
    Write a function to calculate the total of all normal systolic blood pressure readings (even numbers) that were recorded at even-numbered measurement intervals during patient monitoring, where normal readings could indicate stable patient condition. The function should process a sequence of blood pressure measurements taken at regular intervals, considering only the systolic values that occur at even-numbered positions in the monitoring timeline.
    

    
def sum_even_and_even_index(arr):
    """
    Write a function to calculate the total of all normal systolic blood pressure readings (even numbers) that were recorded at even-numbered measurement intervals during patient monitoring, where normal readings could indicate stable patient condition. The function should process a sequence of blood pressure measurements taken at regular intervals, considering only the systolic values that occur at even-numbered positions in the monitoring timeline.
    

    """
def sum_even_and_even_index(arr):
    """
    Write a function to calculate the total of all normal systolic blood pressure readings (even numbers) that were recorded at even-numbered measurement intervals during patient monitoring, where normal readings could indicate stable patient condition. The function should process a sequence of blood pressure measurements taken at regular intervals, considering only the systolic values that occur at even-numbered positions in the monitoring timeline.
    

    """
    i = 0
    sum = 0
    for i in range(0, len(arr), 2):
        if arr[i] % 2 == 0:
            sum += arr[i]
    return sum