Role of Echocardiography in Evaluation of New Murmurs During Pregnancy

Introduction: New cardiac murmurs are frequently detected during pregnancy, which are often related to increased cardiac output. Despite this, further evaluation with echocardiography is often requested to exclude pathological causes. We sought to evaluate the utility of echocardiography in detecting pathological causes for new cardiac murmurs during pregnancy. Methods: We studied consecutive pregnant patients referred to our tertiary hospital between 1st January 2013 and 31st December 2014 who underwent outpatient echocardiography to a evaluate a new murmur. Baseline demographics were retrospectively obtained from medical records and echocardiograms were analysed to determine mean flow across cardiac valves and to identify pathological causes for murmurs. Patients were excluded if they had pre-existing cardiac disease. Results: Forty-nine consecutive pregnant patients were identified with a new murmur, with 6 excluded due to pre-existing cardiac disease. Of 43 eligible patients, mean age was 30+/-5.5 years, mean gestation 24+/-5.7 weeks. All murmurs were systolic. Fourteen (33%) patients were symptomatic, with dyspnoea in 8 (57%) patients being the most common symptom. Only one (2%) echocardiogram identified a pathological cause for murmur: mild pulmonary stenosis (Vmax 2.8 m/sec). Increased flow across cardiac valves was noted, with mean velocities across the aortic, pulmonary, mitral and tricuspid valves of 1.6+/-0.3 m/sec, 0.9+/-0.2 m/sec, 0.6+/-0.2 m/sec and 1.2+/-0.3 m/sec, respectively. Conclusion: Most new murmurs during pregnancy are benign and related to increased cardiac output. There is no contemporary role for routine echocardiography in pregnant patients with a new isolated systolic murmur in the absence of pre-existing cardiac disease.