The American journal of cardiology
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Intravenous heparin is routinely given after thrombolytic therapy for patients with acute myocardial infarction in the United States and in some, but by no means all, other countries. Several trials have documented improved infarct-artery patency in patients treated with heparin; however, none was large enough individually to assess the effect of heparin on clinical outcomes. We performed a systematic overview of the 6 randomized controlled trials (1,735 patients) to summarize the available data concerning the risks and benefits of intravenous heparin versus no heparin after thrombolytic therapy. ⋯ The findings of this overview demonstrate that insufficient clinical outcome data are available to support or to refute the routine use of intravenous heparin therapy after thrombolysis. It is not known if these findings are due to lack of statistical power, inappropriate levels of anticoagulation, or lack of benefit of intravenous heparin. Large randomized studies of heparin (and of new antithrombotic regimens) are needed to establish the role of such therapy.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Effects of bisoprolol on heart rate variability in heart failure.
Analysis of heart rate variability (HRV) provides a non-invasive index of autonomic nervous system activity. HRV has been shown to be reduced in heart failure. Preliminary data indicate that beta blockers improve clinical status in patients with heart failure, but HRV improvement remains to be demonstrated. ⋯ Bisoprolol increased 24-hour rMSSD (p=0.04) and 24-hour pNN50 (p=0.04), daytime SDNN (p=0.05), and daytime high-frequency power (p=0.03) power. Bisoprolol induced a significant increase in HRV parameters related to parasympathetic activity in heart failure. Increased vagal tone may contribute to the protective effect of beta blockers and may have prognostic implications.
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The aim of the study was to describe the course of serum creatine kinase (CK) and its MB fraction (CK-MB) in patients surviving cardiac arrest, and to identify factors influencing CK and CK-MB release. The study was set in the community of Vienna, Austria. Data concerning cardiopulmonary resuscitation, collected within a period of 33 months, were evaluated retrospectively and compared with laboratory blood investigations collected prospectively (on admission and after 6, 12, and 24 hours) in 107 adult patients surviving a witnessed cardiac arrest for 24 hours. ⋯ Of patients with electrocardiographic evidence of AMI, only 49% had an elevated CK-MB/CK ratio. In conclusion, the elevation in serum CK and CK-MB fraction in patients after nontraumatic cardiac arrest is a frequent finding, and is associated with ischemic myocardial injury, as well as physical trauma to the chest. This should be considered when interpreting the course of CK and CK-MB fraction for the diagnosis of AMI.
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Spinal cord stimulation in angina pectoris increases exercise capacity and reduces both anginal attacks and ischemic electrocardiographic signs. This suggests an anti-ischemic action, perhaps through changes in myocardial blood flow. In 9 patients, regional myocardial blood flow was studied with positron emission tomography before and after 6 weeks of spinal cord stimulation, both at rest and during a dipyridamole stress test. ⋯ The coefficient of variation of flow, representing flow heterogeneity, decreased after treatment, both at rest (20.1 +/- 3.8% vs 17.4 +/- 2.6%, p = 0.04) and after dipyridamole stress (26.2 +/- 4.4% vs 22.9 +/- 5.5%, p = 0.02). Thus, spinal cord stimulation is clinically effective due to homogenization of myocardial blood flow. Since flow reserve decreases despite clinical improvement, the dipyridamole effect may be blunted by spinal cord stimulation.
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This study reports the role of biplane transesophageal echocardiography in monitoring surgical repairs of tetralogy of Fallot. In our patients, 3 repairs were revised based on transesophageal echocardiography and continuous-wave Doppler results, and intraoperative management was altered in 2 others.