VENTRICULAR TACHYCARDIA

Introduction: Frequent or complex patterns of ventricular ectopic activity,whether occurring during routine activity or induced by exercise, are often a marker for serious heart disease and aharbinger of sudden death. The detection of such arrhythmias is thus an important responsibility of the physician.Objective: To find the prevalence, associated characteristics and prognostic significance of exercise induced nonsustainedVT in a representative population. Material and Methods: Setting: Nishtar Hospital, Multan. Sample size:1000 patients. Duration: Two years. Study design: Descriptive, analytical study. Sampling Technique: Convenientprobability sampling done. Results: Ten subjects, 7 men and 3 women, with exercise induced VT were identified,representing 1.1% of those tested; only 1 was young than 65 years. All episodes of VT were asymptomatic and nonsustained.In 9 of 10 subjects, VT developed at or near peak exercise. The longest run of VT was 6 beats; multiple runsof VT were present in 4 subjects. Two subjects had exercise induced ST segment depression, but subsequent exercisethallium scintigraphic results were negative in each. Compared with a group of age and sex matched control subjects,those with asymptomatic, non-sustained VT displayed no difference in exercise duration, maximal heart rate, or theprevalence of coronary risk factors or exercise induced ischemia as measured by electrocardiography and thalliumscintigrahy. Over a mean follow period of 2 years, no subject has developed symptoms of heart disease or experiencedsyncope or sudden death. Thus, exercise induced VT in apparently healthy subjects occurs almost exclusively in theelderly, is limited to short, asymptomatic runs of 3 to 6 beats usually near peak exercise, and does not portendincreased cardiovascular morbidity or mortality rates over a 2 year period of observation. Conclusion: Exerciseinduced VT in apparently healthy subjects occurs almost exclusively in the elderly, is limited to short, asymptomaticruns of 3 to 6 beats usually near peak exercise, and does not show increased cardiovascular morbidity or mortalityrates over a 2 year period of observation.