We present the case of a 55-year-old male who presented with symptoms of dyspnoea and pre-syncope. A 12 lead electrocardiogram demonstrated extensive conduction abnormalities with 2:1 heart block, right bundle branch block and a small Q wave in lead V(1.) This indicated significant myocardial and septal involvement. Echocardiography confirmed the presence of right ventricular infiltration and dysfunction whilst cardiac magnetic resonance showed the infiltration to be nodular in nature. Although a diagnosis of cardiac sarcoidosis and lymphoma were initially considered, sarcoidosis was eventually confirmed following a cervical lymph node biopsy. This case firstly demonstrates the usefulness of the 12-lead electrocardiogram in determining the likely anatomical locality of significant bradyarrhythmias. Secondly it highlights the difficulties in diagnosing cardiac sarcoidosis when cardiac dysfunction is the sole manifestation of the disease.