In a systematic review of 150 cases, most women developed an acute myocardial infarction (MI) during the third trimester or postpartum (Elkayam, 2014b). Approximately three fourths presented with ST segment-elevation MI (STEMI). he leading mechanisms of acute infarction included spontaneous coronary dissection (43 percent) and atherosclerotic disease (27 percent). Signiicant complications included heart failure/cardiogenic shock (38 percent), recurrent angina or infarction (19 percent), and ventricular arrhythmias (12 percent). he maternal and fetal mortality rates were 7 and 5 percent, respectively. Of other potential antecedents, coronary artery occlusion in two pregnant smokers with hypercholesterolemia has been described following ergometrine administration (Mousa, 2000; Ramzy, 2015; Sutaria, 2000). Schulte-Sasse (2000) reported myocardial ischemia associated with prostaglandin Ervaginal suppositories given for 1 labor induction.
Diagnosis of acute myocardial infarction during pregnancy does not difer from that in nonpregnant patients and is based on clinical presentation, characteristic ECG changes, and evidence of myocardial necrosis relected by elevated serum troponin levels (Pacheco, 2014). Of note, troponin I levels are undetectable near term in normal pregnancy and do not rise following either vaginal or cesarean delivery (Koscica, 2002; Shivvers, 1999). Importantly, however, troponin I levels are higher in preeclamptic women compared with normotensive controls (Atalay, 2005; Yang, 2006). With spontaneous coronary artery dissection, establishing the diagnosis requires a high index of suspicion in the gravida presenting with chest pain (Codsi, 2016). For this condition, coronary angiography is considered the diagnostic gold standard and should be expediently performed if acute coronary syndrome-deined as myocardial infarction or unstable angina-is present.
Treatment of acute myocardial infarction is similar to that for nonpregnant patients (Pacheco, 2014). An algorithm summarizing one approach to its management during pregnancy is shown in Figure 49-6. Several reports describe successful percutaneous transluminal coronary angioplasty and stent placement during pregnancy (Balmain, 2007; Duarte, 2011;
FIGURE 49-6 Initial management of acute myocardial infarction during pregnancy. Risk stratification refers to the risk ofdeveloping recurrent symptoms despite optimal medical management. (Adapted with permission from Pacheco LO, Saade GR, Hankins GO: Acute myocardial infarction during pregnancy, (lin Obstet Gynecol. 2014 Oec;S7(4):83S-843.)
Dwyer, 2005). Cardiopulmonary resuscitation may be required, as described in Chapter 47 (p. 931). If the infarct has healed suiciently, cesarean delivery is reserved for obstetrical indications, and epidural analgesia is ideal for labor (Esplin, 1999).