Objective It was belived, until recently, that ventricular heart rate disturbance occurs only in the injured myocardium, but today it is known for certain that it can also occur in the generally healthy myocardium.

Methods Twenty children of age 5–16 (average age 10.5) were examined, where various ventricular heart rate disorders were diagnosed by physical examination, ECG and 24 hour Holter monitoring. The patients suffered no individual difficultes. The echocardiographic medical findings were regular. An exercise test was then carried out (Bruce protocol). Pulse, blood pressure and ECG were examined before, during and after the excercise test.

Results While in the motionless state ECG indicated complex ventricular rate disorders in fifteen patients, such as constant ventricular extrasystolics at the bigeminus, trigeminus rate. In the remaining five patients short attacks of non-sustaining ventricular thaicardy were detected.

During the exercise test and phase rehabilitation of the patients, the ventricular heart rate disturbance disappeared and ECG was regular. At the achived level of endurance the patients preserved their inotropic and chronotropic heart capacity with tolerable physical endurance.

Conclusions With our patients the ventricular heart rate disturbance is of a benign nature. It disappears during the exercise test and does not demand antyarrhhytmic therapy.