Systemic sclerosis (SSc) is an autoimmune connective tissue disease which affects various tissues and organs, including skin, lungs, kidneys, gastrointestinal tract and cardiovascular system. Cardiac involvement is the most commonly recognized problem and a significant cause of morbidity. Abnormal ECG is present in 25-75% of patients with SSc and is considered to be an independent predictor of mortality. It is known that the supraventricular arrhythmias are considered as more common in SSc patients, occurring in about two-thirds of the cases, and more often than ventricular tachyarrhythmias. It has been established that right bundle branch block is associated with an increased risk of mortality and that it is an independent predictor of mortality, and should be considered as a marker of the severity of the disease in SSc. Th e prolonged QTc interval is an independent risk factor for a sudden cardiac death reflecting the instability of repolarization and predisposing the onset of cardiac arrhythmias.The prognosis of the disease depends on the SSc subtype and the involvement of internal organs. SSc is a lifelong disease and cannot be cured, but knowing that cardiac dysfunction significantly worsens the prognosis, early detection of cardiac complications and appropriate therapy can influence its progress and improve the patients’ quality of life.