Residual Right-to-Left-Shunt Following Transcatheter Patent Foramen Ovale Closure: The Role of Antithrombotic Treatment.

BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) is a highly effective therapy for patients with left circulation thromboembolism, not attributable to other conditions. OBJECTIVES: This retrospective cohort study investigates the impact of baseline foramen ovale anatomy on the severity of the postclosure shunt. METHODS: Patients with PFO, who underwent percutaneous closure, were followed up for at least 5 years postimplantation. Patients were classified into two groups based on the presence of high-risk features of the baseline PFO anatomy. At the follow-up follow-up, residual right-to-left shunt was assessed for the high and non-highrisk anatomy groups, via transcranial Doppler at rest and after performing the Valsalva maneuver, with the injection of agitated saline. RESULTS: 38 patients were examined after a mean follow-up period of 9 ± 3 years after implantation. After retrospective evaluation of the baseline transthoracic and transesophageal echo studies, 14 patients with high-risk PFO anatomy were identified. The degree of the residual right-to-left shunt, as assessed by the number of microbubbles was higher in the high-risk PFO anatomy group compared to the non-high-risk group, both at rest [1.50 (IQR: 0.00-3.25) vs. 0.00 (IQR: 0.00-0.00), p < 0.001] and post-Valsalva maneuver [7.50 (IQR: 1.50- 10.25) vs. 0.00 (IQR: 0.00-3.75), p = 0.003]. Furthermore, in the high-risk group, more microbubbles were detected at rest (p = 0.008) and post-Valsalva (p = 0.002) in subjects without antiplatelet treatment compared to subjects on prolonged antiplatelet therapy. CONCLUSION: Baseline PFO anatomy affects the severity of the residual right-to-left shunt. Prolonged antiplatelet therapy may benefit patients with high-risk anatomical features.

Avaliação Ecocardiográfica de Pacientes com Forame Oval Patente e Acidente Vascular Cerebral Criptogênico / Echocardiographic Evaluation of Patients with Patent Foramen Ovale and Cryptogenic Stroke

Recentes estudos indicaram que o forame oval patente (FOP) pode ser responsável pelo acidente vascular cerebral criptogênico (AVC) em pacientes jovens que apresentam condições anatômicas favoráveis a essa anomalia e que a oclusão transcateter reduz a incidência do acidente vascular cerebral quando comparada ao tratamento clínico. A injeção de soro agitado durante o estudo ecocardiográfico, associada à manobra de Valsalva, pode evidenciar shunt direita-esquerda com alta sensibilidade (89%) e especificidade (92%) quando se utiliza o ecocardiograma transesofágico. Avaliando as características clínicas de pacientes com acidente vascular cerebral e forame oval patente, o trial Risk of Paradoxical Embolism, conhecido pela sigla RoPE, (Risk of Paradoxical Embolism) estabeleceu um escore de risco para acidente vascular cerebral criptogênico e, por meio de um modelo de regressão multivariada, identificou seis variáveis: idade, presença de isquemia cortical, diabetes, hipertensão, AVC e acidente isquêmico transitório prévio. Os escores mais elevados foram observados em jovens com AVC e sem fatores de risco vascular e os escores mais baixos em idosos com fatores de risco vascular, de modo que o forame oval patente sugere ser acidental. Condições anatômicas do FOP predispõem à embolia sistêmica (separação do FOP > 2 mm; túnel do FOP > 10 mm; ângulo entre a veia cava inferior e o flap do FOP <10°; intensidade do shunt com manobra de Valsalva; presença de aneurisma do septo interatrial e rede de Chiari ou válvula de Eustáquio proeminente). O fechamento do FOP pode prevenir a embolia paradoxal, reduzindo a incidência de acidente vascular cerebral em pacientes considerados com de risco elevado. A relação entre Acidente Vascular Cerebral (AVC) criptogênico e a presença de Forame Oval Patente (FOP) tem despertado particular interesse, baseada em estudos recentes que demonstraram que a oclusão transcateter do FOP reduziu a incidência de AVC criptogênico, quando comparado ao tratamento medicamentoso.1 Trombos atravessando o forame oval podem ser observados em exames ecocardiográficos e em autópsias, confirmando esse mecanismo como responsável pela embolia paradoxal, ou seja, um trombo venoso passando para a circulação arterial por um shunt direita-esquerda. Entretanto, essa visualização ecocardiográfica é rara e existem poucos estudos publicados2,3 (Figura 1). Alguns estudos clínicos demonstram a propensão do FOP ser o responsável pela embolia paradoxal. Pacientes portadores de diabetes, hipertensão arterial sistêmica e doença arterial coronária têm baixa prevalência para o FOP ser o responsável pela embolia paradoxal. Por outro lado, história de trombose venosa profunda, embolia pulmonar, hipertensão pulmonar, viagens prolongadas, manobra de Valsalva precedendo o início de sintomas de AVC, enxaqueca e apneia do sono tem sido descrita como fatores de risco independentes para a associação entre FOP e eventos cerebrovasculares.4 Mesmo sendo pouco frequente a visualização de trombos em forame oval, a observação epidemiológica nos leva a acreditar que o FOP é o responsável por um número considerável de acidentes vasculares cerebrais.5 A prevalência de FOP em um estudo com autópsia em 965 corações normais é de 27%, com similar distribuição entre homens e mulheres. Essa prevalência declina com a idade, sendo de 34% em menores de 30 anos, 25% entre 30 e 80 anos e 20% em maiores de 80 anos.6 Em pacientes com AVC criptogênico, entretanto, a prevalência é particularmente elevada, chegando a 40% em pacientes com idade inferior a 55 anos.7 É importante ressaltar que a presença de FOP em pacientes com AVC criptogênico não é a única etiologia para o embolismo paradoxal. Outros mecanismos podem ser responsáveis, como fibrilação atrial não detectada, tumores cardíacos (mixoma e fibroeslastomas), presença de contraste ecocardiográfico espontâneo em átrio esquerdo, valvopatia mitral reumática, calcificação do anel valvar mitral, próteses cardíacas biológicas e mecânicas, estados de hipercoagulabilidade e ateroma de aorta ascendente.8 O estudo ecocardiográfico é parte da rotina na avaliação do FOP, principalmente o Ecocardiograma Transesofágico (ETE) com utilização de solução salina agitada (macrobolhas). Considera-se um shunt pequeno quando passam de três a dez bolhas, médio de dez a 30 bolhas e grande se mais de 30 bolhas contadas nos primeiros batimentos após a injeção.9 Além da detecção do shunt, o ETE avalia as características anatômicas do FOP, assim como o diagnóstico diferencial com a comunicação interatrial e com o shunt pulmonar.10,11 Trabalhos comparando o ETE utilizando macrobolhas com os achados de autópsia mostram sensibilidade de 89% e especificidade de 92%, sendo que a autópsia é considerada padrão-ouro.12(AU)

[Utility of transesophageal echocardiography for etiologic diagnosis of centrum ovale infarcts].

A small centrum ovale infarct in the territory of the white matter medullary artery can be caused not only by embolism but also small-vessel disease. In our study, thorough screening for emboligenic diseases was performed, including the modality of transesophageal echocardiography (TEE), in patients with an acute, isolated, small (less than 1.5 cm) infarct in the centrum ovale. Of 79 patients enrolled in this study, 45 had emboligenic diseases, in whom a patent foramen ovale was detected in 29 patients, complicated aortic arch lesion in 15, atrial fibrillation in 6, occlusive carotid disease in 2, and others in 2. The majority (80%) of the emboligenic diseases were diagnosed by TEE. Therefore, TEE may be mandatory for the etiologic diagnosis of centrum ovale infarcts.

¿Existe relación entre las lesiones de la sustancia blanca asociadas a migraña y el foramen oval permeable? Análisis de una serie de pacientes con migraña crónica / Is there a relationship between white matter lesions associated with migraine and patent foramen ovale? Analysis of a series of patients with chronic migraine

INTRODUCCIÓN: Las lesiones de la sustancia blanca son más prevalentes en los pacientes migrañosos que en la población general, especialmente en los que tienen una alta frecuencia de ataques. El foramen oval permeable se ha descrito como posible nexo de unión entre la migraña y las lesiones de la sustancia blanca. OBJETIVO: Determinar la existencia de una posible relación entre el foramen oval permeable y las lesiones de la sustancia blanca en una serie de pacientes con migraña crónica. PACIENTES Y MÉTODOS: Estudio observacional, unicéntrico, de casos y controles. Se seleccionó a 89 mujeres con migraña crónica. La persistencia y las características del foramen oval permeable se evaluaron mediante un estudio Doppler transcraneal. El foramen oval permeable se clasificó como pequeño, moderado o masivo. Se consideraron permanentes los detectados en reposo, y latentes, el resto. El protocolo de resonancia magnética incluyó imágenes sagitales potenciadas en T1, axiales potenciadas en FLAIR-T2 y secuencia combinada de densidad protónica y T2-FSE. Las lesiones de la sustancia blanca se clasificaron como profundas, periventriculares o ambas. RESULTADOS: La prevalencia de foramen oval permeable (53,6% frente a 48,5%; p = 0,80) y la proporción de foramen oval permeable masivo y permanente fueron similares entre los pacientes con y sin lesiones de la sustancia blanca. Tampoco se encontraron diferencias en la prevalencia (55,6% frente a 52,6%; p = 1,00) o las características del foramen oval permeable en función de la distribución de las lesiones de la sustancia blanca. CONCLUSIÓN: Los resultados no sugieren la intervención del foramen oval permeable en la fisiopatología de las lesiones de la sustancia blanca observadas en pacientes migrañosos

INTRODUCTION. White matter lesions are more prevalent in migraine patients than in the general population, especially those with a high frequency of attacks. A patent foramen ovale has been described as a possible link between migraine and white matter lesions. AIM. To determine the existence of a possible relationship between a patent foramen ovale and white matter lesions in a series of patients with chronic migraine. PATIENTS AND METHODS. Observational, single-centre, case-control study. Eighty-nine women with chronic migraine were selected. The persistence and characteristics of the patent foramen ovale were assessed by means of a transcranial Doppler study. The patent foramen ovale was classified as small, moderate or massive. Those detected at rest were considered permanent, and the others were classified as latent. The MRI protocol included T1-enhanced sagittal images, FLAIR-T2-enhanced axial images, and a proton density and T2-FSE combined sequence. The white matter lesions were classified as deep, periventricular or both. RESULTS. The prevalence of patent foramen ovale (53.6% versus 48.5%; p = 0.80) and the proportion of massive, permanent patent foramen ovale were similar among patients with and without white matter lesions. Neither was there any difference in the prevalence (55.6% versus 52.6%; p = 1.00) or the characteristics of the patent foramen ovale as a function of the distribution of white matter lesions. CONCLUSION. The results do not suggest that a patent foramen ovale intervenes in the pathophysiology of the white matter lesions observed in patients with migraine

Traumatic tricuspid valve papillary muscle case with concomitant acquired patent foramen ovale and covert right atrial rupture. / Ruptura traumática de músculo papilar da valva tricúspide com forame oval patente adquirido e ruptura atrial direita oculta.

Cardiac trauma often occurs in motor vehicle accidents. A 50-year-old female driver was transported to our hospital with multiple trauma after a high-speed car accident. After admission to the intensive care unit, cardiac ultrasound examination revealed traumatic tricuspid valve papillary muscle rupture and patent foramen ovale, while Lancisi's sign was noted on physical examination. Surgical treatment was performed with valve annuloplasty and closure of the patent foramen ovale and a covert right atrial defect that was detected intraoperatively.

O traumatismo cardíaco é comum em acidentes com veículos automotores. Uma mulher com 50 anos de idade foi transportada para nosso hospital após sofrer múltiplos traumatismos em um acidente de automóvel quando dirigia em alta velocidade. Após admissão à unidade de terapia intensiva, uma ultrassonografia cardíaca revelou ruptura traumática de músculo papilar da valva tricúspide e forame oval patente, enquanto se observou, no exame físico, o sinal de Lancisi. Foi realizado tratamento cirúrgico com anuloplastia da valva e fechamento do forame oval patente; durante o ato cirúrgico, diagnosticou-se ruptura oculta do átrio direito.

Ruptura traumática de músculo papilar da valva tricúspide com forame oval patente adquirido e ruptura atrial direita oculta / Traumatic tricuspid valve papillary muscle case with concomitant acquired patent foramen ovale and covert right atrial rupture

RESUMO O traumatismo cardíaco é comum em acidentes com veículos automotores. Uma mulher com 50 anos de idade foi transportada para nosso hospital após sofrer múltiplos traumatismos em um acidente de automóvel quando dirigia em alta velocidade. Após admissão à unidade de terapia intensiva, uma ultrassonografia cardíaca revelou ruptura traumática de músculo papilar da valva tricúspide e forame oval patente, enquanto se observou, no exame físico, o sinal de Lancisi. Foi realizado tratamento cirúrgico com anuloplastia da valva e fechamento do forame oval patente; durante o ato cirúrgico, diagnosticou-se ruptura oculta do átrio direito.

ABSTRACT Cardiac trauma often occurs in motor vehicle accidents. A 50-year-old female driver was transported to our hospital with multiple trauma after a high-speed car accident. After admission to the intensive care unit, cardiac ultrasound examination revealed traumatic tricuspid valve papillary muscle rupture and patent foramen ovale, while Lancisi's sign was noted on physical examination. Surgical treatment was performed with valve annuloplasty and closure of the patent foramen ovale and a covert right atrial defect that was detected intraoperatively.

Amplatzer patent foramen ovale occluder: safety and efficacy.

INTRODUCTION: The patent foramen ovale (PFO) is a common anatomical variant in humans (prevalence 25%). Most often asymptomatic, it may engender paradoxically embolic strokes, myocardial infarctions, or visceral or peripheral ischemia. It is causatively related to migraine, positional or exertional hypoxemia with dyspnea, diving incidents, high altitude edema, and sleep apnea. Percutaneous closure of atrial septal defects was first performed in the seventies. A dedicated PFO occluder (Amplatzer PFO Occluder) was first used on 10 September 1997 by Kurt Amplatz and Bernhard Meier. Since, percutaneous PFO closure has evolved into one of the most common and the simplest and safest catheter-based intervention in adult cardiology. Randomized studies have proved its benefit for prevention of recurrent ischemic events (particularly strokes) in patients without competing stroke etiology. There are also supportive clinical data for PFO closure in other situations. Areas covered: The Amplatzer PFO Occluder, the first, most implanted, and best-studied PFO occluder, is reviewed, presenting implantation technique, possible complications, and pertinent scientific data of efficacy and safety. Expert commentary: Percutaneous PFO closure has grown to one of the most common procedures in interventional cardiology. Implantation of the Amplatzer PFO Occluder is simple, safe, and effective.

A novel probe attached to the neck can accurately detect a large patent foramen ovale.

PURPOSE: We developed a novel probe (pastable soft ultrasound probe; PSUP) attached to the neck for right-to-left shunt (RLS) detection. The purpose of this study was to evaluate the diagnostic ability of the PSUP for RLS detection by comparison with transesophageal echocardiography (TEE). METHODS: The subjects were patients with ischemic strokes and transient ischemic attacks who underwent TEE. Based on TEE, patients with patent foramen ovale (PFO) were divided into two groups by the number of microbubbles (MBs): small PFO (1-29 MBs) and large PFO (≥30 MBs). Then, PSUP examination of one common carotid artery (CCA) was started using a procedure similar to TEE. RLS was diagnosed by PSUP when one or more microembolic signals were found in the CCA. The detection rate by size of PFO was compared between TEE and PSUP, and the diagnostic accuracy of PSUP was calculated. RESULTS: From May 2014 to July 2016, 84 patients (63 males, median age 63 years) were included; 41 (49%) were diagnosed with PFO by TEE, while PSUP detected PFO in 31 (37%). Using TEE findings as the reference, PSUP for PFO showed sensitivity of 68%, specificity of 93%, and accuracy of 81%. On TEE, 22 patients had large PFOs, and 19 patients had small PFOs. The PSUP could identify large PFOs in grade I and II of International Consensus Criteria more accurately than small ones (58 and 86% vs. 29 and 14%, P = 0.003). CONCLUSIONS: The PSUP has considerable accuracy for diagnosing large PFOs. PSUP should play an important role in detecting large PFOs.

Closure of patent foramen ovale in "cryptogenic" stroke: Has the story come to an end?

Contrasting with three randomized trials that failed to show any superiority of patent foramen ovale closure over antithrombotic therapy, two trials recently reported lower rates of stroke recurrence among patients assigned to patent foramen ovale closure than among those assigned to antiplatelet therapy. In addition, one of the initially negative trials concluded in favor of patent foramen ovale closure after an extended follow-up period. A better selection of patients, the use of reference treatment groups that included patients who received antiplatelet therapy alone (rather than antiplatelet drugs or oral anticoagulants, according to physician preference), and a longer follow-up of patients, may explain the divergent findings across studies. Procedural complications were reported in 1.5% to 5.9% of the patients, none of which led to permanent disability or death. Patent foramen ovale closure was associated with an increased risk of new-onset atrial fibrillation in several studies and of venous thromboembolism in one study.

A single-center experience with 12 consecutive cases of pregnancy among patients with membranous ventricular septal aneurysm.

BACKGROUND: Membranous ventricular septal aneurysm (MVSA) is a rare cardiac anomaly that can occur as an isolated entity or being associated with other cardiac malformations. Complications of MVSA include thromboembolism, arrhythmia, rupture, bacterial endocarditis, right ventricular outflow tract obstruction, and atrioventricular valve diseases.The success rate of pregnancy and delivery in patients with MVSA has not been reported in the literature. This study was to assess the clinical implications of this condition from our center's experience. METHODS: This was a retrospective study for consecutive 12 pregnancies in women with MVSA, who delivered at a tertiary care center in west China between May 2008 and March 2015. RESULTS: All patients with MVSA delivered via caesarian section. One patient with severe pulmonary arterial hypertension expired from pulmonary infection and heart failure after delivery. One patient terminated pregnancy in the second trimester- necessitated by cardiogenic shock. The other mothers had varying degrees of cardiac morbidity, but survived. Ten of thirteen newborns survived. Congenital heart disease and small-for-gestational-age (SGA) of newborn occurred in two cases (one twin and one single gestation). Two of these babies expired. CONCLUSIONS: Maternal and neonatal risk appeared associated with heart functional classifications, pulmonary hypertension and histories of cardiac events such as serious cardiac arrhythmia. Accurate diagnosis and care by a multidisciplinary team is recommended for pregnant woman with MVSA.

Hypercoagulability and Migraine.

BACKGROUND: A growing body of literature suggests that migraineurs, particularly those with aura, have an increased risk for ischemic stroke, but not via enhanced atherosclerosis. The theory that micro-emboli induced ischemia provokes cortical spreading depression (ie, symptomatic aura) in migraineurs but transient ischemic attacks in others highlights a potential role for hypercoagulability as a link between migraine (with aura) and stroke. AIM: Our objective is to summarize the literature evaluating the association of migraine with various acquired or inheritable thrombophilic states, including those related to elevated estrogen levels, endothelial activation and dysfunction, antiphospholipid antibodies (aPL), deficiency of coagulation inhibitors, and presence of certain genetic polymorphisms. FINDINGS: Although definitive studies are lacking, a preponderance of available evidence links migraine, and especially aura, to increased levels of estradiol (eg, oral contraceptive pill [OCP] use, pregnancy), thrombo- and erythrocytosis, von Willebrand factor (vWF) antigen, fibrinogen, tissue plasminogen activator (tPA) antigen, and endothelial microparticles. Studies of a link to migraine are conflicting for aPL, homocysteine, Protein S, and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. No association with migraine was found in meta-analyses of Factor V Leiden, and of prothrombin gene mutation. Within a large, young ischemic stroke sample, migraine with aura was associated with a thrombophilic state and with patent foramen ovale (PFO). In the non-stroke population, meta-analyses show an association of PFO and migraine with aura (MA), but two population-based studies do not support the link. RECOMMENDATIONS: For persons with MA and (1) a personal history or family history of thrombosis, or (2) MRI evidence of micro-vascular ischemia or of stroke, an evaluation for hypercoagulability is warranted. In cases of MA alone, consider screening for markers of endothelial activation (eg, vWF, high sensitivity c-reactive protein [hs CRP], and fibrinogen). Rigorous management of other stroke risk factors is paramount, but efficacy of anti-thrombotic agents in the treatment of migraine is unproven. Closure of PFO is not routinely recommended based on negative randomized trials.

The multiple dimensions of Platypnea-Orthodeoxia syndrome: A review.

Platypnea-Orthodeoxia syndrome (POS) is a rare clinical entity characterized by dyspnea and arterial desaturation while in the upright position. The various pathophysiologic mechanisms leading to POS has puzzled clinicians for years. The hypoxia in POS has been attributed to the mixing of the deoxygenated venous blood with the oxygenated arterial blood via a shunt. The primary mechanisms of POS in these patients can be broadly classified based on intracardiac abnormalities, extracardiac abnormalities and miscellaneous etiologies. A Patent Foramen Ovale (PFO) was the most common reported site of an intracardiac shunt. In addition to PFO, intracardiac shunt leading to POS has been reported from either an Atrial Septal Defect (ASD) or an Atrial Septal Aneurysm (ASA). Most patients with an intracardiac shunt also demonstrated a secondary anatomic or a functional defect. Extracardiac causes of POS included intra-pulmonary arteriovenous malformations and lung parenchymal diseases. A systematic evaluation is necessary to identify the underlying cause and institute an appropriate intervention. We conducted a review of literature and reviewed 239 cases of POS. In this article, we review the etiology and pathophysiology of POS and also summarize the diagnostic algorithms and treatment modalities available for early diagnosis and prompt treatment of patients presenting with symptoms of platypnea and/or orthodeoxia.

Dyspnea following thoracostomy closure after right pneumonectomy: An uncommon echocardiographic diagnosis and therapeutic approach.

Dyspnea and hypoxemia are common postoperative problems after pneumonectomy. One of the rarer causes of respiratory distress after right pneumonectomy is the development of a significant right-to-left shunt across a patent foramen ovale (PFO), which can evolve at a variable interval of time after the operation. We report here our experience with a patient who underwent right pneumonectomy, followed by several complications, and who presented severe dyspnea 7 months later, after the closure of a right thoracostomy. This report outlines the management of this challenging clinical condition; transesophageal echocardiography (TOE) provided a clear diagnosis and guided an effective percutaneous treatment.

Decompression illness with hypovolemic shock and neurological failure symptoms after two risky dives: a case report.

Hypovolemia is known to be a predisposing factor of decompression illness (DCI) while diving. The typical clinically impressive neurological symptoms of DCI may distract from other symptoms such as an incipient hypovolemic shock. We report the case of a 61-year-old male Caucasian, who presented with an increasing central and peripheral neural failure syndrome and massive hypovolemia after two risky dives. Computed tomography (CT) scans of the chest and Magnetic resonance imaging scans of the head revealed multiple cerebral and pulmonary thromboembolisms. Transesophageal echocardiography showed a patent foramen ovale (PFO). Furthermore, the patient displayed hypotension as well as prerenal acute kidney injury with elevated levels of creatinine and reduced renal clearance, indicating a hypovolemic shock. Early hyperbaric oxygen (HBO) therapy reduced the neurological deficits. After volume expansion of 11 liters of electrolyte solution (1000 mL/h) the cardiopulmonary and renal function normalized. Hypovolemia increases the risk of DCI during diving and that of hypovolemic shock. Early HBO therapy and fluid replacement is crucial for a favorable outcome.

Patent Foramen Ovale in Recreational and Professional Divers: An Important and Largely Unrecognized Problem.

Patent foramen ovale (PFO) is associated with an increased risk of decompression sickness (DCS) in divers that results from a paradoxical embolization of nitrogen bubbles. The number of scuba divers worldwide is estimated in the millions, and the prevalence of PFO is 25%-30% in adults. It is interesting that despite these numbers, many important issues regarding optimal screening, risk stratification, and management strategy still remain to be resolved. Recently published data suggest the possible effectiveness of both PFO closure and conservative diving measures in preventing arterial gas embolization. This review aims to introduce the basic principles of physiology and the pathophysiology of bubble formation and DCS, summarize the current literature on PFO and diving, and review the possibilities of diagnostic workup and management.

Acute respiratory distress syndrome (ARDS)-associated acute cor pulmonale and patent foramen ovale: a multicenter noninvasive hemodynamic study.

INTRODUCTION: Acute cor pulmonale (ACP) and patent foramen ovale (PFO) remain common in patients under protective ventilation for acute respiratory distress syndrome (ARDS). We sought to describe the hemodynamic profile associated with either ACP or PFO, or both, during the early course of moderate-to-severe ARDS using echocardiography. METHODS: In this 32-month prospective multicenter study, 195 patients with moderate-to-severe ARDS were assessed using echocardiography during the first 48 h of admission (age: 56 (SD: 15) years; Simplified Acute Physiology Score: 46 (17); PaO2/FiO2: 115 (39); VT: 6.5 (1.7) mL/kg; PEEP: 11 (3) cmH2O; driving pressure: 15 (5) cmH2O). ACP was defined by the association of right ventricular (RV) dilatation and systolic paradoxical ventricular septal motion. PFO was detected during a contrast study using agitated saline in the transesophageal bicaval view. RESULTS: ACP was present in 36 patients, PFO in 21 patients, both PFO and ACP in 8 patients and the 130 remaining patients had neither PFO nor ACP. Patients with ACP exhibited a restricted left ventricle (LV) secondary to RV dilatation and had concomitant RV dysfunction, irrespective of associated PFO, but preserved LV systolic function. Despite elevated systolic pulmonary artery pressure (sPAP), patients with isolated PFO had a normal RV systolic function. sPAP and PaCO2 levels were significantly correlated. CONCLUSIONS: In patients under protective mechanical ventilation with moderate-to-severe ARDS, ACP was associated with LV restriction and RV failure, whether PFO was present or not. Despite elevated sPAP, PFO shunting was associated with preserved RV systolic function.