• To assess the effects of β-blockade on right ventricular performance in patients with and without right ventricular dysfunction due to coronary artery disease, we performed radionuclide ventriculography on eight patients with normal right ventricular ejection fraction (RVEF≥35%) and 14 patients with mild to moderate right ventricular dysfunction (RVEF<35%) at rest. All patients had chronic stable angina pectoris, and nine patients had prior myocardial infarction. Radionuclide ventriculography was performed on placebo and during clinical β-blockade (heart rate, 50 to 60 beats per minute and ≤20% increase in heart rate over baseline during stage I treadmill exercise, Bruce protocol) with the oral, cardioselective β-blocking agent, betaxolol. The resting RVEF (mean±1 SD) was 33%±7% on placebo and 34%±7% during clinical β-blockade. Mean exercise RVEF was 40%±8% on placebo and 39%±8% during clinical β-blockade. These differences were not statistically significant. Resting left ventricular ejection fraction ranged from 22% to 60% (mean, 42%± 8%). On placebo, one of eight patients with a resting RVEF≥35% had a normal exercise RVEF response (≥5% increment) whereas nine of 14 patients with resting RVEF <35% had normal exercise response. The discordant relationship between baseline RVEF and exercise response on placebo became less marked during clinical β-blockade. We conclude that β-blockade does not produce significant deterioration of right ventricular systolic function or right ventricular reserve either in patients with normal or in those with mild to moderately impaired resting right ventricular systolic function.
(Arch Intern Med 1986;146:2135-2139)