A) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle B) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle C) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle D) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle E) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle F) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle G) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle H) ? Atrial systole Diastole ECG trace End of QRS spike Left AV valve closes Left AV valve opens Onset of QRS spike P wave Pressure in the aorta Pressure in the left atrium Pressure in the left ventricle Semilunar valve closes Semilunar valve opens T wave Ventricular systole Volume of left ventricle