Question explored with the scientific record
What does an ultrasound examination of the heart show?
An ultrasound of the heart is a structural and functional exam, not a diagnosis. It shows how the pump and valves are working, and it is only as good as the operator and the image quality.
An echocardiogram bounces sound off the heart and builds a moving picture. What it actually measures is the pump: how much blood the left ventricle holds and how much it pushes out per beat, the ejection fraction [1][4]. It also shows chamber sizes, wall thickness, and valve motion [8]. In one study of 234 people with high blood pressure, echo found wall thickening or increased heart mass in 61% of them, while ECG and chest X-ray missed many of those [8].
It can also catch specific problems. In people with a very weak pump (ejection fraction under 35%), echo found a blood clot inside the heart in about 6 in 100, and 80% of those clots sat at the tip of the ventricle [2]. It detects fluid around the heart after a heart attack, seen in about 18 in 100 patients in one series [7]. It can show a torn or leaking valve, a bulging wall, or a dissection flap in the aorta [5][6].
The catch is accuracy. Ejection fraction by echo is an estimate, not a measurement. A review of 43 studies found the margin of error around the true value ranged from about 7 to 25 points depending on the method [3]. Adding contrast dye improved correct classification into normal, mild, and severely reduced function from 86% to 99% in one study of 100 patients [4].
| Finding | What echo showed | Source |
|---|---|---|
| Weak pump, clot risk | 6.1% had a clot | [2] |
| Fluid after heart attack | 18.1% had effusion | [7] |
| High blood pressure, structural change | 61% abnormal | [8] |
| EF error margin | ±7 to ±25 points | [3] |
My call: it is a genuinely useful, low-risk test for structure and pump function, but treat the ejection fraction number as an estimate with real error bars, and ask whether contrast was used if the image was poor. Confidence: moderate.
Sources used 8
-
Accurate Determination of Left Ventricular Ejection Fraction by Transesophageal Echocardiography With a Nonvolumetric Method
This study adapts the nonvolumetric multiple-diameter method for estimating left ventricular ejection fraction (EF) to single-plane transesophageal echocardiography (TEE) and validates its accuracy against transthoracic EF in retrospective and prospective patient populations, sh…
DOI: 10.1016/S0894-7317(14)80466-5 -
The prevalence of left ventricular thrombus among patients with low ejection fraction by trans-thoracic echocardiography
In patients with EF below 35%, left ventricular thrombus was present in 6.1%; most thrombi were apical and in IHD/dilated cardiomyopathy patients; khat chewing and smoking were common but showed no significant relationship.
DOI: 10.12669/pjms.36.4.1972 -
Reliability of reporting left ventricular systolic function by echocardiography: A systematic review of 3 methods
A comprehensive systematic review comparing three echocardiographic methods (Simpson's rule, wall motion index, and subjective visual assessment) for reporting left ventricular systolic function against reference standards (CVG/RNVG), finding that nongeometric methods are genera…
DOI: 10.1016/s0002-8703(03)00248-5 -
Accurate and reproducible measurement of left ventricular volume and ejection fraction by contrast echocardiography
This study evaluates the accuracy and reproducibility of contrast-enhanced 2D echocardiography for measuring left ventricular volumes and ejection fraction (EF) against magnetic resonance imaging (MRI), showing improved feasibility, accuracy, and inter-/intra-observer reproducib…
DOI: 10.1016/j.jacc.2004.05.068 -
Role of transesophageal echocardiography in the assessment of patients with blunt chest trauma: Correlation of echocardiographic findings with the electrocardiogram and creatine kinase monoclonal antibody measurements
A multicenter prospective study evaluating transesophageal echocardiography (TEE) for detecting cardiac injury after blunt chest trauma (BCT) and comparing its diagnostic performance with ECG and CK-MB measurements, finding TEE to be more accurate and safer for identifying cardi…
DOI: 10.1016/s0002-8703(98)70324-2 -
Utility of two-dimensional echocardiography in suspected ascending aortic dissection
This study evaluates the diagnostic value and prognostic implications of bedside two-dimensional echocardiography for suspected ascending aortic dissection in 56 consecutive adults, showing perfect sensitivity, a high negative predictive value, and useful ancillary information w…
DOI: 10.1016/0002-9149(85)90579-x -
Frequency and severity of pericardial effusion after acute myocardial infarction
In a cross-sectional study of 160 Pakistani AMI patients, pericardial effusion occurred in 18.1%, mostly mild, and was significantly associated with mitral regurgitation, LV dysfunction, LV clot, ventricular aneurysm, and ventricular septal rupture.
DOI: 10.12692/ijb/15.6.441-449 -
Echocardiographic assessment of cardiac anatomy and function in hypertensive subjects.
This study used echocardiography to assess cardiac anatomy and function in 234 asymptomatic hypertensive adults, adjusting for age and body size, and found a high prevalence of structural abnormalities (notably septal and LV wall thickening and increased LV mass) with echocardio…
DOI: 10.1161/01.CIR.59.4.623