Johnson Francis

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Catecholaminergic polymorphic ventricular tachycardia (VT) is a rare arrhythmogenic disease characterized by exercise- or stress-induced ventricular tachyarrhythmias, syncope, or sudden death, usually in the pediatric age group. Familial occurrence has been noted in about 30% of cases. Inheritance can be autosomal dominant or recessive, usually with high(More)
AIMS Takotsubo cardiomyopathy (TC) or the apical ballooning syndrome is a reversible cardiomyopathy mimicking acute myocardial infarction (AMI). Although malignant arrhythmia is considered less likely to occur in TC than with AMI, sporadic reports of malignant arrhythmia with TC, however, have been reported. We reviewed the medical literature on TC and(More)
Atrial fibrillation occurs in 10 - 15% of patients with hyperthyroidism. Low serum thyrotropin concentration is an independent risk factor for atrial fibrillation. Thyroid hormone contributes to arrythmogenic activity by altering the electrophysiological characteristics of atrial myocytes by shortening the action potential duration, enhancing automaticity(More)
Brugada syndrome is characterized by right bundle branch block pattern with ST-segment elevation in leads V(1) to V(3) and a propensity for sudden cardiac death due to ventricular arrhythmias. The arrhythmogenic substrate in Brugada syndrome may not be restricted to the ventricles, and atrial arrhythmias are being increasingly reported. Incidences of(More)
The rate of implantable cardioverter defibrillator (ICD) implantation has gone up as primary and secondary prevention trials have relatively consistently shown significant improvement in mortality and morbidity. Most patients with ICDs are followed routinely at intervals ranging from 3 to 6 months. Many patients require additional non-scheduled visits to(More)
Initial acceleration and a subsequent deceleration of sinus rhythm following a ventricular ectopic beat with a compensatory pause has been termed heart rate turbulence (HRT). The changes in sinus rhythm are thought to be mediated by a baroreflex response to the lower stroke volume of the ectopic beat. HRT is vagally mediated and abolished by atropine,(More)
Idiopathic fascicular ventricular tachycardia is an important cardiac arrhythmia with specific electrocardiographic features and therapeutic options. It is characterized by relatively narrow QRS complex and right bundle branch block pattern. The QRS axis depends on which fascicle is involved in the re-entry. Left axis deviation is noted with left posterior(More)
Radiofrequency catheter-mediated ablation is a recently developed technique of achieving cure of certain rhythm disorders, notably supraventricular tachycardia. In less than a decade, it has evolved from a theoretic concept to first line therapy for many patients, including those in the pediatric age group. The most common types of arrhythmias amenable to(More)
Dual ventricular response to a single supraventricular impulse is an interesting possibility in the presence of dual atrioventricular nodal physiology. Double His bundle and ventricular responses to a single atrial impulse caused by a simultaneous fast and slow pathway conduction is the hallmark of this condition. One of the earliest descriptions of(More)