Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 1 1 2017 10 15 e10 e10 Mehran Sotoodehnia Department of Emergency Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran 2017 10 13 2017 10 15 In this case, changes are made to the shape or amplitude of ECG complexes change alternatively. In the most common form, alternative changes can be viewed better in QRS complexes and in mid precordial leads. These alternative changes can be seen simultaneously in every other QRS complex and T wave. This means that in one beat the amplitude or shape of QRS complexes and T wave are normal and in the next beat the amplitude or shape of QRS complexes and T wave change. Since at times QRS complexes get closer, then they collapse and overlap and after that they gain distance from each other again. The answer to this ECG is a heterotropic transplanted heart.     https://fem.tums.ac.ir/index.php/fem/article/view/7 https://fem.tums.ac.ir/index.php/fem/article/download/7/8