I have an incomplete right bundle branch block is it dangerous nd can cause a cardiac arrest?

Irbbb usually safe: Irbbb is usually an ECG anomaly that may speak of some right sided enlargement or strain (can occur in atrial septal defect or in pulmonary processes with right heart strain ). It can also occur innocuously and unrelated to cardiac structural changes. It does not typically imply impending conduction system collapse and is not a predictor for cardiac arrest or sudden cardiac death.

No and no: By itself a rbbb is not a problem unless it is associated with structural heart disease. An echo would answer the question.