Augmentation of ECG QRS complexes after fluid removal via a mechanical ultrafiltration pump in patients with congestive heart failure.

BACKGROUND: Augmentation of the amplitude of ECG QRS complexes, correlating with loss of weight or fluid volume removed, has been documented in patients with congestive heart failure (CHF).
METHODS: We investigated the effect of an ultrafiltration (UF) pump on the fluid removal and the amplitude of ECG QRS complexes in patients with CHF. Nine patients aged 48.3 +/- 10.4 years with CHF were treated with an UF system, and weights, fluid removed, and sums of the amplitude of QRS complexes (SigmaQRS), were inter-correlated.
RESULTS: UF resulted in removal of 4.62 +/- 1.82 L of fluid, 5.0 +/- 2.9% decrease in the weights (P = 0.002) and 18.1 +/- 16.8% increase in the SigmaQRS (P = 0.012). There was a moderate correlation of % increase in the SigmaQRS and net fluid volume losses (UF + urine - oral intake), (r = 0.67, P = 0.0471, and a poor correlation between % increase in the SigmaQRS and % decrease in weights (r = 0.11, P = 0.77). Correlations of the change in weights after UF with the fluid removed by UF, or with the volume of total fluid loss (including insensible losses) were moderate but barely statistically significant (r = 0.65, P = 0.0559), and (r = 0.65, P = 0.0577), correspondingly.
CONCLUSION: Augmentation of the amplitude of QRS complexes correlates well with net fluid loss in response to UF in patients with CHF, and can be employed as an index of effectiveness of therapy. Also, a model of fluid losses in patients treated for CHF is being proposed.