A. Subramanian

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A theoretical analysis is presented with experimental confirmation to conclusively demonstrate the critical role that annealing plays in efficient PCR amplification of GC-rich templates. The analysis is focused on the annealing of primers at alternative binding sites (competitive annealing) and the main result is a quantitative expression of the efficiency(More)
The dopamine receptor-D4 and the dopamine transporter have been investigated for their role in attention deficit hyperactivity disorder (ADHD) in children. Reports of their genetic association with ADHD have shown mixed results. The aim of the study was to evaluate the association of variable number tandem repeats (VNTRs) of the DRD4 and DAT1 genes with(More)
Bidirectional ventricular tachycardia (BDVT) is a rare form of ventricular arrhythmia, characterized by changing QRS axis of 180 degrees. Digitalis toxicity is considered as commonest cause of BDVT; other causes include aconite toxicity, myocarditis, myocardial infarction, metastatic cardiac tumour and cardiac channelopathies. We describe a case of BDVT in(More)
Implantable cardioverter defibrillator (ICD) is the currently accepted treatment for prevention of sudden cardiac death (SCD). Left ventricular ejection fraction is the only useful tool currently available to risk stratify patients at risk of SCD. Several other parameters have been studied for further risk stratification of SCD. Selection of appropriate(More)
Abrupt changes in heart rate, particularly short-long-short sequences in the ventricular cycle length (CL), might precede initiation of ventricular tachycardia/fibrillation (VT/VF). These changes may be facilitated or caused by pacing activity in patients with pacemakers or implantable-cardioverter defibrillators (ICDs). We describe a patient with two(More)
Radiofrequency catheter ablation (RFCA) is the treatment of choice for cardiac arrhythmias. However, sometimes, RFCA may be insufficient to eliminate the arrhythmias. Arrhythmic foci that are deep seated in the myocardium may not be amenable to catheter ablation from either the endocardium or the epicardium. Catheter ablation may also fail to produce a(More)
A 49 year-old-man presented to the emergency room with sudden onset palpitation of four hour duration. He also complained of retrosternal chest discomfort and giddiness. There was no history of palpitations in the past. Twelve lead ECG (Figure 1A) showed regular narrow complex tachycardia at the rate of 208/min. No clear P waves were seen. There was ST(More)
A 64 year old lady underwent electrophysiologic study for recurrent episodes of palpitation and documented narrow complex tachycardia. 12 lead ECG showed normal sinus rhythm and no evidence of preexcitation. At baseline, the cycle length, AH and HV intervals were 776, 52 and 46 ms respectively. Para-Hisian pacing was done at baseline and the response is(More)
Premature beats can trigger ventricular arrhythmias in heart disease, but the mechanisms are not well defined. We studied the effect of premature beats on activation and repolarization dispersion in seven patients with cardiomyopathy (57 ± 10 yr, left ventricular ejection fraction 31 ± 7%). Activation time (AT), activation-recovery interval (ARI), and total(More)