Saline Contrast Echocardiography Research Articles

Optimizing agitated saline volume for contrast echocardiography: Balancing diagnostic performance and operator fatigue

AbstractBackgroundAgitated saline contrast echocardiography, essential for patent foramen ovale detection, typically uses a 10‐mL saline protocol, which may lead to operator fatigue and compromise diagnostic accuracy. This study aimed to identify an optimal saline volume that balances diagnostic efficacy and minimizes operator fatigue.MethodsFifty‐three patients with suspected patent foramen ovale underwent echocardiography using three saline protocols: 10 mL (9 mL saline + 1 mL air), 7 mL (6.4 mL saline + 0.6 mL air), and 5 mL (4.6 mL saline + 0.4 mL air). The protocols were evaluated for their impact on microbubble signal intensity in the right atrium, right‐to‐left shunt grading, and operator fatigue, as assessed by the Borg CR10 scale.ResultsThe signal intensities were comparable between the 10‐mL and 7‐mL protocols, while the 5‐mL protocol showed significantly lower signal intensities at all time points (p < 0.001). The 7‐mL protocol achieved 100% right‐to‐left shunt grading concordance with the 10‐mL protocol, while the 5‐mL protocol showed decreased accuracy and recall. Operator fatigue significantly decreased with the reduction in saline volume (p < 0.001), and the 7‐mL protocol demonstrated optimal diagnostic accuracy and reduced fatigue.ConclusionA 7‐mL agitated saline volume is recommended for contrast echocardiography to maintain diagnostic accuracy while significantly reducing operator fatigue, offering a practical balance between diagnostic precision and operator comfort.

Transesophageal echocardiography guidance for percutaneous closure of PFO and a new method to improve the diagnosis and safety during the procedures.

Percutaneous patent foramen ovale (PFO) closure is becoming more and more common for the treatment or prevention of PFO-associated right-to-left shunt (RLS). This study aims to investigate the value of transesophageal echocardiography (TEE) in percutaneous PFO closure, and to explore a new method that can improve intraoperative diagnosis and surgical safety. Based on our inclusion and exclusion criteria, we enrolled 73 patients between 16 and 70 years old (average age 43.25 ± 14.87 years) who underwent percutaneous PFO closure at the Department of Cardiac Surgery, Zhongshan Hospital (Xiamen), Fudan University, from January 2022 to December 2023. Out of the 73 enrolled patients, there were 28 males (38.36%) and 45 females (61.64%), 29 migraine patients (39.73%), 14 patients (19.19%) with headache and dizziness, 14 patients (19.18%) with a history of cerebral infarction (CI), and 25 patients (34.25%) with CI, lacunar infarction or ischemic focus on magnetic resonance imaging (MRI). All patients received routine transthoracic echocardiography (TTE) and agitated saline contrast echocardiography (ASCE) before operations. Percutaneous closure of PFO was completed under the guidance of TEE. In 12 patients, the method of "injection of heparinized sterile saline through the delivery sheath" was used to observe their RLS, and the anatomical characteristics of the PFO according to the shunt path were monitored and evaluated. This method was also applied to some patients to guide the conveyor to pass through the foramen ovale (FO) channel safely and effectively, thereby improving the success rate of PFO closure. The application of TEE during the procedure of percutaneous PFO closure, including preoperative evaluation, intraoperative guidance, and postoperative reevaluation, can offer further details about the anatomical and shunt characteristics of PFO, improve the diagnosis rate, and confirm the safety of the surgical path. It ensures the safety and reliability of the whole operation, greatly improving the success rate and reducing postoperative complications. TEE guidance of percutaneous PFO closure has the advantages of minimal trauma, no radiation and real-time visualization, while injecting heparinized sterile saline through the delivery sheath is safer and more effective in improving the success rate and reducing postoperative complications.

Evaluation of intrapulmonary arteriovenous anastomoses before and after oxygen supplementation, using transthoracic agitated saline contrast echocardiography in rescued Korean raccoon dogs.

Intrapulmonary arteriovenous anastomoses (IPAVAs) are defined as relatively large, dynamic shunt vessels that connect the pulmonary arterial and venous systems, thereby bypassing the pulmonary capillary system. IPAVAs lower elevated pulmonary arterial pressure; however, the presence of the shunt can result in impaired pulmonary gas exchange and paradoxical embolism. Furthermore, the prevalence and effects of IPAVAs in raccoon dogs remain unknown. This study aimed to determine the prevalence of IPAVA among rescued Korean raccoon dogs and evaluate the changes in IPAVA following oxygen supplementation. Nineteen raccoon dogs rescued by the Jeonbuk Wildlife Centre between August 2022 and December 2023 were subjected to echocardiography. Sixteen healthy and three abnormal raccoon dogs were subjected to transthoracic agitated saline contrast echocardiography (bubble study) based on the echocardiography results. IPAVA was considered to be present if the left heart contrast was visualised after four cardiac cycles following the visualisation of the first right heart contrast. Bubble scores (BS0-5) were assigned based on the maximum number of microbubbles observed in the left ventricular lumen per frame of the ultrasound image. BS was assigned before and after supplementation with 100% oxygen for 5 min. IPAVA was detected in 12 of the 16 healthy raccoon dogs at rest (75%). The BS of the 15 IPAVA-positive raccoon dogs ranged from 1 to 4 points (BS1, 1; BS2, 4; BS3, 8; and BS4, 2). Blood flow through the IPAVA (QIPAVA) was reduced or absent in the 15 IPAVA-positive raccoon dogs after supplementation with 100% oxygen (BS0, 11; BS2, 4). Moreover, BS of the IPAVA showed a significant correlation with the cardiac output per body weight (BW). The prevalence of IPAVA in healthy raccoon dogs at rest was 75%. Adequate oxygen supplementation was found to be effective in reducing QIPAVA, which may help prevent potential negative factors such as pulmonary gas exchange impairments and paradoxical embolism that can occur with IPAVA.

Absent right superior vena cava and persistent left superior vena cava: An incidental finding.

A patient with Marfan syndrome undergoing Bentall operation was found to have an absent right superior vena cava and persistent left superior vena cava. The dilation of coronary sinus raised the suspicion of persistent left superior vena cava. The diagnosis was confirmed by agitated saline contrast echocardiography and computed tomography of the chest.

The predictive value of abnormal electrocardiogram for patent foramen ovale: A retrospective study.

The objective of this study was to identify the characteristics of electrocardiogram (ECG) in adult patients with patent foramen ovale (PFO)and to analyze the predictive value of the characteristics of ECG for PFO in adult patients. Retrospectively, 267 patients who had undergoneECG, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) with agitated saline contrastechocardiography in our hospital, were recruited continuously from January2021 to March2023. Electrocardiographs were analyzed to investigate the presence of right bundle branch block (RBBB) and crochetage R wave. The ratio of crochetage R wave in inferior leads in patients with PFO was 45.3% and 21.2% without PFO. There were 17 (6.4%) patients with coexistence of crochetage R wave and RBBB, including 13 (6.5%) patients with PFO and four (6.1%) patients without PFO. The accuracies of TTE, crochetage R wave, and RBBB were 0.637, 0.535, and 0.314, respectively. A combination of crochetage R wave and RBBB demonstrated a sensitivity of 0.507 and a specificity of 0.758. When TTE, crochetage R wave, and RBBB were combined, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 0.712, 0.801, 0.439, 0.813, and 0.420, respectively. Logistic regression analysis revealed a correlation between PFO and the presence of crochetage R wave (odds ratio[OR]: 3.073, 95% confidence interval [CI]: 1.601-5.899, p < 0.001), and also a combination between crochetage R wave and RBBB (OR: 3.220, 95% CI: 1.720-6.028, p < 0.001). Crochetage R wave in ECG was associated with PFO. Crochetage R wave, especially combined with RBBB and TTE, may be helpful in the early detection of patients withPFO.

White matter lesions predominantly located in deep white matter represent embolic etiology rather than small vessel disease

AbstractBackgroundIndividuals with cerebral small vessel disease (CSVD) usually have both periventricular and deep white matter hyperintensities (dpWMH). However, we often encounter individuals whose WMH lesions are mainly located in the corticomedullary or deep white matter with minimal periventricular WMHs (dWMH). We aimed to determine if the dWMH pattern could be attributed to embolic etiologies.MethodsWe retrospectively recruited participants who had undergone comprehensive dementia evaluation, agitated saline contrast echocardiography, and brain MRI. The participants were classified into two groups according to WMH distributions, the dWMH (WMHs in deep and corticomedullary area, with minimal periventricular WMHs) and the dpWMH (mainly periventricular WMHs with or without deep WMHs) groups. We hypothesized that dWMH is more likely associated with embolism, whereas dpWMH with CSVD. We compared the clinical characteristics, WMH distributions, and the positive rate of agitated saline study between the two groups.ResultsOf the 90 participants, 27 fulfilled the dWMH criteria and 12 met the dpWMH criteria. The dWMH group was younger (62.2±7.5 vs 78.9±7.3, p&lt;0.001), and had a lower prevalence of hypertension (29.6% vs. 75%, p = 0.008), DM (3.7% vs. 25%, p = 0.043), and hyperlipidemia (33.3% vs. 83.3%, p = 0.043) than the dpWMH group. Regarding deep white matter lesions, the number of small lesions (&lt;3 mm) was higher in the dWMH (10.9±9.7) than the dpWMH (3.1±6.4) group (p = 0.008), and WMHs were predominantly distributed in border‐zones of major cerebral arteries and corticomedullary areas.Most importantly, the positive rate of agitated saline was higher in the dWMH than the dpWMH group (81.5% vs. 33.3%, p = 0.003).ConclusionsThe dWMH group with younger age, fewer cardiovascular risk factors showed more border‐zone distributions, and higher positivity of agitated saline test than dpWMH group, indicating that WMH distributions mainly in the corticomedullary or deep area with minimal periventricular WMH lesions suggest embolic etiologies.

Hyperoxia-induced stepwise reduction in blood flow through intrapulmonary, but not intracardiac, shunt during exercise.

Blood flow through intrapulmonary arteriovenous anastomoses (IPAVA) (QIPAVA) increases during exercise breathing air, but it has been proposed that QIPAVA is reduced during exercise while breathing a fraction of inspired oxygen ([Formula: see text]) of 1.00. It has been argued that the reduction in saline contrast bubbles through IPAVA is due to altered in vivo microbubble dynamics with hyperoxia reducing bubble stability, rather than closure of IPAVA. To definitively determine whether breathing hyperoxia decreases saline contrast bubble stability in vivo, the present study included individuals with and without patent foramen ovale (PFO) to determine if hyperoxia also eliminates left heart contrast in people with an intracardiac right-to-left shunt. Thirty-two participants consisted of 16 without a PFO; 8 females, 8 with a PFO; 4 females, and 8 with late-appearing left-sided contrast (4 females) completed five, 4-min bouts of constant-load cycle ergometer exercise (males: 250 W, females: 175 W), breathing an [Formula: see text] = 0.21, 0.40, 0.60, 0.80, and 1.00 in a balanced Latin Squares design. QIPAVA was assessed at rest and 3 min into each exercise bout via transthoracic saline contrast echocardiography and our previously used bubble scoring system. Bubble scores at [Formula: see text]= 0.21, 0.40, and 0.60 were unchanged and significantly greater than at [Formula: see text]= 0.80 and 1.00 in those without a PFO. Participants with a PFO had greater bubble scores at [Formula: see text]= 1.00 than those without a PFO. These data suggest that hyperoxia-induced decreases in QIPAVA during exercise occur when [Formula: see text] ≥ 0.80 and is not a result of altered in vivo microbubble dynamics supporting the idea that hyperoxia closes QIPAVA.

Quantification of shunt fraction using contrast ultrasound and indicator dilution in an in vitro model

Transthoracic saline contrast echocardiography is commonly used to assess intrathoracic shunt flow in vivo. Though the technique has many advantages (safe, simple, repeatable), the measurement technique lacks specificity, and the contrast agent has limited stability. This study sought to determine if the indicator dilution modeling technique could be applied to ultrasound contrast data to quantify shunt fraction and to determine if buoyant force has a significant effect on microbubble pathway determination at a “vascular” bifurcation. A model of the pulmonary circuit was perfused with blood at three distinct flow rates (low, medium and high) over shunt fractions ranging from ∼2–10 %. The buoyancy effect on contrast was quantified using a simplified in vitro model of a vascular bifurcation that had an upper and lower outflow tract where saline contrast formed from carbon monoxide (CO) gas passed through the bifurcation, was collected and quantified. The indicator dilution model was found to have a mean bias of − 3.2 % for the low flow stage, − 2.6 % for the medium flow stage and − 1.4 % for the high flow stage compared to volumetric measurements, suggesting agreement increases with increasing flow rate. Investigations of the buoyant effects revealed that at lower flow rates, contrast bubbles that encounter a bifurcation will favor the upper outflow tract over the lower. However, this effect is reduced by increasing the flow rate two-fold. These data identify that application of indicator dilution theory to contrast ultrasound data and the pathway ultrasound contrast travels in a network of tubules is flow dependent.

White Matter Lesions Predominantly Located in Deep White Matter Represent Embolic Etiology Rather Than Small Vessel Disease

We investigated the correlation between the deep distribution of white matter hyperintensity (WMH) (dWMH: WMH in deep and corticomedullary areas, with minimal periventricular WMH) and a positive agitated saline contrast echocardiography result. We retrospectively recruited participants with comprehensive dementia evaluations, an agitated saline study, and brain imaging. The participants were classified into two groups according to WMH-distributions: dWMH and dpWMH (mainly periventricular WMH with or without deep WMH.) We hypothesized that dWMH is more likely associated with embolism, whereas dpWMH is associated with small-vessel diseases. We compared the clinical characteristics, WMH-distributions, and positive rate of agitated saline studies between the two groups. Among 90 participants, 27 and 12 met the dWMH and dpWMH criteria, respectively. The dWMH-group was younger (62.2±7.5 vs. 78.9±7.3, p<0.001) and had a lower prevalence of hypertension (29.6% vs. 75%, p=0.008), diabetes mellitus (3.7% vs. 25%, p=0.043), and hyperlipidemia (33.3% vs. 83.3%, p=0.043) than the dpWMH-group. Regarding deep white matter lesions, the number of small lesions (<3 mm) was higher in the dWMH-group(10.9±9.7) than in the dpWMH-group (3.1±6.4) (p=0.008), and WMH was predominantly distributed in the border-zones and corticomedullary areas. Most importantly, the positive agitated saline study rate was higher in the dWMH-group than in the dpWMH-group (81.5% vs. 33.3%, p=0.003). The dWMH-group with younger participants had fewer cardiovascular risk factors, showed more border-zone-distributions, and had a higher agitated saline test positivity rate than the dpWMH-group, indicating that corticomedullary or deep WMH-distribution with minimal periventricular WMH suggests embolic etiologies.

218 PERSISTENT LEFT SUPERIOR VENA CAVA IN AN ADULT PATIENT WITH AN IMPLANTED PACEMAKER: A CASE REPORT

Abstract Introduction Persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly, although infrequent in the general population (prevalence estimates as 0.2-3%). It begins at the junction of the left subclavian and internal jugular veins, passes through the left side of the mediastinum adjacent to the aortic arch, and mostly drains into the right atrium via the coronary sinus (CS). For the majority of cases it is asymptomatic and it is mostly detected incidentally. More rarely it can be associated with other congenital abnormalities, such as aortic bicuspid valve, aortic coartation or atrial septal defects. Besides, in less than 10% of the cases the left superior vena cava drains in the left atrium, leading to a right-to-left shunt. Lastly, it can lead to arrhythmic problems. Case presentation A 85-year-old man was admitted to the emergency department for syncope. Previous medical history was unknown and there was no clinical documentation available. The electrocardiogram showed an atrial fibrillation and some pacemaker-induced beats. An echocardiogram was performed, which showed dilation and dysfunction of the right chambers and a dilated CS. Moreover, the same exam revealed the two pacemaker leads passing through the CS and ending their course into the right atrium and ventricle. The chest X-ray displayed the pacemaker leads passing to the left side of the aorta. Furthermore, a computed tomography angiography was performed in the suspicion of a pulmonary embolism. The exam showed small vascular filling defects in arteries of the right inferior lung lobe, but also the presence of two superior vena cavas, with the left one draining into the CS. The pacemaker leads passed from the left subclavian vein through the left superior vena cava reaching the right chambers. Therefore, the diagnosis of PLSVC was confirmed. Discussion and Conclusions Despite the benign natural history of this diagnosis, it is important to know the existence of this condition. PLSVC can be suspected when a dilated CS is detected on a transthoracic echocardiogram, with a parasternal long axis view. The best projections to visualize the dilatation of CS are also the apical four-chamber and the subcostal view. Besides, the direct detection of left superior vena cava can be obtained with a suprasternal view. The presence of the right superior vena cava should also be confirmed with a subcostal or suprasternal view. The differential diagnosis for a dilatation of the CS includes anomalous pulmonary venous return with a pulmonary vein draining in the CS, the “unroofed coronary sinus”, a tricuspid regurgitation with a jet directed towards the CS, elevated right-chamber filling pressures. The diagnosis of PLSVC can be confirmed with a saline contrast echocardiography (“bubble-test”) or with other radiological investigations (computed tomography or magnetic resonance). It should be reported in radiological reports even when it is an incidental finding because of its clinical relevance: it is essential to know its presence in advance in invasive procedures, such as pacemaker implantation, ablative procedures, cardiac surgery, because it could affect the proper approaches and could lead to complications. Moreover, in a minority of cases, it can be associated with other congenital abnormalities or with arrhythmic problems.

High prevalence of patent foramen ovale in recreational to elite breath hold divers

ObjectivesDuring apnea diving, a patent foramen ovale may function as a pressure relief valve under conditions of high pulmonary pressure, preserving left-ventricular output. Patent foramen ovale prevalence in apneic divers has not been previously reported. We aimed to determine the prevalence of patent foramen ovale in apneic divers compared to non-divers. DesignCross sectional. MethodsApnea divers were recruited from a training camp in Cavtat, Croatia and the diving community of Split, Croatia. Controls were recruited from the population of Split, Croatia and Eugene, Oregon, USA. Participants were instrumented with an intravenous catheter and underwent patent foramen ovale screening utilizing transthoracic saline contrast echocardiography. Appearance of microbubbles in the left heart within 3 cardiac cycles indicated the presence of patent foramen ovale. Lung function was measured with spirometry. Comparison of patent foramen ovale prevalence was conducted using chi-square analysis, p < .05. ResultsApnea divers had a significantly higher prevalence of patent foramen ovale (19 of 36, 53%) compared to controls (9 of 36, 25%) (X2 (1, N = 72) = 5.844, p = .0156). ConclusionsWhy patent foramen ovale prevalence is greater in apnea divers remains unknown, though hyperbaria during an apnea dive results in a translocation of blood volume centrally with a concomitant reduction in lung volume and alveolar hypoxia during ascent results in hypoxic pulmonary vasoconstriction. These conditions increase pulmonary arterial pressure, increasing right-atrial pressure allowing for right-to-left blood flow through a patent foramen ovale which may be beneficial for preserving cardiac output and reducing capillary hydrostatic forces.

Party Balloon Inflation Maneuver During Saline Contrast Transthoracic Echocardiography to Detect Patent Foramen Ovale

Saline contrast echocardiography requires an adequate provocation method for the detection of patent foramen ovale. The party balloon inflation maneuver during saline contrast transthoracic echocardiography is easy to explain to patients and objectively assesses the performance of provocative maneuvers by a clinician by watching balloon inflation. (Level of Difficulty: Intermediate.)

Utility of Normal Saline Contrast Echocardiography for Diagnosis of Respiratory Failure: A Case Report

Utility of Normal Saline Contrast Echocardiography for Diagnosis of Respiratory Failure: A Case Report

Reduction in Pulmonary Arterial Pressure at Rest and During Exercise and Improvement in Gas Exchange Efficiency Following Percutaneous Closure of Patent Foramen Ovale

PURPOSE The patent foramen ovale (PFO) is a source of intracardiac right-to-left shunt and is present in ~1/3rd of the adult population. Deficits in pulmonary gas exchange efficiency associated with PFO have been well-documented (Lovering et al, J Appl Physiol 2016). However, changes in pulmonary artery pressure and total pulmonary resistance (TPR) following closure have not previously been reported. METHODS Four candidates (3F, 1M) for closure of PFO were identified by local cardiologists and referred to our laboratory as subjects. 3 subjects (3F) received physician clearance to participate in the exercise trials. 1 subject (1M) was not cleared for exercise so only resting measures were taken. Presence and size of PFO was confirmed utilizing transthoracic saline contrast echocardiography (TTSCE). A radial arterial catheter was placed utilizing aseptic technique. Subjects exercised at 4 sub-maximal workloads (25%, 50%, 75% and 90% of pre-closure VO2Max), with arterial blood drawn anaerobically during the last 30 seconds of each workload and immediately analyzed in duplicate for gas content. Transthoracic ultrasound measures of cardiac output (QT) and pulmonary arterial systolic pressure (PASP) were taken prior to exercise and during the final minute of each workload. TPR was calculated as PASP/ QT. Subjects then underwent percutaneous closure of PFO utilizing a commercially available closure device (Amplatzer PFO Occluder, Abbott, Illinois; Cardioform Septal Occluder, GORE, Arizona). All measures were repeated in the laboratory 3-6 months after closure of PFO following confirmation of endothelialization of the closure device with TTSCE. RESULTS Data were analyzed by a 2-way (Closure x Workload) RMANOVA. There was a main effect of closure on PASP F(1, 11) = 21.05, p = 0.0008, and a main effect of closure on TPR F(1, 11) = 9.899, p = 0.0093, with reductions in both following closure. There was a main effect of workload, but not closure, on cardiac output F(4, 11) = 60.18, p < 0.0001. There were main effects of both workload F(4,11) = 73665, p = .0033 and closure F(1,11) = 28.31, p = .0002 on pulmonary gas exchange efficiency. CONCLUSION Improvements in pulmonary gas exchange efficiency are expected with removal of the intracardiac right-to-left shunt. However, our results demonstrating a significantly reduced pulmonary artery pressure, due to a significantly reduced TPR, are intriguing and deserve more attention to better understand the contributing factors of a PFO to exercise-induced pulmonary hypertension.

Reliable Detection of Intrapulmonary Shunts Using Contrast-Enhanced Echocardiography in Children With Portal Hypertension or Portosystemic Shunt.

The aim of this study was to analyze if contrast-enhanced echocardiography (CEE) is as reliable as lung perfusion scintigraphy (LPS) to detect intrapulmonary shunting (IPS) in children with portal hypertension (PHTN) or congenital/surgical portosystemic shunts (PSS) and to define the number of cardiac cycles required to exclude intrapulmonary shunting. Inclusion criteria for this cross-sectional study were: (1) presence of PHTN or PSS diagnosed on abdominal ultrasound, (2) technically valid saline contrast echocardiography, (3) lung perfusion scintigraphy within 6 months of CEE. The number of cardiac cycles between right atrial opacification and the arrival of contrast in the left atrium were counted. We analyzed our CEE data at three and five cardiac cycles and compared them with LPS results. The study population was composed of 78 children (38 girls, 49%) ages 2.1-18.8 years (mean 9.8). Sixty-nine patients had PHTN (88%), and nine had a PSS (11%). Eleven subjects (14%) presented evidence of IPS on LPS. Peripheral oxygen saturation was lower in the subjects with IPS detected on LPS (95.3 ± 1.7% vs 99.0 ± 1.4%; P < 0.01). Comparison of LPS with CEE before three and five cardiac cycles showed that CEE is highly specific (95.7%) as early as three cardiac cycles with markedly better sensitivity (72.7%) when using five cardiac cycles. Furthermore, a negative study using five cardiac cycles ruled out IPS with a 95% negative predictive value. The cardiac cycle at which the bubbles appeared in the left atrium was inversely correlated to the shunt index measured using LPS (r = -0.563; P = 0.001). CEE is sufficient for the screening of IPS in children with PHTN or congenital/surgical PSS, obviating the need for LPS.

A Review of the Surgical Management of Aorto-ventricular Tunnels

We present a synthesis of 95 published investigations of the exceedingly rare tunnels that can exist between the aortic root and the left or right ventricles. From the 220 suitable cases included in these investigations, we reviewed the clinical presentations, modalities used for diagnosis, surgical approaches, and outcomes. Diagnostic information was provided by clinical presentation, radiographic findings, saline contrast echocardiography, computed tomographic angiocardiography, magnetic resonance imaging, cardiac catheterization, and angiocardiography. These techniques elucidated the coronary arterial origins and associated defects and defined the disease before surgery. Patients occasionally present with an asymptomatic cardiac murmur and cardiomegaly, but most suffer cardiac failure in the first year of life when the tunnel enters the left ventricle. Antenatal diagnosis by fetal echocardiography is reliable after 18 weeks of gestation. Associated defects, involving the proximal coronary arteries or the aortic or pulmonary valves, are present in nearly half the cases. Prompt diagnosis and surgical repair are important for a favorable outcome. Overall, operative mortality has been cited to be between 3% and 8.3%. Associated congenital coronary arterial anomalies, residual severe aortic stenosis, poor left ventricular function, and rupture of an infected suture line have been the reported causes of death. Despite early surgical intervention, an incidence of 16% to 60% postoperative residual aortic regurgitation of varying severity has been reported. The requirement of further repair or replacement of the aortic valve ranges from 0% to 50%. We submit that an increased appreciation of these details relative to the tunnels will contribute to improved surgical management.

Supracardiac total anomalous pulmonary venous connection with cor triatriatum sinister: A rare diagnosis confirmed by saline contrast echocardiography.

In cor triatriatum sinister, the left atrium is divided by a membrane into a proximal and a distal chamber. Usually proximal chamber receives all the pulmonary veins and drains through an opening in the dividing membrane into distal chamber, which empties into left ventricle through the mitral valve. Rarely, the two chambers lack a communication and there is associated total anomalous pulmonary venous connection (TAPVC). We report a 1-month-old infant with cyanosis and heart failure, who had cor triatriatum sinister associated with supracardiac TAPVC. The case is reported for rarity of the association with a focus on contrast echocardiographic imaging.

A Review of the Surgical Management of Anomalous Connection of the Right Superior Caval Vein to the Morphologically Left Atrium and Biatrial Drainage of Right Superior Caval Vein.

The present perspective is a synthesis of published investigations in the setting of anomalous connection of the right superior caval vein to the morphologically left atrium or biatrial drainage of the right caval vein. We identified 57 suitable cases from 97 investigations, reviewing the clinical presentation, diagnostic modalities utilized, surgical techniques used, and their outcomes. Clinical presentation, radiographic findings, saline contrast echocardiography, computed tomographic angiocardiography, radionuclide perfusion scan, magnetic resonance imaging, and angiocardiography provided the diagnostic information and were used to define the disease entities before surgery. We have also addressed several issues concerning the influence of the so-called heterotaxy: the establishment of the diagnosis, the variation in clinical presentation, and subsequent management. For the overall group of patients undergoing either surgical intervention or transcatheter treatment with an Amplatzer vascular plug, the operative mortality remains high at 9.5%. We submit that an increased appreciation of these disease entities will contribute to improved future surgical management.

Right-to-left shunts in lowlanders with COPD traveling to altitude: a randomized controlled trial with dexamethasone.

Right-to-left shunts (RLS) are prevalent in patients with chronic obstructive pulmonary disease (COPD) and might exaggerate oxygen desaturation, especially at altitude. The aim of this study was to describe the prevalence of RLS in patients with COPD traveling to altitude and the effect of preventive dexamethasone. Lowlanders with COPD [Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1-2, oxygen saturation assessed by pulse oximetry () >92%] were randomized to dexamethasone (4 mg bid) or placebo starting 24 h before ascent from 760 m and while staying at 3,100 m for 48 h. Saline-contrast echocardiography was performed at 760 m and after the first night at altitude. Of 87 patients (81 men, 6 women; mean ± SD age 57 ± 9 yr, forced expiratory volume in 1 s 89 ± 22% pred, 95 ± 2%), 39 were assigned to placebo and 48 to dexamethasone. In the placebo group, 19 patients (49%) had RLS, of which 13 were intracardiac. In the dexamethasone group 23 patients (48%) had RLS, of which 11 were intracardiac (P = 1.0 vs. dexamethasone). Eleven patients receiving placebo and 13 receiving dexamethasone developed new RLS at altitude (P = 0.011 for both changes, P = 0.411 between groups). RLS prevalence at 3,100 m was 30 (77%) in the placebo and 36 (75%) in the dexamethasone group (P = not significant). Development of RLS at altitude could be predicted at lowland by a higher resting pulmonary artery pressure, a lower arterial partial pressure of oxygen, and a greater oxygen desaturation during exercise but not by treatment allocation. Almost half of lowlanders with COPD revealed RLS near sea level, and this proportion significantly increased to about three-fourths when traveling to 3,100 m irrespective of dexamethasone prophylaxis.NEW & NOTEWORTHY The prevalence of intracardiac and intrapulmonary right-to-left shunts (RLS) at altitude in patients with chronic obstructive pulmonary disease (COPD) has not been studied so far. In a large cohort of patients with moderate COPD, our randomized trial showed that the prevalence of RLS increased from 48% at 760 m to 75% at 3,100 m in patients taking placebo. Preventive treatment with dexamethasone did not significantly reduce the altitude-induced recruitment of RLS. Development of RLS at 3,100 m could be predicted at 760 m by a higher resting pulmonary artery pressure and arterial partial pressure of oxygen and a more pronounced oxygen desaturation during exercise. Dexamethasone did not modify the RLS prevalence at 3,100 m.

Perfusion of Intrapulmonary Arteriovenous Anastomoses Is Not Related to VO2max in Hypoxia and Is Unchanged by Oral Sildenafil.

Background: Perfusion of intrapulmonary arteriovenous anastomoses (IPAVA) is increased during exercise and in hypoxia and is associated with variations in oxygen saturation (SPO2), resulting in blood bypassing the pulmonary microcirculation. Sildenafil is a pulmonary vasodilator that improves SPO2 and endurance performance in hypoxia. The purpose of this study was to determine if 50 mg sildenafil would reduce IPAVA perfusion (QIPAVA) and if the decrement in maximal exercise capacity (VO2max) in hypoxia is related to QIPAVA. We hypothesized that during progressive levels of hypoxia at rest (FIO2 = 0.21, 0.14, 0.12), sildenafil would increase SPO2 and reduce bubble score (estimate of QIPAVA) compared to placebo, and that the decrement in VO2max in hypoxia would be positively correlated with bubble score at rest in hypoxia. Materials and Methods: Fourteen endurance-trained men performed a graded maximal exercise test at sea level and at a simulated altitude of 3000 m, followed by two experimental visits where, after randomly ingesting sildenafil or placebo, they underwent agitated saline contrast echocardiography during progressive levels of hypoxia at rest. Results: All participants experienced a decrement in power output in hypoxia that ranged from 9% to 19% lower than sea level values. Compared to normoxia, bubble score increased significantly in hypoxia (p < 0.001) with no effect of sildenafil (p = 0.580). There was a negative correlation between SPO2 and bubble score (p < 0.001). The decrement in peak power output at VO2max in hypoxia was unrelated to IPAVA perfusion in resting hypoxia (p = 0.32). Several participants demonstrated QIPAVA greater than zero in room air, indicating that arterial hypoxemia may not be the sole mechanism for QIPAVA. Conclusion: These results indicate that the VO2max decrement caused by hypoxia is not related to QIPAVA and that sildenafil does not improve VO2max in hypoxia through modulation of QIPAVA.