VENTRICULAR TACHYCARDIA

PREVALENCE AND PROGNOSIS

Abstract

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 a
harbinger 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 nonsustained
VT 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: Convenient
probability 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 runs
of VT were present in 4 subjects. Two subjects had exercise induced ST segment depression, but subsequent exercise
thallium 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 the
prevalence of coronary risk factors or exercise induced ischemia as measured by electrocardiography and thallium
scintigrahy. Over a mean follow period of 2 years, no subject has developed symptoms of heart disease or experienced
syncope or sudden death. Thus, exercise induced VT in apparently healthy subjects occurs almost exclusively in the
elderly, is limited to short, asymptomatic runs of 3 to 6 beats usually near peak exercise, and does not portend
increased cardiovascular morbidity or mortality rates over a 2 year period of observation. Conclusion: Exercise
induced VT in apparently healthy subjects occurs almost exclusively in the elderly, is limited to short, asymptomatic
runs of 3 to 6 beats usually near peak exercise, and does not show increased cardiovascular morbidity or mortality
rates over a 2 year period of observation.