Kumaraswamy Natarajan

Heart-type fatty acid-binding protein (H-FABP) as an early diagnostic biomarker in patients with acute chest pain.

BACKGROUND Heart-type fatty acid-binding protein (H-FABP) is an emerging biomarker, which was found to be sensitive for the early diagnosis of acute myocardial infarction (AMI). We prospectively investigated the usefulness of H-FABP determination for the evaluation of acute chest pain in patients arriving at the emergency department. METHODS Fifty-four patients presenting with acute ischemic chest pain were evaluated. H-FABP was estimated at admission using latex-enhanced immunoturbidimetric assay. Serial cardiac troponin I (cTnI), creatinine kinase-MB (CK-MB) determination, ischemia workup with stress testing, and/or coronary angiogram (CAG) were performed according to standard protocols. RESULTS The sensitivity and specificity of H-FABP was 89.7% and 68%, for cTnI it was 62.1% and 100%, and for CK-MB it was 44.8% and 92%, respectively for diagnosis of AMI. The sensitivity of H-FABP was found to be far superior to initial cTnI and CK-MB, for those seen within 6h (100% vs. 46.1%, 33% respectively). On further evaluation of patients with positive H-FABP and negative cTnI, 71.4% of the patients had significant lesion on CAG, indicating ischemic cause of H-FABP elevation. Six patients with normal cTnI and CK-MB with high H-FABP had ST elevation on subsequent ECGs and were taken for primary angioplasty. CONCLUSION H-FABP is a highly sensitive biomarker for the early diagnosis of AMI. H-FABP as early marker and cTnI as late marker would be the ideal combination to cover the complete diagnostic window for AMI. Detection of myocardial injury by H-FABP may also be applied in patients with unstable angina. H-FABP can also be used as a marker for early detection of STEMI before the ECG changes become apparent.

The Utility of Exercise Testing in Risk Stratification of Asymptomatic Patients With Type 1 Brugada Pattern

Risk stratification of asymptomatic patients with a Brugada type 1 ECG pattern remains an unresolved clinical conundrum. In contrast to provocative pharmacological testing in Brugada syndrome, there is limited data on the role of exercise stress testing as a risk stratification modality. The objective of this study was to evaluate the utility of exercise testing in asymptomatic patients with type 1 Brugada pattern to prognosticate major arrhythmic events (MAE) during follow‐up.

Coronary Stent Infection Successfully Diagnosed Using 18F-Flurodeoxyglucose Positron Emission Tomography Computed Tomography.

Infection of coronary stents is extremely rare. We report a case of a 60-year-old gentleman with recurrent fever after acute stent occlusion and reintervention. A coronary angiogram showed an occluded stented segment and the blood cultures were positive for infection. The presence of inflammation in the stented region was confirmed using 18F-flurodeoxyglucose positron emission tomography computed tomography. The patient underwent surgery and the diagnosis was proven by examination of the surgical material. This article highlights the need to have a high index of suspicion of stent infection, and the use of 18F-flurodeoxyglucose positron emission tomography computed tomography along with coronary angiogram in aiding the diagnosis.

Primary transcatheter closure of post-myocardial infarction ventricular septal rupture using amplatzer atrial septal occlusion device: A study from tertiary care in South India

Objective The study investigated effectiveness of transcatheter closure of post-myocardial infarction (MI) ventricular septal rupture (VSR) using atrial septal device (ASD) occluder in a cohort of patients admitted at our institute. Method This was a retrospective, observational and single center study, which included patients who were treated with transcatheter closure for post-MI VSR at our tertiary care center between May 2000 and August 2014 depending upon inclusion and exclusion criteria. Primary outcome was all-cause mortality at 30-days follow-up. The MELD-XI (Model for End Stage Liver Disease) score was used as a predictor for poor outcome in these patients. Results A total of 21 patients (mean age 66.4 ± 5.9 years) were included in the study. Study cohort predominantly included male patients (n = 15; 71.4%) and patients with single vessel disease (n = 15; 71.4%). Revascularization of the culprit lesion, before VSR closure, was attempted in 6 patients. Except one patient (treated with Cera® occluder), all patients were treated with Amplatzer® ASD occluders. Average diameter of VSR was 20.8 ± 6.9 mm. Diameter of the device used in the study ranged from 10 mm to 30 mm. Residual defect was detected in 13 patients (62%). All-cause mortality at 30-day follow-up was observed in 9 (42.9%) patients. Time to VSR closure, diameter of VSR, and serum creatinine levels were significantly related to the 30-day mortality. MELD-XI score was found to be strongly associated with increased risk of mortality. Conclusion Primary transcatheter VSR closure using ASD occluders is a feasible approach which can provide reasonable survival outcomes along with equitable mortality rates.

Familial atrioventricular nodal re-entrant tachycardia: A case seriers and a systematic review

Multiple reports of familial clustering suggest that genetic factors may contribute in the pathogenesis of atrioventricular nodal re-entrant tachycardia (AVNRT). We report three cases of AVNRT in a father and his two sons along with a review of literature of other similar cases. Electrophysiological studies induced typical AVNRT, which was successfully eliminated by radiofrequency ablation in all of them. Of the 22 reported cases, 96% had typical (slow-fast) variant of AVNRT. The predominant pattern of inheritance appears to be autosomal dominant, though other patterns may exist. Further research is needed to understand the genetic influence of AVNRT and its pathophysiology.

An unusual type of accessory pathway in tricuspid atresia

The occurrence of pre-excitation in tricuspid atresia (TA) is slightly more common than that in normal children. The accessory pathway (AP), when it occurs in the setting of congenital atrioventricular valvar disease, is usually ipsilateral to the side of the abnormal valve. This report describes a patient with TA who had pre-excitation due to a left-sided AP that masked and modified the typical electrocardiographic features. The electrophysiological study confirmed an epicardial left posterior AP that was successfully ablated with radiofrequency energy, through the coronary sinus. Left-sided APs including epicardial ones may rarely be seen in TA and can potentially cause difficulties due to lack of vascular access to the heart after the Fontan surgery if arrhythmias occur. They are amenable to successful radiofrequency ablation and need to be dressed prior to Fontan surgery. <Learning objective: Pre-excitation may become manifest during follow-up even if minimal at initial presentation. Accessory pathways may occur in the left side of the heart in tricuspid atresia, in contrast to the usual notion that APs occur ipsilateral to the side of the abnormal valve. Electrophysiological study may be useful prior to Fontan-type procedures as this helps in identifying and to prognosticate pre-excitation so that ablation of the pathway can be performed prior to the Fontan procedure.>.