A Study of Caffeine on Cardiac Arrhythmias
Condition: Supraventricular Tachycardia (SVT); Atrial Fibrillation
MeSH terms: Atrial Fibrillation; Tachycardia; Tachycardia, Supraventricular
Study type: Interventional

Summary: 
      Stimulants and drugs are often associated with cardiac effects. Caffeine, a therapeutic
      xanthine, has been described as a sympathomimetic and has shown to have stimulatory effects
      on the heart. Patients with symptomatic cardiac arrhythmias are generally informed by their
      physician to stop or significantly reduce caffeine intake. However, in spite of numerous
      reports that have reviewed the cardiac effects of caffeine, it remains unclear to what extent
      this stimulant may be detrimental, and what subgroups of patients may be most vulnerable. The
      investigators propose to evaluate the effects of caffeine in patients with previously
      diagnosed cardiac arrhythmias. The results of our report will provide important new
      information for physicians and patients regarding the effects of caffeine on symptomatic
      cardiac arrhythmias.
    

Detailed description: 
      Caffeine is one of the most frequently consumed pharmacologic active substances in the world.
      The potential effects of caffeinated beverages and chocolate on human health remains of great
      interest. The increased prevalence of cardiac arrhythmias in the general population has
      resulted in greater concern about the potential effects of caffeine on cardiac arrhythmias.
      Patients diagnosed with a cardiac dysrhythmia are generally informed by their physician to
      restrict or even abstain from caffeine, despite a lack of evidence of this causal
      relationship.

      Although there have been numerous reports published on the effects of caffeine on human
      health, there have been few reports on the relation between caffeinated beverages and
      chocolate in different subgroups of patients with previously diagnosed cardiac arrhythmias,
      including supraventricular tachycardia (SVT), atrial fibrillation (AF), atrial flutter, and
      ventricular arrhythmias. These patients frequently undergo interventional ablation
      procedures, and have a potential for a recurrence of their arrhythmia. A greater knowledge of
      the effects of caffeine in different subgroups of patients with cardiac arrhythmias is thus
      essential to properly guide patients and physicians in their treatment.

      The objective of our study is to evaluate the effects of caffeine through noninvasive and/or
      invasive means on patients with documented symptomatic cardiac arrhythmias.

      One group will consist of 80 patients with Supraventricular Tachycardia (SVT): This group
      will undergo Invasive testing, which will be completed in the electrophysiology laboratory
      prior to their ablation procedure to evaluate the electrophysiologic effects of caffeine or
      placebo on the human heart. This testing will include a measure of the effective refractory
      periods, inducibility of tachyarrhythmias, and conduction intervals during programmed
      electrical stimulation.

      The other group will consist of up to 80 patients with Atrial Fibrillation: This group will
      undergo non-invasive testing, consisting of two consecutive 48-hr Ambulatory monitors while
      they consume caffeinated or noncaffeinated products.
    

Intervention name(s): Caffeine; Placebo
Intervention type(s): Drug; Other
Intervention description(s): SVT group: Oral tablets of Caffeine prior to the electrophysiology study in patients with SVT.
AF group: Dark chocolate and Caffeinated substances in patients with AF at the time of Ambulatory monitoring.; SVT group: Oral tablets of placebo prior to the electrophysiology study in patients with SVT.
AF group: White chocolate and Decaffeinated substances in patients with AF at the time of Ambulatory monitoring.
Intervention MeSH terms: Caffeine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Supraventricular Tachycardia; Atrial Fibrillation; Electrophysiology Study; Programmed Electrical Stimulation