def metrics_dict(data_list):
    """Organize calculated ECG data into a dictionary

    The ECG test characteristics of concern are extracted from the metrics
    list and organized into a dictionary to make the data more readable
    and easier to navigate.

    :param data_list: list of ECG metrics

    :returns: dictionary of metrics containing the keywords: 'duration',
              'voltage_extremes', 'num_beats', 'mean_hr_bpm', and 'beats'
    """
    metrics_dict = {'duration': data_list[0],
                    'voltage_extremes': data_list[1],
                    'num_beats': data_list[2],
                    'mean_hr_bpm': data_list[3],
                    'beats': data_list[4]
                    }
    return metrics_dict