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There is accumulating evidence that β blockers improve symptoms and prognosis in patients with ischaemic heart disease (IHD). 1 Impaired filling of the left ventricle is often found in association with IHD. 2 Improvement in diastolic left ventricular function may be an important mechanism of action of β blockers. This study investigated the effect of β adrenergic blockade on diastolic filling in patients with IHD.
We carried out a retrospective analysis of left ventricular filling in 265 consecutive patients attending our department for routine clinical evaluation of chest pain. All patients underwent our standard imaging protocol of thallium-201 myocardial perfusion imaging and list mode radionuclide ventriculography (RNVG). Left ventricular filling was assessed using RNVG, which has been previously validated for the assessment of cardiac diastolic function. 3 4 It has also been extensively used in the assessment of left ventricular filling in various conditions. 4
Background corrected left ventricular activity-time curves were generated using a fixed left ventricular and background region of interest. Left ventricular ejection fraction (LVEF) was calculated in the usual manner. The normal lower limit of LVEF with this technique is 40% in our institution. The percentage of left ventricular filling in the first third of the diastolic period was defined as the first third filling fraction (1/3FF), expressed as a percentage of the stroke volume. The previously described heart rate adjusted first third filling fraction index (which is equal to 1/3FF/R-R interval) was also used. 5
Values are expressed as mean (SD). Spearman's correlation coefficient (rs ) was used for correlation between variables. Non-parametric Kruskal-Wallis statistic was used for data comparison between three groups. Individual pairs of parameters were further compared by...