“Left ventricular filling pressure(s)” - Ambiguous and misleading terminology, best abandoned

- The physiology of left atrial and left ventricular end diastolic pressures is reviewed.
- The ambiguity of the term “filling pressure(s)” is highlighted.
- The clinical importance of specificity in terminology is discussed.

The use of the terms “left ventricular filling pressure” and “left ventricular filling pressures” is widespread in the cardiology literature, but the meanings ascribed to these terms have not been consistent. Left ventricular end-diastolic pressure (LVEDP) and mean left atrial pressure (LAP) cannot be used interchangeably as they will often differ in magnitude in the presence of cardiac disease and they also have different clinical significance. LVEDP is the best pressure to use when considering left ventricular function, whereas mean LAP is the most relevant pressure when considering the tendency to pulmonary congestion. The mean LAP is also the most relevant pressure for determining whether pulmonary hypertension has a left heart (post-capillary) component. If only a left ventricular pressure tracing is available then a technique to measure the mean left ventricular diastolic pressure is the best option for estimating the mean LAP. If only right heart pressures are available then the pulmonary artery end-diastolic pressure will provide a reasonable estimate of LVEDP, but only when the heart and pulmonary circulation are normal. If there is mitral valve disease, left ventricular disease or pulmonary hypertension the LVEDP cannot be estimated from right heart pressures. The problem of the ambiguity of “filling pressure (s)” is readily solved by the abandonment of this term and the use of either LVEDP or mean LAP as appropriate.