Lectures Series Of Congenital Heart Disease (1)

Abstract

The incidence of congenital heart disease (CHD) is reported around 6 to 8 in every 1000 live births. Depending upon the anatomical defects and physiological changes after birth, various clinical presentations of CHD are expected; some present as very unstable immediately after birth, whereas others do not become symptomatic until after several weeks of life. There are specific physiological principles that determine clinical presentation of CHD including signs and symptoms, onset, and severity. To manage these infants properly, it is imperative to understand the specific underlying pathophysiology caused by the anatomical defects. CHD can present with varying degrees of cyanosis, respiratory distress, congestive heart failure, decreased cardiac output, or even cardiovascular collapse. In this review, a new classification of cyanotic CHD is introduced. Cyanotic CHD is classified into the following four categories based upon the underlying pathophysiology: (1) ductus-dependent pulmonary blood flow, (2) abnormal mixing, (3) parallel circulation, and (4) obstruction of pulmonary venous drainage. Understanding the specific mechanisms of cyanotic CHD will provide us with proper management guidelines for cyanotic babies and will outline the rationale of surgical emergency in certain cases.