Contributions of cardiac dysfunction and volume status to central haemodynamics in chronic heart failure

Abstract

Aims: Elevated cardiac filling pressures producing clinical congestion in heart failure (HF) patients may be secondary to intravascular volume expansion or abnormalities in cardiac diastolic properties. The objective of this study was to assess the extent to which measures of myocardial function and intravascular volume correlate with haemodynamic abnormalities in chronic HF.

Methods and results: Subjects underwent invasive haemodynamic assessment, measurement of total blood volume (TBV) using radiolabel indicator-dilution methodology, and echocardiography to evaluate cardiac structure and function. Patients were divided into those with hypervolaemia (defined as TBV > +8% above referenced normal volume) and normal volume ('euvolaemia') (TBV ≤ + 8%). Of 66 patients, 39 (59%) were hypervolaemic and 27 (41%) normal TBV. Central venous pressure (CVP, P = 0.01) and pulmonary capillary wedge pressure (PCWP, P < 0.001) were higher in hypervolaemic compared with euvolaemic patients; however, 15% of hypervolaemic patients displayed normal pressures. Of euvolaemic patients, 70% displayed elevated CVP and 63% elevated PCWP. PCWP was moderately correlated with TBV (r = 0.42), left ventricular diastolic function (e' velocity, r = -0.44), and left atrial strain (r = -0.47). In multivariable regression TBV, left ventricular e', and left atrial strain were independently associated with PCWP (all P < 0.05).

Conclusions: While hypervolaemic patients displayed elevations in filling pressures, a substantial proportion (15%) had normal pressures, and of all subjects with elevated filling pressures nearly one third had normal TBVs. Importantly, of patients with normal volumes, a majority (>60%) display elevated filling pressures. Combined analysis of volume, pressure, and cardiac function may be helpful to guide comprehensive assessments of HF status.

Keywords: Cardiac filling pressures; Cardiac function; Heart failure; Intravascular volume.

Figure 1.

Compared to normal volume HF patients (euvolemic, black), patients with increased intravascular volume (hypervolemic, red) displayed more right ventricular dilatation (end diastolic area, RVEDA), greater left atrial enlargement (left atrial volume index, LAVI), and lower left atrial strain. *p<0.001 compared to normal volume.

Figure 2.

While central venous pressure (CVP, left) and pulmonary capillary wedge pressure (PCWP, right) were higher on average in hypervolemic patients (red boxes), >60% of euvolemic patients (black circles) still displayed elevated CVP (>6 mmHg) and elevated PCWP (>15 mmHg, dotted lines).

Figure 3.

Compared to euvolemic patients with normal PCWP (black), patients with euvolemia but high PCWP (gray) displayed more myocardial dysfunction, with lower left ventricular global longitudinal strain (GLS), lower early diastolic relaxation velocities (e’), and decreased left atrial strain. *p<0.05 compared to normal PCWP.

Figure 4.

Correlations between pulmonary artery (PA) wedge pressures, left atrial function (strain), diastolic relaxation (e’), and intravascular blood volume.