Transthoracic Contrast Echocardiography Research Articles

Multidisciplinary assessment of PFO with substantial right-to-left shunting and medium-term follow-up after PFO device closure: A single-center experience.

ObjectivesTo describe the multidisciplinary assessment of patent foramen ovale (PFO) with substantial right‐to‐left shunting (RLS) and medium‐term follow‐up after PFO closure for stroke or transient ischemic attack (TIA).BackgroundPFO closure is a therapeutic option to prevent recurrent ischemic event in patients with cryptogenic stroke and TIA. The apparent lack of benefit seen in previous studies was in part due to the inclusion of patients with alternate mechanisms of stroke/TIA. However, the long‐term follow‐up results of RESPECT trial confirmed that PFO closure could reduce the recurrence rate of stroke compared to medical therapy. The obvious difference between RESPECT and the other studies is that RESPECT recruited more relevant patients with substantial RLS.MethodsFrom May 2013 to October 2015, all subjects diagnosed as cryptogenic stroke or TIA with substantial RLS who underwent PFO closure at our institution were included. All patients underwent multidisciplinary assessment to exclude stroke/TIA with definite etiology. Baseline characteristics, clinical manifestations, procedural, and follow‐up data were reviewed.ResultsA total of 219 consecutive patients with substantial RLS undergoing PFO closure were identified. There were no procedure‐related deaths, strokes, or TIA. Mean follow‐up was 2.0 ± 0.7 years. Early residual shunting was visible in 9 patients (4.1%); however, during follow‐up, only 3 patients (1.4%) had residual RLS detected by contrast transthoracic echocardiography (cTTE). The annual risk of recurrent ischemic stroke or TIA was 0.457%.ConclusionsPFO closure can be performed safely and effectively in patients with cryptogenic stroke or TIA. In selected patients with substantial RLS, following appropriate multidisciplinary assessment, excellent results with low incidence of recurrent events may be achieved.

Short-Term and Midterm Follow-Up of Transthoracic Device Closure of Atrial Septal Defect in Infants

The purpose of this study was to outline the safety and feasibility of transthoracic device closure of an atrial septal defect (ASD) with a domestic occluder in infants. Sixty-eight infants underwent transthoracic device closure of an ASD at Union Hospital, Fujian Medical University, Fuzhou, China from January 2010 to January 2015. All relevant clinical data were recorded and analyzed. All patients were invited to undergo contrast transthoracic echocardiography for 12 to 60 months after ASD closure, and telephone interviews were conducted with the infants' parents to evaluate the patients' clinical status further. All patients had successful ASD occlusion using this approach. The most frequent complication was transient cardiac arrhythmia, which was easily treated or automatically recovered during the perioperative period. During the follow-up period, no recurrence, thrombosis, device embolization, valve damage, device failure, or death was reported. The total occlusion rate was 100% in the 12months of follow-up, and all patients showed significant improvement in their clinical status. From transthoracic echocardiographic data, intracardiac structure and cardiac function were significantly improved at follow-up. Transthoracic device closure of an ASD with a domestic occluder in infants is a safe and feasible technique. The short- and medium-term follow-up results were satisfactory, but long-term follow-up is required to assess the safety and feasibility of this method in infants more accurately.

Relationship between quantitative and descriptive methods of studying blood flow through intrapulmonary arteriovenous anastomoses during exercise

Several methods exist to study intrapulmonary arteriovenous anastomoses (IPAVA) in humans. Transthoracic saline contrast echocardiography (TTSCE), i.e., bubble scores, is minimally-invasive, but cannot be used to quantify the magnitude of blood flow through IPAVA (QIPAVA). Radiolabeled macroaggregates of albumin (99mTc-MAA) have been used to quantify QIPAVA in humans, but this requires injection of radioactive particles. Previous work has shown agreement between 99mTc-MAA and TTSCE, but this has not been tested simultaneously in the same group of subjects. Thus, the purpose of this study was to determine if there was a relationship between QIPAVA quantified with 99mTc-MAA and bubble scores obtained with TTSCE. To test this, we used 99mTc-MAA and TTSCE to quantify and detect QIPAVA at rest and during exercise in humans. QIPAVA significantly increased from rest to exercise using 99mTc-MAA and TTSCE and there was a moderately-strong, but significant relationship between methods. Our data suggest that high bubble scores generally correspond with large QIPAVA quantified with 99mTc-MAA during exercise.

Diffuse Pulmonary Arteriovenous Malformation in Children: Essential Value of Contrast Echocardiography in Diagnosis

Pulmonary arteriovenous malformations (PAVM) are abnormal communications between pulmonary arteries and pulmonary veins, and most commonly congenital in nature. Although rare, it is an important consideration in cyanotic patients of unknown cause. We report 3 cases with diffuse PAVM in children with different clinical manifestations and initial diagnosis was made by transthoracic contrast echocardiogram. Transthoracic contrast echocardiography (TTCE) is valuable as initial diagnostic tools for diffuse PAVM. Pulmonary angiography should be reserved for therapeutic purposes for PAVM rather than diagnostic.

Safety and efficacy of Cardi-O-fix occluder for percutaneous closure of a patent foramen ovale

Background:Amplatzer occluder and Cardio-O-fix occluder are currently used in percutaneous closure of patent foramen ovale. However, there is still a lack of relevant reports comparison the differences between them. The aim of this study was to evaluate the short-term and mid-term safety and efficacy of the Cardi-O-fix occluder in preventing recurrent cerebrovascular events in patients with a patent foramen ovale (PFO).Methods:We enrolled 246 patients (105 men) with a PFO from May 30, 2013 to March 30, 2015 in this single-center prospective study. All patients were treated by PFO interventional closure, with the Cardi-O-fix PFO occluder being used in 180 patients and the Amplatzer PFO occluder being utilized in the remaining 66 patients. After the procedure, we verified the safety and efficacy of different devices using contrast transthoracic echocardiography.Results:Neither recurrent stroke nor death was encountered during the follow-up of 12 months. Transient ischemic attack (TIA) was noted in 2 patients (1.1%) in the Cardi-O-fix PFO occluder group, and 1 patient suffered from TIA (1.5%) in the Amplatzer PFO occluder group. Among them, only 1 patient exhibited a small right to left shunt (RLS). There was no statistical difference in recurrent cerebral ischemic events. Three cases of paroxysmal atrial fibrillation were observed in the Cardi-O-fix PFO occluder group. One reverted spontaneously to sinus rhythm and the other 2 cases had pharmacologic conversion to sinus rhythm. One case of paroxysmal atrial fibrillation occurred in the Amplatzer group, which underwent pharmacologic conversion to sinus rhythm. There was no significant difference between the 2 groups regarding incidence of arrhythmia. No occluder translocation, erosion, pericardial effusion, and puncture site bleeding were observed in the 2 groups within 12 months of follow-up. The complete closure rates of the Cardi-O-fix and Amplatzer PFO occluder devices at the 12 months after the procedure were 73.9% and 63.6%, respectively, and the effective closure rates were 90.6% and 86.4%, respectively. There was no statistically significant difference in the complete closure rate and effective occlusion rate (P > 0.05) between the devices.Conclusions:There was no significant difference in the short- and mid-term efficacy and safety between the Cardi-O-fix PFO occluder and Amplatzer PFO occluder. The efficacy and safety of the Cardi-O-fix occluder were comparable to those of the Amplatzer PFO occluder.

Characterization of blood flow through intrapulmonary arteriovenous anastomoses and patent foramen ovale at rest and during exercise in stroke and transient ischemic attack patients.

We determined whether stroke and/or TIA subjects have exercise-induced blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) and/or patent foramen ovale (QPFO ) and a genetic predisposition for ischemic stroke. Twenty-eight stroke and/or TIA subjects (33-63years old) underwent transthoracic saline contrast echocardiography concomitant with transcranial Doppler to detect QIPAVA and QPFO at rest and during supine exercise with and without breathing 100% O2 . We also examined genetic polymorphisms in FV Leiden (G1691A; rs6025), factor II (FII) prothrombin (G20210A; rs1799963), methylene tetrahydfropholate reductase (C677T, rs1801133), and plasminogen-activator inhibitor-1 (PAI-1) (4G/5G; rs1799889) and angiotensin-converting enzyme (ACE; I/D, rs4646994) in 24/28 subjects. No subject without PFO had QIPAVA at rest (n=17), but 12/17 did with exercise. All PFO subjects had QPFO at rest (n=11) and 7/11 had either QIPAVA or QPFO with exercise. Breathing 100% O2 during exercise reduced or eliminated left heart contrast in all subjects. Gene analyses revealed that 15/24 patients were either heterozygous or homozygous for methylenetetrahydrofolate reductase gene polymorphism; 4G/4G and 4G/5G genotypes of plasminogen-activator inhibitor-1 were present in 7/24 and 13/24 patients, respectively; polymorphisms of ACE D/D genotype were present in 6/24 and I/D in 14/24 patients. Having both I/D and 4G/4G genotypes was more prevalent in PFO+ subjects (P=.03), and there was a trend (P=.06) for PFO- subjects to have a greater D/D genotype prevalence. Novel genetic predispositions reported here in PFO subjects should be investigated further in larger stroke and/or TIA patient datasets.

Transthoracic contrast echocardiography using vitamin B6 and sodium bicarbonate as contrast agents for the diagnosis of patent foramen ovale

To evaluate the utility of transthoracic contrast echocardiography (cTTE) using vitamin B6 and sodium bicarbonate as contrast agents for diagnosing right-to-left shunt (RLS) caused by patent foramen ovale (PFO) compared to that of transesophageal echocardiography (TEE). We investigated 125 patients admitted to our neurology department with unexplained cerebral infarction and migraine. All patients underwent cTTE using vitamin B6 and sodium bicarbonate as contrast agents, after which they underwent transthoracic echocardiography. The Doppler signal was recorded during the Valsalva maneuver, and TEE examinations were performed. The feasibility, diagnostic sensitivity, and safety of cTTE and TEE for PFO recognition were compared. Evidence of PFO was found in 49 (39.20%) patients with cTTE, more than were detected with TEE (39, 31.20%) (χ2=5.0625, P=0.0244). cTTE had a sensitivity of 92.31% and a specificity of 84.88% for diagnosing PFO, showing high concordance with TEE for PFO recognition (κ=0.72). Further, results of a semi-quantitative evaluation of PFO-RLS by cTTE were better than those with TEE (Z=-2.011, P=0.044). No significant adverse reaction was discovered during cTTE examination. cTTE using vitamin B6 and sodium bicarbonate as contrast agents has relatively good sensitivity and specificity for diagnosing RLS caused by PFO when compared with those for TEE. Using vitamin B6 and sodium bicarbonate as contrast agents to perform cTTE is recommended for detecting and diagnosing the PFO due to its simplicity, non-invasive character, low cost, and high feasibility.

Comparison of Different Contrast Agents in Detecting Cardiac Right-to-Left Shunt in Patients with a Patent Foramen Ovale during Contrast-Transthoracic Echocardiography.

The aim of this study is to evaluate the ability of two different contrast agents to detect cardiac right-to-left shunting in patients with a patent foramen ovale during contrast transthoracic echocardiography and transesophageal echocardiography. Eighty-four patients who had migraines or experienced cryptogenic stroke were prospectively enrolled. Contrast echocardiography of the right portion of the heart was performed using an injection of either (i) 8 ml of agitated saline, 1 ml of blood, and 1 ml of air (ASB) or (ii) 4 ml of vitamin B6 and 6 ml of sodium bicarbonate solution (VSBS). All patients underwent contrast echocardiography with different contrast agents successively before undergoing transesophageal echocardiography. The diagnostic sensitivity of VSBS and ASB for cardiac shunting diagnosis was 94.23% and 78.85%, respectively. The diagnostic sensitivity in the VSBS group was significantly higher than that in the ASB group (χ2 = 5.283, P = 0.022). The observed semiquantitative shunt grading suggests that the positive rate in the VSBS group was higher than that in the ASB group (Z = −1.998, P = 0.046). The use of vitamin B6 and sodium bicarbonate solution as a TTE contrast agent yielded a high sensitivity compared with ASB. However, further trials with large sample size are required to confirm this finding.

The Diagnostic Value of Contrast Enhanced Ultrasound in Acute Aortic Dissection

Acute aortic dissection is an life-threatening disease that symptoms come on abruptly and progress quickly. patients without treatment have a mortality approaching 1%-2% in the acute stage. Prompt and accurate diagnosis and timely treatment are profoundly important. CTA is first examination method selected to patents who are suspected for AD, but it has some limitations such as contrast agent allergy and radiation exposure. contrast enhanced ultrasound is convenient and safe, however the research on the AD is rare. From November 2015 to Jaunary 2017, We enrolled 41 patients (28 males and 13 females, mean age 57.8±11.1 years) with clinical suspicion of AD in Wuhan Union hospital. Conventional transthoracic echocardiography (TTE)、contrast transthoracic echocardiography (c-TEE) and multislice computed tomography angiography (MS-CTA) were performed to scan the whole aorta in sequence. Serving CTA as the reference standard, We compared conventional ultrasound with CEUS in diagnosing the characterization of AD. Of the 41 patients, 22 patients were diagnosed for AD and 20 underwent surgical repair. Using Stanford classification system, type A were detected in 40.9% (9/22) of patients, type B were seen in 59.1% (13/22). C-TEE correctly diagnosed all the patients, however Conventional TEE had 5 false-positive results because of artifacts (4 in ascending aorta and 1 in the arch). C-TEE distinguished a flap from an artifact in 5 cases, identifed the false lumen slow blood flow in 1 and defined the border of false lumen thrombosis clearly in 8. Conventional TEE visualized intmal flaps in 20 of 22 cases, with the use of contrast enhancement increased to 22 (p=0.49). Conventional TEE correctly identified the true lumen from false lumen in 19/22 (86.4%) cases, and c-TEE in 22/22 (100%) ( P = 0.23) cases. Specificity of conventional TEE increased after contrast enhancement from 73.68 to 100% (P =0.046) for the diagnosis of AD, and both two methods’ sensitivity are 100% (P=1.0). CEUS can accurately diagnose and analysis the characteristics of AD, it is superior than conventional ultrasound in discovering the details lesions of AD, and will provide important information for the diagnosis of AD.

P594Contrast transthoracic echocardiography as a gatekeeper for patent foramen ovale closure.

The presence of patent foramen ovale (PFO) has been linked to many illness, including cryptogenic stroke, transient ischemic attack, migraine, platypnea-orthodeoxia syndrome and decompression sickness in scuba divers. Transesophageal echocardiography is the gold standard technique for the visualization of atrial septal anatomy, but it is a secondary level exam, not always available, with additional associated costs and not completely free from procedural risks. Standard transthoracic echocardiography (TTE) has a too low sensitivity for PFO screening. The aim of the study was to assess the role of TTE associated with agitated saline contrast injection (contrast-TTE) as a gatekeeper for the identification of PFO in a large cohort of patients undergoing selection for percutaneous closure. A total of 200 patients undergoing a diagnostic work-up for the identification of PFO was imaged by contrast-TTE at rest and after provocative maneuvers (PM: Valsalva in all cases). Contrast TTE was graded from 0 to 4 on the bases of bubbles counting (0: no bubbles; 1: < 10 bubbles; 2: 10-30 bubbles; 3: >30 bubbles; 4: complete LV opacification). PFO closure was performed after a consensual clinical decision by the cardiologist and the neurologist taking into account comprehensive imaging, clinical evaluation and thrombophilia screening. PFO closure was always monitored by intracardiac echocardiography. At baseline contrast TTE was positive (≥2) in 34 patients (17%) while contrast TTE with PM was positive in 94 cases (47%). 27 out of 200 patients (14%) had an interatrial septal aneurysms. PFO closure was performed in 34 cases (17%). All of these had severe right-to-left shunting (≥3) at contrast TTE and 9 cases had also an interatrial septal aneurysms. The procedure was aborted in only 1 patient due to a complex defect anatomy. Contrast TTE with PM may be not only considered an accurate tool for the detection of PFO but may be also inserted in the diagnostic work- up as a primary gatekeeper for percutaneous closure. Severe shunting at contrast TTE influences final decision making in a large cohort of cases undergoing screening for PFO closure.

The Impact of Hypoxaemia on the Outcome in Liver Cirrhosis.

Prognostic factors for poor evolution are critical in the setting of limited access to liver transplantation for patients with cirrhosis. We aimed to investigate the impact of hypoxaemia on the outcome in cirrhosis and the evolution of arterial oxygen tension during long-term follow-up in these patients. Consecutive cirrhotic patients were prospectively enroled and followed-up in our tertiary referral center. Clinical features, biological tests, arterial blood gases, NT-proBNP levels, pulse oximetry measurements, 12-lead ECG, and transthoracic contrast echocardiography were documented on enrolment. The main outcomes were death and decompensation due to liver disease. 87 cirrhotic patients were included in the analysis and followed-up for a mean of 16 months. At enrolment, 27 (31%) patients were hypoxaemic, 19 had hepatopulmonary syndrome (HPS), but only 6 of those who were sampled at follow-up had persistent hypoxaemia. During the study period, 22 patients died of liver-related complications. Nine of them (41%) were hypoxaemic on enrolment but none had severe hypoxaemia. Hypoxaemia present at enrollment was not a risk factor for death (p=0.29) or decompensation of liver disease (p=0.7). A higher MELD score at baseline or increase during follow-up was a risk factor for death (p=0.02) and correlated with the presence of hypoxaemia. Normalization of the arterial oxygen levels was accompanied by a significant decrease in NT-proBNP (83 pg/ml vs 0 pg/mL, p=0.023). Mild and moderate hypoxaemia was frequent in our patients but was not associated with adverse outcome in cirrhosis. Repeated arterial blood gas sampling is advisable, especially in patients diagnosed with hepatopulmonary syndrome.

Quantification of aortic stenosis diagnostic parameters: comparison of fast 3 direction and 1 direction phase contrast CMR and transthoracic echocardiography

BackgroundAortic stenosis (AS) is a common valvular disorder, and disease severity is currently assessed by transthoracic echocardiography (TTE). However, TTE results can be inconsistent in some patients, thus other diagnostic modalities such as cardiovascular magnetic resonance (CMR) are demanded. While traditional unidirectional phase-contrast CMR (1Dir PC-CMR) underestimates velocity if the imaging plane is misaligned to the flow direction, multi-directional acquisitions are expected to improve velocity measurement accuracy. Nonetheless, clinical use of multidirectional techniques has been hindered by long acquisition times. Our goal was to quantify flow parameters in patients using 1Dir PC-CMR and a faster multi-directional technique (3Dir PC-CMR), and compare to TTE.MethodsTwenty-three patients were prospectively assessed with TTE and CMR. Slices above the aortic valve were acquired for both PC-CMR techniques and cine SSFP images were acquired to quantify left ventricular stroke volume. 3Dir PC-CMR implementation included a variable density sampling pattern with acceleration rate of 8 and a reconstruction method called ReVEAL, to significantly accelerate acquisition. 3Dir PC-CMR reconstruction was performed offline and ReVEAL-based image recovery was performed on the three (x, y, z) encoding pairs. 1Dir PC-CMR was acquired with GRAPPA acceleration rate of 2 and reconstructed online. CMR derived flow parameters and aortic valve area estimates were compared to TTE.ResultsReVEAL based 3Dir PC-CMR derived parameters correlated better with TTE than 1Dir PC-CMR. Correlations ranged from 0.61 to 0.81 between TTE and 1Dir PC-CMR and from 0.61 to 0.87 between TTE and 3Dir-PC-CMR. The correlation coefficients between TTE, 1Dir and 3Dir PC-CMR Vpeakwere 0.81 and 0.87, respectively. In comparison to ReVEAL, TTE slightly underestimates peak velocities, which is not surprising as TTE is only sensitive to flow that is parallel to the acoustic beam.ConclusionsBy exploiting structure unique to PC-CMR, ReVEAL enables multi-directional flow imaging in clinically feasible acquisition times. Results support the hypothesis that ReVEAL-based 3Dir PC-CMR provides better estimation of hemodynamic parameters in AS patients in comparison to 1Dir PC-CMR. While TTE can accurately measure velocity parallel to the acoustic beam, it is not sensitive to the other directions of flow. Therefore, multi-directional flow imaging, which encodes all three components of the velocity vector, can potentially outperform TTE in patients with eccentric or multiple jets.

Modified Right Heart Contrast Echocardiography Versus Traditional Method in Diagnosis of Right-to-Left Shunt: A Comparative Study.

SummaryBackgroundThe purpose of this study was to evaluate the reliability, effectiveness, and safety of modified right heart contrast transthoracic echocardiography (cTTE) in comparison with the traditional method.Material/MethodsWe performed a modified right heart cTTE using saline mixed with a small sample of patient’s own blood. Samples were agitated with varying intensity. This study protocol involved microscopic analysis and patient evaluation. 1. Microscopic analysis: After two contrast samples had been agitated 10 or 20 times, they underwent a comparison of bubble size, bubble number, and red blood cell morphology. 2. Patient analysis: 40 patients with suspected RLS (right- to-left shunt) were enrolled. All patients underwent right heart contrast echocardiography. Oxygen saturation, transit time and duration, presence of RLS, change in indirect bilirubin and urobilinogen concentrations were compared afterward.ResultsModified method generated more bubbles (P<0.05), but the differences in bubble size were not significant (P>0.05). Twenty-four patients were diagnosed with RLS (60%) using the modified method compared to 16 patients (40%) with the traditional method. The transit time of ASb20 group was the shortest (P<0.05). However, the duration time in this group was much longer (P<0.05). Also, in semi-quantitative analysis mean rank of RLS was higher after injecting the modified contrast agent agitated 20 times (P<0.05).ConclusionsModified right heart contrast echocardiography is a reliable, effective and safe method of detecting cardiovascular RLS.

Patent foramen ovale and cryptogenic stroke: from studies to clinical practice: Position paper of the Italian Chapter, International Society Cardiovascular Ultrasound.

Over the last two decades the interest on patent foramen ovale (PFO) as a cause of cardioembolism in cryptogenic stroke has tremendously increased, thanks to the availability of better techniques to diagnose cardiac right-to-left shunt by ultrasounds and of percutaneous means of PFO treatment with interventional techniques. Many studies have been published that have attempted to define diagnostic methodology, prognosis, and optimal treatment (pharmacological or percutaneous closure) of PFO patients with cryptogenic stroke. Unfortunately, even today, definitive evidence is still lacking, and clinical management is not consistent among cardiologists. This review aims to evaluate the role of PFO in cryptogenic stroke, the diagnostic accuracy of transcranial Doppler, contrast transthoracic and transesophageal echocardiography in the diagnosis of left-fright shunt and PFO; and discuss the indications to medical treatment and percutaneous closure of PFO. All studies published in the literature on PFO and cryptogenic stroke are considered and discussed. We define an appropriate diagnostic and clinical management of PFO patients with cryptogenic stroke. After many years of interest on PFO and many concluded studies, there are still no definitive data. However, we are on good track for an appropriate management of PFO patients and cryptogenic stroke.

Decreased arterial PO2, not O2 content, increases blood flow through intrapulmonary arteriovenous anastomoses at rest.

The mechanism(s) that regulate hypoxia-induced blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) are currently unknown. Our previous work has demonstrated that the mechanism of hypoxia-induced QIPAVA is not simply increased cardiac output, pulmonary artery systolic pressure or sympathetic nervous system activity and, instead, it may be a result of hypoxaemia directly. To determine whether it is reduced arterial PO2 (PaO2) or O2 content (CaO2) that causes hypoxia-induced QIPAVA , individuals were instructed to breathe room air and three levels of hypoxic gas at rest before (control) and after CaO2 was reduced by 10% by lowering the haemoglobin concentration (isovolaemic haemodilution; Low [Hb]). QIPAVA , assessed by transthoracic saline contrast echocardiography, significantly increased as PaO2 decreased and, despite reduced CaO2 (via isovolaemic haemodilution), was similar at iso-PaO2. These data suggest that, with alveolar hypoxia, low PaO2 causes the hypoxia-induced increase in QIPAVA , although where and how this is detected remains unknown. Alveolar hypoxia causes increased blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) in healthy humans at rest. However, it is unknown whether the stimulus regulating hypoxia-induced QIPAVA is decreased arterial PO2 (PaO2) or O2 content (CaO2). CaO2 is known to regulate blood flow in the systemic circulation and it is suggested that IPAVA may be regulated similar to the systemic vasculature. Thus, we hypothesized that reduced CaO2 would be the stimulus for hypoxia-induced QIPAVA . Blood volume (BV) was measured using the optimized carbon monoxide rebreathing method in 10 individuals. Less than 5days later, subjects breathed room air, as well as 18%, 14% and 12.5% O2 , for 30min each, in a randomized order, before (CON) and after isovolaemic haemodilution (10% of BV withdrawn and replaced with an equal volume of 5% human serum albumin-saline mixture) to reduce [Hb] (Low [Hb]). PaO2 was measured at the end of each condition and QIPAVA was assessed using transthoracic saline contrast echocardiography. [Hb] was reduced from 14.2±0.8 to 12.8±0.7gdl(-1) (10±2% reduction) from CON to Low [Hb] conditions. PaO2 was no different between CON and Low [Hb], although CaO2 was 10.4%, 9.2% and 9.8% lower at 18%, 14% and 12.5% O2 , respectively. QIPAVA significantly increased as PaO2 decreased and, despite reduced CaO2, was similar at iso-PaO2. These data suggest that, with alveolar hypoxia, low PaO2 causes the hypoxia-induced increase in QIPAVA . Whether the low PO2 is detected at the carotid body, airway and/or the vasculature remains unknown.

Resting arterial hypoxaemia in subjects with chronic heart failure, pulmonary hypertension and patent foramen ovale.

What is the central question of this study? Does a patent foramen ovale contribute to resting arterial hypoxaemia, defined as arterial oxygen saturation <95%, in subjects with chronic heart failure with or without pulmonary arterial hypertension? What is the main finding and its importance? The presence of a patent foramen ovale contributed to resting arterial hypoxaemia only in subjects with chronic heart failure with pulmonary arterial hypertension. These data suggest that the presence of a patent foramen ovale should be considered in chronic heart failure patients with arterial hypoxaemia and pulmonary hypertension. The roles of intrapulmonary and intracardiac shunt in contributing to arterial hypoxaemia at rest in subjects with chronic heart failure (CHF) have not been well investigated. We hypothesized that blood flow through intrapulmonary arteriovenous anastomoses (Q̇ IPAVA ) and/or patent foramen ovale (Q̇ PFO ) could potentially contribute to arterial hypoxaemia and, with pulmonary hypertension (PH) secondary to CHF, this contribution may be exacerbated. Fifty-six subjects with CHF (New York Heart Association Classes I-III), with (+) or without (-) PH [defined as peak tricuspid regurgitation velocity ≥2.9ms(-1) (CHF PH+, n=32) and peak tricuspid regurgitation velocity ≤2.8ms(-1) (CHF PH-, n=24)], underwent arterial blood gas analysis and transthoracic saline contrast echocardiography concomitant with transcranial Doppler to detect Q̇ IPAVA and Q̇ PFO . Seventeen of 56 subjects with CHF (30%) had Q̇ PFO , but only four of 56 subjects with CHF had Q̇ IPAVA (7%), both similar to age- and sex-matched control subjects. Mean arterial oxygen saturation (SaO2) was lower in subjects with Q̇ PFO . Only CHF PH+ subjects with Q̇ PFO had arterial hypoxaemia (mean SaO2 <95%). Bubble scores assessed using transthoracic saline contrast echocardiography were correlated with microembolic signals detected with transcranial Doppler in subjects with Q̇ PFO . Significant Q̇ IPAVA was not present in either CHF PH+ or PH- subjects, suggesting that Q̇ IPAVA is not dependent on increased pulmonary pressure and does not contribute significantly to arterial hypoxaemia in older subjects with CHF. Given that SaO2 was lower in all subjects with CHF who had Q̇ PFO compared with those without Q̇ PFO , a patent foramen ovale should be considered when determining potential causes of arterial hypoxaemia, because Q̇ PFO was present in 30% of these subjects.

Follow-up of pulmonary right-to-left shunt in hereditary haemorrhagic telangiectasia.

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurological complications in hereditary haemorrhagic telangiectasia (HHT). Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary right-to-left shunts (RLS). Although growth of PAVMs is shown in two small studies, no studies on follow-up with TTCE exist.All HHT patients underwent a second TTCE 5 years after initial screening. Patients with a history of PAVM embolisation were excluded. Pulmonary RLS grade on TTCE after 5 years was compared to the grade at screening.200 patients (53.5% female, mean±sd age at screening 44.7±14.1 years) were included. Increase in RLS grade occurred in 36 (18%) patients, of whom six (17%) underwent embolisation. The change in grade between screening and follow-up was not more than one grade. Of patients with nontreatable pulmonary RLS at screening (n=113), 14 (12.4%) underwent embolisation. In patients without pulmonary RLS at initial screening (n=87), no treatable PAVMs developed during follow-up.Within 5 years, no treatable PAVMs developed in HHT patients without pulmonary RLS at initial screening. Increase in pulmonary RLS grade occurred in 18% of patients, and never increased by more than one grade. Of patients with nontreatable pulmonary RLS at initial screening, 12% underwent embolisation.

Hepatopulmonary syndrome: What we know and what we would like to know.

Hepatopulmonary syndrome (HPS) is characterized by abnormalities in blood oxygenation caused by the presence of intrapulmonary vascular dilations (IPVD) in the context of liver disease, generally at a cirrhotic stage. Knowledge about the subject is still only partial. The majority of the information about the etiopathogenesis of HPS has been obtained through experiments on animals. Reported prevalence in patients who are candidates for a liver transplantation (LT) varies between 4% and 32%, with a predominance of mild or moderate cases. Although it is generally asymptomatic it does have an impact on their quality of life and survival. The diagnosis requires taking an arterial blood gas sample of a seated patient with alveolar-arterial oxygen gradient (AaO2) ≥ 15 mm Hg, or ≥ 20 mm Hg in those over 64 years of age. The IPVD are identified through a transthoracic contrast echocardiography or a macroaggregated albumin lung perfusion scan ((99m)Tc-MAA). There is currently no effective medical treatment. LT has been shown to reverse the syndrome and improve survival rates, even in severe cases. Therefore the policy of prioritizing LT would appear to increase survival rates. This paper takes a critical and clinical look at the current understanding of HPS, as well as the controversies surrounding it and possible future research.

Peak velocity estimation in aortic stenosis patients using a fast three-directional two-dimensional phase contrast technique in a single breath-hold: comparison to unidirectional phase contrast MRI and transthoracic echocardiography

Peak velocity estimation in aortic stenosis patients using a fast three-directional two-dimensional phase contrast technique in a single breath-hold: comparison to unidirectional phase contrast MRI and transthoracic echocardiography

Platypnea-orthodeoxia syndrome: Importance of patient position for correct diagnosis at the time of 99mTc-MAA injection

A 65-year-old male presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome) secondary to hepatopulmonary syndrome (HPS). A (99m)Tc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 29% in the sitting position, which had not been previously detected when the radiotracer injection was performed with the patient in supine position, nor was it diagnosed using another non-invasive imaging method (transthoracic contrast echocardiography and angio-CT). A transesophageal echocardiography was contraindicated due to the presence of esophageal varices. The administration of the radiopharmaceutical in sitting position for the study of the pulmonary perfusion allowed us to confirm the presence of the shunt and consider the patient a candidate for liver transplantation.