Review: b blockers reduce mortality and therapy withdrawal in heart failure but increase dizziness and bradycardia Ko DT, Hebert PR, Coffey CS, et al. Adverse effects of b-blocker therapy for patients with heart failure: a quantitative overview of randomized trials. Arch Intern Med 2004;164:1389-94. Clinical impact ratings GP/FP/Primary care wwwwwqq IM/Ambulatory care wwwwwwq Internal medicine wwwwwwq Cardiology wwwwwqq