Cyanotic Congenital Heart Lesions

Cyanosis is caused by lesions that lead to right-to-left shunting of blood, in which blood coming from the right ventricle bypasses lungs to various degrees before entering systemic circulation. These lesions can be remembered as the 5 Ts: 1. Tetralogy of Fallot (most common cause of early cyanosis) 2. Transposition of the great vessels 3. […]

Aorticopulmonary Septum – Development

The aorticopulmonary (AP) septum is derived from neural crest cells that migrate into the primitive ventricular outflow tract. It is responsible for separating the truncus arteriosus into the aorta and pulmonary artery. As the septum descends, it spirals 180 degrees so that the aorta becomes the left ventricular outflow tract and the pulmonary trunk becomes […]

Interventricular Septum – Development

The interventricular septum consists of two parts: the muscular portion and the membranous portion. ■ The muscular interventricular septum forms as an upward expansion of the base of the primitive ventricle. It extends toward the AV septum but does not reach it; the resulting gap is the interventricular foramen. ■ The membranous interventricular septum is […]

Peripheral oedema

Swelling of the ankles/legs (or sacrum if bed-bound) occurs when the rate of capillary filtration > rate of drainage. • Increased capillary filtration occurs due to i venous pressure, hypoalbuminaemia, or local inflammation • Decreased drainage occurs due to lymphatic obstruction Consider whether swelling is acute or chronic, symmetrical or asymmetrical, localized, or generalized. Ask […]