For women with critical aortic stenosis, intensive monitoring during labor is essential. Pulmonary arteY catheterization may be helpful because of the narrow margin separating fluid overload from hypovolemia. Women with aortic stenosis are dependent on adequate end-diastolic ventricular filling pressures to maintain cardiac output and systemic perfusion. Abrupt drops in end-diastolic volume may result in hypotension, syncope, myocardial infarction, and sudden death. hus, avoiding diminished ventricular preload and maintaining cardiac output are key. During labor and delivery, afected women are best managed on the "wet" side. his provides a margin of safety in intravascular volume in anticipation of possible hemorrhage. In women with a competent mitral valve, pulmonary edema is rare.
During labor, narcotic epidural analgesia seems ideal and avoids potentially hazardous hypotension. Easterling and coworkers (1988) studied the efects of epidural analgesia in ive women with severe stenosis and demonstrated immediate and profound efects from decreased illing pressures. Xia and associates (2006) emphasize slow administration of dilute local anesthetic agents into the epidural space. In hemodynamically stable women, forceps or vacuum delivery is used for standard obstetrical indications.
Aortic valve regurgitation or insuiciency allows diastolic Bow of blood from the aorta back into the let ventricle. Frequent causes of abnormal insuiciency are rheumatic fever, connective tissue abnormalities, and congenital lesions. With Marfan syndrome, the aortic root may dilate and create regurgitation (p. 967). Acute insuiciency may also develop with bacterial endocarditis or aortic dissection (pp. 965 and 967). Last, aortic and mitral vlve insuiciency have both been linked to the appetite suppressants fenBuramine and dexfenBuramine and to the ergot-derived dopamine agonists cabergoline and pergolide (Gardin, 2000; Schade, 2007; Zanettini, 2007). With chronic insuiciency, let ventricular hypertrophy and dilation develop and are followed by slow-onset fatigue, dyspnea, and pulmonary edema, although rapid deterioration usually follows (see Table 49-6).
Aortic insuiciency is generally well tolerated during pregnancy. Like mitral valve insuiciency, diminished vascular resistance is thought to improve hemodynamic function. If symptoms of heart failure develop, diuretics are given and bed rest is encouraged.
his lesion is usually congenital and also may be associated with Fallot tetralogy or Noonan syndrome. The greater hemodynamic burden of pregnancy can precipitate right-sided heart failure or atrial arrhythmias in women with severe stenosis. Surgical correction ideally is done before pregnancy, but if symptoms progress, a balloon valvuloplasty may be necessary antepartum (Galal, 2015; Siu, 2001a).
In studying pregnancy outcomes, Drenthen and colleagues (2006) found infrequent cardiac complications in a group of 81 pregnancies in 51 Dutch women with pulmonic stenosis. The NHA classification worsened in two women, and nine experienced palpitations or arrhythmias. No changes in pulmonary valvular function or other adverse cardiac events were reported. However, non cardiac complication rates were significant-17 percent had preterm delivery, 15 percent had hypertension, and 4 percent developed thromboembolism.