Effect of tissue harmonic imaging and contrast upon between observer and test-retest reproducibility of left ventricular ejection fraction measurement in patients with heart failure.

AIMS: To investigate the effects of tissue harmonic imaging (THI) and contrast chamber opacification (LVO) upon measurement variability and reproducibility of echocardiographic left ventricular (LV) volume and ejection fraction (EF) measurements in patients with heart failure (HF).
BACKGROUND: Echocardiography is often used in HF patients to determine LV volumes and EF. However, current echo methods are variable and may not be applicable for repeat testing in individual patients. THI and LVO have both been shown to improve endocardial visualisation, but it remains to be determined whether this results in better measurement reproducibility.
METHODS: Thirty-one HF patients and 30 control subjects underwent echocardiography on two separate days. LV volumes were measured under four different imaging conditions: fundamental, THI, LVO and LVO with ECG-triggered Power Doppler. Chamber opacification, pulmonary transit time (PTT), endocardial enhancement, reproducibility and bias were assessed.
RESULTS: Chamber opacification was inferior and the PTT longer in the HF patients. PTT was related to LV volumes, EF, jugular venous pressure and mitral filling pattern. THI improved endocardial visualisation, and although LVO improved endocardial visualisation in the controls, it offered no benefit over THI in the HF patients. LV volumes and EF were different for each method and THI was the least variable method for repeat measurements.
CONCLUSIONS: THI improved endocardial visualisation and was the least variable of the techniques. LVO offered no further advantage in patients with HF and thus cannot be routinely advocated and since LV volumes and EF were different for each, these methods are neither comparable nor interchangeable for follow-up assessments.