Table 1.
Techniques Used to Assess Cardiac Structure and Function
| 12-Lead ECG | Transthoracic Echocardiogram | Cardiac CT | Cardiac MR | |
|---|---|---|---|---|
| LA enlargement | Usually based on the duration of the negative phase of the P-wave in lead V1 >40 ms, with a sensitivity and specificity of 83% and 80%, respectively (83). | Usually based on LA volume index >40 ml/m2. Provides diagnostic and prognostic information. Accuracy is dependent on the image quality and operator experiences (84). | Better than 2D echo in estimating LA volume and anatomy. Radiate, time-consuming, more expensive, and less available than echo. | Gold standard for estimation of LA volume. Time-consuming, expensive, and limited accessible (85). |
| LV hypertrophy | Based on the Sokolow-Lyon criteria (SV1 or SV2 plus RV5 or RV6 >3.5 mV), or the Cornell criteria (RI plus SIII >2.5 mV). Low sensitivity (6.9%) but high specificity (98.8%) (86). | Based on LV mass index >115 g/m2 for men and >95 g/m2 for women. Higher sensitivity than ECG. More accessible, cheaper, and higher operator-dependent than cardiac CT/MR (87). | The utility of cardiac CT for assessment of LV hypertrophy is relatively limited. May be appropriate test for assessment of LV hypertrophy in individuals with known or suspected HF (88). | Gold standard for diagnosing LV hypertrophy. Time-consuming, expensive, and limited accessible (85). Appropriate test for assessment of LV hypertrophy in individuals with known or suspected HF (88). |
| LV enlargement | N/A | Available and reproducible. Apex foreshortened, endocardial dropout, and shape distortion compromise the accuracy of LV volume estimation. | May be appropriate test for assessment of LV enlargement in individuals with known or suspected HF (88). | Gold standard for evaluation of LV volume. Appropriate test for assessment of LV enlargement in individuals with known or suspected HF (88). |
| LV systolic dysfunction | N/A | LVEF is easily obtained but limited by high interobserver and intraobserver variability (89). GLS has reduced interobserver and intraobserver variability, and is more sensitive and specific in identifying subclinical LV systolic dysfunction (90). | May be appropriate test for assessment of LV systolic dysfunction in individuals with known or suspected HF (88). | Gold standard for evaluation of LV systolic function. Appropriate test for assessment of LV systolic dysfunction in individuals with known or suspected HF (88). |
| LV diastolic dysfunction | N/A | Diagnosed based on increased LA volume index, reduced septal or lateral e’ velocity, increased average E/e’ ratio and increased TR systolic jet velocity. | May be appropriate test for assessment of LV diastolic dysfunction in individuals with known or suspected HF (88). | Good agreement of cardiac MR and echo in assessment of LV diastolic dysfunction (91). Appropriate test for assessment of LV diastolic dysfunction in individuals with known or suspected HF (88). |
2D = 2-dimensional; CT = computed tomography; ECG = electrocardiogram; echo = echocardiogram; GLS = global longitudinal strain; HF = heart failure; LA = left atrial; LV = left ventricular; LVEF = left ventricular ejection fraction; MR = magnetic resonance; N/A = not applicable; TR = tricuspid regurgitation.