Left atrial volume by echocardiography in patients with false positive myocardial perfusion scans.

A stress-induced myocardial perfusion abnormality (MPS), in the absence of angiographically significant epicardial coronary artery disease, is considered a "false-positive" test result. We hypothesized that echocardiography would provide complementary prognostic and pathophysiologic data relevant to the management of patients with MPS and normal coronary angiograms. Accordingly, left atrial volume index (LAVi) was assessed by echocardiography in 38 patients with false positive MPS as defined by normal coronary angiograms and 26 patients with true negative MPS from a total of 1,356 patients stressed from July 2006-May 2008. Pathologically abnormal elevation of LAVi (≥ 32 mL/m(2)) was observed in 16 of 19 women (84%) and 11 of 19 men (58%) in the false positive MPS (FPMPS) group while none of the patients in the true negative MPS (TNMPS) group had elevated LAVi. In the FPMPS group mean LAVi was significantly higher in women than men (40.64 ± 11.4 mL/m(2) versus 32.6 ± 10.5 mL/m(2), P = 0.01). The mean LAVi in the FPMPS group was significantly different from the TNMPS group (36.6 ± 11.6 versus 21 ± 7 mL/m(2), P = 0.000). A stepwise logistic regression determined BSA, LAV and LAVi as useful in predicting false positive and true negative MPS. All three were significant predictors (P < 0.01) and the area under the ROC curve was 0.91. Our findings in this relatively small cohort suggest that patients with false positive MPS have a greater increased LAVi.

Chronic pulmonary dysfunction following acute inhalation of butyl acrylate.

Butyl Acrylate (BA) (2-propionic acid; CH2 = CHCOOC4H9) is a colorless liquid commonly used in impregnation agents and adhesives. Dermal contact with BA has previously been reported to cause moderate skin irritation with skin sensitizing potential in humans. Health effects of inhalation of BA have not been previously reported. Accordingly, we document the health conditions of a bystander, first responder and landfill worker exposed to butyl acrylate (BA) released to the atmosphere following a collision and roadside spill in October 1998. Retrospective data were collected via chart review and analyzed for exposure, symptoms, physical findings and radiological, laboratory and spirometry results over a ten-year period. All three patients had similar respiratory symptoms including a dramatic hacking cough and dyspnea. Findings included abnormal pulmonary function tests and breath sounds. These data underscore the potential hazards of BA inhalational exposure and the need to wear additional protective equipment.

Gender and geographic differences in CAD risk factors and CHADS2 scores in atrial fibrillation patients.

Atrial fibrillation (AF) is a cardiac arrhythmia associated with a wide range of other co-morbid medical conditions. The state of West Virginia has a higher prevalence of coronary artery disease (CAD) and CAD risk factors compared to the national average. We hypothesized that West Virginians with atrial fibrillation would also have a higher prevalence of CAD risk factors and higher CHADS2 stroke risk scores. This is particularly important since Louisiana is the only high CAD risk southern state included in the original verification of the CHADS2 risk scoring system (i.e. California, Connecticut, Louisiana, Maine, Missouri, New Hampshire, and Vermont). Accordingly, we performed a retrospective analysis of the association between AF and CAD, CAD risk factors and CHADS2 scores in a cohort of men and women in the West Virginia University Hospital population. We report a greater positive association between AF and hypertension, diabetes mellitus and obesity than the national average. AF was seen more commonly among men. But, CHADS2 scores were higher among women as a result of a higher prevalence of diabetes mellitus. This study indicates that AF is associated with a greater prevalence of CAD risk factors and higher CHADS2 scores among West Virginians in comparison with the rest of the nation.

p38 MAP kinase inhibitor reverses stress-induced myocardial dysfunction in vivo.

Recent clinical reports strongly support the intriguing possibility that emotional stress alone is sufficient to cause reversible myocardial dysfunction in patients. We previously reported that a combination of prenatal stress followed by restraint stress (PS+R) results in echocardiographic evidence of myocardial dysfunction in anesthetized rats compared with control rats subjected to the same restraint stress (Control+R). We now report results of our catheter-based hemodynamic studies in both anesthetized and freely ambulatory awake rats, comparing PS+R vs. Control+R. Systolic function [positive rate of change in left ventricular pressure over time (+dP/dt)] was significantly depressed (P < 0.01) in PS+R vs. Control+R both under anesthesia (6,287 +/- 252 vs. 7,837 +/- 453 mmHg/s) and awake (10,438 +/- 741 vs. 12,111 +/- 652 mmHg/s). Diastolic function (-dP/dt) was also significantly depressed (P < 0.05) in PS+R vs. Control+R both under anesthesia (-5,686 +/- 340 vs. -7,058 +/- 458 mmHg/s) and awake (-8,287 +/- 444 vs. 10,440 +/- 364 mmHg/s). PS+R also demonstrated a significantly attenuated (P < 0.05) hemodynamic response to increasing doses of the beta-adrenergic agonist isoproterenol. Intraperitoneal injection of the p38 MAP kinase inhibitor SB-203580 reversed the baseline reduction in +dP/dt and -dP/dt as well as the blunted isoproterenol response. Intraperitoneal injection of SB-203580 also reversed p38 MAP kinase and troponin I phosphorylation in cardiac myocytes isolated from PS+R. Thus the combination of prenatal stress followed by restraint stress results in reversible depression in both systolic and diastolic function as well as defective beta-adrenergic receptor signaling. Future studies in this animal model may provide insights into the basic mechanisms contributing to reversible myocardial dysfunction in patients with ischemic and nonischemic cardiomyopathies.

An analysis of the efficacy and safety of enhanced external counterpulsation at West Virginia University Hospitals.

A retrospective analysis was conducted of 79 consecutive patients who underwent enhanced external counterpulsation (EECP) at West Virginia University Hospitals during the period of November 1998 to September 2005 to determine its efficacy and safety in treating angina. A chart review and/or phone survey was performed to analyze pertinent clinical data (sublingual nitroglycerin use and angina class) pre and post EECP. A total of 60 (76%) patients who were referred for EECP successfully finished the 35 treatments. Seventy-five percent of the patient population improved at least one angina class after a full course of treatment. Therapy was discontinued due to adverse effects in 12 (15%) patients. Statistically significant improvements in angina class and reduction in anti-angina medications were observed in every co-morbid subgroup analyzed, including patients with peripheral vascular disease, diabetes, hyperlipidemia, hypertension, smoking, Post-MI, and LVEF < 40% (P < .05, Wilcoxon Signed-Rank test). Overall, EECP was effective in improving angina as reflected in a substantial reduction in antiangina medications in 59 (75%) patients.

Emotional stress and reversible myocardial dysfunction.

A growing body of clinical and experimental literature supports a strong association between emotional stress and adverse outcomes from CVD. Effects of emotional stress on coronary blood flow and cardiac arrhythmias provide only a partial explanation. A direct impact of emotional stress on myocardial function has recently received attention as a result of reports of patients presenting with new onset of unexplained reversible heart failure following episodes of emotional stress. Potential mechanisms responsible for myocardial dysfunction following emotional stress remain to be elucidated. This review will explore potential pathophysiologic mechanisms linking emotional stress to adverse cardiovascular outcomes beginning with primary and secondary risk factors and leading to direct effects of emotional stress on reversible myocardial dysfunction.

Platelet/endothelial biomarkers in depressed patients treated with the selective serotonin reuptake inhibitor sertraline after acute coronary events: the Sertraline AntiDepressant Heart Attack Randomized Trial (SADHART) Platelet Substudy.

BACKGROUND: Depression after acute coronary syndromes (ACSs) has been identified as an independent risk factor for subsequent cardiac death. Enhanced platelet activation has been hypothesized to represent 1 of the mechanisms underlying this association. Selective serotonin reuptake inhibitors (SSRIs) are known to inhibit platelet activity. Whether treatment of depressed post-ACS patients with SSRIs alters platelet function was not known. Accordingly, we serially assessed the release of established platelet/endothelial biomarkers in patients treated with sertraline vs placebo in the Sertraline AntiDepressant Heart Attack Randomized Trial (SADHART). METHODS AND RESULTS: Plasma samples (baseline, week 6, and week 16) were collected from patients randomized to sertraline (n=28) or placebo (n=36). Anticoagulants, aspirin, and ADP-receptor inhibitors were permitted in this study. Platelet factor 4, beta-thromboglobulin (betaTG), platelet/endothelial cell adhesion molecule-1, P-selectin, thromboxane B2, 6-ketoprostaglandin F1a, vascular cell adhesion molecule-1, and E-selectin were measured by ELISA. Treatment with sertraline was associated with substantially less release of platelet/endothelial biomarkers than was treatment with placebo. These differences attained statistical significance for betaTG (P=0.03) at weeks 6 and 16 and for P-selectin (P=0.04) at week 16. Repeated-measures ANOVA revealed a significant advantage for sertraline vs placebo for diminishing E-selectin and betaTG concentrations across the entire treatment period. CONCLUSIONS: Treatment with sertraline in depressed post-ACS patients is associated with reductions in platelet/endothelial activation despite coadministration of widespread antiplatelet regimens including aspirin and clopidogrel. The antiplatelet and endothelium-protective properties of SSRIs might represent an attractive additional advantage in patients with depression and comorbid coronary artery and/or cerebrovascular disease.

p38 MAP kinase inhibitor reverses stress-induced cardiac myocyte dysfunction.

Stress is gaining increasing acceptance as an independent risk factor contributing to adverse cardiovascular outcomes. Potential mechanisms responsible for the deleterious effects of stress on the development and progression of cardiovascular disease remain to be elucidated. An established animal model of stress in humans is the prenatally stressed (PS) rat. We stressed rats in their third trimester of pregnancy by daily injections of saline and moving from cage to cage. Male offspring of these stressed dams (PS) and age-matched male control offspring (control) were further subjected to restraint stress (R) at 6 and 7 wk of age. Echocardiography revealed a significant decrease in fractional shortening in PS + R vs. controls + R (45.8 +/- 3.9 vs. 61.9 +/- 2.4%, PS + R vs. controls + R; P < 0.01; n = 12). Isolated adult rat ventricular myocytes from PS + R also revealed diminished fractional shortening (6.7 +/- 0.8 vs. 12.7 +/- 1.1%, PS + R vs. controls + R; P < 0.01; n = 24) and blunted inotropic responses to isoproterenol (P < 0.01; n = 24) determined by automated border detection. The p38 mitogen-activated protein (MAP) kinase inhibitor SB-203580 blocked p38 MAP kinase phosphorylation, reversed the depression in fractional shortening, and partially ameliorated the blunted adrenergic signaling seen in adult rat ventricular myocytes from PS + R. Phosphorylation of p38 MAP kinase in cardiac myocytes by stress may be sufficient to lead to myocardial dysfunction in animal models and possibly humans.

Enhanced platelet/endothelial activation in depressed patients with acute coronary syndromes: evidence from recent clinical trials.

Platelets play a key role in the progression of acute coronary syndromes (ACS). Clinical depression alone is also associated with enhanced platelet activation. The purpose of this study was to compare concentrations of established biomarkers of enhanced platelet/endothelial activation in clinically depressed versus non-depressed patients enrolled in recent clinical trials for ACS. Two hundred and eighty-one baseline plasma samples from patients with acute myocardial infarction (ASSENT-2; n = 41), with ACS (PRONTO; n = 126) and with clinical depression plus previous acute coronary syndrome within 6 months (SADHART; n = 64), and from normal healthy controls (n = 50) were analyzed. Blood was drawn before applying any therapeutic strategies including interventions, thrombolytics, infusions, and selective serotonin re-uptake inhibitors. Platelet factor 4, beta-thromboglobulin, platelet/endothelial cell adhesion molecule-1, P-selectin, thromboxane, prostacyclin, vascular cell adhesion molecule-1, and E-selectin were measured by enzyme-linked immunosorbent assay by a single core laboratory. Patients with ACS exhibited a higher degree of platelet activation than controls independently of the presence of depression. Plasma levels of P-selectin, thromboxane, prostacyclin, and vascular cell adhesion molecule-1 were the highest in the acute myocardial infarction group when compared with ACS despite the presence or absence of clinical depression. Surprisingly, patients with ACS and depression exhibited the highest levels of platelet factor 4, beta-thromboglobulin, and platelet/endothelial cell adhesion molecule-1 when compared with myocardial infarction or angina patients without clinical depression. E-selectin plasma level was constantly elevated compared with controls but did not differ among the groups dependent on the incidence of depression. The depressed plus ACS group had higher plasma levels of all biomarkers compared with the non-depressed patients. Retrospective analysis of the data from several clinical trials reveals that clinical depression is associated with enhanced activation of platelet/endothelial biomarkers even above the level expected in ACS. These findings may contribute to the unfavorable outcome associated with clinical depression in patients with ACS.

Cardiovascular health and depression.

Research has shown that depression increases the likelihood that otherwise healthy people will develop ischemic heart disease (IHD) and worsens the prognosis of patients who already have IHD. Moreover, concerns about safety (e.g., cardiac side effects, drug-drug interactions) have caused physicians to be hesitant about using antidepressant agents in patients with IHD. This article is based on a recent roundtable of experts who met to discuss risk, diagnosis, and treatment options for depression in patients with IHD. This article reviews clinical and epidemiological studies that have described a link between depression and the subsequent development of IHD and have examined the role of depression as a predictor of cardiac events in patients with existing IHD. The article addresses the issue of whether depression can be safely and efficaciously treated both in patients with stable IHD and in those with acute coronary syndromes. The authors discuss safety issues related to the potential for interactions between antidepressants and cardiovascular medications, the use of nonpharmacologic treatment options such as psychosocial interventions, and the effect of antidepressant therapy on quality of life in patients with IHD. The article concludes with practical clinical guidance concerning the management of depression in patients who have recently experienced myocardial infarction.

N-acetylcysteine reverses cardiac myocyte dysfunction in a rodent model of behavioral stress.

Compelling clinical reports reveal that behavioral stress alone is sufficient to cause reversible myocardial dysfunction in selected individuals. We developed a rodent stress cardiomyopathy model by a combination of prenatal and postnatal behavioral stresses (Stress). We previously reported a decrease in percent fractional shortening by echo, both systolic and diastolic dysfunction by catheter-based hemodynamics, as well as attenuated hemodynamic and inotropic responses to the ß-adrenergic agonist, isoproterenol (ISO) in Stress rats compared with matched controls (Kan H, Birkle D, Jain AC, Failinger C, Xie S, Finkel MS. J Appl Physiol 98: 77-82, 2005). We now report enhanced catecholamine responses to behavioral stress, as evidenced by increased circulating plasma levels of norepinephrine (P < 0.01) and epinephrine (P < 0.01) in Stress rats vs. controls. Cardiac myocytes isolated from Stress rats also reveal evidence of oxidative stress, as indicated by decreased ATP, increased GSSG, and decreased GSH-to-GSSG ratio in the presence of increased GSH peroxidase and catalase activities (P < 0.01, for each). We also report blunted inotropic and intracellular Ca(2+) concentration responses to extracellular Ca(2+) (P < 0.05), as well as altered inotropic responses to the intracellular calcium regulator, caffeine (20 mM; P < 0.01). Treatment of cardiac myocytes with N-acetylcysteine (NAC) (10(-3) M) normalized calcium handling in response to ISO and extracellular Ca(2+) concentration and inotropic response to caffeine (P < 0.01, for each). NAC also attenuated the blunted inotropic response to ISO and Ca(2+) (P < 0.01, for each). Surprisingly, NAC did not reverse the changes in GSH, GSSG, or GSH-to-GSSG ratio. These data support a GSH-independent salutary effect of NAC on intracellular calcium signaling in this rodent model of stress-induced cardiomyopathy.

N-acetylcysteine reverses cardiac myocyte dysfunction in HIV-Tat proteinopathy.

HIV cardiomyopathy remains highly prevalent among the estimated 33 million HIV-infected individuals worldwide. This is particularly true in developing countries. Potential mechanisms responsible for myocardial dysfunction following HIV infection include direct effects of HIV proteins. We have previously reported that cardiac myocyte-specific expression of HIV-Tat (Tat) results in a murine cardiomyopathy model. We now report that Tat exhibits decreased myocardial ATP [wild type (WT) vs. Tat transgenic (TG), P < 0.01] and myocyte GSH levels (WT vs. TG, P < 0.01), decreased GSH/GSSG ratio (WT vs. TG, P < 0.01), increased H(2)O(2) levels (WT vs. TG, P < 0.05), and increased catalase (TG vs. WT, P < 0.05) and GPX1 (glutathione peroxidase 1) activities (WT vs. TG, P < 0.05), blunted cardiac myocyte positive inotropy (% peak shortening, WT vs. TG, P < 0.01; +dl/dt, WT vs. TG, P < 0.01) and negative inotropy (-dl/dt, WT vs. TG, P < 0.01), and blunted inotropic responses to Ca(2+) (P < 0.01, for each) and shortened anatomical and functional survival in vitro (P < 0.01). The sulfhydryl donor, N-acetylcysteine (NAC; 10(-4) M), completely reversed both the positive and negative inotropic defects in Tat; increased GSH (P < 0.01) and GSH/GSSG (P < 0.01); reversed H(2)O(2) level (P < 0.05) and GPX1 activity (P < 0.05); and normalized the blunted inotropic response to Ca(2+) (P < 0.01). NAC (10(-7)) M normalized duration of contractile function from <40 min to >120 min (P < 0.01), with no effect on GSH and GSH/GSSG. NAC (10(-4) M) reverses cardiac myocyte dysfunction and markers of oxidative stress. NAC (10(-7) M) enhances myocyte function independent of changes in glutathione. Elucidating the molecular mechanisms involved in the GSH-dependent and GSH-independent salutary effects of NAC should identify novel therapeutic targets for myocardial proteinopathies recently appreciated in human cardiomyopathies.

p38 MAP kinase inhibitor prevents diastolic dysfunction in rats following HIV gp120 injection in vivo.

HIV infection in patients is associated with a surprisingly high frequency of diastolic dysfunction followed by the development of a dilated cardiomyopathy. Potential mechanisms include direct effects of HIV proteins, including gp120. We have previously reported direct inotropic and p38 MAP kinase signaling effects of HIV gp120 on isolated cardiac myocytes in vitro. We now report effects of a single injection of HIV gp120 on cardiac hemodynamics in vivo. HIV gp120 (50 microg/kg) was injected intravenously and hemodynamics assessed at 1, 24, 48 and 72 h in freely ambulatory, awake rats. Rats injected with gp120 demonstrated a blunted diastolic response to increasing intravenous (IV) injections of the beta-adrenergic agonist, isoproterenol (ISO), compared with similarly instrumented controls at 48 h (gp120 vs. control, P < 0.01; n = 6, for each). Pre-treatment with the p38 MAP kinase inhibitor, SB 203580, prevented the diastolic dysfunction (gp120 + SB vs. control, P = NS; n = 6, for each). Hemodynamic changes correlated with inhibition of both p38 MAP kinase and troponin I phosphorylation by SB in vivo. There were no differences in ISO dose-response curves between gp120-treated and control rats at 1, 24 or 72 h (P = NS; n = 6, for each). Thus, evidence of diastolic dysfunction is apparent in vivo in rats following a single dose of HIV gp120. To our knowledge, this is the first report of a hemodynamic effect of an HIV protein in vivo. These findings lend further support to the hypothesis that the HIV virus, itself, may contribute to myocardial dysfunction in patients infected with HIV via a p38 MAP kinase mechanism.

Dilated cardiomyopathy in transgenic mice expressing HIV Tat.

Mechanisms responsible for HIV cardiomyopathy are unknown, but may include direct effects of HIV proteins on the heart. Transgenic mice (TG) expressing HIV Tat protein targeted to the myocardium, +/- Tat TG, have revealed anatomical and biochemical defects in the heart. The present studies were conducted to clarify the effect of Tat on cardiac function. In vivo hemodynamics was measured in awake mice after inserting a catheter tip in the left ventricle under general anesthesia. Under the age of 3 months, the heart rate (HR) was significantly lower in TG (591 +/- 47 vs. 716 +/- 45 bpm, TG versus FVB control (FVB), respectively (P < 0.05; n = 8-12). Other hemodynamic indexes, including left ventricular systolic pressure (LVSP), positive and negative dp/dt (mmHg/s), and left ventricular end diastolic pressure (LVEDP) remained indistinguishable from FVB. At 6 months, however, ventricular dysfunction was evident in TG (HR = 580 +/- 47 vs. 673 +/- 25 bpm, TG versus FVB, P < 0.05); LVSP (132 +/- 6 vs. 147 +/- 6 mmHg, TG versus FVB; P < 0.05); LVEDP (15 +/- 4 vs. 8 +/- 6 mmHg, TG vs. FVB, P < 0.05); +dp/dt = 8872 +/- 331 vs. 10026 +/- 796 mmHg/s TG versus FVB, P < 0.01) and -dp/dt (7403 +/- 432 vs. 8835 +/- 368 mmHg/s, TG versus FVB, P < 0.01; n = 8-12, in each group). The change in percentage of fractional shortening in response to isoproterenol was also significantly reduced in cardiac myocytes isolated from TG versus FVB (P < 0.05). Thus, targeted myocardial transgenic expression of HIV Tat in mice results in relative bradycardia, depression in systolic and diastolic functions in vivo, and blunted adrenergic responsiveness in vitro.

CXCR4 receptor antagonist blocks cardiac myocyte p38 MAP kinase phosphorylation by HIV gp120.

The prognosis for patients with human immunodeficiency virus (HIV) infection has improved remarkably as a result of effective antiretroviral therapy. This has resulted in an increased awareness of cardiac complications from HIV infection, including cardiomyopathy and overt heart failure. Mechanisms responsible for HIV cardiomyopathy and heart failure are unknown, but may include direct effects of HIV proteins on the heart. We have previously reported that the HIV envelope glycoprotein, gp120, has a p38 MAP kinase-dependent negative inotropic effect on adult rat ventricular myocytes (ARVM). This signaling pathway presumably results from the binding of gp120 to a specific receptor on the surface of cardiac myocytes. HIV gp120 has been shown to bind to CD4, CXCR4, and CCR5 receptors on lymphocytes and macrophages. Accordingly, we sought to determine if HIV gp120 regulated its negative inotropic effect through activation of one of these binding sites on cardiac myocytes. AMD3100, a highly selective CXCR4 receptor antagonist, reversed HIV gp120-induced negative inotropic effect on ARVM. AMD3100 also blocked HIV gp120 phosphorylation of both p38 MAP kinase and Troponin I. The binding of gp120 to the CXCR4 receptor on ARVM was confirmed by co-immunoprecipitation. We conclude that the negative inotropic effect of HIV gp120 is mediated by a novel signaling pathway that begins with binding to a cardiac myocyte CXCR4 receptor, followed by phosphorylation of both p38 MAP kinase and Troponin I.

Inducible nitric oxide synthase attenuates adrenergic signaling in alcohol fed rats.

Chronic, excessive alcohol consumption is associated with myocardial dysfunction in humans. The molecular mechanisms and cellular signaling pathways contributing to this cardiac dysfunction remain largely unknown. This study examined the effects of chronic alcohol consumption on myocardial function and cardiac myocyte signaling pathways. Adult male rats were fed a commercially prepared diet containing either ethanol (13 g/kg/d) or isocaloric control diet for 1 month. In vivo hemodynamics were measured in awake rats after inserting a catheter tip in the left ventricle under general anesthesia. Ventricular dysfunction was evidenced in awake, alcohol-fed rats by increased left ventricular end diastolic pressure, decreased systolic developed left ventricular pressure, and decreases in both positive and negative dp/dt compared with controls. Cardiac myocytes isolated from alcohol-fed rats also demonstrated an attenuated response to the beta-adrenergic agonist, isoproterenol, compared to controls. This response was significantly reversed by the nitric oxide synthase (NOS) inhibitor, N-monomethyl-L-arginine (L-NMMA). Western analyses confirmed inducible nitric oxide synthase (iNOS) protein synthesis in cardiac myocytes isolated from alcohol fed rats. It is therefore concluded that chronic alcohol ingestion results in iNOS-mediated attenuation of adrenergic signaling and depression in both systolic and diastolic function in rats.

iPLA2 inhibitor blocks negative inotropic effect of HIV gp120 on cardiac myocytes.

Recent improvements in survival from AIDS have been accompanied by an increased recognition of the potential importance of other manifestations of HIV infection, including cardiomyopathy. Mechanisms responsible for HIV cardiomyopathy are unknown, but may include direct effects of HIV proteins on the heart. We previously provided support for direct effects of HIV proteins by demonstrating a negative inotropic effect of the HIV coat protein, gp120, on isolated adult rat ventricular myocytes (ARVM). We now report that this negative inotropic effect of HIV gp120 is mediated by a signaling pathway involving p38 MAP kinase, iPLA2 and troponin I. Exposure of ARVM to HIV gp120 resulted in maximal activation of iPLA2 by 60 min as reflected in hydrolysis of arachidonyl thiophosphatidylcholine that was completely blocked by the iPLA2 inhibitor, bromoenol lactone (BEL) or the p38 MAP kinase inhibitor, SB203580. The negative inotropic effect of gp120 was blocked by BEL, as well as SB203580. BEL did not block gp120 stimulated phosphorylation of p38 MAP kinase itself, and/or its downstream effectors, ATF2 or MAPKAP2. However, BEL did block gp120-stimulated phosphorylation of troponin I. Thus, the negative inotropic effect of HIV gp120 requires activation of p38 MAP kinase and iPLA2; as well as troponin I phosphorylation. Activation of this novel p38 MAP kinase-iPLA2-troponin I signaling pathway may contribute to HIV cardiomyopathy.

Molecular signaling pathways that link depression and heart disease.

Patients with clinical depression and coronary artery disease (CAD) risk factors have chronic, persistent activation of potentially toxic mediators optimized for short-term survival from ischemia, infection, and hemorrhage. The mediators and pathways involved in these processes are beginning to be elucidated. This basic research has uncovered novel potential therapeutic targets to prevent or attenuate adverse cardiovascular consequences of clinical depression. Well-designed randomized controlled studies will be required to definitively demonstrate that treating depression decreases cardiac mortality and morbidity. The results of controlled clinical trials support the use of selective serotonin reuptake inhibitors (SSRIs) for patients with CAD. The possibility that the use of an SSRI may confer additional benefit through a platelet inhibitory effect independent of the level of depression warrants further investigation.