interpreted in the frequency domain rather than the time domain.

Correlation of Central with Jugular and Upper-limb Venous Pressure Measurements.

Correlation data of different external reference points and methods used to measure venous pressures are scarce in the literature. We correlated central venous pressure with jugular venous pressure measured from sternal angle and with jugular and upper-limb venous pressures from zero level corresponding to mid-right-atrium level. A hospital-based observational study in the medical and surgical intensive care units was conducted for period of one year. Central venous pressure was measured from right fourth intercostal space in mid-axillary line and jugular venous pressure from sternal angle and jugular and upper-limb venous pressures from horizontal plane through the midpoint of anteroposterior line from anterior end of right fourth intercostal space to back. We measured central venous pressure by central venous cannulation and jugular and upper-limb venous pressures clinically by JVP Meter®. Upper-limb venous pressure was indicated by collapse of visible veins in dorsum of hands as the arm was slowly raised from dependent position. Correlation coefficient (r) values were 0.61 between central venous pressure and jugular venous pressure from zero level, 0.48 between central venous pressure and jugular venous pressure from sternal angle, and 0.31 between central and upper-limb venous pressures; and 0.67 and 0.50 between central venous pressure measured from right internal jugular vein and jugular venous pressure from zero level and sternal angle respectively and 0.52 and 0.44 between central venous pressure from right sub-clavian vein and jugular venous pressure from zero level and sternal angle respectively. Different correlation values indicate the need to have future investigations and consensus on the common external reference point and methods to measure venous pressures.

Technical note for post processing of jugular venous pulse, central venous pressure and velocity trace

In this paper an original reasoning about the post processing elaboration of medical studies is presented. The aim is to suggest a method to extrapolate numerical information from clinical images. The here described elaboration is referred to ultrasound examination of internal jugular veins and central venous pressure (CVP) measures. Firstly, the operator has to collect clinical images following precise indications, then specific techniques are applied to analyze the stored data and extrapolate quantifiable measures. Analyzing the studies with ImageJ software, jugular venous pulse, velocity, CVP and electrocardiogram traces can be drown in detail. Then, significant details can be highlighted using Matlab software. Finally, using R software, the traces can be cropped, aligned and synchronized together. The obtained results allow the operator to compare different kinds of traces of the same subject, or the same type of traces between a particular group of subjects. Before using these contents, everyone is invited to verify the accuracy of assumptions, calculations and conclusions.

Association of Exercise and Swimming Goggles With Modulation of Cerebro-ocular Hemodynamics and Pressures in a Model of Spaceflight-Associated Neuro-ocular Syndrome

Astronauts on International Space Station missions demonstrate adverse neuro-ocular changes. Reversing a negative translaminar pressure gradient (TLPG) by modulating cerebral blood flow, decreasing intracranial pressure, or increasing intraocular pressure (IOP) has been proposed as potential intervention for spaceflight-associated neuro-ocular syndrome (SANS). To examine whether exercise (resistance, moderate-intensity aerobic, and high-intensity aerobic) or artificially increasing IOP is associated with modulated cerebro-ocular hemodynamic and pressure changes during head-down tilt (HDT), an analogue of spaceflight, in healthy adults. A single-center investigation was conducted at Johnson Space Center, Houston, Texas, from January 1, 2014, to December 31, 2016, in 20 healthy men. On 3 separate days, participants rested supine, were tilted to -15° HDT, and then completed 1 of 3 experimental exercise conditions (moderate-intensity aerobic, resistance, or high-intensity interval aerobic). A subset of 10 participants wore swimming goggles on all days. Applanation rebound tonometry was used to noninvasively assess IOP, and compression sonography was used to assess internal jugular venous pressure (IJVP). Estimated TLPG was calculated as the difference between IOP and IJVP. Cerebral inflow and outflow were measured in extracranial arteries using color-coded duplex ultrasonography. Twenty men participated in the study (mean [SD] age, 36 [9] years). Compared with supine IOP (mean [SD], 19.3 [3.7] mm Hg), IJVP (mean [SD], 21.4 [6.0] mm Hg), and estimated TLPG (mean [SD], -2.1 [7.0] mm Hg), -15° HDT was associated with increased IOP (mean difference, 2.3 mm Hg; 95% CI, 1.4-3.3 mm Hg; P < .001) and IJVP (mean difference, 10.5 mm Hg; 95% CI, 8.9-12.2 mm Hg; P < .001) and with decreased TLPG (mean difference, -8.2 mm Hg; 95% CI, -10.1 to -6.3 mm Hg; P < .001). Exercise (regardless of modality) at -15° HDT was associated with decreased IOP (mean difference, -1.6 mm Hg; 95% CI, -2.6 to -0.6 mm Hg; P = .002) and TLPG (mean difference, -3.5 mm Hg; 95% CI, -6.2 to -0.7 mm Hg; P = .01) compared with rest. Both IOP (mean difference, 2.9 mm Hg; 95% CI, 0.7-5.1 mm Hg; P = .01) and TLPG (mean difference, 5.1 mm Hg; 95% CI, 0.8-9.4 mm Hg; P = .02) were higher in participants who wore swimming goggles compared with those not wearing goggles. In this study, exercise was associated with decreased IOP and estimated translaminar pressure gradient in a spaceflight analogue of HDT. The addition of swimming goggles was associated with increased IOP and TLPG in HDT. Further evaluation in spaceflight may be warranted to determine whether modestly increasing IOP is an effective SANS countermeasure.

Influence of lung volume on the interaction between cardiac output and cerebrovascular regulation during extreme apnoea

What is the central question of this study? Does the reduction in cardiac output observed during extreme voluntary apnoea, secondary to high lung volume, result in a reduction in cerebral blood flow, perfusion pressure and oxygen delivery in a group of elite free divers? What is the main finding and its importance? High lung volumes reduce cardiac output and ventricular filling during extreme apnoea, but changes in cerebral blood flow are observed only transiently during the early stages of apnoea. This reveals that whilst cardiac output is important in regulating cerebral haemodynamics, the role of mean arterial pressure in restoring cerebral perfusion pressure is of greater significance to the regulation of cerebral blood flow. We investigated the role of lung volume-induced changes in cardiac output (Q̇) on cerebrovascular regulation during prolonged apnoea. Fifteen elite apnoea divers (one female; 185±7cm, 82±12kg, 29±7years old) attended the laboratory on two separate occasions and completed maximal breath-holds at total lung capacity (TLC) and functional residual capacity (FRC) to elicit disparate cardiovascular responses. Mean arterial pressure (MAP), internal jugular venous pressure and arterial blood gases were measured via cannulation. Global cerebral blood flow was quantified by ultrasound and cardiac output was quantified by via photoplethysmography. At FRC, stroke volume and Q̇ did not change from baseline (P>0.05). In contrast, during the TLC trial stroke volume and Q̇ were decreased until 80 and 40% of apnoea, respectively (P<0.05). During the TLC trial, global cerebral blood flow was significantly lower at 20%, but subsequently increased so that cerebral oxygen delivery was comparable to that during the FRC trial. Internal jugular venous pressure was significantly higher throughout the TLC trial in comparison to FRC. The MAP increased progressively in both trials but to a greater extent at TLC, resulting in a comparable cerebral perfusion pressure between trials by the end of apnoea. In summary, although lung volume has a profound effect on Q̇ during prolonged breath-holding, these changes do not translate to the cerebrovasculature owing to the greater sensitivity of cerebral blood flow to arterial blood gases and MAP; regulatory mechanisms that facilitate the maintenance of cerebral oxygen delivery.

Internal jugular pressure increases during parabolic flight.

One hypothesized contributor to vision changes experienced by >75% of International Space Station astronauts is elevated intracranial pressure (ICP). While no definitive data yet exist, elevated ICP might be secondary to the microgravity‐induced cephalad fluid shift, resulting in venous congestion (overfilling and distension) and inhibition of cerebrospinal and lymphatic fluid drainage from the skull. The objective of this study was to measure internal jugular venous pressure (IJVP) during normo‐ and hypo‐gravity as an index of venous congestion. IJVP was measured noninvasively using compression sonography at rest during end‐expiration in 11 normal, healthy subjects (3 M, 8 F) during normal gravity (1G; supine) and weightlessness (0G; seated) produced by parabolic flight. IJVP also was measured in two subjects during parabolas approximating Lunar (1/6G) and Martian gravity (1/3G). Finally, IJVP was measured during increased intrathoracic pressure produced using controlled Valsalva maneuvers. IJVP was higher in 0G than 1G (23.9 ± 5.6 vs. 9.9 ± 5.1 mmHg, mean ± SD P < 0.001) in all subjects, and IJVP increased as gravity levels decreased in two subjects. Finally, IJVP was greater in 0G than 1G at all expiration pressures (P < 0.01). Taken together, these data suggest that IJVP is elevated during acute exposure to reduced gravity and may be elevated further by conditions that increase intrathoracic pressure, a strong modulator of central venous pressure and IJVP. However, whether elevated IJVP, and perhaps consequent venous congestion, observed during acute microgravity exposure contribute to vision changes during long‐duration spaceflight is yet to be determined.

Evaluation of ivc and ijv dimensions in prediction of fluid responsiveness in spontaneous breathing patients with septic shock

Prediction of fluid responsiveness (FR) is a critical step in management of patients with septic shock. Using ultrasound in detection of inferior vena cava (IVC) diameters and collapsibility is established in mechanically ventilated patients; however its use in spontaneous breathing patients is still controversial [1]. Few studies reported a correlation between internal jugular vein dimensions and central venous pressure (CVP) [2, 3] but no data are available about the use of IJV dimensions in detection of FR.

Effects of low level of positive end expiratory pressure on cerebral hemodynamics in patient undergoing laparo-scopic radical gastrostomy with general anesthesia

Objective To observe the effects of low levels of positive end expiratory pressure on cerebral hemodynamics in patients with gastric cancer undergoing laparoscopic radical resection surgery under general anesthesia. Methods 80 patients(ASAⅠ-Ⅱ), scheduled to undergo laparoscopic radical gastrostomy, were randomly divided into group A, and group B, each group had 40 cases. The ventilation parameters of group A:tidal volume(VT): 8 ml/kg, respiratory rate(RR): 12 min, positive end expiratory pressure (PEEP):5 cm H2 O(1 cm H2 O= 0.098 kPa). Group B was:VT:8 ml/kg, RR:12 min.Recording the average blood flow velocity in the middle cerebral artery(Vm),mean arterial pressure(MAP),heart rate(HR), transcutaneous oxygen saturation(SpO2),end-tidal carbon dioxide pressure(PetCO2)of the two group before pneumoperitoneum(T0),30 min after pneumoperitoneum(T1), 1 hours(T2)and 2 hours(T3)after pneumoperitoneum. Blood samples of jugular bulb and radial artery were obtained at each time point for blood gas analysis, detection the arterial oxygen pressure(PaO2), arterial carbon dioxide pressure(PaCO2), arterial oxygen saturation(SaO2), hemoglobin concentration(Hb), internal jugular venous blood oxygen partial pressure(PjvO2), internal jugular venous oxygen saturation(SjvO2), jugular venous oxygen content(CjvO2), and arterial-jugular venous oxygen content difference(Da-jvO2). Results Compared with T0,the Vm,SjvO2, PaCO2 of the two groups increased significantly at each time point(P<0.05).But the Vm, SjvO2 of group A at T2 was significantly lower than that in group B(P<0.05),and the PaCO2 of group A at T1 and T2 were(35.5±2.7),(40.7±3.5)mm Hg respectively, which significantly lower than that of group B [(39.9±3.1),(49.4±4.7)mm Hg,P<0.05].And the Vm of group A at T2 was(68.9±8.1)cm/s,significantly lower than that of group B(P<0.05).Compared with T0, the Da- jvO2 at T2 of two groups decreased significantly(P<0.05),and between the two groups, A group decreased significantly than that in B group(P<0.05). Conclusion The low level of positive end expiratory pressure in patients undergoing laparoscopic radical gastrostomy with general anesthesia can effectively reduce the hypercapnia during operation, and improve cerebral hyperperfusion state,so as to improve the cerebral blood flow and improve cerebral oxygen supply and demand balance. Key words: Positive end expiratory pressure; Laparoscopy; Radical gastrectomy; Cerebral hemodynamics

Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure.

A siphon is suggested to support cerebral blood flow but appears not to be established because internal jugular venous (IJV) pressure is close to zero in upright humans. Thus, in eleven young healthy males, IJV pressure was 9 ± 1 mmHg (mean ± SE) when supine and fell to 3 ± 1 mmHg when seated, and middle cerebral artery mean blood velocity (MCA Vmean; P < 0.007) and the near-infrared spectroscopy-determined frontal lobe oxygenation (ScO2; P = 0.028) also decreased. Another subject, however, developed (pre)syncopal symptoms while seated and his IJV pressure decreased to −17 mmHg. Furthermore, his MCA Vmean decreased and yet within the time of observation ScO2 was not necessarily affected. These findings support the hypothesis that a negative IJV pressure that is a prerequisite for creation of a siphon provokes venous collapse inside the dura, and thereby limits rather than supports CBF.

Correlation between cross-sectional area of the internal jugular vein and central venous pressure

Correlation between cross-sectional area of the internal jugular vein and central venous pressure

Monitoring pulmonary artery pressure in children undergoing the Fontan procedure

To compare external and internal jugular venous pressures to monitor pulmonary artery pressure during the Fontan procedure. During the Fontan procedure, the internal jugular vein is used to assess pulmonary artery pressure. The risk of venous thrombosis in the low-pressure Fontan circuit may compromise the long-term success of cavopulmonary anastomosis. This study compared external and internal jugular venous pressures, femoral venous pressure, and actual pulmonary artery pressure during the Fontan procedure. 32 children undergoing a single-stage Fontan on cardiopulmonary bypass were monitored for mean external and internal jugular venous pressures and femoral venous pressure pre- and post-cardiopulmonary bypass. Pulmonary artery pressure was also recorded directly after cardiopulmonary bypass. The pressure data were analyzed using analysis of variance, and the coefficient of correlation was found. The differences between external jugular, internal jugular, and femoral venous pressure pre-cardiopulmonary bypass, and between the 3 venous pressures and the pulmonary artery pressure after cardiopulmonary bypass were found to be non-significant. The coefficient of correlation of external jugular venous pressure and internal jugular venous pressure was 0.8163 (p < 0.0001) pre-cardiopulmonary bypass, and 0.6465 (p = 0.0001) post-cardiopulmonary bypass. The external jugular venous pressure correlates well with both internal jugular venous pressure and femoral venous pressure as a marker of pulmonary artery pressure in children undergoing the Fontan procedure. The use of external jugular venous pressure may also preclude the risk of thrombosis.

A comparison of external and internal jugular venous pressures to monitor pulmonary artery pressure after superior cavopulmonary anastomosis

The internal jugular vein continues to be the preferred site for cannulation to monitor central venous pressure despite the reported evidence of the accuracy of external jugular venous pressure (EJVP) to reliably predict internal jugular venous pressure (IJVP). Internal jugular venous cannulation carries a risk of thrombosis that can be life-threatening in children undergoing superior cavopulmonary anastomosis and a subsequent Fontan procedure. The present study compared IJVP and EJVP in children undergoing superior cavopulmonary anastomosis and found no statistical and clinical difference between IJVP and EJVP. Thus, external jugular vein cannulation reliably predicts IJVP and pulmonary artery pressures in children undergoing superior cavopulmonary anastomosis, and may obviate the risk of life-threatening cavopulmonary thrombosis.

Ultrasound Accurately Reflects the Jugular Venous Examination but Underestimates Central Venous Pressure

Bedside ultrasound examination could be used to assess jugular venous pressure (JVP), and thus central venous pressure (CVP), more reliably than clinical examination. The study was a prospective, blinded evaluation comparing physical examination of external jugular venous pressure (JVPEXT), internal jugular venous pressure (JVPINT), and ultrasound collapse pressure (UCP) with CVP measured using an indwelling catheter. We compared the examination of the external and internal JVP with each other and with the UCP and CVP. JVPEXT, JVPINT, UCP, and CVP were compared graphically using Bland-Altman plots, and correlation coefficients were calculated. The correlation coefficients comparing CVP to UCP, JVPEXT, and JVPINT were 0.62, 0.57, and 0.50, respectively. When UCP was compared with JVPEXT and JVPINT, correlation coefficients were 0.91 and 0.81, respectively. Last, the correlation coefficient comparing JVPEXT and JVPINT was 0.98. The Bland-Altman graphical comparison of methods technique revealed that CVP was often underestimated by UCP, and clinical examination of JVPEXT and JVPINT. In contrast, there was no systematic bias between UCP and either JVPEXT or JVPINT, nor between JVPEXT and JVPINT. Ultrasound examination is capable of measuring accurately the JVP as judged from the internal or external jugular vein. However, like the JVP, ultrasound typically underestimates CVP. A systematic bias between UCP and CVP suggests the presence of a variable degree of venous tone, possibly signaling contraction of jugular venous smooth muscle. ClinicalTrials.gov; No.: NCT01099241; URL: clinicaltrials.gov.

Venoatrial Shunt-Assisted Cavopulmonary Anastomosis

The bidirectional Glenn shunt operation is conventionally performed under cardiopulmonary bypass. Between June 2007 and September 2009, 218 consecutive patients underwent off-pump bidirectional Glenn shunt institution for single ventricle with pulmonary stenosis complex. Their mean age was 4.72 ± 1.80 years (range, 4 months to 6 years) and median weight was 10.12 kg (range, 4.1-19 kg). A temporary shunt was created between the innominate vein and the right atrium, with a 3-way connector for de-airing. Fifty-five patients had bilateral cavae. The mean internal jugular venous pressure on clamping the superior vena cava was 24.69 ± 1.81 mm Hg. Continuous end-tidal CO₂ and O₂ saturation were monitored. Adequate oxygen saturation and blood pressure were maintained by optimizing inotropics, volume, and inspired oxygen. The mean duration of ventilation was 10.17 ± 8.96 h (range, 1-73 h). There were no gross neurological complications. Postoperative pleural effusion developed in 6 (2.75%) patients, and 4 (1.83%) had nodal rhythm. Four (1.83%) patients died in the immediate postoperative period due to low cardiac output syndrome. Venoatrial shunt-assisted bidirectional Glenn shunt surgery can be performed safely by optimizing intraoperative management strategies. It is economical and avoids the deleterious effects cardiopulmonary bypass.

Veno-venous shunt-assisted cavopulmonary anastomosis

Objective:The bidirectional Glenn shunt is commonly performed under cardiopulmonary bypass for conditions that lead to a single ventricle repair. We report our experience of bidirectional Glenn shunt done without cardiopulmonary bypass.Methods:Between June 2007 and May 2009, 186 consecutive patients underwent off-pump bidirectional Glenn shunt for a variety of complex cyanotic congenital heart defects. Age ranged from four months to six years and the median weight was 11.17 kg (range 4.3 - 18). After systemic heparinization, the procedure was done by creating a temporary shunt between the innominate vein and the right atrium connected across a three way connector for de-airing. Fifty one patients had bilateral cavae. All cases underwent complete clinical neurological examination.Results:No case required conversion onto cardiopulmonary bypass. Four patients (2.14%) died in the immediate postoperative period. The mean internal jugular venous pressure on clamping the decompressed superior vena cava was 24.69 ± 1.81 mm Hg. There was no intra-operative hemodynamic instability and oxygen saturation was maintained at more than 70% throughout. Post Glenn shunt, the saturations improved to mid 80s. Seventy four cases had documented forward flow across the pulmonary valve. The mean duration of ventilation was 10.17 ± 8.96 hours and there were no neurological complications. Six patients (3.22%) developed pleural effusions, 4 patients (2.15%) had nodal rhythm and 9 patients (4.83%) had superficial sternal wound infection.Conclusions:Our results show that off-pump bidirectional Glenn shunt can be done safely in patients not requiring associated intra-cardiac correction. It avoids cardiopulmonary bypass and its related complications, is economical and associated with excellent results. In our opinion, this is the largest series of off-pump bidirectional Glenn shunt in the literature.

The bidirectional cavopulmonary (Glenn) shunt without cardiopulmonary bypass: is it a safe option?

The bidirectional cavopulmonary (Glenn) shunt is a commonly performed procedure for a variety of cyanotic congenital heart diseases that lead eventually to a single ventricle repair. It is usually performed under cardiopulmonary bypass with its associated adverse effects and costs. We report our results of bidirectional Glenn operation done without cardiopulmonary bypass. Between January 2002 and July 2003, 37 patients with complex cyanotic congenital heart defects underwent bidirectional Glenn operation by a single surgeon at our center. Of these, 22 patients had the procedure performed without cardiopulmonary bypass. Age of the patients ranged from 7 months to 11 years (mean 3.11+/-2.38 years). The procedures were done with temporary clamping of the superior vena cava. Four patients had bilateral Glenn procedure done and one had additional right pulmonary artery-plasty done. All the patients underwent complete neurological examination, CT scan of head and developmental quotient/intelligence quotient test both preoperatively as well as postoperatively. There was no operative mortality in our patients. Mean follow-up was 17.18+/-5.28 months. The mean internal jugular venous pressure on clamping the superior vena cava was 34.04+/-10.15 mmHg, and the mean clamp time was 6.85+/-1.52 min. There was no hemodynamic instability during any of the procedures and oxygen saturation was maintained at more than 65-70% throughout the procedure. The mean intensive care unit stay was 1.27+/-0.45 days. There were no neurological complications in any patient as assessed clinically and by CT scan of the head. None of the patients showed deterioration of developmental quotient/intelligence quotient score during follow-up evaluation. Our results show that in selected patients, bidirectional Glenn operation without cardiopulmonary bypass is a safe procedure. It avoids cardiopulmonary bypass related problems and is economical, with excellent results.

CASE 5—2000 redo coronary revascularization without cardiopulmonary bypass

The patient was a 53-year-old man with a history of 3 previous coronary artery bypass graft (CABG) operations (1978, 1991, 1997) who presented to an outside hospital with severe unstable angina and tachycardia (heart rate 140 BPM). Because of his extensive cardiac history and unfavorable coronary anatomy, he was deemed a poor surgical candidate for a fourth reoperation. During his third revascularization procedure, the right ventricle had been entered at sternotomy; the aorta was also noted to be densely adherent and heavily calcified with no sites for proximal graft anastomosis (vein grafts to the left anterior descending and right coronary artery had their proximal anastomoses to a previously existing circumflex saphenous vein graft near the coronary graft ostium). The heart was supplied entirely by this single vein graft with its 3 divisions; all native coronary vessels were totally occluded. The patient was transferred to this institution for further surgical evaluation. Past medical history was significant for myocardial infarction, permanent pacemaker, history of hepatitis C, gastritis, depression, bipolar disorder, posttraumatic stress disorder, remote 30 pack-year smoking history, recent history of alcohol abuse, and history of marijuana use. The patient was not considered a transplant candidate. Medications at presentation included captopril, 12.5 mg orally three times a day; furosemide, 40 mg orally two times a day; omeprazole (prilosec), 20 mg orally daily; heparin infusion, 1200 U/h; digoxin, 0.125 mg orally daily; aspirin daily; sertraline (Zoloft), 50 mg orally daily; and diazepam, 5 mg orally daily. The preoperative electrocardiogram (ECG) showed an incomplete left bundle-branch block with diffuse STand T-wave abnormalities. Pulmonary function tests showed forced expiratory volume in 1 second, 2.03 L, and forced vital capacity, 2.87 L. A preoperative chest radiograph showed cardiomegaly with pulmonary congestion. Laboratory data, including a complete blood count, renal and electrolyte panel, coagulation profile, and liver panel, were normal except for activated partial thromboplastin time, 46.7 seconds; hematocrit, 31.5%; and elevated CK-MB fraction suggestive of acute non–Q wave myocardial infarction. Preoperative testing included a dual isotope cardiac study, which showed a large reversible perfusion defect involving the anteroapical region; a small reversible perfusion defect involving the septum, left ventricular hypokinesia, and a calculated left ventricular ejection fraction of 19%. A dipyridamolethallium scan was strongly positive for global ischemia. A transthoracic echocardiogram was significant for severe global left ventricular dysfunction, normal right ventricular function, and mild-to-moderate mitral regurgitation. Cardiac catheterization revealed a single 50% proximal stenosis of the circumflex saphenous vein graft compromising flow to the existing associated right coronary artery and left anterior descending artery vein grafts, whose proximal anastomotic sites were distal to this obstruction. Despite aggressive medical management, the patient could not be weaned from intra-aortic balloon pump support. Percutaneous transluminal coronary angioplasty was not considered to be an option. He presented for elective coronary artery bypass graft (CABG) surgery without cardiopulmonary bypass by a left thoracotomy approach. His estimated operative risk was 50%. In the operating room, routine monitors, a femoral arterial catheter, a femoral venous catheter (8F introducer sheath), and a left internal jugular 12F central venous pressure (CVP) catheter were placed. External defibrillator pads were also applied. A right internal jugular pulmonary artery catheter and a left femoral intra-aortic balloon pump at 1:1 counterpulsation were already in situ. The patient was on no inotropic support at this time. Preinduction vital signs were heart rate (HR), 80 beats/ min; mean arterial pressure (MAP), 95 mmHg; CVP, 17 mmHg; pulmonary artery pressure (PAP), 62/39 mmHg; and cardiac index (CI), 2.8 L/min/m2. The ECG showed diffuse ST-T wave changes in all leads. Anesthetic induction with etomidate, midazolam, and fentanyl proceeded uneventfully. A 39F leftsided double-lumen endotracheal tube was inserted easily, and the position was verified with a pediatric fiberoptic bronchoscope. Postinduction transesophageal echocardiography (TEE)

Influence of negative intrathoracic pressure on right atrial and systemic venous dynamics.

To investigate the effect of a sustained fall in intrathoracic pressure (Mueller manoeuvre) on blood flow through the right heart and on systemic venous dynamics, 16 patients were studied using thermodilution, cinevenograms and simultaneous pressure recordings with two micromanometric transducers. The reductions in airway pressure (median [range]) during two graded Mueller manoeuvres were 25 (20-30) and 42 (22-52) mmHg. Right atrial mean pressure decreased by 17 (2-25) mmHg during the former and 38 (0-49) mmHg during the latter, and simultaneously, pressure gradients of 23 (1-32) and 45 (1-82) mmHg developed between the inferior vena cava and right atrium (P < 0.003 for all). Internal jugular venous pressure decreased by 16 (4-25) and 24 (4-43) mmHg (P < 0.03 for both), respectively, and no pressure gradient developed between internal jugular and superior caval veins. The minimum diameter of the proximal inferior vena cava decreased by 69 (-49-84)% (P = 0.002) during the greater manoeuvre. Cardiac index tended to increase by 26 (-17-40)% (P < 0.066) during the lesser manoeuvre but did not change statistically significantly during the greater. In conclusion, during negative intrathoracic pressure caused acutely by the Mueller manoeuvre, right atrial pressure decreases and the inferior vena cava collapses partially at or below the diaphragm. Despite a significant venous obstruction between the lower body and right atrium, blood flow through the right heart increases or remains constant.