Guidelines for the peri-operative management of people with cardiac implantable electronic devices: Guidelines from the British Heart Rhythm Society.

This document provides practical guidance for the management of people with cardiac implantable electronic devices who are undergoing surgical intervention. Increasing numbers of people have cardiac device implants including pacemakers, implantable defibrillators and cardiac resynchronisation devices. During surgical procedures, exposure to electromagnetic interference may lead to inappropriate device function including withholding of pacing function or shock therapies. The guideline summarises key aspects of pre-operative assessment protocols to ensure that all people have their device clearly identified and have had appropriate device follow-up pre-operatively. It outlines general measures which can minimise the risk of potentially problematic electromagnetic interference in the surgical environment. It also includes detailed guidance according to the type of device, whether individuals are dependent on the pacing function of the device and the nature of the procedure they are undergoing. People identified as being at significant risk of harmful procedure-related inappropriate device function may require temporary alteration to the device programming. This may be carried out by a trained cardiac physiologist using a device programmer or, in some cases, can be achieved by clinical magnet application. Guidance on the safe use of magnets and emergency situations is included. Common diagnostic procedures and dental interventions are covered. The guidance aims to provide specific and pragmatic advice which can be applied to provide safe and streamlined care for people with cardiac implantable devices.

Spectrum and management of complement immunodeficiencies (excluding hereditary angioedema) across Europe.

INTRODUCTION: Complement immunodeficiencies (excluding hereditary angioedema and mannose binding lectin deficiency) are rare. Published literature consists largely of case reports and small series. We collated data from 18 cities across Europe to provide an overview of primarily homozygous, rather than partial genotypes and their impact and management. METHODS: Patients were recruited through the ESID registry. Clinical and laboratory information was collected onto standardized forms and analyzed using SPSS software. RESULTS: Seventy-seven patients aged 1 to 68 years were identified. 44 % presented in their first decade of life. 29 % had C2 deficiency, defects in 11 other complement factors were found. 50 (65 %) had serious invasive infections. 61 % of Neisseria meningitidis infections occurred in patients with terminal pathway defects, while 74 % of Streptococcus pneumoniae infections occurred in patients with classical pathway defects (p < 0.001). Physicians in the UK were more likely to prescribe antibiotic prophylaxis than colleagues on the Continent for patients with classical pathway defects. After diagnosis, 16 % of patients suffered serious bacterial infections. Age of the patient and use of prophylactic antibiotics were not associated with subsequent infection risk. Inflammatory/autoimmune diseases were not seen in patients with terminal pathway, but in one third of patients classical and alternative pathway defects. CONCLUSION: The clinical phenotypes of specific complement immunodeficiencies vary considerably both in terms of the predominant bacterial pathogen, and the risk and type of auto-inflammatory disease. Appreciation of these phenotypic differences should help both immunologists and other specialists in their diagnosis and management of these rare and complex patients.

Effect of short-term exercise training on aerobic fitness in patients with abdominal aortic aneurysms: a pilot study.

BACKGROUND: Patients with abdominal aortic aneurysms (AAA) represent a high-risk surgical group. Despite medical optimization and radiological stenting interventions, mortality remains high and it is difficult to improve fitness. The aim of this pilot study was to evaluate the effect of a 6 week, supervised exercise programme (30 min continuous moderate intensity cycle ergometry, twice weekly) on anaerobic threshold (AT) in subjects with AAA. METHODS: Thirty participants with an AAA under surveillance were randomized to either the supervised exercise intervention (n=20) or a usual care control group (n=10). AT was measured using cardiopulmonary exercise testing, at baseline (AT1), week 5 (AT2), and week 7 (AT3). The change in AT (AT3-AT1) between the groups was compared using a mixed model ancova, providing the mean effect together with the standard deviation (sd) for individual patient responses to the intervention. The minimum clinically important difference (MCID) was defined as an improvement in AT of 2 ml O(2) kg(-1) min(-1). RESULTS: Of the 30 participants recruited, 17 of 20 (exercise) and eight of 10 (control) completed the study. The AT in the intervention group increased by 10% (equivalent to 1.1 ml O(2) kg(-1) min(-1)) compared with the control (90% confidence interval 4-16%; P=0.007). The sd for the individual patient responses to the intervention was 8%. The estimated number needed to treat (NNT) for benefit was 5 patients. CONCLUSIONS: The small mean benefit was lower than the MCID. However, the marked variability in the individual patient responses revealed that a proportion of patients did benefit clinically, with an estimated NNT of 5.

Reliability of the anaerobic threshold in cardiopulmonary exercise testing of patients with abdominal aortic aneurysms.

Anaerobic threshold (AT), determined by cardiopulmonary exercise testing (CPET), is a well-documented measure of pre-operative fitness, although its reliability in patient populations is uncertain. Our aim was to assess the reliability of AT measurement in patients with abdominal aortic aneurysms. Eighteen patients were recruited. CPET was performed four times over a 6-week period. We examined shifts in the mean AT to evaluate systematic bias with random measurement error assessed using typical within-patient error and intraclass correlation coefficient (ICC, 3,1) statistics. There was no significant or clinically substantial change in mean AT across the tests (p = 0.68). The typical within-patient error expressed as a percentage coefficient of variation was 10% (95% CI, 8-13%), with an ICC of 0.74 (95% CI, 0.55-0.89). We consider the reliability of the AT to be acceptable, supporting its clinical validity and utility as an objective marker of pre-operative fitness in this population.

Acute myocarditis secondary to Campylobacter jejuni enterocolitis.

Myocarditis is a rare condition that can mimic an acute coronary syndrome (ACS). We present the case of a 24-year-old male with Noonan syndrome who presented with a diarrhoeal pro-dromal illness, acute onset chest pain, elevated cardiac biomarkers and an abnormal ECG with ST elevation in the absence of obstructive coronary artery disease. The patient had acute myocarditis secondary to Campylobacter jejuni enterocolitis. Infective myocarditis is most commonly due to a viral infection. Myocarditis is very rarely due to a bacterial infection with only isolated reports of myocarditis induced by Campylobacter jejuni infection. At follow-up he remains well. Myocarditis should be considered in all patients presenting with acute onset chest pain and elevated cardiac biomarkers.

Strain rate imaging pre- and post-percutaneous coronary intervention: a potential role in the objective detection of ischaemia in exercise stress echocardiography.

AIMS: To determine the feasibility of strain rate imaging (SRI) in the objective detection of exercise-induced ischaemia. METHODS AND RESULTS: Sixteen patients undergoing elective percutaneous coronary intervention (PCI) underwent treadmill exercise stress echocardiography (ESE) pre- and post-PCI. Measurement of systolic SRI parameters was attempted in all myocardial segments at baseline, peak stress, and in recovery. Segments were divided into those supplied by target (Group 1) and non-target vessels (Group 2). Percutaneous coronary intervention was successful in all patients. In Group 1, there was no significant difference in post-systolic strain rate (SRps) at baseline or at peak stress but there was significantly greater SRps pre-PCI compared with post-PCI at 30 min into recovery (-0.37 +/- 0.53 vs. -0.07 +/- 0.44 s(-1), P = 0.004). There were similar findings with the SRps index [ratio of SRps:peak systolic strain rate (SRsys)]. Group 2 segments did not demonstrate any significant differences in SRI parameters pre- and post-PCI. At peak exercise pre-PCI, Group 1 segments had significantly delayed time to SRsys compared with Group 2 (0.12 +/- 0.05 vs. 0.09 +/- 0.05 s, P = 0.013), a difference that was abolished post-PCI. CONCLUSION: This suggests a potential role for SRI in the objective detection of exercise-induced ischaemia by echocardiography at peak stress and during recovery at the time of improved image quality.

Simultaneous presentation of coronary heart disease in identical twins.

The development of coronary artery disease involves a complex interplay between environmental and genetic factors, with premature coronary artery disease having a strong genetic component. We present the case a pair of monozygotic identical twins presenting near simultaneously with coronary artery disease and identical atherosclerotic lesions despite significant differences in environmental risk factors and being divided geographically by 12,000 miles. This is of enormous importance and not merely curiosity value as it will have implications for the prevention of coronary artery disease, provide an opportunity for the development of new therapeutic strategies, and aid targeted primary prevention through family screening.

Pre-excited atrial fibrillation triggered by intravenous adenosine: a commonly used drug with potentially life-threatening adverse effects.

Although serious adverse events following adenosine administration are rare, it should only be administered in an environment where continuous ECG monitoring and emergency resuscitation equipment are available. The case report describes the development of pre-excited atrial fibrillation in a 31-year-old woman with Wolff-Parkinson-White syndrome following the administration of adenosine. She had previously been fit and well and was admitted to the coronary care unit with a 2 h history of regular palpitations. A 12-lead ECG showed a narrow QRS complex tachycardia. Carotid sinus massage was unsuccessful in terminating the tachycardia and the patient subsequently received rapid boluses of intravenous adenosine. The cardiac rhythm degenerated into atrial fibrillation with ventricular pre-excitation following 12 mg adenosine.

NT-proBNP and the diagnosis of left ventricular systolic dysfunction within two acute NHS trust catchment areas: the initial Teesside experience.

PURPOSE: To evaluate the predictive value of N-terminal pro B-type natiuretic peptide (NT-proBNP) reference cut-off values as diagnostic markers for left ventricular systolic dysfunction (LVSD). STUDY DESIGN: A retrospective study assessing the use of NT-proBNP in the diagnostic algorithm for the investigation of patients with suspected signs and symptoms of LVSD presenting to primary care. RESULTS: A generic NT-proBNP cut-off (150 ng/l) value has similar negative and positive predictive valves, specificity and sensitivity compared to age and sex specific cut-off values. CONCLUSION: When using NT-proBNP as a triage tool for screening patients with signs and symptoms suggestive of LVSD, a simple generic cut-off level is as effective as more complex age sex specific cut-off values.

Acute rheumatic fever mimicking an acute coronary syndrome.

An elevated troponin measurement does not always reflect myocardial ischaemia secondary to obstructive coronary artery disease. Troponin levels can also be elevated in other disease states including pulmonary emboli, myo-pericarditis, acute rheumatic fever, and in the critically ill. Thus, patients presenting with chest pain and electrocardiological and biochemical evidence of myocardial necrosis are not always suffering from an acute coronary syndrome.

The dancing heart.

A woman with palliative breast cancer presents with dyspnoea and is noted to have an unusual electrocardiogram, with an alternating electrical axis observed. Subsequent echocardiogram demonstrates the classical findings of a large pericardial effusion causing 'electrical alternans' aptly illustrating why this rare phenomenon occurs.

External validation of established risk adjustment models for procedural complications after percutaneous coronary intervention.

BACKGROUND: Workable risk models for patients undergoing percutaneous coronary intervention (PCI) are needed urgently. OBJECTIVE: To validate two proposed risk adjustment models (Mayo Clinic Risk Score (MC), USA and North West Quality Improvement Programme (NWQIP), UK models) for in-hospital PCI complications on an independent dataset of relatively high risk patients undergoing PCI. SETTING: Tertiary centre in northern England. METHODS: Between September 2002 and August 2006, 5034 consecutive PCI procedures (validation set) were performed on a patient group characterised by a high incidence of acute myocardial infarction (MI; 16.1%) and cardiogenic shock (1.7%). Two external models-the NWQIP model and the MC model-were externally validated. MAIN OUTCOME MEASURE: Major adverse cardiovascular and cerebrovascular events: in-hospital mortality, Q-wave MI, emergency coronary artery bypass grafting and cerebrovascular accidents. RESULTS: An overall in-hospital complication rate of 2% was observed. Multivariate regression analysis identified risk factors for in-hospital complications that were similar to the risk factors identified by the two external models. When fitted to the dataset, both external models had an area under the receiver operating characteristic curve >or=0.85 (c index (95% CI), NWQIP 0.86 (0.82 to 0.9); MC 0.87(0.84 to 0.9)), indicating overall excellent model discrimination and calibration (Hosmer-Lemeshow test, p>0.05). The NWQIP model was accurate in predicting in-hospital complications in different patient subgroups. CONCLUSIONS: Both models were externally validated. Both predictive models yield comparable results that provide excellent model discrimination and calibration when applied to patient groups in a different geographic population other than that in which the original model was developed.

Bilateral thoracoscopic cervical sympathectomy for the treatment of recurrent polymorphic ventricular tachycardia.

Congenital long QT syndrome (LQTS) is a disorder of prolonged cardiac repolarisation, manifest by a prolonged QT interval and characterised by recurrent presyncope/syncope, polymorphic ventricular tachycardia (PMVT), or sudden cardiac death. A 46 year old woman with no family history of sudden death or deafness presented with recurrent syncope. Physical examination and electrolytes were normal and a 12 lead ECG showed a corrected QT interval of 458 ms. A monitored syncopal episode documented PMVT. Despite potassium and magnesium supplements, beta blockade, implantation of a single then dual chamber implantable cardioverter defibrillator (ICD), amiodarone, nicorandil, and mexiletine, the patient continued to experience arrhythmia storms, receiving more than 700 ICD discharges over seven months. She was ultimately treated successfully with bilateral thoracoscopic cervicothoracic sympathectomies. This is the first reported bilateral thoracoscopic treatment of a patient with LQTS and symptomatic life threatening ventricular tachyarrhythmias refractory to current pharmacological and pacing techniques.

Paradoxical embolism through a patent foramen ovale: an unexpected complication of tracheal extubation.

A 41-year-old male with insulin-dependent diabetes mellitus was admitted for an elective arthroscopic release of adhesive capsulitis of his left shoulder. At the end of the surgical procedure, he appeared to regain consciousness but then became unresponsive at the time of tracheal extubation after a violent bout of coughing, developing bilateral up-going plantar responses, decorticate posturing and abnormal pupillary reflexes. He was transferred to the intensive care unit. The following day, the patient made a full neurological recovery. Contrast echocardiography, performed using agitated saline delivered through a femoral venous line, revealed a large patent foramen ovale with evidence of right to left shunting. In the absence of risk factors for air embolism, the clinical diagnosis was one of paradoxical embolism of venous thrombus resulting in brain stem ischaemia. The patient was commenced on life-long aspirin to minimise future embolic risk.

Human ACE gene polymorphism and distilled water induced cough.

BACKGROUND: Inhibitors of angiotensin converting enzyme (ACE) cause a non-productive cough. The insertion/deletion polymorphism of ACE was used as a genetic marker to investigate the relationship between ACE genotype and cough sensitivity. METHODS: A double blind cough challenge was performed in 66 normotensive subjects (34 men) of mean age 34.8 years (range 18-80) using aerosols of distilled water. The number of coughs during the one minute exposure to water was recorded. DNA samples from venous blood were amplified by the polymerase chain reaction and resolved on a 1% agarose gel. They were analysed for the presence of a polymorphism in intron 16 of the ACE gene consisting of an insertion (I) or deletion (D) of an Alu repetitive sequence 287 base pairs long. RESULTS: The distribution of genotypes was 20 II, 26 ID, and 20 DD. The cough response was significantly (p < 0.01) related to the ACE genotype, the mean number of coughs being 15.8, 11.3, and 9.6, respectively, in subjects with the II, ID, and DD genotypes. CONCLUSIONS: The observation that cough challenge is dependent on ACE genotype in normal subjects is evidence of a link between ACE activity and the cough reflex.