Not all unexplained hypoxia is pulmonary embolism

Acute myocardial infarction is one of the conditions frequently managed in the emergency department. There are many complications associated with right ventricular infarction, and the incidence of right ventricular infarction associated with inferior myocardial infarction is as high as 51% based on electrocardiographic findings. We herein report the case of a 45-year-old Chinese man with inferior myocardial infarction complicated by right ventricular failure. He had hypoxaemia refractory to supplemental oxygen due to an acute right-to-left shunting through a patent foramen ovale (PFO). He underwent coronary angioplasty and closure of the PFO. It is crucial for the attending physician to consider the presence of a right-to-left shunt when there is persistent uncorrectable hypoxaemia despite maximal oxygen supplementation in the setting of right ventricular infarction, as there are clinical implications and certain clinical managing principles that should be applied.     

Wandering spleen with chronic torsion in a patient with thalassaemia

Wandering spleen or splenoptosis is an uncommon entity and often an asymptomatic finding of acute abdomen in the emergency department. A high index of suspicion for splenic torsion is required, particularly in patients with known splenomegaly, as this condition could potentially lead to splenic infarction. Recognition of this condition can help avoid potential confusion with acute abdomen of other aetiologies. Herein, we present a unique case of wandering spleen with chronic torsion, which, to the best of our knowledge, has never been described in an elderly patient with haemoglobin H thalassaemia. We also review the literature for the aetiology and pathogenesis of wandering spleen, and discuss the relevant diagnostic modalities and treatment options.     

Imaging in noncardiovascular thoracic emergencies: a pictorial review

Cardiovascular and noncardiovascular conditions are commonly encountered in the emergency department. While the majority of patients have underlying cardiovascular aetiologies, such as acute myocardial infarction, congestive heart failure, aortic dissection and pulmonary embolism, a small subset of patients have underlying noncardiovascular conditions, although they present with similar symptoms of chest pain, dyspnoea, cough, haemoptysis and haematemesis. This article aims to describe the imaging findings in common noncardiovascular conditions of the chest that are frequently encountered in the emergency department, with a review of the existing literature.     

Coronary anatomy,anatomic variations and anomalies: a retrospective coronary angiography study

INTRODUCTION

The incidence of coronary artery anomalies (CAAs) varies from 0.2% to 8.4%. Knowledge of such anatomical variations is important as coronary procedures are regularly performed these days. We aimed to find the coronary dominance pattern, intermediate artery (IMA) frequency and CAA incidence in our clinic, and compare them to those in the literature.

METHODS

The medical reports of 5,548 patients who had undergone coronary angiography (CAG) between 2005 and 2009 were retrospectively investigated. Dominance pattern and presence of IMA and CAA were recorded. CAAs were described using two different classifications: Angelini and Khatami’s classification, and a new modified classification that was derived from Angelini and Khatami’s classification. Some procedural details and clinical features of the patients with CAA were also investigated.

RESULTS

Coronary dominance pattern was: 81.6% right coronary artery, 12.2% circumflex artery and 6.2% co-dominant. IMA was present in 613 (11.0%) patients. The incidences of overall anomaly were 2.7% and 1.4%, according to the different classifications. Absent left main coronary artery, which was the most common anomaly in the present study, was found in 51 (0.9%) patients. Incidences of myocardial bridge, coronary arteriovenous fistulae and aneurysms were 1.1%, 0.2% and 0.3%, respectively.

CONCLUSION

CAAs are generally asymptomatic, isolated lesions. Some may lead to anginal symptoms, myocardial infarction or sudden death. We found that CAA was associated with increased radiation and contrast exposure in patients who underwent CAG. This risk could be reduced if appropriate catheters were designed and training programmes on ostial cannulation were developed.     

Acute myocardial infarction and subclavian artery occlusion in a 41-year-old woman with Beh?et’s disease: coronary and large vessel arteritis

We report the case of a 41-year-old Chinese woman with Behçet’s disease (BD) complicated by acute myocardial infarction, requiring inotropic and ventilatory support. Angiography showed critical left anterior descending coronary artery stenosis, a blocked left subclavian artery and left carotid artery stenosis. The patient was successfully treated with a high dose of immunosuppressants, standard anti-ischaemic therapy and percutaneous coronary intervention. Although life-threatening, coronary arteritis is a treatable manifestation of BD. We suggest that the diagnosis of coronary arteritis be considered in patients with BD who present with chest pain. Involvement of other arteries should also be looked out for in these patients.     

Recurrent myocardial infarction secondary to Prinzmetal’s variant angina

Prinzmetal’s variant angina describes chest pain secondary to reversible coronary artery vasospasm in the context of both diseased and non-diseased coronary arteries. Symptoms typically occur when the patient is at rest and are associated with transient ST-segment elevation. Acute episodes respond to glyceryl trinitrate, but myocardial infarction and other potentially fatal complications can occur, and long-term management can be challenging. Although it is not well understood, the underlying mechanism appears to involve a combination of endothelial damage and vasoactive mediators. In this case, a 35-year-old woman with myocardial infarction secondary to coronary artery vasospasm experienced recurrent chest pain. Coronary angiography revealed severe focal stenosis in the mid left anterior descending artery, which completely resolved after administration of intracoronary glyceryl trinitrate. The patient was discharged on nitrates and calcium channel blockers. The patient re-presented with another myocardial infarction, requiring up-titration of medical therapy.     

Gastric variceal bleeding precipitated by a mycotic splenic arteriovenous fistula in a cirrhotic patient: radiological diagnosis and endovascular treatment

Splenic arteriovenous fistula (SAVF) is an unusual cause of portal hypertension, and is rarely associated with an infective aetiology. It is often difficult to identify SAVF clinically, and thus, radiological modalities are invariably required for diagnosis and treatment. We herein describe a case of SAVF occurring in a patient with compensated cirrhosis as a sequel to salmonella gastroenteritis, and presenting with acute gastric variceal bleeding. Selective transcatheter embolisation of the splenic artery was effective in controlling bleeding.     

ECG series. Importance of QT interval in clinical practice

Long QT interval is an important finding that is often missed by electrocardiogram interpreters. Long QT syndrome (inherited and acquired) is a potentially lethal cardiac channelopathy that is frequently mistaken for epilepsy. We present a case of long QT syndrome with multiple cardiac arrests presenting as syncope and seizures. The long QTc interval was aggravated by hypomagnesaemia and drugs, including clarithromycin and levofloxacin. Multiple drugs can cause prolongation of the QT interval, and all physicians should bear this in mind when prescribing these drugs.     

Clinics in diagnostic imaging (160). Levocardia with abdominal situs inversus

Levocardia (left-sided cardiac apex) with abdominal situs inversus is extremely rare. This is also known as isolated levocardia and is almost always associated with severe forms of congenital heart defects with poor prognosis. We report isolated levocardia in a 13-year-old symptomatic male patient. The purpose of this paper is to outline the imaging features of isolated levocardia and to highlight the role of cardiovascular magnetic resonance imaging (CMR) in the diagnosis and management of such cases. Other forms of cardiac malposition, including dextrocardia, mesocardia and criss-cross heart, with chest radiograph and CMR correlation, are also discussed.     

Imaging of acute cholecystitis and cholecystitis-associated complications in the emergency setting

Acute cholecystitis is a common cause of right upper quadrant pain in patients presenting at the emergency department. Early diagnosis and recognition of associated complications, though challenging, are essential for timely management. Imaging studies, including ultrasonography, computed tomography and magnetic resonance imaging, are increasingly utilised for the evaluation of suspected cases of cholecystitis. These investigations help in diagnosis, identification of complications and surgical planning. Imaging features of acute cholecystitis have been described in the literature and are variable, depending on the stage of inflammation. This article discusses the spectrum of cholecystitis-associated complications and their imaging manifestations. We also suggest a checklist for the prompt and accurate identification of complications in acute cholecystitis.     

Anaesthetic management of a premature low-birth-weight neonate with congenital complete heart block for implantation of temporary epicardial pacing wires

The optimal anaesthetic management of neonates with complete congenital heart block (CCHB) is unknown, as there is a low incidence of such cases. Neonates with CCHB often require surgery for the initiation of electronic pacing. In addition to the challenges of anaesthetising a neonate, this procedure is risky due to the potential for hypotension, arrhythmias and cardiac arrest. We herein present the case of a premature low-birth-weight neonate with antibody-related CCHB and normal heart structure who underwent anaesthesia and surgery for epicardial pacing wire insertion on Day 1 of life. We also compare our patient’s anaesthetic conduct and outcome with similar previously reported cases.     

Acute myocardial infarction found by multi-detector computed tomography ordered for suspected aortic dissection.

Urgent requests for contrast computed tomographic scans of the thorax are often performed for suspected aortic dissections and pulmonary embolisms, both of which have clinical features similar to those seen in acute myocardial infarction. We present two cases with computed tomographic scans showing decreased myocardial enhancement, suggestive of acute myocardial infarction, but no evidence of aortic dissection. Acute myocardial infarction was subsequently confirmed by coronary angiography.     

Multiple oesophago-respiratory fistulae: sequelae of pulmonary tuberculosis in retroviral infection

Pulmonary tuberculosis (PTB) is a common infectious disease worldwide. However, mediastinal tuberculous lymphadenitis complicated by oesophageal involvement and oesophago-respiratory fistula is now uncommon due to improved anti-tuberculous regimes and better general awareness. The overall incidence of acquired oesophago-respiratory fistula due to infection is low, and therefore, the lesion is not often a frontrunner in differential diagnosis. Still, tuberculous oesophago-respiratory fistulae can potentially occur in patients with retroviral disease, as they tend to have atypical and more virulent manifestations. In this study, we report the case of multiple oesophago-respiratory fistulae in a patient with PTB and retroviral disease, and highlight the computed tomography features of these lesions as an atypical presentation of PTB in retroviral disease. Clinicians should suspect oesophago-respiratory fistulae if patients present with Ono’s sign, and remain particularly vigilant for patients with underlying PTB and retroviral disease, as early diagnosis and treatment could help to reduce mortality.     

Neurogenic heterotopic ossification after a stroke: diagnostic and radiological challenges

Heterotopic ossification (HO) is the aberrant formation of ectopic bone within the soft tissues, of which the aetiology is usually either traumatic or neurogenic. Neurogenic HO is a known but uncommon complication that occurs after a cerebral or spinal insult. The condition may present with a spectrum of symptoms and is often difficult to diagnose clinically. Although different imaging modalities have been used to diagnose HO, clinicians and radiologists may occasionally encounter radiological features of HO that may mimic other disease conditions. We herein report a rare case of neurogenic HO occurring in the non-paretic limb of a patient, and the diagnostic and radiological challenges encountered.     

Clinics in diagnostic imaging (155). Incidental PDA with secondary pulmonary arterial hypertension.

We report the case of a 70-year-old man with an asymptomatic large patent ductus arteriosus (PDA) incidentally detected on triple-rule-out computed tomography (CT). CT clearly demonstrated a vascular structure connecting the descending thoracic aorta to the roof of the proximal left pulmonary artery, consistent with a PDA. Secondary pulmonary arterial hypertension was also evident on CT. The patient was eventually diagnosed with acute coronary syndrome and was successfully treated with coronary artery bypass graft surgery and concomitant patch closure of the PDA. This article aims to outline the imaging features of PDA and highlight the information provided by CT, which is crucial to treatment planning. The pathophysiology, clinical manifestations and closure options of PDA are also briefly discussed.     

Magnetic resonance imaging of diabetic foot complications

This pictorial review aims to illustrate the various manifestations of the diabetic foot on magnetic resonance (MR) imaging. The utility of MR imaging and its imaging features in the diagnosis of pedal osteomyelitis are illustrated. There is often difficulty encountered in distinguishing osteomyelitis from neuroarthropathy, both clinically and on imaging. By providing an accurate diagnosis based on imaging, the radiologist plays a significant role in the management of patients with complications of diabetic foot.     

Hypereosinophilic syndrome with large intracardiac thrombus

As the nonspecific clinical presentation of hypereosinophilic syndrome (HES) may mimic many multisystemic diseases, it often presents as a diagnostic challenge. Herein, we report the case of a 60-year-old man who presented with progressive heart failure symptoms and eosinophilia. Despite extensive diagnostic evaluation, no underlying cause was found. Transthoracic echocardiography revealed a large left ventricular thrombus, which is suggestive of hypereosinophilic cardiac involvement. The patient was started on steroids and responded clinically and haematologically.     

Recurrent wheeze and cough in young children: is it asthma?

A clinical diagnosis of asthma is often considered when a child presents with recurrent cough, wheeze and breathlessness. However, there are many other causes of wheeze in a young child. These range from recurrent viral infections to chronic suppurative lung disease, gastro-oesophageal reflux disease and rare structural abnormalities. Arriving at a diagnosis includes taking into consideration the symptomatology, triggers, atopic features, family history, absence of red flags and therapeutic trial, where indicated.     

Imaging features of an intraosseous arteriovenous malformation in the tibia

Primary intraosseous arteriovenous malformations (AVMs) are rare and have only been occasionally reported. We herein report a histologically proven case of primary intraosseous AVM in the tibia, which mimicked a fibrous tumour on radiography. This presentation carries a risk of triggering acute large haemorrhage through unnecessary biopsy. In intraosseous AVM, the magnetic resonance (MR) imaging features typical of a soft tissue AVM are absent, making diagnosis difficult. In this report, peculiar MR features in the presence of a connecting vessel between the normal deep venous system of the lower extremity and the tumour provide a clue for the early diagnosis of primary intraosseous AVM.     

Clinics in diagnostic imaging (152). Right lower lobe segmental pulmonary embolus.

A 56-year-old man presented to the Accident and Emergency Department with pleuritic chest pain of sudden onset. He gave a history of short-distance air travel ten days earlier. Chest radiograph showed a peripheral-based opacity in the right lower zone, which was not seen in a previous study done three months ago, suggestive of Hampton’s hump. The D-dimer level was raised. Computed tomography pulmonary angiography confirmed the diagnosis of pulmonary embolism in a right lower lobe segmental branch, with adjacent collapsed lung, consistent with lung infarction. The patient was started on heparin injection with significant relief of his symptoms. The clinical and imaging features of pulmonary embolism are described, with emphasis on the historical radiographic signs and the current dual-energy computed tomography innovations.