Agitated Saline Contrast Echocardiography in the Identification of Intra- and Extracardiac Shunts: Connecting the Dots

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

BACKGROUND AND HYPOTHESIS

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.

METHODS

Retrospectively, 267 patients who had undergone ECG, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) with agitated saline contrast echocardiography in our hospital, were recruited continuously from January 2021 to March 2023. Electrocardiographs were analyzed to investigate the presence of right bundle branch block (RBBB) and crochetage R wave.

RESULTS

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).

CONCLUSIONS

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 with PFO.

Overcoming a stubborn patent foramen ovale

Transesophageal echocardiography (TEE) with agitated saline contrast ("bubble study") is the gold standard for detection of patent foramen ovale (PFO). Standard provocative maneuvers help facilitate right-to-left shunting necessary for diagnosing PFO but may be difficult to implement during TEE. Hypovolemia related to preprocedural fasting may challenge detection of PFO in TEE, and additional optimization measures such as fluid replenishment with passive leg raise (PLR) can enhance PFO detection. We present a 57-year-old male with history of cryptogenic stroke and stubborn PFO which during TEE bubble study responded only to ample fluid replenishment with PLR following a period of prolonged preprocedural fasting.

Increasing Venous Return Blood Flow to the Right Atrium Using the Party Balloon Inflation Maneuver

The party balloon inflation maneuver increases intrathoracic pressure, decreases venous return, and after release enhances venous return to the right atrium more effectively than does the conventional Valsalva maneuver. Therefore, it shows potential for more effective detection of right-to-left shunts in patients with a patent foramen ovale. (Level of Difficulty: Intermediate.).

Pearls and Pitfalls in the Transesophageal Echocardiographic Diagnosis of Patent Foramen Ovale

Large randomized controlled trials have shown the benefits of percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke and PFO. Recent studies have highlighted the clinical significance and prognostic implication of various anatomical features of PFO and the adjacent atrial septum, such as atrial septal aneurysm (ASA), PFO size, large shunt, and hypermobility. Transthoracic echocardiography with contrast study is used for the indirect diagnosis of PFO, as it reveals the passage of the contrast into the left atrium. In contrast, transesophageal echocardiography (TEE) offers a direct demonstration of PFO by measuring its size using the maximum separation distance between the septum primum and septum secundum. Furthermore, TEE enables the acquisition of detailed anatomical features of the adjacent atrial septum including ASA, hypermobility, and PFO tunnel length, which carry significant prognostic implications. Transesophageal echocardiography also facilitates the diagnosis of pulmonary arteriovenous malformation, a relatively rare cause of paradoxical embolism. This review provides evidence for supporting TEE as a useful screening test for patients with cryptogenic stroke to identify suitable candidates for percutaneous device closure of PFO. Additionally, cardiac imaging specialists with proficiency in comprehensive TEE examination should be part of the heart-brain team for proper evaluation of and decision-making in patients with cryptogenic stroke.

Role of Quantitation of Saline Bubble Studies in Patients with Liver Cirrhosis

OBJECTIVE

Microbubble contrast echocardiography with a late positive signal enables the detection of intrapulmonary vascular dilation, including hepatopulmonary syndrome, in patients with end-stage liver disease. We assessed the relationship between the severity of bubble study and clinical outcome.

METHODS

We retrospectively analyzed 163 consecutive patients with liver cirrhosis who underwent an echocardiogram with bubble study from 2018 to 2021. Patients who were diagnosed with a late positive signal were divided into three groups: grade 1 (1-9 bubbles), grade 2 (10-30 bubbles) and grade 3 (>30 bubbles).

RESULTS

Fifty-six percent of the patients had a late positive bubble study (grade 1: 31%, grade 2: 23%, grade 3: 46%). Patients with grade 3 had a significantly higher international normalized ratio, model for end-stage liver disease score and Child-Pugh score and a lower peripheral oxygen saturation compared with patients with a negative study. In patients undergoing liver transplant (LT), survival rates were similar among the groups (3-mo: >87%, 1-y: >87%, 2-y: >83%). However, survival rate was lower in grade 3 patients without LT (3-mo: 81%, 1-y: 64%, 2-y: 39%).

CONCLUSION

Patients with grade 3 had much worse mortality without LT compared with other groups. However, after LT, all grades had equal survival. Therefore, patients with grade 3 may be considered as higher priority for LT.

Migrated Inferior Vena Cava (IVC) Filter Presenting as Tricuspid Valve Mass, Right-Sided Heart Failure, and Parodoxical Emboli

A 58-year-old male with an unknown medical history presented with acute encephalopathy, receptive aphasia, and hypertensive emergency. The patient did not have any family members from whom a collateral history could be obtained. He underwent X-rays of the abdomen and bilateral humeri/femurs to check for foreign bodies. He was found to have right femoral open reduction and internal fixation with retained screw fragments. He was diagnosed with ischemic stroke on MRI. Transthoracic echocardiogram (TTE) revealed right-sided heart failure and a tricuspid valve mass as well as right to left shunting. This raised concern for large atrial septal defect (ASD) with paradoxical embolization from tricuspid valve mass. Transesophageal echocardiogram (TEE) redemonstrated large ASD. Concern was raised for the ASD closure device as the cause of this "tricuspid mass." Due to history of orthopedic procedure, it was hypothesized that the patient had an IVC filter placed in the setting of pulmonary embolism (PE) prior to an orthopedic procedure. The tricuspid valve was visualized under fluoroscopy and was confirmed to be a migrated IVC filter. He was taken to the operating room (OR) for cardiac surgery for the removal of the IVC filter and repair of ASD. Surprisingly, no ASD was found.

Neglected intrapulmonary arteriovenous anastomoses: A comparative study of pulmonary right-to-left shunts in patients with patent foramen ovale

Objective

Pulmonary right-to-left shunt (P-RLS) and patent foramen ovale right-to-left shunt (PFO-RLS) often appear in combination, and there are often differences and connections between them. Intrapulmonary arteriovenous anastomoses (IPAVAs), as part of P-RLS, are often overlooked because there are no technologies to detect and identify them. This study aimed to further clarify the incidence and characteristics of P-RLS with the help of contrast transesophageal echocardiography (c-TEE) and contrast transthoracic echocardiography (c-TTE), providing a reference for clinically relevant research and patent foramen ovale (PFO) management disposal decisions.

Methods

We retrospectively investigated 414 subjects who came to our hospital for c-TEE from October 2021 to July 2022, and all subjects completed c-TTE simultaneously. 7 Patients who were newly diagnosed with an atrial septal defect were excluded. Eventually, 407 patients were included in this study. Among them, 157 patients with PFO (58 patients were treated with PFO closure subsequently) and 250 patients without PFO confirmed by c-TEE were finally enrolled. In the process, we observed and analysed the presence of P-RLS.

Results

A total of 407 patients were included in the final analysis and divided into PFO group (N = 157) and non-PFO group (N = 250) according to the results of c-TEE. Whether at rest or after Valsalva maneuver, the incidence of P-RLS was significantly higher under c-TEE than under c-TTE in the two groups (P &lt; 0.001). For both c-TTE and c-TEE, the incidence of P-RLS was slightly higher after Valsalva maneuver than at rest, but the difference was not significant (c-TTE: rest vs. Valsalva maneuver, P = 0.214; c-TEE: rest vs. Valsalva maneuver, P = 0.076). The Valsalva maneuver increased the incidence of P-RLS in the group without PFO, which was more significant in c-TEE (c-TTE: rest vs. Valsalva maneuver, P = 0.591; c-TEE: rest vs. Valsalva maneuver, P = 0.008). In both groups, the P-RLS semiquantitative grading was statistical significance under different states and examinations (P &lt; 0.001).

Conclusion

The vast majority of P-RLS are grade 1–2 and are derived from physiological IPAVAs. Even so, attention should be given to the differentiation between P-RLS and PFO-RLS. c-TEE is an effective method to detect P-RLS; however, the recruitments of c-TEE and Valsalva maneuver to P-RLS should be noted.

Agitated Saline Contrast Injection in Patients with Severe Hypoxemia

The use of agitated saline contrast (ASC) during echocardiographic examinations is a well-established practice, most commonly performed to identify atrial septal abnormalities in the context of stroke. In the intensive care unit, this technique may be employed to identify anatomic right-to-left shunts (either intracardiac or transpulmonary) that may be contributing to hypoxemic respiratory failure. This narrative review will describe the technique of ASC injection, summarize clinical scenarios where it may be useful, and review the strengths and limitations of the tool.

An Unusual Presentation of Eisenmenger Syndrome in a Middle-Aged Woman Without Known Cardiac History

Eisenmenger syndrome (ES) is a severe cardiac complication that arises from an untreated congenital cardiac defect, leading to the reversal of shunt flow, pulmonary hypertension, and cyanosis. This uncommon complication most frequently arises from small ventricular septal defects that are undiagnosed due to a lack of symptoms. However, it may arise from the reversal of any left-to-right cardiac shunt. In the following report, we present a case of acute-onset ES in a 52-year-old woman with no past cardiac history. The patient presented to the emergency department with a clinical presentation consistent with likely pulmonary embolism; however, after extensive work-up, this etiology of respiratory failure was deemed incorrect. After rapid respiratory decline requiring mechanical ventilation, the medical team performed two transthoracic echocardiograms (one with agitated saline study), one transesophageal echocardiogram, and a right cardiac catheterization on the patient. This work-up revealed pulmonary hypertension, right heart failure, and an atrial septal defect. Given these findings, the work-up was suggestive of ES secondary to an atrial septal defect shunt reversal. Because of the complexity of treatment, the patient was transferred via air to a university tertiary medical institution for extracorporeal membrane oxygenation along with other advanced treatments. This case provides a framework for the clinical presentation and treatment of this life-threatening disease. We hope that this information will help providers understand the clinical presentation, work-up, treatment, and prognosis of patients with Eisenmenger syndrome.

Calf muscle pump tensing as a novel maneuver to improve the diagnostic performance of detecting patent foramen ovale during transesophageal echocardiography

Objective

The Valsalva maneuver is the most sensitive provocative maneuver for patent foramen ovale detection. However, nearly half of patients are unable to perform the Valsalva maneuver well. The aim of this study was to investigate the mechanism of action of calf muscle pump tensing (TENSE) as a novel patent foramen ovale (PFO) provocative maneuver and to evaluate the diagnostic value for PFO and the effect on right-to-left shunt volume compared with the Valsalva maneuver.

Methods

This study prospectively investigated 171 patients who were highly suspected to have PFO clinically. Five patients with atrial septal defects newly diagnosed on transesophageal echocardiography (TEE) were excluded. 166 patients were injected with agitated saline under three provocative maneuvers: Valsalva maneuver, TENSE, and Valsalva + TENSE combined maneuver. The patients were divided into the effective Valsalva group (n = 93) and ineffective Valsalva group (n = 73) according to whether they could perform an effective Valsalva maneuver. TENSE consisted of the straightening of both lower limbs, and when the right atrium was filled with microbubbles, the patient performed instantaneous ankle dorsiflexion movements while maintaining dorsiflexion for 3-5 s.

Results

Overall, the PFO detection rate of the Valsalva + TENSE combined maneuver (78 [50.1%]) was significantly higher than that of the Valsalva maneuver (51 [30.7%]) and TENSE maneuver (57 [34.3%]) (P < 0.001). In the patients who were able to perform an effective Valsalva maneuver, the PFO detection rate by TENSE was not significantly different from that by the Valsalva maneuver (Valsalva 37/93 [39.8%] vs. TENSE 31/93 [33.3%], P > 0.05), while for the patients who performed an ineffective Valsalva maneuver, the PFO detection rate by the TENSE maneuver was higher than that by the Valsalva maneuver (TENSE 26/73 [35.6%] vs. Valsalva14/73[19.2%], P = 0.017).

Conclusion

TENSE is a simple and effective provocative maneuver in the diagnosis of PFO using TEE and can assist the Valsalva maneuver. For patients who cannot perform an effective Valsalva maneuver, TENSE can be an alternative to the Valsalva maneuver to some extent.

Cause of profound hypoxemia following a bilateral bidirectional Glenn shunt: Clue suggested by agitated saline echo contrast

Following a bilateral bidirectional Glenn shunt, a child had persistent hypoxemia. Agitated saline contrast injection into the jugular vein during transesophageal echocardiography displayed a rapid appearance of saline particles in the cardiac chambers suggesting the presence of pulmonary arteriovenous malformations. However, the clinical picture was not in agreement and an angiographic contrast injection during an immediate cardiac catheterization revealed the underlying pathology which was immediately corrected surgically.

Undiagnosed Atrial Septal Defect in the Setting of Comorbidities and Ventricular Failure: Seemingly Simple Disease with a Challenging Diagnosis

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In adults, ASD remains underdiagnosed, particularly in the setting of comorbidities.

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A high index of suspicion is needed to find ASD in PH and/or ventricular dysfunction.

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Multiple views, including subcostal view, and ASC injection improve ASD diagnosis.

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Multimodality imaging is essential with nondiagnostic TTE and suspected CHD.

Acute Respiratory Distress Syndrome and Shunt Detection With Bubble Studies: A Systematic Review and Meta-Analysis

Acute respiratory distress syndrome (ARDS) is a life-threatening respiratory injury with multiple physiological sequelae. Shunting of deoxygenated blood through intra- and extrapulmonary shunts may complicate ARDS management. Therefore, we conducted a systematic review to determine the prevalence of sonographically detected shunts, and their association with oxygenation and mortality in patients with ARDS.

DATA SOURCES

Medical literature analysis and retrieval system online, Excerpta Medica dataBASE, Cochrane Library, and database of abstracts of reviews of effects databases on March 26, 2021.

STUDY SELECTION

Articles relating to respiratory failure and sonographic shunt detection.

DATA EXTRACTION

Articles were independently screened and extracted in duplicate. Data pertaining to study demographics and shunt detection were compiled for mortality and oxygenation outcomes. Risk of bias was appraised using the Joanna-Briggs Institute and the Newcastle-Ottawa Scale tools with evidence rating certainty using Grading of Recommendations Assessment, Development and Evaluation methodology.

DATA SYNTHESIS

From 4,617 citations, 10 observational studies met eligibility criteria. Sonographic detection of right-to-left shunt was present in 21.8% of patients (range, 14.4-30.0%) among included studies using transthoracic, transesophageal, and transcranial bubble Doppler ultrasonographies. Shunt prevalence may be associated with increased mortality (risk ratio, 1.22; 95% CI, 1.01-1.49; p = 0.04, very low certainty evidence) with no difference in oxygenation as measured by Pao2:Fio2 ratio (mean difference, -0.7; 95% CI, -18.6 to 17.2; p = 0.94, very low certainty).

CONCLUSIONS

Intra- and extrapulmonary shunts are detected frequently in ARDS with ultrasound techniques. Shunts may increase mortality among patients with ARDS, but its association with oxygenation is uncertain.

Pitfalls of Using Imaging Technique in the Presence of Eustachian Valve or Chiari Network: Effects on Right-to-Left Shunt and Related Influencing Factors

When patent foramen ovale (PFO) combines with the prominent Eustachian valve or Chiari network (EV/CN), contrast transthoracic echocardiography (cTTE) may miss the diagnosis of PFO. We sought to determine the characteristics of right-to-left shunt (RLS) in PFO patients with prominent EV/CN on cTTE and identify the causal factors of missed diagnosis. We consecutively enrolled 98 patients who suffered from PFO-related stroke and with prominent EV/CN. All patients were divided into the delayed and non-delayed groups according to the characteristics of RLS on cTTE. The characteristics of RLS were compared with those of 42 intrapulmonary shunt patients. The anatomical characteristics of PFO and EV/CN were analyzed in the 98 PFO patients. Upon cTTE, significantly delayed occurrence and longer duration of the RLS in the delayed group were found both at rest and during the Valsalva maneuver, similar to the intrapulmonary shunt. Multivariate logistic analysis revealed that the length of EV/CN (>19 mm) and the diameter of PFO at the left atrium aspect (<1.2 mm) were high-risk factors for missed diagnosis. In conclusion, RLS showed delayed emergence and disappearance in some of the PFO patients with prominent EV/CN. The length of EV/CN and the diameter of PFO may have been related to the missed diagnosis of PFO.

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.)

Platypnoea-Orthodeoxia Syndrome as an Uncommon Cause of Dyspnoea: a Literature Review

Platypnoea-Orthodeoxia syndrome (POS) is an uncommon but challenging clinical condition characterized by positional dyspnoea (platypnoea) and arterial desaturation (orthodeoxia) in the upright position that improve in the supine position. Since its first description, many cases have been reported and many conditions have been associated with this syndrome. Herein we review the clinical presentation, pathophysiology, diagnostic work-up and management of patients with POS, aiming at increasing the awareness of this often misdiagnosed condition. This article is protected by copyright. All rights reserved.

Transesophageal Echocardiography-Guided Aspiration of Venous Air Embolism During Liver Transplantation: A Case Report

Transesophageal echocardiography can be useful not only in diagnosing venous air embolism but also in guiding aspiration of air from the pulmonary artery. A 59-year-old man with a history of cirrhosis underwent combined kidney and liver transplantations. He developed acute hypotension after the native liver was removed due to a massive venous air embolism via a retained transjugular intrahepatic portosystemic shunt catheter. Transesophageal echocardiography revealed air in the pulmonary artery resulting in outflow obstruction. Under echocardiographic guidance, the pulmonary arterial catheter was withdrawn to the air pocket and aspirated, resulting in improved hemodynamics and successful completion of transplantations.

Contrast-Enhanced Echocardiography Application in Patients Supported by Extracorporeal Membrane Oxygenation (ECMO): A Narrative Review

Extracorporeal membrane oxygenation (ECMO) is a lifesaving intervention increasingly used to support patients with severe respiratory and cardiac dysfunction. Echocardiography is an important tool, aiding implantation and monitoring during ECMO therapy, but often its use is limited by poor acoustic windows. This limitation may be overcome by the use of echocardiography contrast agents to improve diagnostic yield and reduce the need for other imaging modalities that may require patient transfer, involve ionizing radiation and, occasionally, nephrotoxic radio-opaque contrast medium. In this article the authors review the literature addressing the use of contrast-enhanced echocardiography (CEE) in ECMO-supported patients. The authors discuss the role of CEE in guiding implantation of ECMO, cardiac assessment and diagnosis of complications during ECMO therapy, as well as the safety of ultrasound-enhancing agents in this cohort of patients.