Right Ventricle
The Right Ventricle
The contractile function of the RV is difficult to measure due to the complex anatomy. Historically in clinical practice there was very little attention paid to this part of the heart, since it was assumed that they previously played a passive role. Only in the last three decades it has been shown that the function of the RV plays an important role in the survival of several disease states. There is also a number of echocardiographic measurements to measure RV function and provide insight into the mechanisms of RV dysfunction.
Right ventricular dimensions
| Reference range | Mildly abnormal | Moderately abnormal | Severely abnormal | |
|---|---|---|---|---|
| RV dimensions | ||||
| Basal RV diameter (RVD 1), cm | 2.0–2.8 | 2.9–3.3 | 3.4–3.8 | ≥3.9 |
| Mid-RV diameter (RVD 2), cm | 2.7–3.3 | 3.4–3.7 | 3.8–4.1 | ≥4.2 |
| Base-to-apex length (RVD 3), cm | 7.1–7.9 | 8.0–8.5 | 8.6–9.1 | ≥9.2 |
| *RV diastolic area, cm2 | 11–28 | 29–32 | 33–37 | ≥38 |
| *RV systolic area, cm2 | 7.5–16 | 17–19 | 20–22 | ≥23 |
| RVOT diameters | ||||
| Above aortic valve (RVOT 1), cm | 2.5–2.9 | 3.0–3.2 | 3.3–3.5 | ≥3.6 |
| Above pulmonic valve (RVOT 2), cm | 1.7–2.3 | 2.4–2.7 | 2.8–3.1 | ≥3.2 |
| *Reference limits and partition values of right ventricular size and function as measured in apical 4-chamber view. | ||||
Right ventricular function
| Reference range | Mildly abnormal | Moderately abnormal | Severely abnormal | |
|---|---|---|---|---|
| *RV fractional area change, % | 32–60 | 25–31 | 18–24 | ≤17 |
| *TAPSE, cm | 1.5-2.0 | 1.3-1.5 | 1.0-1.2 | <1.0 |
| *RV MPI | <0.28 | |||
| *Dp/DT | >400mmHg | |||
| *RV TDI doppler (S'), cm/s | >11.5 | |||
| *Reference limits and partition values of right ventricular size and function as measured in apical 4-chamber view. [1] | ||||
Fractional Area Change
With this method, the percentage difference in the surface traced by the RV measured during systole and diastole is measured. Here again the apical 4CH is used for accuracy. The difference in surface limited to less than 35%, then this fits a reduced function. This method is frequently used in clinical practice.
Dp/DT
These methods make use of determining the speed of the myocardium itself and determination of pressure differences between the compartments of the right heart. A simple physiological measure of RV function is the systolic pressure buildup in the time of the RV. This can be determined as Dp/DT, for this purpose, the systolic acceleration speed of the tricuspid insufficiency signal is determined during the isovolumetric contraction phase. This can be done by measuring the time interval in the continuous wave signal TR is between 1 and 2 m/s.
Due to that, by definition, a differential pressure of 12mmHg is concerned, this size will be determined by dividing by 12, the measured time interval. Quite simply the pressure build-up is less than 400mmHg/sec then this is an indication for a reduced right ventricular function.
RV myocardial performance index (MPI)
References
- Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K, Solomon SD, Louie EK, and Schiller NB. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010 Jul;23(7):685-713; quiz 786-8. DOI:10.1016/j.echo.2010.05.010 |