Vasovagal syncope is a complex interaction of neurologic and cardiovascular mechanisms resulting in cardiac inhibition by the parasympathetic nervous system via vagus nerve associated ganglionic plexi. Some types tachycardia may be induced bradycardia, LQT type 3 being most common example. In these patients, pacemaker sometimes indicated to avoid bradycardia trigger for tachycardia. Cardioneura...

OBJECTIVES We prospectively evaluated the mechanism of syncope in patients with positive adenosine triphosphate (ATP) tests (defined as the induction of atrioventricular [AV] block with a ventricular pause >/=6 s after an intravenous bolus of 20 mg ATP). BACKGROUND Patients with unexplained syncope tend to have more positive ATP tests results than those without syncope. METHODS An implantab...

Clinical and electrophysiological studies of a 13-year-old boy with sinus bradycardia revealed sinus node dysfunction. Long-term follow-up data of members of his family indicated familial sinus node dysfucntion. Increased vagal tone was present in all patients. It is suggested that excessive vagal discharge for a pronlonged time may be the basic mechanism of sinus node dysfunction in these pati...

Sinus corticosteroids-induced bradycardia with high dose steroids has been reported in literature. Although the association is still not clearly understood but several mechanisms have been prompted to explain causality. The authors had a case of 54 years female who presented with slurred speech and confusion that was noted while she was at work. In the emergency department the patient was hypot...

AIM Asystole >3 s or sinus bradycardia with a ventricular rate <40 in association with complete heart block or sinus node dysfunction are considered to be Class 1 indications for permanent cardiac pacing. Nevertheless, these phenomena may be observed in symptomatic patients with neurocardiogenic syncope, who may not respond to pacing therapy. We hypothesized that the pattern of spontaneous brad...

Sinus node dysfunction (SND) is commonly encountered in the clinic. The clinical phenotype ranges from asymptomatic sinus bradycardia to complete atrial standstill. In some cases, sinus bradycardia is associated with other myocardial conditions such as congenital abnormalities, myocarditis, dystrophies, cardiomyopathies as well as fibrosis or other structural remodeling of the SA node.1-8 Altho...

An obese man, with an attack of myocardial ischaemia, developed arrhythmias only when he was asleep. Episodes of sinus bradycardia occurred progressing to arterioventricular block and sinus arrest. These changes in the cardiac rhythm coincided with periods of sleep apnoea.