Eric McWilliams

Perforation of right ventricular free wall by pacemaker lead detected by multidetector computed tomography

Pacemaker lead perforation is a recognized complication of lead implantation, particularly with active fixation leads. Multidetector computed tomography (MDCT) is emerging as the imaging modality of choice in diagnosing lead perforation, identifying associated sequelae such as pericardial effusion and planning extraction. We present a case illustrating the use of MDCT in a case of right ventricular (RV) lead perforation manifesting 5 days after cardiac resynchronization therapy pacing.

Economic analysis of the use of coronary calcium scoring as an alternative to stress ECG in the non-invasive diagnosis of coronary artery disease

ObjectiveTo conduct an economic analysis (EA) of coronary calcium scoring (CCS) using a 0 score, as alternative to stress electrocardiography (sECG) in diagnosing coronary artery disease (CAD).MethodA decision tree was constructed to compare four strategies for investigation of suspected CAD previously assessed in the formulation of clinical guidelines for the United Kingdom (UK) to two new strategies incorporating CCS. Sensitivity (96%; 95% CI 95.4–96.4%) and specificity (40%; 95% CI 38.7–41.4%) values for CCS were derived from a meta-analysis of 10,760 patients. Other input variables were obtained from a previous EA and average prices for hospital procedures in the UK. A threshold of £30,000/Quality-adjusted Life Year (QALY) was considered cost-effective.ResultsUsing net monetary benefit calculations, CCS-based strategies were found to be cost-effective compared to sECG equivalents at all assessed prevalence of CAD. Using CCS prior to myocardial perfusion scintigraphy (MPS) and catheter angiography (CA) was found to be cost-effective at pre-test probabilities (PTP) below 30%.ConclusionsAdoption of CCS as an alternative to sECG in investigating suspected stable angina in low PTP population (<30%) would be cost-effective. In patients with PTP of CAD >30%, proceeding to MPS or CA would be more cost-effective than performing either CCS or sECG.Key PointsCoronary calcium scoring (CCS) is useful for assessing coronary artery atherosclerosisIt can be performed with multi-detector CT, which is now widely availableIt plays a role in excluding disease in suspected stable anginaOur study assesses its role in this setting as alternative to stress-ECGAdoption of CCS as an alternative to sECG could prove cost-effective

Diagnosis of prosthetic aortic valve endocarditis with gallium-67 citrate single-photon emission computed tomography/computed tomography hybrid imaging using software registration.

Prosthetic valve endocarditis can be challenging to diagnose and is associated with high mortality rates even if recognized and managed early. We present a case of staphylococcal sepsis soon after aortic valve surgery and permanent pacemaker implantation for which conventional investigation with echocardiography and computed tomography (CT) failed to identify an infective focus. Subsequent gallium–single-photon emission CT (67Ga-SPECT) imaging with software registration of the SPECT data helped to correctly identify the prosthetic aortic value as the source of sepsis, with resolution of changes on subsequent imaging. A 70-year-old woman underwent bioprosthetic aortic valve replacement and coronary artery bypass grafting for symptomatic severe aortic stenosis and significant 2-vessel coronary disease. Her postoperative course was complicated by significant bradycardia necessitating dual-chamber permanent pacemaker implantation. She presented 3 months after surgery in a confused state, with low-grade pyrexia. The examination identified a soft systolic aortic murmur but no diastolic component, normal breath sounds, absence of cutaneous markers of endocarditis, and no evidence of …

Aortic root abscess: Multimodality imaging with computed tomography and gallium-67 citrate single-photon emission computed tomography/computed tomography hybrid imaging

Culture negative endocarditis and aortic root abscess can prove difficult diagnostic challenges. Computed tomography can be extremely useful in this setting. We report a case of an aortic root abscess 3 months after elective aortic valve replacement in which cardiac CT and hybrid imaging with Gallium-67 SPECT complemented workup with transesophageal echocardiography in establishing the diagnosis of an abscess.

‘Biting the hand that feeds’: fever and altered sensorium following a dog bite

Capnocytophaga canimorsus infection is the most severe and rapidly progressive bacterial infection transmitted by dog bite and fortunately is very rare. The authors describe a 68-year-old gentleman who presented in an acute confusional state 2 days after having been bitten on the left hand by a dog. Despite immediate broad-spectrum intravenous antibiotics, he developed significant sequelae including disseminated intravascular coagulopathy, microvascular emboli leading to peripheral necrosis, widespread local tissue destruction and septic arthritis. Our case illustrates a life-threatening presentation of infection with C canimorsus, which is known as ‘the dog bite organism’. Early diagnosis and aggressive treatment is key to survival.

Primary systemic amyloidosis presenting as idiopathic inflammatory colitis

A 75-year old-female was referred with chest pain. She was fully investigated and it was felt that her symptoms were non-cardiac. Four months later, she was seen in gastroenterology outpatients with bloody diarrhoea and abdominal pain. Colonoscopy demonstrated inflammation up to the splenic flexure and histology confirmed inflammatory colitis. Later, she developed dyspepsia and weight loss. An oesophagogastroduodenoscopy (OGD) showed Helicobacter pylori negative erosive gastritis with a benign duodenal ulcer. Whole body CT scan was normal. Ten months later, she was admitted with dyspnoea due to severe heart failure. The admission ECG had significantly changed, now showing low voltage complexes and repeat echocardiography showed restrictive cardiomyopathy. Specific congo red staining on the biopsy specimens from the previous OGD and colonoscopy confirmed amyloid deposits. Further investigations detected an underlying light chain myeloma causing systemic (AL) amyloidosis. Unfortunately, her condition deteriorated rapidly and she died shortly afterwards.

The utility of cardiac CT beyond the assessment of suspected coronary artery disease

Extensive work has been done over recent years to improve the spatial and temporal resolution of electrocardiogram (ECG)-gated cardiac computed tomography (CT). Advances in both hardware and software analysis have enabled the development of non-invasive coronary angiography. However, these high-quality examinations lend themselves to multiple additional applications beyond coronary angiography. In this review, we illustrate and discuss some established and some emerging applications of ECG-gated cardiac CT beyond the assessment of suspected coronary disease, particularly in light of recent recommendations on the appropriate use of this technology.

Dietzia species pacemaker pocket infection: an unusual organism in human infections

An 87-year-old man presented 10 months following permanent pacemaker insertion with cellulitis-like inflammation around the impulse generator. Symptoms improved with oral flucloxacillin, but only days after stopping, the infection recurred, and he was admitted from clinic for intravenous antibiotics. Suspecting the source was likely Staphylococcal, intravenous flucloxacillin was started, and the patient’s inflammatory markers responded adequately. Two samples of fluid were aspirated from the pacemaker site. These showed no bacterial growth using routine microbiological culture techniques. The samples were sent for 16S rDNA PCR and Dietzia species was detected in both samples. Dietzia species is an Actinomyces-like organism, which is not commonly associated with human infection, but is reported to have been isolated from clinical specimens and thus presumptively associated with human disease. The pacemaker was explanted and the pocket debrided with no complications. He made a full recovery after a prolonged course of flucloxacillin.

Pulmonary vein stenosis may still occur after ablation

Pulmonary vein stenosis is less common with the newer techniques of atrial fibrillation ablation but must always be considered especially in symptomatic patients. This 54-year-old man …

'Biting the hand that feeds': fever and altered sensorium following a dog bite.

Capnocytophaga canimorsus infection is the most severe and rapidly progressive bacterial infection transmitted by dog bite and fortunately is very rare. The authors describe a 68-year-old gentleman who presented in an acute confusional state 2 days after having been bitten on the left hand by a dog. Despite immediate broad-spectrum intravenous antibiotics, he developed significant sequelae including disseminated intravascular coagulopathy, microvascular emboli leading to peripheral necrosis, widespread local tissue destruction and septic arthritis. Our case illustrates a life-threatening presentation of infection with C canimorsus, which is known as ‘the dog bite organism’. Early diagnosis and aggressive treatment is key to survival.