Managing ventricular ectopics: are ventricular ectopic beats just an annoyance?

How important are PVCs and what should we do about them? PVCs are not a disease in themselves, but a marker of possible underlying conditions that may increase the risk of cardiac death. They serve as a flag to alert us to exclude structural heart disease, the presence of which is the strongest predictor of adverse events. However, it is important to know that PVCs are common in people with no structural heart disease. In this situation, the prognosis is generally excellent. Suppression of PVCs with antiarrhythmic medication is not indicated routinely, unless the patient is symptomatic or at risk of tachycardia-induced cardiomyopathy owing to the very high frequency of PVCs. Where pharmacological therapy has failed, there is now the option of radiofrequency ablation for elimination of frequent symptomatic PVCs. The ECG is a simple yet useful tool to improve risk assessment, especially in those with known cardiovascular disease.

Brugada pattern masking anterior myocardial infarction.

A middle-aged male smoker presented with atypical chest pain. Initial electrocardiogram (ECG) showed Brugada Type 1 pattern. Subsequent ECGs demonstrated evolving anterior ST elevation myocardial infarction (STEMI), consistent with the elevated cardiac enzymes. Coronary angiogram showed significant stenoses in the left anterior descending artery, which were stented emergently. In retrospect, subtle changes were noted in the initial ECG, which could have alerted one to the STEMI. However, the presence of a Brugada Type 1 pattern masked the ECG changes of anterior STEMI and made the diagnosis difficult. A discussion of the literature surrounding Brugada syndrome is undertaken, including its clinical features, risk stratification and management.

Utilisation of emergency medical service among Singapore patients presenting with ST-segment elevation myocardial infarction: prevalence and impact on ischaemic time.

BACKGROUND: Previous studies in Western countries found that the emergency medical service (EMS) was under-used in patients with myocardial infarction. AIM: We sought to determine the prevalence of immediate EMS utilisation among Singapore patients presenting with ST-segment elevation myocardial infarction (STEMI), and correlated the use of the EMS with the symptom-to-balloon and door-to-balloon times. METHODS: We studied 252 patients admitted with STEMI to our institution from August 2008 to September 2009. Information regarding demographic characteristics, whether EMS was used, reperfusion procedural details and mortality rates were collected prospectively. RESULTS: Among the recruited patients, 89 (35.3%) used the EMS (EMS group) and 163 (64.7%) did not use the EMS (non-EMS group). In the latter group, 98 (60.1%) arrived at our institution through their own transport, 56 (34.4%) first consulted general practitioners, and 9 (5.5%) initially consulted another hospital without acute medical services. Among the 245 (out of 252, 97.2%) patients who received percutaneous coronary intervention (PCI), the EMS group was more likely to undergo primary PCI (P= 0.003) while the non-EMS group was more likely to undergo non-urgent PCI (P= 0.002). In patients who underwent primary PCI, the EMS group had a shorter symptom-to-balloon time (average difference 81.6 min, P= 0.002). The door-to-balloon time was similar for both groups. CONCLUSION: Despite the availability of a centralised EMS, 64.7% of patients with STEMI did not contact EMS at presentation. These patients were less likely to receive primary PCI and had a significantly longer symptom-to-balloon time.

High-sensitivity C-reactive protein is predictive of medium-term cardiac outcome in high-risk Asian patients presenting with chest pain syndrome without myocardial infarction.

INTRODUCTION: High-sensitivity C-reactive protein (hs-CRP) has been shown to be predictive of cardiac events but data among Asians is comparatively few. We evaluated the role of hs-CRP in the prediction of adverse cardiac outcome in a cohort of high-risk patients presenting with chest pain syndrome without myocardial infarction (MI). MATERIALS AND METHODS: Three hundred and forty-seven patients were prospectively recruited over an 18-month period and patients with MI as documented by serial electrocardiogram abnormalities, and creatinine kinase or troponin elevation were excluded. Mean follow-up duration was 901 +/- 306 days. Kaplan-Meier and Cox proportional hazards modelling were used to evaluate outcome and determine association with predictor variables. RESULTS: The composite primary endpoint of cardiac mortality, non-fatal MI, cardiac failure or coronary revascularisation procedure (coronary artery bypass grafting or angioplasty) unrelated to the index admission was reached in 37 patients. History of previous MI (P = 0.002), presence of at least 1 coronary artery with > or =50% stenosis (P = 0.028) and elevated hs-CRP levels were associated with an adverse cardiac outcome (P = 0.001 for CRP in the upper quartile, and 0.002 for CRP > or = 1mg/L, respectively). None of the traditional cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, significant family history, smoking, male gender and increased age) was predictive. Multivariate modelling showed elevated hs-CRP to confer the highest risk for an adverse cardiac outcome (P <0.001). CONCLUSION: Hs-CRP is useful in further stratifying high-risk multi-ethnic patients presenting with chest pain despite no evidence of MI. Close follow-up and aggressive management of these patients may be warranted.

Isolation of dengue viruses by intracerebral inoculation of mosquito larvae.

The isolation of dengue viruses from clinical specimens has always posed a particularly difficult problem. The use of invertebrate cell cultures such as AP-61 and C6/36 has reduced the time required for definitive diagnosis to within a week. More recently, inoculation of adult mosquitoes has been used but it requires more than a week to reach a confirmed laboratory diagnosis. We describe a method using intracerebral inoculation of immobilized fourth instar of Toxorhynchites splendens larvae for the isolation of dengue viruses from clinical specimens which yields results within a few days following incubation at 32 degrees C.