Coronary Sinus Atrial Septal Defects Clinical Presentation

Updated: Jul 03, 2019
  • Author: Louis I Bezold, MD; Chief Editor: Syamasundar Rao Patnana, MD  more...
  • Print


Patients with atrial septal defects (ASDs) may be recognized during infancy; however, ASDs are often not diagnosed until later in childhood because of lack of symptoms and subtlety of physical signs. Most patients undergo their initial evaluation because a cardiac murmur is detected. On the contrary, frequent use of echocardiography has resulted in identification of some of these ASDs.

  • Small and even moderate-to-large coronary sinus ASDs usually result in no clinically significant symptoms in childhood. However, on occasion, even infants develop clinically important symptoms of congestive heart failure, generally in conjunction with additional contributing factors.

  • Failure to thrive because of an ASD alone rarely, if ever, occurs.

  • Mild exercise intolerance, frequent respiratory infections, or reactive airway disease may be observed in some patients.

  • Patients with other associated complex congenital cardiac abnormalities generally present earlier because of their other hemodynamically significant associated defects.

  • In a surgical series of 25 patients with partial coronary sinus fenestrations, 7 had signs or symptoms at least partially attributable to these defects, including cerebral abscess, transient ischemic attacks, and cyanosis. [2]


Physical Examination

Relatively normal precordial impulse may be present with small defects. A precordial bulge, main pulmonary artery impulse, or hyperdynamic right ventricular impulse (heave) occurs with large shunts, especially in thin patients. A right ventricular tap or particularly prominent main pulmonary artery impulse in the second left intercostal space suggests pulmonary hypertension. Cyanosis may occur with pulmonary vascular obstructive disease.

The first heart sound is normal or split with an accentuated pulmonary component. The loud second component is caused by a larger-than-normal excursion of tricuspid valve leaflets during contraction of the volume-loaded right ventricle. The second heart sound is characteristically widely split and fixed in regard to respiration (except in small left-to-right shunts), with the aortic and pulmonic components widely and constantly separated. This separation changes little with inspiration or with Valsalva maneuver. Narrow splitting and increased intensity of the pulmonic component of S2 suggests the onset of elevated pulmonary vascular resistance.

Normal splitting of the second heart sound is due to an inspiratory increase in the interval between the descending limbs of the pulmonary arterial and right ventricular pressure curves reflecting increased pulmonary vascular bed capacitance. In the patient with ASD, the overall pulmonary vascular bed capacitance is already increased, with no additional increase during inspiration. Furthermore, the inspiratory increase in systemic venous return approximately compensates for the diminution of left-to-right shunting. The net result is that little respiratory variation occurs in right and left ventricular filling.

A pulmonary ejection systolic murmur is noted in moderate-to-large shunts. The presence of a thrill is unusual in ASDs and may suggest pulmonary valve stenosis. A mid diastolic low-frequency tricuspid valve inflow murmur may be heard with Qp/Qs ratios of greater than approximately 2 to 1, and a low-pitched pulmonary regurgitation murmur may be present. A higher-pitched pulmonary regurgitation murmur suggests pulmonary hypertension.