Aortic Stenosis with Midsystolic Ejection Murmur
The clinical presentation of exertional chest pain, small heart, and dilated aorta is most consistent with aortic stenosis, which produces a midsystolic (systolic ejection) murmur that is crescendo-decrescendo in configuration, heard best at the second right intercostal space with radiation to the carotid arteries. 1
Key Diagnostic Features
The combination of findings points specifically to valvular aortic stenosis:
Midsystolic murmur characteristics: The murmur starts shortly after S1 when ventricular pressure rises sufficiently to open the semilunar valve, increases as ejection increases, and diminishes as ejection declines 1
Dilated ascending aorta: This is common in valvular aortic stenosis, particularly after age 40 years, and helps differentiate it from other causes of left ventricular outflow obstruction 1
Small heart: The left ventricle remains relatively normal in size until late-stage disease, unlike conditions causing volume overload 1
Physical Examination Findings to Confirm
Additional findings that support severe aortic stenosis include:
Soft or absent A2 component of the second heart sound, or reversed splitting of S2, which denotes severe aortic stenosis 1
Carotid pulse: Parvus et tardus (weak and delayed) pulse is characteristic of valvular aortic stenosis 1
Ejection click: Present in most cases unless the valve is heavily calcified 1
Fourth heart sound (S4): Present if stenosis is severe 1
Dynamic Auscultation Maneuvers
The murmur intensity changes predictably with hemodynamic interventions:
Post-ventricular premature beat: The murmur increases in intensity due to increased stroke volume, distinguishing it from mitral regurgitation which does not change 1
Valsalva maneuver: The murmur decreases during strain phase, unlike hypertrophic cardiomyopathy which increases 1
Respiration: Left-sided murmurs like aortic stenosis are typically louder during expiration 1
Critical Pitfall to Avoid
Do not dismiss this as aortic sclerosis (a benign flow murmur in older patients with sclerotic valve leaflets but no significant stenosis). The presence of exertional chest pain mandates echocardiography to rule out hemodynamically significant aortic stenosis, as symptoms of angina, syncope, or heart failure indicate severe disease requiring intervention 1
Immediate Next Step
Obtain echocardiography urgently to quantify the severity of aortic stenosis, assess valve area and gradient, evaluate left ventricular function, and measure the ascending aorta dimensions 1. The presence of symptoms with a midsystolic murmur requires aggressive diagnostic evaluation regardless of murmur grade 1