Management of cardiogenic shock complicating acute myocardial infarction: The Henry Ford Hospital experience and review of the literature.

Cardiogenic shock complicating acute myocardial infarction (MI) carries a high mortality which in some series prior to 1980 exceeded 80%. Neither the use of inotropic and vasopressor agents nor intraaortic balloon counterpulsation was found to improve survival in this group of patients. Intravenous thrombolytic agents improve survival in patients with acute MI, but their role in cardiogenic shock is unknown. Reports of the use of surgical and mechanical interventions in patients with severe left ventricular dysfunction were examined to determine if there was any benefit to be derived from restoring blood flow to ischemic areas of the myocardium. It was found that urgent placement of intraaortic balloon counterpulsation followed by coronary bypass surgery may improve survival rates and successful coronary angioplasty also appeared to benefit patients with cardiogenic shock. Similar improvement in survival has been reported after successful coronary reperfusion. In surgical series with predominantly nonmechanical causes of shock, survival has varied from 40% to 88%. Data from our five-year experience in the management of MI patients with cardiogenic shock suggest that coronary revascularization with coronary angioplasty or bypass surgery improves survival in patients with cardiogenic shock especially when performed within 24 hours of the onset of shock.     

Predominance of antibodies to hepatitis C virus envelope proteins in various disease statuses of hepatitis C

The antibody profile to various proteins of hepatitis C virus (HCV) was studied in 113 patients positive for HCV RNA in various disease statuses of hepatitis C (HC). A single peptide (E2/NS1, aa 413-436 of HCV polyprotein) chosen from a conserved region at the C-terminus of the hypervariable region (HVR) HVR1 of HCV was found to be sufficient for reliable diagnosis of the infection, even in the acute phase. Six hundred and one suspected HC cases and 200 voluntary blood donors were tested by this peptide. The sensitivity of detection of HCV antibodies by this peptide did not increase with addition of peptides from other HCV proteins. Our results clearly demonstrate that antibodies to HCV envelope proteins occur in a higher percentage of the infected population than those to other proteins. This emphasizes the necessity of using representative sequences from HCV envelope proteins in diagnostic immunoassays of this viral infection.     

Complications of Transplantation. Part 1: Renal Transplants

Vascular complications after solid-organ transplantation are not uncommon and may lead to graft dysfunction and ultimately graft loss. A thorough understanding of the surgical anatomy, etiologies, and types of vascular complications, their presentation, and the options for management are important for managing these complex patients. This article reviews the basic surgical anatomy, vascular complications, and endovascular management options of vascular complications in patients with renal transplants.     

Identification of rare hepatitis C virus genotype 5a among Indian population

In Indian population, hepatitis C virus (HCV) genotypes 1 and 3 are prevalent and predominant with the highest frequency. However, other genotypes are seldom reported, and among them the HCV genotype 5a is exceptionally rare. The presented case had no history for either blood transfusion or using any type of IV drugs and never traveled to any other country. He was serologically positive with HCV antibodies and HCV RNA. 5′UTR-specific amplification and sequencing of infected viral genome confirmed that he had been infected with HCV genotype 5a which is not closely related to other common prevalent genotypes like 1a, 1b, 3a, and 3b in India. Patient’s wife and children tested negative for anti-HCV and HCV-RNA. This unique case report could be attributed to circulation of HCV genotype 5a from other geographic area at very low frequency in India as determined by phylogenetic analysis and nucleic acid-sequencing methods.     

Echocardiographic evaluation of left ventricular function during coronary artery angioplasty

Balloon occlusion of a stenotic coronary artery during percutaneous coronary artery angioplasty provides a unique opportunity to study the effect of acute myocardial ischemia on left ventricular (LV) function. Simultaneous M-mode and 2-dimensional (2-D) echocardiograms and a 6-lead electrocardiogram were recorded during 20 episodes of coronary artery occlusion and release in 12 patients. No patient had previous myocardial infarction and all had normal LV function by angiography. All patients had isolated single coronary artery disease, with left anterior descending stenosis in 8 and right coronary stenosis in 4. In 18 of 20 episodes (90%), M-mode echocardiography during balloon occlusion revealed a significant (p less than 0.001) decrease in LV systolic, diastolic and percent systolic wall thickness; systolic excursion; systolic and diastolic endocardial velocities; and fractional shortening. These changes were observed in the area of the ventricular septum in patients with left anterior descending occlusion and posteroinferior wall in those with right coronary artery occlusion. Two-dimensional echocardiography revealed varying degrees of hypokinesia, akinesia and dyskinesia during balloon occlusion in 18 instances. The echocardiographic changes were observed within 15 to 20 seconds of balloon occlusion and resolved 10 to 20 seconds after balloon deflation. All patients who had echocardiographic changes during balloon occlusion also had concomitant electrocardiographic (ECG) ST-segment elevation, whereas 2 patients with normal LV function had no ECG changes. Both of these patients had profuse collateral blood supply to the stenotic coronary artery. The echocardiographic and ECG abnormalities increased proportionately to the length of balloon occlusion. This study confirms previous animal and recent human studies of transient LV dysfunction during coronary occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Effects of Intravenous Levofloxacin on the QT Interval and QT Dispersion

The QT dispersion (QT_d) is a non-invasive means of identifying those patients at an increased risk of developing sudden cardiac death (SCD). Although levofloxacin has a minimal effect on the QT_c interval, isolated reports of QT prolongation, polymorphic ventricular tachycardia with a normal QT interval and TdP have been reported. The purpose of this study was to examine the effect of intravenous levofloxacin on the QT interval and QT_d. Of the 50 patients who were deemed candidates to receive intravenous levofloxacin, 29 met the eligibility criteria and were enrolled in this study. A 12-lead ECG was performed before the initiation of levofloxacin (baseline), and on days 3 and 5. The QT^c _min, QT^c _max and the QT_d were calculated. Measurements where made by two independent observers blinded to the patients’ clinical status. The QT_d increased significantly on days 3 and 5 following the initiation of therapy [QT_d (baseline) 33.3 ± 20 ms, QT_d (day 3) 64.4 ± 31.3 ms (p = 0.023), QT_d (day 5) 66.8 ± 20.3 ms, (p = 0.008)]. The increase in the QT_d was significantly longer in men than women. Although women had a shorter baseline QT_d compared to men, this did not achieve statistical significance. Intravenous levofloxacin was found to significantly increase the QT_d, which was more pronounced in men compared to women. Its effect on the QT_d may increase the risk of developing a potentially fatal ventricular arrhythmia. Therefore, care must be taken when prescribing this medication to patients with a pre-existing risk of developing SCD.     

Assessment of coronary bypass graft patency by electron-beam computed tomography

Twenty-one patients undergoing coronary artery bypass grafting were prospectively evaluated by conventional selective coronary angiography and electron-beam computed tomography. Eighty bypass grafts (60 saphenous vein and 20 left or right internal mammary artery) were evaluated for patency. The sensitivity and specificity of electron-beam computed tomography were 72% and 100%, respectively; positive and negative predictive values were 100% and 92.5%, respectively. Sensitivity and specificity according to coronary region were: left anterior descending artery, 33% and 100%; diagonal artery, 67% and 100%; circumflex artery, 75% and 100%; right coronary artery, 100% and 100%. Electron-beam computed tomography is relatively accurate and a promising tool for noninvasive evaluation of graft patency after coronary artery bypass graft surgery.     

KATP channels are up-regulated with increasing age in human myometrium

It is well established that ageing is associated with decrease in myometrial efficiency and higher incidence of labour complications. In myometrium, the presence of ATP-sensitive K⁺ (K_ATP) channels has been detected and they could be a factor in regulating uterine quiescence in pregnancy and contractions during labour. Here, we have examined a possibility of ageing-mediated regulation of K_ATP channels in the human myometrium. Myometrial samples were taken from non-pregnant women undergoing hysterectomy (n = 34) and from women undergoing caesarean section in late pregnancy (n = 36). Real time RT-PCR revealed that mRNAs of all known K_ATP channel subunits were present in the human myometrium. In non-pregnant myometrium, ageing up-regulated SUR2B/Kir6.1, subunits forming K_ATP channels in this tissue, without affecting the expression of other channel subunits. In the late pregnant myometrium, the level of subunits that do not form functional K_ATP channels was not affected by age within 20–41 age range. However, uterine SUR2B and Kir6.1 were up-regulated in parturient over 35 years. An ageing-induced increase in those channel subunits was confirmed by Western blotting. Thus, this study suggests that K_ATP channels are up-regulated with increasing age in human myometrium. This may help explain, at least partially, increased rate of birth complications in women aged over 35 years.