Regular pulse rate but irregular heart rate?

This 30-year-old male patient attended the emergency department because of dizziness accompanied by selfassessed regular pulse rates of 30–40 bpm. Physical examination was normal but cardiac auscultation revealed frequent premature beats. A subsequent 12-lead ECG documented the arrhythmia (Fig. 1). Similar episodes had occurred 12 months ago but thorough cardiac evaluation, including echocardiography and exercise stress testing, did not show any signs of underlying organic heart disease. Thus, empiric beta-blockade with metoprolol 95 mg 1-0-1 was initiated but did not relieve the symptoms. Instead, beta-blockade yielded fatigue due to arterial hypotension and was discontinued. What is the diagnosis of the arrhythmia, which can be made just by the morphology of the premature beats in the 12-lead ECG? Why did the patient report slow and regular pulse rates? What is the prognosis of the arrhythmia? And finally, is there any cure for this arrhythmia?