Intracardiac shunts

Anesthetic management of cesarean delivery in parturients with ruptured sinus of Valsalva aneurysm: CARE-compliant 2 case reports and literature review

RATIONALE

Ruptured sinus of Valsalva aneurysm is rare and dangerous in parturients. Few cases of ruptured SVA in pregnancy are reported, and the anesthetic management for cesarean delivery has scarcely been described.

PATIENT CONCERNS

A parturient at 37-week gestation complained of a sore throat and cough that started 3 days before admission, followed 1 day later by fever, dizziness, breathlessness, and palpitation on exertion. Case two at 36-week gestation complained of a 1-day history of bloating in the lower abdomen.

DIAGNOSES

Full term and preterm parturients with ruptured sinus of Valsalva aneurysm.

INTERVENTIONS

Cesarean deliveries were performed with incremental epidural anesthesia technique under invasive monitoring. Surgical correction of the ruptured sinus of Valsalva aneurysms and ventricular septal defect were performed uneventfully 13 days and 7 days postpartum, respectively, for the 2 cases.

OUTCOMES

No complications were observed in the intra- or postoperative period for both mothers and babies.

LESSONS

We reviewed the pertinent literature and reached the following conclusions: use of a multidisciplinary team to guide anesthetic management is helpful and necessary; and both general anesthesia and incremental epidural anesthesia can be safely used in parturients with ruptured sinus of Valsalva aneurysm.

Intracardiac shunting and stroke in children: a systematic review

In adults, patent foramen ovale or other potential intracardiac shunts are established risk factors for stroke via paradoxical embolization. Stroke is less common in children and risk factors differ. The authors examined the literature on intracardiac shunting and stroke in children, identifying the methods employed, the prevalence of detectible intracardiac shunts, associated conditions, and treatments. PubMed searches with keywords related to intracardiac shunting and stroke in children identified articles of interest. Additional articles were identified via citations in these articles or in reviews. The authors found that studies of intracardiac shunting in children with stroke are limited. No controlled studies were identified. Detection methods vary and the prevalence of echocardiographically detectible intracardiac shunting appears lower than reported in adults and autopsy studies. Defining the role of intracardiac shunting in pediatric stroke will require controlled studies with unified detection methods in populations stratified by additional risk factors for paradoxical embolization. Optimal treatment is unclear.

Acute right to left shunt through patent foramen ovale presenting as hypoxemia after myocardial infarction: a case report

Introduction

This is a report of a 56-year-old man who became hypoxic due to an acute right to left shunt after sustaining a myocardial infarction involving the right ventricle. This case provides the opportunity to review several key pathophysiologic concepts in the setting of acute right ventricular infarction. Although the development of an acute right to left shunt is a rare complication of myocardial infarction, it is important to recognize the diagnosis early in order to prevent life threatening or debilitating clinical sequelae that may result from tissue hypoxia and embolic events. Transesophageal echocardiography is the noninvasive study of choice to confirm the diagnosis. Treatment involves optimization of right ventricular function to minimize shunting. However, medical therapy may provide only temporary relief, and closure of the atrial septal defect should be considered if a clinically significant shunt persists.

Case presentation

A 56-year-old Caucasian man with severe aortic insufficiency presented to the emergency department for evaluation of substernal chest pain. An inferior myocardial infarction was diagnosed by the electrocardiogram and serologic markers. Cardiac catheterization revealed complete occlusion of the right coronary artery as well as a 50-75% stenosis of the left anterior descending artery. Angioplasty of the right coronary artery was performed, but immediate re-occlusion occurred. Subsequently, hypotension and severe hypoxemia developed and persisted despite intubation and mechanical ventilation with 100% oxygen. A significant right-to-left shunt through a patent foramen ovale was diagnosed by contrast transesophageal echocardiogram. Surgical intervention was required and included coronary artery bypass grafting, aortic valve replacement as well as closure of his atrial septal defect.

Conclusion

A right to left atrial shunt is a rare complication of inferior myocardial infarction with right ventricular infarction. The diagnosis should be considered in the presence of inferior myocardial infarction when hypoxemia persists despite administration of 100% oxygen. Early diagnosis and treatment are critical in order to reduce the risk of embolization and to prevent end-organ damage due to hypoxemia.

Echocardiography for management of hypotension in the intensive care unit

Hypotension is a common problem in critically ill patients. Rapid diagnosis and intervention may prevent this deterioration and improve eventual outcome. Echocardiography may make a critical difference in the rapid diagnosis of both common and uncommon but important causes of hypotension, such as pericardial tamponade. The differential diagnosis for hypotension differs between acutely admitted septic or trauma patients and the chronic patient in the intensive care unit. A better approach to patient evaluation is the performance of a comprehensive evaluation on every patient. A comprehensive examination is less likely to miss an unexpected diagnosis. With practice, a complete examination may be performed in minutes. Preload, contractility, systolic function (global and focal), and assessment of diastolic dysfunction (common cause of congestive heart failure) can be performed quickly. Specific situations like pericardial tamponade, pulmonary embolism, left ventricular outflow tract obstruction, unexplained hypoxemia, and aortic dissection, among others, can all be reliably performed using transesophageal echocardiography. Appropriate training and utilization of this technology will essentially help better manage hypotension in critically ill patients and thereby may improve their outcome. An algorithm to this effect has been suggested, although the same results can be achieved with different algorithms or approaches.

Paradoxical embolism: a rare life- and limb-threatening emergency

This article presents a case of a 43-year-old man with paradoxical embolism. The patient had simultaneous deep venous thrombosis, pulmonary embolism and bilateral limb-threatening arterial occlusions. The unifying diagnosis was paradoxical embolism through a previously undetected atrial septal defect. Suggestions for the evaluation and emergency management of paradoxical embolism are outlined, and the literature is briefly reviewed.

Echo contrast-enhanced diagnosis of atrial septal defect

Pulsed wave, continuous wave, and color flow Doppler imaging as well as intravenously administered agitated saline solution can detect intracardiac shunts during transthoracic echocardiography. Ultrasonographic contrast agents have greatly improved the visualization of left heart chambers and can enhance signals from blood flow within chambers and across valves, increasing the sensitivity of Doppler techniques. We describe a patient in whom the use of echo contrast media during transthoracic echocardiography allowed the detection of a previously unseen atrial septal defect. Combining such modalities may help to increase the sensitivity of transthoracic echocardiography and may eliminate the need for transesophageal echocardiography in selected patients.

Transcatheter closure of patent foramen ovale for hypoxemia during left ventricular assist device support

A patent foramen ovale with right-to-left shunting was responsible, in part, for profound hypoxemia in a patient who required mechanical support with a left ventricular assist device for cardiogenic shock. The patent foramen ovale was detected with contrast transesophageal echocardiography, and the defect was closed successfully with a transcatheter septal defect closure device.