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.

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.

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.

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.

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.

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.

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.