ventricular septal defect

[nerai]

ive read that usually in  ventricular septal defect there is a right ventricular hypertrophy and pulmonic valve dilatation since there is a higher pressure in the left side which pushes blood to the right ventricle. but i know someone who has left atrial and ventricular enlargement with the same disease. the echocardiograph showed no obstructions.. how can this be possible?? can you pls explain the pathophysiology.. thank you.. ^_^

[kenkeith]

Etiology:  Increased pulmonary resistance often develops over time, reversing left-to-right shunting to right-to-left shunting. Deoxygenated blood enters the systemic circulation, causing symptoms of hypoxia (low oxygen level to heart, other organs and skeletal muscle.

Hemodynamics consequences: VSDs may develop congestive heart failure. The extra blood flows from the left ventricle through the right ventricle to the lungs and back to the left atrium and on to the left ventricle. This causes the left atrium and left ventricle to handle an increased amount of blood, and the workload on the heart increases. The increased workload on the heart also increases the heart rate and the body's demand for energy. Volume overload and workload increases left ventricle and atrium dimensions.