Cardiac Stent Restenosis and New Heart Murmurs

Characteristics of the Murmur

• The murmur associated with stent restenosis is typically midsystolic in nature, with a crescendo-decrescendo configuration, and starts shortly after S1, when ventricular pressure rises sufficiently to open the semilunar valve 2
• The intensity of the murmur depends on the velocity of blood flow across the narrowed area 1
• The murmur is best heard over the cardiac base, with radiation to the carotids 3, 4
• The murmur is often harsh, with a crescendo-decrescendo pattern, and has a variable intensity, typically grade 2-4/6 2, 4

Dynamic Auscultation Findings

• The murmur will increase with maneuvers that increase cardiac output, such as exercise 1
• The murmur may increase after a ventricular premature beat or during the beat after a long cycle in atrial fibrillation 5
• During amyl nitrite inhalation, the murmur would likely increase due to increased stroke volume 5

Clinical Implications

• The presence of a new murmur in a patient with coronary stents should prompt careful cardiac auscultation during various hemodynamic states to characterize the murmur 1
• Evaluation for other signs of cardiac compromise, such as heart failure or angina, is necessary 4
• Echocardiography should be performed to assess for stent restenosis and rule out valvular disease 4

Differential Diagnosis

• Valvular heart disease, particularly aortic stenosis, should be considered as a potential cause of the new murmur 3
• Other causes of outflow tract obstruction should also be evaluated 6
• Innocent flow murmurs due to increased cardiac output may be a possible diagnosis 2